Everything Solar Forum

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com
------------------------------

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

William - I have enjoyed mine for five years now, and it is pretty much as you describe - although it is more like a window air conditioner unit  - except that it pushes its captured heat into the hot water storage tank instead of out into the outdoor air. And yes, there is a condensate port that needs to be connected to a drain. But if it is in fairly dry conditioned space (as mine is), it does not really generate very much condensate.
Roger asked about the dewpoint. Because the unit is condensing water on its cold (refrigerant evaporator) coil, the unit is removing some water from the supply air, and thus lowering the air's dewpoint. But more importantly, if it is in a small room (or an unducted closet), it will quickly cool the room (or closet) down before it removes much water, thereby raising the relative humidity (RH) to a level that supports mold growth. This is exactly the same problem that happens when a HVAC contractor installs an overly large air conditioning system on a house - the whole house can quickly cool down and stay uncomfortably humid in the summertime.
According to the Image Permanence Institute's Dew Point Calculator (dpcalc.org) , mold can form in less than two weeks at 75 degrees F and 80%RH, even though the conditions are noncondensing. (Dewpoint at that temp and RH is 69 degrees F).

The key point here is that if you are going to put your Heat Pump Water Heater in an enclosed closet or small room, you want to provide it with an adequate air supply (louvered door, for example), AND you will want to take the cold exhaust air to someplace it can be used (in summer), or dump it outside (in cooler weather). And if you don't live in a place that is warm year-round, you might want to switch from heat pump to traditional electrical hot water mode (using the unit's resistance heating element) in winter. Otherwise the warm air you are supplying to the unit and exhausting outside will be replaced by cold outside air sucked into your house through whatever cracks and crannies are available.

------------------------------
Hugh Willis
Engrs Never Really Retire
GREENSBORO, NC
------------------------------

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Hi Hugh: Yes I would think there is a payoff on them depending on the amount of hot water usage, etc.. The biggest difference I see between you and Andrew is the location. His HDD is pretty much non existent where as I suspect yours in NC is probably more 50/50 with the CCD. Depending on his exact 'closet' size and location relating to the kitchen, a top and bottom louvered door or just a complete louvered door may do the trick without active 'ducting' into his kitchen. Allot of variables. If he is a family of one or two, probably not many issues. Family of four or more with younger ones, different story. For me, I get so much solar thermal energy, a simple 40 gal electric water heater with the top and bottom elements wired in series (2250W total) on one thermostat, allows me 90+% of my DHW to be covered. I don't even bother with a de-superheater on my geo-thermal HP. HVAC is always interesting. Today it is so much more intertwined with everything else from a controls perspective regarding the whole house and outdoor environmental's, it can get pretty complex.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 13, 2021 11:29 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

William - I have enjoyed mine for five years now, and it is pretty much as you describe - although it is more like a window air conditioner unit  - except that it pushes its captured heat into the hot water storage tank instead of out into the outdoor air. And yes, there is a condensate port that needs to be connected to a drain. But if it is in fairly dry conditioned space (as mine is), it does not really generate very much condensate.
Roger asked about the dewpoint. Because the unit is condensing water on its cold (refrigerant evaporator) coil, the unit is removing some water from the supply air, and thus lowering the air's dewpoint. But more importantly, if it is in a small room (or an unducted closet), it will quickly cool the room (or closet) down before it removes much water, thereby raising the relative humidity (RH) to a level that supports mold growth. This is exactly the same problem that happens when a HVAC contractor installs an overly large air conditioning system on a house - the whole house can quickly get cold and uncomfortably humid in the summertime. (According to the Image Permanence Institute's Dew Point Calculator (dpcalc.org) , mold can form in less than two weeks at 75 degrees F and 80%RH, even though the dewpoint at those conditions is only 69 degrees F).
The key point here is that if you are going to put your Heat Pump Water Heater in an enclosed closet or small room, you want to provide it with an adequate air supply (louvered door, for example), AND you will want to take the cold exhaust air to someplace it can be used (in summer), or dump it outside (in cooler weather). And if you don't live in a place that is warm year-round, you might want to switch from heat pump to traditional electrical hot water mode (using the unit's resistance heating element) in winter. Otherwise the warm air you are supplying to the unit and exhausting outside will be replaced by cold outside air sucked into your house through whatever cracks and crannies are available.

------------------------------
Hugh Willis
Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com
------------------------------

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Innovation is great!!

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running, and so duct condensate is not an issue) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could off-grid retrofit my old and inefficient ranch-style home (very high surface area in relation to the building's volume, with a long NW-facing exterior wall, and forced air HVAC) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC
------------------------------

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com
------------------------------

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Very Nice!!

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC
------------------------------

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Indeed, this thread has been bringing out the point that to do the job right , one needs to look at all the available technologies and then make a comparative life cycle cost estimate for whatever mix may seem right for the specific location.

One thing that I came to realize not too long ago when comparing relative performance of solar DHW vs PV is what happens when the owner is a part-time resident?  We have quite a few of these in FL, which means if they come from elsewhere, they are also partial residents of elsewhere.

With PV, when no one is home, the PV system still operates at 100% of its capacity, selling back anything unused to the utility.  Regrettably, when no one is home, the DHW tank is not able to sell back any excess.  Then add a HPWH (WHHP?) with a COP of 3 and the 3x advantage of DHW goes out the window.  If one does the math with 1 kWh = 3413 Btu and a typical energy production of 1400 kWh/kW/yr for PV, we have now reached the point (which I never thought we would reach) where the life cycle cost of DHW from PV becomes less than the LCC of DHW from a solar water heater.

Note that I am not suggesting that one water heating method is better than the other.  I'm simply suggesting that it is worth the effort to do the math, especially in Florida.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com
------------------------------

Original Message:
Sent: Oct 15, 2021 06:58 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Yes, the part time resident "life style" brings out the advantage/dis-advantage of the PV or SDHW comparison you point out. But at the core of this is the fact that a GRID-TIE PV system's energy (Electricity) can be used for many, many functions and is distributive, where as SDHW is in fact just SDHW and local. The picture of his house reminded me of the many solar houses constructed in the 70's spanning double envelope, super-insulated with passive solar, etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 16, 2021 10:46 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Indeed, this thread has been bringing out the point that to do the job right , one needs to look at all the available technologies and then make a comparative life cycle cost estimate for whatever mix may seem right for the specific location.

One thing that I came to realize not too long ago when comparing relative performance of solar DHW vs PV is what happens when the owner is a part-time resident?  We have quite a few of these in FL, which means if they come from elsewhere, they are also partial residents of elsewhere.

With PV, when no one is home, the PV system still operates at 100% of its capacity, selling back anything unused to the utility.  Regrettably, when no one is home, the DHW tank is not able to sell back any excess.  Then add a HPWH (WHHP?) with a COP of 3 and the 3x advantage of DHW goes out the window.  If one does the math with 1 kWh = 3413 Btu and a typical energy production of 1400 kWh/kW/yr for PV, we have now reached the point (which I never thought we would reach) where the life cycle cost of DHW from PV becomes less than the LCC of DHW from a solar water heater.

Note that I am not suggesting that one water heating method is better than the other.  I'm simply suggesting that it is worth the effort to do the math, especially in Florida.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 15, 2021 06:58 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

William, not too long after OPEC's first (1973) oil embargo, I remember doing a tour of a number of solar homes in central PA.  (Probably in 1975, or thereabouts).
Some were open floorplan passive (radiant capture) solar designs much like you describe, as in your picture. Others on the tour were doing water loop thermal capture. Photovoltaic was not yet any significant part of the picture.
Joe Utasi's home may have reminded you of those early passive solar homes, But don't let the visual similarity fool you. There's so much more to it than that.
I think his home, with its range of currently available technologies (tight and well-insulated envelope, radiant floors, heat pump water heater, mini-splits, ERV, etc - all powered by a combination of thermal capture and pv) show us one very effective example using the advances made over the last 45 years,
... Just my two cents' worth.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC
------------------------------

Original Message:
Sent: Oct 16, 2021 12:08 PM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Yes, the part time resident "life style" brings out the advantage/dis-advantage of the PV or SDHW comparison you point out. But at the core of this is the fact that a GRID-TIE PV system's energy (Electricity) can be used for many, many functions and is distributive, where as SDHW is in fact just SDHW and local. The picture of his house reminded me of the many solar houses constructed in the 70's spanning double envelope, super-insulated with passive solar, etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 16, 2021 10:46 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Indeed, this thread has been bringing out the point that to do the job right , one needs to look at all the available technologies and then make a comparative life cycle cost estimate for whatever mix may seem right for the specific location.

One thing that I came to realize not too long ago when comparing relative performance of solar DHW vs PV is what happens when the owner is a part-time resident?  We have quite a few of these in FL, which means if they come from elsewhere, they are also partial residents of elsewhere.

With PV, when no one is home, the PV system still operates at 100% of its capacity, selling back anything unused to the utility.  Regrettably, when no one is home, the DHW tank is not able to sell back any excess.  Then add a HPWH (WHHP?) with a COP of 3 and the 3x advantage of DHW goes out the window.  If one does the math with 1 kWh = 3413 Btu and a typical energy production of 1400 kWh/kW/yr for PV, we have now reached the point (which I never thought we would reach) where the life cycle cost of DHW from PV becomes less than the LCC of DHW from a solar water heater.

Note that I am not suggesting that one water heating method is better than the other.  I'm simply suggesting that it is worth the effort to do the math, especially in Florida.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 15, 2021 06:58 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Hugh's last message reinforces the point I tried making earlier.  What may have been absolutely true 20 years ago, now may be in question.  In 1976, when PV modules were selling for about $100/watt, who would have believed the price would drop to under 30 cents per watt in 2021. Who would have believed that utility scale PV installed cost would be about $1/watt (in 2021 dollars) in 2021?  So, all bets are off.  We need to keep our calculators on to check whether what was a bad deal in 1990 is a good one now and vice versa.  For example, try calculating the cost of hot water made by a heat pump water heater vs water heated directly by the sun for YOUR particular situation.  Yours and mine might be different.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com
------------------------------

Original Message:
Sent: Oct 22, 2021 10:52 AM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

William, not too long after OPEC's first (1973) oil embargo, I remember doing a tour of a number of solar homes in central PA.  (Probably in 1975, or thereabouts).
Some were open floorplan passive (radiant capture) solar designs much like you describe, as in your picture. Others on the tour were doing water loop thermal capture. Photovoltaic was not yet any significant part of the picture.
Joe Utasi's home may have reminded you of those early passive solar homes, But don't let the visual similarity fool you. There's so much more to it than that.
I think his home, with its range of currently available technologies (tight and well-insulated envelope, radiant floors, heat pump water heater, mini-splits, ERV, etc - all powered by a combination of thermal capture and pv) show us one very effective example using the advances made over the last 45 years,
... Just my two cents' worth.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 16, 2021 12:08 PM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Yes, the part time resident "life style" brings out the advantage/dis-advantage of the PV or SDHW comparison you point out. But at the core of this is the fact that a GRID-TIE PV system's energy (Electricity) can be used for many, many functions and is distributive, where as SDHW is in fact just SDHW and local. The picture of his house reminded me of the many solar houses constructed in the 70's spanning double envelope, super-insulated with passive solar, etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 16, 2021 10:46 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Indeed, this thread has been bringing out the point that to do the job right , one needs to look at all the available technologies and then make a comparative life cycle cost estimate for whatever mix may seem right for the specific location.

One thing that I came to realize not too long ago when comparing relative performance of solar DHW vs PV is what happens when the owner is a part-time resident?  We have quite a few of these in FL, which means if they come from elsewhere, they are also partial residents of elsewhere.

With PV, when no one is home, the PV system still operates at 100% of its capacity, selling back anything unused to the utility.  Regrettably, when no one is home, the DHW tank is not able to sell back any excess.  Then add a HPWH (WHHP?) with a COP of 3 and the 3x advantage of DHW goes out the window.  If one does the math with 1 kWh = 3413 Btu and a typical energy production of 1400 kWh/kW/yr for PV, we have now reached the point (which I never thought we would reach) where the life cycle cost of DHW from PV becomes less than the LCC of DHW from a solar water heater.

Note that I am not suggesting that one water heating method is better than the other.  I'm simply suggesting that it is worth the effort to do the math, especially in Florida.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 15, 2021 06:58 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Those 4 thermal panels are a German make (not sure what it was) but they were NOT cheap! Considering they are more than enough to keep the floors at 80 degrees all winter, I guess the payback is reasonable. I traded some solar work for a customer that bought them for pool heating, but never installed them. Instead he put up TWO 60 panel ground mounts, and just burns power whenever he needs it. Money talks!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com
------------------------------

Original Message:
Sent: Oct 22, 2021 12:02 PM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Hugh's last message reinforces the point I tried making earlier.  What may have been absolutely true 20 years ago, now may be in question.  In 1976, when PV modules were selling for about $100/watt, who would have believed the price would drop to under 30 cents per watt in 2021. Who would have believed that utility scale PV installed cost would be about $1/watt (in 2021 dollars) in 2021?  So, all bets are off.  We need to keep our calculators on to check whether what was a bad deal in 1990 is a good one now and vice versa.  For example, try calculating the cost of hot water made by a heat pump water heater vs water heated directly by the sun for YOUR particular situation.  Yours and mine might be different.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 22, 2021 10:52 AM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

William, not too long after OPEC's first (1973) oil embargo, I remember doing a tour of a number of solar homes in central PA.  (Probably in 1975, or thereabouts).
Some were open floorplan passive (radiant capture) solar designs much like you describe, as in your picture. Others on the tour were doing water loop thermal capture. Photovoltaic was not yet any significant part of the picture.
Joe Utasi's home may have reminded you of those early passive solar homes, But don't let the visual similarity fool you. There's so much more to it than that.
I think his home, with its range of currently available technologies (tight and well-insulated envelope, radiant floors, heat pump water heater, mini-splits, ERV, etc - all powered by a combination of thermal capture and pv) show us one very effective example using the advances made over the last 45 years,
... Just my two cents' worth.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 16, 2021 12:08 PM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Yes, the part time resident "life style" brings out the advantage/dis-advantage of the PV or SDHW comparison you point out. But at the core of this is the fact that a GRID-TIE PV system's energy (Electricity) can be used for many, many functions and is distributive, where as SDHW is in fact just SDHW and local. The picture of his house reminded me of the many solar houses constructed in the 70's spanning double envelope, super-insulated with passive solar, etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 16, 2021 10:46 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Indeed, this thread has been bringing out the point that to do the job right , one needs to look at all the available technologies and then make a comparative life cycle cost estimate for whatever mix may seem right for the specific location.

One thing that I came to realize not too long ago when comparing relative performance of solar DHW vs PV is what happens when the owner is a part-time resident?  We have quite a few of these in FL, which means if they come from elsewhere, they are also partial residents of elsewhere.

With PV, when no one is home, the PV system still operates at 100% of its capacity, selling back anything unused to the utility.  Regrettably, when no one is home, the DHW tank is not able to sell back any excess.  Then add a HPWH (WHHP?) with a COP of 3 and the 3x advantage of DHW goes out the window.  If one does the math with 1 kWh = 3413 Btu and a typical energy production of 1400 kWh/kW/yr for PV, we have now reached the point (which I never thought we would reach) where the life cycle cost of DHW from PV becomes less than the LCC of DHW from a solar water heater.

Note that I am not suggesting that one water heating method is better than the other.  I'm simply suggesting that it is worth the effort to do the math, especially in Florida.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 15, 2021 06:58 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Roger - Your general point about "putting the calculators to work" is valid whenever life-cycle cost is the prime consideration.

But sometimes simplicity is desirable, even if it might cost a bit more. (Trained as an engineer, and analytical by nature, I am often accused of "overthinking the problem" by the skilled craftspeople who work with me, and must constantly work to not "overdo" my analyses and designs).
You propose calculating the cost of domestic hot water made by one of only two alternatives, for YOUR particular situation - by a heat pump water heater vs water heated directly by the sun. 
Of course, Joe's house shows a third alternative - In winter, he is indirectly using his HPWH to move solar heat into his DHW tank. By doing it his way, his solar thermal capture system - directly used only for warming his house - is quite simple. And his HPWH, used to "recycle" some of that solar heat by taking it from the house at large and pushing it into his DHW tank, is likewise simple. (And in summer brings the added bonus of some a/c cooling and dehumidification, which he finds useful).
Rarely have I seen a dedicated single-purpose direct solar thermal DHW design which is as simple as what Joe has done. (One collector loop pump, minimal thermal control instrumentation, a large solar thermal collector tank that is allowed to range from about 95 degrees up to maybe 140 degrees over the course of the day, etc., all combined with an "off-the-shelf" HPWH). And never have I seen one that provides the bonus of some summertime a/c to boot.

I expect if you worked at it hard enough you might be able to calculate a comprehensive cost/benefit analysis for the total of the benefits from his several different systems, all integrated into his multifaceted solution. But he seems happy enough with his result without having gone to that extent.

I am surprised at how often "back of the envelope" calculations are sufficient to point in the right direction to get to an optimal solution.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC
------------------------------

Original Message:
Sent: Oct 22, 2021 12:02 PM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Hugh's last message reinforces the point I tried making earlier.  What may have been absolutely true 20 years ago, now may be in question.  In 1976, when PV modules were selling for about $100/watt, who would have believed the price would drop to under 30 cents per watt in 2021. Who would have believed that utility scale PV installed cost would be about $1/watt (in 2021 dollars) in 2021?  So, all bets are off.  We need to keep our calculators on to check whether what was a bad deal in 1990 is a good one now and vice versa.  For example, try calculating the cost of hot water made by a heat pump water heater vs water heated directly by the sun for YOUR particular situation.  Yours and mine might be different.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 22, 2021 10:52 AM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

William, not too long after OPEC's first (1973) oil embargo, I remember doing a tour of a number of solar homes in central PA.  (Probably in 1975, or thereabouts).
Some were open floorplan passive (radiant capture) solar designs much like you describe, as in your picture. Others on the tour were doing water loop thermal capture. Photovoltaic was not yet any significant part of the picture.
Joe Utasi's home may have reminded you of those early passive solar homes, But don't let the visual similarity fool you. There's so much more to it than that.
I think his home, with its range of currently available technologies (tight and well-insulated envelope, radiant floors, heat pump water heater, mini-splits, ERV, etc - all powered by a combination of thermal capture and pv) show us one very effective example using the advances made over the last 45 years,
... Just my two cents' worth.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 16, 2021 12:08 PM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Yes, the part time resident "life style" brings out the advantage/dis-advantage of the PV or SDHW comparison you point out. But at the core of this is the fact that a GRID-TIE PV system's energy (Electricity) can be used for many, many functions and is distributive, where as SDHW is in fact just SDHW and local. The picture of his house reminded me of the many solar houses constructed in the 70's spanning double envelope, super-insulated with passive solar, etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 16, 2021 10:46 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Indeed, this thread has been bringing out the point that to do the job right , one needs to look at all the available technologies and then make a comparative life cycle cost estimate for whatever mix may seem right for the specific location.

One thing that I came to realize not too long ago when comparing relative performance of solar DHW vs PV is what happens when the owner is a part-time resident?  We have quite a few of these in FL, which means if they come from elsewhere, they are also partial residents of elsewhere.

With PV, when no one is home, the PV system still operates at 100% of its capacity, selling back anything unused to the utility.  Regrettably, when no one is home, the DHW tank is not able to sell back any excess.  Then add a HPWH (WHHP?) with a COP of 3 and the 3x advantage of DHW goes out the window.  If one does the math with 1 kWh = 3413 Btu and a typical energy production of 1400 kWh/kW/yr for PV, we have now reached the point (which I never thought we would reach) where the life cycle cost of DHW from PV becomes less than the LCC of DHW from a solar water heater.

Note that I am not suggesting that one water heating method is better than the other.  I'm simply suggesting that it is worth the effort to do the math, especially in Florida.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 15, 2021 06:58 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

One has to step back and remember that, to put it as simply as possible, financial calculations are just financial calculations. In short, money is just money , an idea. In reality it has no tangible reality. Engineering is just the opposite. It only deals with what is real, what is true reality and all its intertwining's. The main difference that any of the solar thermal configurations gives you when dealing with fluid based ST, is storage. My 3000 lb solar thermal water tank yields about 90K BTU's of heat storage (Delta 30), or about 27KWH's. Cost is only incurred by the holding vessel and xchangers, as opposed to the storage medium itself, which of course lasts forever and is easily replaceable if desired. My solar non pressurized tank can provide SDHW and a boost to my geo-thermal HP's temp when its internal temp rises above 140 Degs, and of course in heating season. Being in PA our HDD exceeds our CDD easily (AT least at this point in history). I actually want to increase my tank size by about 30% (Space allowed) for greater heat storage in trans seasonal and times with 3+ PSD's in a row in Winter. My geo thermal heat pump which normally might run a 50 DegF incoming water loop temp as example, being boosted to 85 DegF, in the real world cuts its run time by almost 50%. Goes to electricity reduction, extended time if off grid, and higher temps at the duct vents (As high as 114 DegF output). 
Anyway, going into every causal interconnection between the thermal and electric systems can get tedious, and I have not had my coffee yet. To be blunt, I always say my solar thermal liquid systems are a pain in the ass sometimes (Such is plumbing), but I would not trade them for pure PV. My solar thermal hot air systems are less of a pain, and of course an air leak inspires a yawn, as opposed to a panic attack...lol...
Standing on the moon and gazing at our blue spec (Big picture), lest we not forget, all of us here are using, innovating, and designing with RE, as opposed to the furry energy other guy in the room.
Cheers to us..!!..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 22, 2021 12:02 PM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Hugh's last message reinforces the point I tried making earlier.  What may have been absolutely true 20 years ago, now may be in question.  In 1976, when PV modules were selling for about $100/watt, who would have believed the price would drop to under 30 cents per watt in 2021. Who would have believed that utility scale PV installed cost would be about $1/watt (in 2021 dollars) in 2021?  So, all bets are off.  We need to keep our calculators on to check whether what was a bad deal in 1990 is a good one now and vice versa.  For example, try calculating the cost of hot water made by a heat pump water heater vs water heated directly by the sun for YOUR particular situation.  Yours and mine might be different.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 22, 2021 10:52 AM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

William, not too long after OPEC's first (1973) oil embargo, I remember doing a tour of a number of solar homes in central PA.  (Probably in 1975, or thereabouts).
Some were open floorplan passive (radiant capture) solar designs much like you describe, as in your picture. Others on the tour were doing water loop thermal capture. Photovoltaic was not yet any significant part of the picture.
Joe Utasi's home may have reminded you of those early passive solar homes, But don't let the visual similarity fool you. There's so much more to it than that.
I think his home, with its range of currently available technologies (tight and well-insulated envelope, radiant floors, heat pump water heater, mini-splits, ERV, etc - all powered by a combination of thermal capture and pv) show us one very effective example using the advances made over the last 45 years,
... Just my two cents' worth.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 16, 2021 12:08 PM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Yes, the part time resident "life style" brings out the advantage/dis-advantage of the PV or SDHW comparison you point out. But at the core of this is the fact that a GRID-TIE PV system's energy (Electricity) can be used for many, many functions and is distributive, where as SDHW is in fact just SDHW and local. The picture of his house reminded me of the many solar houses constructed in the 70's spanning double envelope, super-insulated with passive solar, etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 16, 2021 10:46 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Indeed, this thread has been bringing out the point that to do the job right , one needs to look at all the available technologies and then make a comparative life cycle cost estimate for whatever mix may seem right for the specific location.

One thing that I came to realize not too long ago when comparing relative performance of solar DHW vs PV is what happens when the owner is a part-time resident?  We have quite a few of these in FL, which means if they come from elsewhere, they are also partial residents of elsewhere.

With PV, when no one is home, the PV system still operates at 100% of its capacity, selling back anything unused to the utility.  Regrettably, when no one is home, the DHW tank is not able to sell back any excess.  Then add a HPWH (WHHP?) with a COP of 3 and the 3x advantage of DHW goes out the window.  If one does the math with 1 kWh = 3413 Btu and a typical energy production of 1400 kWh/kW/yr for PV, we have now reached the point (which I never thought we would reach) where the life cycle cost of DHW from PV becomes less than the LCC of DHW from a solar water heater.

Note that I am not suggesting that one water heating method is better than the other.  I'm simply suggesting that it is worth the effort to do the math, especially in Florida.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 15, 2021 06:58 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Yes I agree... a Wolf in sheep's clothing...lol.... I was active back in that time as well. The super-insulated homes of the 70's and 80's were the pre-curser to passivhaus designs...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 22, 2021 10:52 AM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

William, not too long after OPEC's first (1973) oil embargo, I remember doing a tour of a number of solar homes in central PA.  (Probably in 1975, or thereabouts).
Some were open floorplan passive (radiant capture) solar designs much like you describe, as in your picture. Others on the tour were doing water loop thermal capture. Photovoltaic was not yet any significant part of the picture.
Joe Utasi's home may have reminded you of those early passive solar homes, But don't let the visual similarity fool you. There's so much more to it than that.
I think his home, with its range of currently available technologies (tight and well-insulated envelope, radiant floors, heat pump water heater, mini-splits, ERV, etc - all powered by a combination of thermal capture and pv) show us one very effective example using the advances made over the last 45 years,
... Just my two cents' worth.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 16, 2021 12:08 PM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Yes, the part time resident "life style" brings out the advantage/dis-advantage of the PV or SDHW comparison you point out. But at the core of this is the fact that a GRID-TIE PV system's energy (Electricity) can be used for many, many functions and is distributive, where as SDHW is in fact just SDHW and local. The picture of his house reminded me of the many solar houses constructed in the 70's spanning double envelope, super-insulated with passive solar, etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 16, 2021 10:46 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Indeed, this thread has been bringing out the point that to do the job right , one needs to look at all the available technologies and then make a comparative life cycle cost estimate for whatever mix may seem right for the specific location.

One thing that I came to realize not too long ago when comparing relative performance of solar DHW vs PV is what happens when the owner is a part-time resident?  We have quite a few of these in FL, which means if they come from elsewhere, they are also partial residents of elsewhere.

With PV, when no one is home, the PV system still operates at 100% of its capacity, selling back anything unused to the utility.  Regrettably, when no one is home, the DHW tank is not able to sell back any excess.  Then add a HPWH (WHHP?) with a COP of 3 and the 3x advantage of DHW goes out the window.  If one does the math with 1 kWh = 3413 Btu and a typical energy production of 1400 kWh/kW/yr for PV, we have now reached the point (which I never thought we would reach) where the life cycle cost of DHW from PV becomes less than the LCC of DHW from a solar water heater.

Note that I am not suggesting that one water heating method is better than the other.  I'm simply suggesting that it is worth the effort to do the math, especially in Florida.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 15, 2021 06:58 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

I agree and congratulate Joe for his Net Zero home.  The one thing that needs to change with future homes is to mostly eliminate closed cell spray foam which is an extremely high emitter of greenhouses gases.   Most of every home can be well insulated with rock wool or dense packed cellulose.  We use expanded polystyrene (with a layer of thick poly) under slabs, and polyiso foam sheets on concrete walls - two places that fiberous insulations don't work,  and occasionally in small hard to insulate spaces around the framing.  The one place where CCSF continues to be needed is non-flat stone surfaces such as rock foundations in existing homes.  In our homes, the poly under the slab and the aluminum faced polyiso keep moisture from penetrating the concrete and adding moisture to the house, so that our basements have, like the rest of the house, low humidity levels.  (We're in New England).  We typically use ASHPs, HRV's and HPHW.

------------------------------
Bob Irving
Builder/Architect
RH Irving Homebuilders
rhirving@tds.net
------------------------------

Original Message:
Sent: Oct 16, 2021 10:46 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Indeed, this thread has been bringing out the point that to do the job right , one needs to look at all the available technologies and then make a comparative life cycle cost estimate for whatever mix may seem right for the specific location.

One thing that I came to realize not too long ago when comparing relative performance of solar DHW vs PV is what happens when the owner is a part-time resident?  We have quite a few of these in FL, which means if they come from elsewhere, they are also partial residents of elsewhere.

With PV, when no one is home, the PV system still operates at 100% of its capacity, selling back anything unused to the utility.  Regrettably, when no one is home, the DHW tank is not able to sell back any excess.  Then add a HPWH (WHHP?) with a COP of 3 and the 3x advantage of DHW goes out the window.  If one does the math with 1 kWh = 3413 Btu and a typical energy production of 1400 kWh/kW/yr for PV, we have now reached the point (which I never thought we would reach) where the life cycle cost of DHW from PV becomes less than the LCC of DHW from a solar water heater.

Note that I am not suggesting that one water heating method is better than the other.  I'm simply suggesting that it is worth the effort to do the math, especially in Florida.

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 15, 2021 06:58 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, I get it - How brilliant! You've done everything I've only imagined for my dream house.
I really love that you have made effective use of both pv and solar thermal capture. (Last I looked, "thermal" captures about 3x as much solar energy per sq ft as does a high-performance pv array of the same size).
And thermal mass radiant flooring - even on the main level! Plus, if I understand correctly what you've done, you get some wintertime direct passive solar sunshine into your home through the clerestory windows, although the roof overhang shades them from the noonday sun in summer.

Is there anything you didn't think of? Or anything you would do differently were you to do it all over again?

This thread has come a long way from Andrew's original question about duct kits for heat pump domestic water heaters, and I am glad.
Thank you for showing us what is possible when one puts all the "green building" pieces together in such an effective way.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 15, 2021 02:24 PM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Well, the condensate drain goes directly to a floor drain that flows into my septic. It runs almost continuously when the water heater is running. My house is entirely insulated with spray foam and has LESS than 1 air change per hour, which is EXTREMELY tight. My basement has NO sign of mold or mildew, nor is there any anywhere in the home. It remains comfortable year round. I have an ERV that provides fresh air changes whenever we have the house closed up tight (mostly for only the coldest or hottest weather)  I have a minisplit in my basement office (which represents about 450 sq.ft.) of a 1700 sq.ft footprint. I use SOLAR HOT WATER for heating. in the basement I have a hot water to air conversion that feeds 8 inch ductwork to the 3 rooms that are finished.  I have four 4X8 german thermal panels which feed a 105 gallon insulated holding tank. The tank water is circulated through 1/2 inch pex buring in 1 1/2 inches of gypsum concrete on the main floor. Winter days start out at about 95 degree tank temp, and by day's end it's up around 130 to 140.  LOTS of thermal "mass" in the gypsum concrete and ceramic tile to keep the temperature fairly constant year round. The entire heating system

consumes 70 watts ( two grundfos pumps - one for the roof loop and one for the house loop) no "head" is encountered, since both systems are balanced. During the summer, the output from the heat pump water heater provides extra cooling to the rec room, which has NO minisplit. Just dehumidifying it, and dropping the temp a bit makes the room pleasureable to be in. Even the basement walls have 4 inches of spray foam. Studs are floated off the cement walls about 1 1/2 inches, and the whole place is drywalled. I have no attic - the house has clerestory row of windows. The lower pitch roof faces south. Structural trusses comprise both the roof joists as well as the floor (to handle the load of the concrete above!)  I have a 9KW propane fired generator that only kicks in when my state of charges goes below 20% (I'm using LiFePo4 Energy storage from YIY in China). I have 40KWH of storage across 4  Ten KW banks, all in parallel. Roof has 7.9KW of solar panels driving microinverters. They backfeed the house and provide the advantage of EXTRA power when the sun is out - which allows me to run 3 or 4 mini-splits in the summer and still end the day with a FULL charge in the batteries. Winter is easy as well, as my night time (overnight) load is only about 500 to 600 watts of phantom loads and the fridge and water heater. We do laundry when the sun is out. We have an ELECTRIC DRYER and use it regularly. It's a standard electric dryer.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 15, 2021 12:17 PM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe - I wonder how much it dehumidifies your basement. (With it running, what is your basement's typical humidity level, and how much condensate per day does it generate?)
All my ductwork is in my basement's sealed and conditioned space. To wholly prevent mold and condensation on the ducts when the a/c is running, I run a dehumidifier to keep the summertime dewpoint in my basement below 57 degrees F. I have found my heat pump water heater produces very little condensate in this dry (and wholly mold and mildew-free) basement. Only in spring and fall, when I back off on my dehumidifier's setting (since the a/c is not running) do I collect much condensate with my heat pump water heater.
I also wonder how much it costs you to heat up the cold replacement air that must get sucked into your house somewhere, to replace the chilled exhaust air you are venting to the outside in winter.
Depending on your outside ambient air temperature and your home's heat source, it may be indirectly costing you more than it is saving you to run it in heat pump mode in winter.
Kudos to you for your off-grid home. However, since you are off-grid, I am guessing you might be heating with natgas or propane, or with wood, all of which are CO2 producers. 
I realize it is tough to be off-grid and get enough solar power to heat your home. The only way I could do it with my old and inefficient ranch-style home (high surface area to volume, with a lot of NW-facing wall) here in central NC, without a huge pv array, would be natgas. So I am staying grid-tied, and heat the house with a high-efficiency heat pump. I comfort myself by remembering that by drawing power from the grid in winter and paying it back with my surplus in summer (which is peak season for electric usage hereabouts), I am somewhat helping to balance my utility's demand over the year, even if not on an hour-to-hour basis.

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Joe, when you first mentioned the heat pump water heater in your basement, venting its cold air outside in the wintertime, I wondered where all the heat would come from - both that needed to heat the water, and that needed to heat the cold outside air that must be replacing the heat pump water heater's vented exhaust air. 
Now that you have provided additional details about your house, I think I understand.
In addition to pv, you are collecting highly efficient solar thermal heat, storing it both in the large (105 gallon) holding tank and in the thermal mass of your two levels of water-warmed radiant floors. From there, some is transferred from the house at large into the heat pump water heater's own hot water tank.
It must be the case that your roof-mounted solar thermal array provides adequate heat for both your house and also your domestic hot water, Otherwise, "robbing from Peter to pay Paul", your HPWH would drive your house into being uncomfortably cold.
Is this pretty much the way you see it?
Thanks

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC
------------------------------

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

I never gave it much thought, but what you suggest MUST be the case!! The water heater runs VERY intermittantly, i.e. after a nice shower, it runs for maybe 15 minutes. After doing the dinner dishes, it might run for 10 minutes. So AT MOST, it runs 1 hour a day. Hardly anything to worry about. I'd do all the BTU calcs, but it's been 48 years since I got my BSEE (and a VERY well rounded "traditional" engineering background!). Suffice it to say that the entire house simply runs as you'd expect!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com
------------------------------

Original Message:
Sent: Oct 22, 2021 10:17 AM
From: Hugh Willis
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Joe, when you first mentioned the heat pump water heater in your basement, venting its cold air outside in the wintertime, I wondered where all the heat would come from - both that needed to heat the water, and that needed to heat the cold outside air that must be replacing the heat pump water heater's vented exhaust air. 
Now that you have provided additional details about your house, I think I understand.
In addition to pv, you are collecting highly efficient solar thermal heat, storing it both in the large (105 gallon) holding tank and in the thermal mass of your two levels of water-warmed radiant floors. From there, some is transferred from the house at large into the heat pump water heater's own hot water tank.
It must be the case that your roof-mounted solar thermal array provides adequate heat for both your house and also your domestic hot water, Otherwise, "robbing from Peter to pay Paul", your HPWH would drive your house into being uncomfortably cold.
Is this pretty much the way you see it?
Thanks

------------------------------
Hugh Willis
Old Engrs Never Really Retire
GREENSBORO, NC

Original Message:
Sent: Oct 14, 2021 09:37 AM
From: Joe Utasi
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have a heat pump water heater in my basement. It dehumidifies the basement. During the summer I connect the output (cold air) to a vent in my recreation room in the basement, so I get "free" AC!! During the winter, I connect the output to a vent in my sill plate - or the basement gets too cold... all in all, a VERY cost effective and convenient way to heat water in my OFF GRID home!!

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 13, 2021 09:32 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I don't have a HPWH (I have solar DHW), however I would guess it goes like this. The cold coils on the low pressure side cause condensation on its associated coil, just like a dehumidifier has. That water should be "captured" and "hosed" away to a drain by gravity, preferably. I would expect there to be a condensate port on the unit for that. This reduces the humidity and temp in that "areas" space. A good thing. The trick, in a closet like that, is to have top and bottom louvers in the door. Other wise the air will get too cold inside and the HPWH will become ineffective.
In the Winter time, you will be stealing from Peter to give to Paul..... when in space heating mode... According to CCD and HDD records for your area, HDD is <200 where as CDD >5000. So I don't think Peter will become too poor. 

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 13, 2021 09:14 AM
From: Roger Messenger
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I have never seen a WHHP in "person" so have similar questions.  Clearly, it is a win-win in a Florida garage, providing air conditioning to the garage and heating to the DHW, but, perhaps, a more interesting situation in colder climates.
I live in a condo with the water heater in a closet near the kitchen.  We are soon due for  a replacement and I am seriously considering a WHHP.  In my case, my concern is that when the water heater is in a cramped corner, is there a possibility that the "waste cool" resulting from the water heating process will cool the space below the dew point, resulting in mold growth?  So the ducting possibility that is of concern for winter use also becomes a concern for summer use (about 363 days per year).
Any experience here?

------------------------------
Roger Messenger
Senior Project Engineer
Highland Beach FL
roger@llcengineers.com

Original Message:
Sent: Oct 12, 2021 10:43 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

IMHO, the way you describe the "process Flow" around HPWH's is confusing. A heat pump water heater is nothing more than an "air conditioner" if you wish, who's high pressure side has its heat removed by xchanger to heat your less hot DHW cold inlet. To keep it simpler, its better to talk in heat movement, to or from. "Coolth" as noted doesn't really exist. HPWH's are great to use in areas that need de-humidification in Summer and or Winter, like non finished basements, etc.. When you pull heat from "somewhere" there is no free lunch, if the space is conditioned. Examples are Winter heated spaces. Conditioned spaces that get AC in Summer are a win, win of course, which I think you were saying above. Regarding not shooting yourself in the foot during Winter time, there really is not any easy way to do that as long as you have a closed loop to the inside of the house. And if its Winter its going to be cold outside so the 'able to be extracted heat' if an outside loop was engaged can be questionable, and the increased energy use (Another powered flow), etc.. All this of course is assuming I understood your intent above...

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Andrew - You are on the right track. I love my heat pump hot water heater. And it does help both cool and (a little bit) dehumidify my house in summer.

To answer your question about "off the shelf ducting kits" for hybrid "heat pump" residential water heaters - custom kits might not be needed. Depending on your manufacturer, ordinary HVAC ductwork and fittings (either flexible duct or "hard pipe") may work just fine. Although not typical when I bought mine five years ago, I suspect many models today can connect directly to regular HVAC ducting.

("Hybrid" because in addition to the heat pump, it also has conventional resistance electrical heating elements exactly like a regular electric hot water heater, for use when demand is high or temperatures too cold).

The installation manuals I could find tonight on line are ones that come with the Rheem line of hybrid (heat pump/resistance heat) residential hot water heaters (in 40 to 80 gallon sizes)  Those manuals recommend the unit be placed in rooms of at least 700 sq ft, or use other methods (louvered doors, supply and/or exhaust ducts, etc.)  to provide sufficient air to the heat pump.

I mention Rheem, only because I recently bought one for my daughter, and knew where to find the installation manual. It states, "The inlet and outlet ducting connections on the water heater accepts 8 inch diameter ducting. No additional adaptors are needed". 3c9717fd-0b98-43d3-ada9-73b6b8928948.pdf (thdstatic.com)

Although my own hybrid "heat pump" residential water heater five years ago did not make ducting easy, I luckily did not need to use ducts.

Mine, (not a Rheem) is in my sealed/conditioned crawlspace/basement (200 sq ft of 8' ceiling "basement" slab which is fully open to an additional 1800 sq ft of 3' surrounding crawlspace). That total volume is the equivalent of an 875 sq ft room with 8' ceilings, and has a lot of available thermal mass to buffer any temperature changes. So my space is more than adequate to fulfill Rheem's requirements, no ductwork required.

I monitor the basement temperature and humidity, and have never seen the temperature drop by more than a couple of degrees when my unit is heating water with its heat pump.

I am extremely happy with my unit as it, along with my high-efficiency HVAC whole-house heat pump, is an integral part of my "all-electric" strategy as I work toward making my nearly 70 year old house annually "net zero" with a 10 kw solar pv array.


------------------------------
Hugh Willis
Engrs Never Really Retire
Hugh Willis
GREENSBORO, NC NC
hughwill@bellsouth.net
------------------------------

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

 

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

We have a Rheem Heat Pump Water heater and they are crazy efficient.  It does cool down the laundry room but not to the point of a problem and the condensate has a line I run into a drain.  In the winter it does take some heat out of the house but overall our bills have been noticeably less and I highly recommend them.  If you have an EV you if you swap from a normal water heater to a heap pump variety that is enough power saved to drive some 11,000 miles a year.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net
------------------------------

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

What part of what country are you in? Climate etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 18, 2021 06:55 PM
From: David Hrivnak
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

We have a Rheem Heat Pump Water heater and they are crazy efficient.  It does cool down the laundry room but not to the point of a problem and the condensate has a line I run into a drain.  In the winter it does take some heat out of the house but overall our bills have been noticeably less and I highly recommend them.  If you have an EV you if you swap from a normal water heater to a heap pump variety that is enough power saved to drive some 11,000 miles a year.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

We are in NE Tennessee, and summer cooling is nearly the same cost as winter heating with our Heat Pump.   About every other year we will see a morning in the single digits.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net
------------------------------

Original Message:
Sent: Oct 19, 2021 05:02 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

What part of what country are you in? Climate etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 18, 2021 06:55 PM
From: David Hrivnak
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

We have a Rheem Heat Pump Water heater and they are crazy efficient.  It does cool down the laundry room but not to the point of a problem and the condensate has a line I run into a drain.  In the winter it does take some heat out of the house but overall our bills have been noticeably less and I highly recommend them.  If you have an EV you if you swap from a normal water heater to a heap pump variety that is enough power saved to drive some 11,000 miles a year.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

I think most places where you have a fairly even balance between heating and cooling loads or hotter, they will do very well without outside connections.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 19, 2021 05:29 AM
From: David Hrivnak
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

We are in NE Tennessee, and summer cooling is nearly the same cost as winter heating with our Heat Pump.   About every other year we will see a morning in the single digits.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net

Original Message:
Sent: Oct 19, 2021 05:02 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

What part of what country are you in? Climate etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 18, 2021 06:55 PM
From: David Hrivnak
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

We have a Rheem Heat Pump Water heater and they are crazy efficient.  It does cool down the laundry room but not to the point of a problem and the condensate has a line I run into a drain.  In the winter it does take some heat out of the house but overall our bills have been noticeably less and I highly recommend them.  If you have an EV you if you swap from a normal water heater to a heap pump variety that is enough power saved to drive some 11,000 miles a year.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Located on Lake KEOWEE in Extreme NW corner of South Carolina

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com
------------------------------

Original Message:
Sent: Oct 19, 2021 05:02 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

What part of what country are you in? Climate etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 18, 2021 06:55 PM
From: David Hrivnak
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

We have a Rheem Heat Pump Water heater and they are crazy efficient.  It does cool down the laundry room but not to the point of a problem and the condensate has a line I run into a drain.  In the winter it does take some heat out of the house but overall our bills have been noticeably less and I highly recommend them.  If you have an EV you if you swap from a normal water heater to a heap pump variety that is enough power saved to drive some 11,000 miles a year.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Original Message:
Sent: 10/19/2021 2:42:00 PM
From: Joe Utasi
Subject: RE: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Located on Lake KEOWEE in Extreme NW corner of South Carolina

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com
------------------------------

Original Message:
Sent: Oct 19, 2021 05:02 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

What part of what country are you in? Climate etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 18, 2021 06:55 PM
From: David Hrivnak
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

We have a Rheem Heat Pump Water heater and they are crazy efficient.  It does cool down the laundry room but not to the point of a problem and the condensate has a line I run into a drain.  In the winter it does take some heat out of the house but overall our bills have been noticeably less and I highly recommend them.  If you have an EV you if you swap from a normal water heater to a heap pump variety that is enough power saved to drive some 11,000 miles a year.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

So its "pile on time" huh....lol....  I remember when HPWH's were first introduced. The "hoopla" as the end all water heater was quite the rush. But as things go, and people began to figure the optimal locations for them, they figured out that it wasn't for everybody. They are just part of the general landscape of green solutions that my be a fit for people. As it usually goes with DHW, the more you use the better the return when efficiency is increased.

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net
------------------------------

Original Message:
Sent: Oct 20, 2021 09:38 AM
From: Dave Erb
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I was going to jump in anyway, but now that it's a regional party ...

I wrote about my own experience with a heat pump water heater in Chapter 1 of David Hrivnak's book, "Driving to Net 0:  Stories of Hope for a Carbon-Free Future."  It's available on biblio.com.

Dave Erb

Asheville, NC

https://www.youtube.com/channel/UC5I9P0dwflssm6M_75VaJCg

Original Message:
Sent: 10/19/2021 2:42:00 PM
From: Joe Utasi
Subject: RE: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

Located on Lake KEOWEE in Extreme NW corner of South Carolina

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
joe@cincihomesolar.com

Original Message:
Sent: Oct 19, 2021 05:02 AM
From: william fitch
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

What part of what country are you in? Climate etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
fcfcfc@ptd.net

Original Message:
Sent: Oct 18, 2021 06:55 PM
From: David Hrivnak
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

We have a Rheem Heat Pump Water heater and they are crazy efficient.  It does cool down the laundry room but not to the point of a problem and the condensate has a line I run into a drain.  In the winter it does take some heat out of the house but overall our bills have been noticeably less and I highly recommend them.  If you have an EV you if you swap from a normal water heater to a heap pump variety that is enough power saved to drive some 11,000 miles a year.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member

Original Message:
Sent: 10/18/2021 9:56:00 PM
From: David Hrivnak
Subject: RE: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

We have a Rheem Heat Pump Water heater and they are crazy efficient.  It does cool down the laundry room but not to the point of a problem and the condensate has a line I run into a drain.  In the winter it does take some heat out of the house but overall our bills have been noticeably less and I highly recommend them.  If you have an EV you if you swap from a normal water heater to a heap pump variety that is enough power saved to drive some 11,000 miles a year.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net
------------------------------

Original Message:
Sent: Oct 12, 2021 09:56 AM
From: Andrew Stone
Subject: Heat Pump Water Heater: who's also using the waste extracted 'coolth'?

I see the excitement around using https://www.energy.gov/energysaver/heat-pump-water-heaters.

In the summer, the waste "coolth" from heating the water could be used to help cool your house, and in the winter, it could be shunted outside to NOT cool your house.

Are there off-the-shelf ducting kits for common models which duct away the produced waste 'coolth' seasonally?

Andrew Stone

PACE Fund NM

Commercial Solar Lending

Renewable Energy Industry Association board member

NM Solar Energy Association board member

National Community Solar Partnership founding member