Ask a Renewable Energy Expert

I have extensive experience with solar thermal systems, all of them using flat plate collectors. I'm being offered a presumably great deal on a four year old evacuated tube system (SunMaxx) that is in bad shape. Many of the tubes didn't come out of the manifolds properly and the soft copper rods are stuck in the manifolds. Our first step is to figure out how to remove the rods without damaging them, and if we do wind up damaging them: 1) how to salvage them, and; 2) how to remove all the contents of rod inside the manifold opening so we can install a new one. 

Anyone here have experience with evacuated tube systems?

------------------------------
Dan Antonioli
Owner
Going Green
Dryden NY
solardan26@gmail.com
------------------------------

Dan:
If you are being offered a great deal, does that mean you are being paid to removed system?
Perhaps photos might better define "bad shape". Sometimes bad shape means it was not installed correctly, but removing glass tubes should not be too difficult. I am not sure what you mean by "rods". Do you mean a structural parts, water pipe in/out of glass tube or the heat-pipe inside the evacuated tube that transfers heat to the manifold/header? The heat-pipe type panels use some heat transfer paste that can harden, making removal difficult/tedious. 
So. depending upon models/generation of panels/system answers might be a little different. Find the model number and get an installation manual on the Sunmaxx website that match. Then if you can identify questions more I might be able to help, but since the Sunmaxx has/had an address in Bainbridge, NY they too might have some answers/parts if needed.
Good luck,
Henry

------------------------------
Henry Vandermark
Solar Wave Energy, Inc.
Cambridge MA
hkv@solarwave.com
------------------------------

Original Message:
Sent: 10-18-2022 04:49 AM
From: Dan Antonioli
Subject: Salvaging a used evacuated tube system

I have extensive experience with solar thermal systems, all of them using flat plate collectors. I'm being offered a presumably great deal on a four year old evacuated tube system (SunMaxx) that is in bad shape. Many of the tubes didn't come out of the manifolds properly and the soft copper rods are stuck in the manifolds. Our first step is to figure out how to remove the rods without damaging them, and if we do wind up damaging them: 1) how to salvage them, and; 2) how to remove all the contents of rod inside the manifold opening so we can install a new one. 

Anyone here have experience with evacuated tube systems?

------------------------------
Dan Antonioli
Owner
Going Green
Dryden NY
solardan26@gmail.com
------------------------------

Henry, 

The SunMaxx system was installed properly and the SunMaxx Bainbridge office is just down the road from the site where this system lived. SunMaxx customer service is virtually non-existent, unless you regard virtual people who have no technical information to offer customer service. They have offered zero information and have a bad rap in the solar thermal community. 

Evacuated tubes have a copper rod that attaches into the heat manifold....the rods are at the center of the tube assembly and heat up and transfer that heat to the manifold where the water passing through is heated. If you take apart a tube there are the evacuated tubes, the rods, and the heat fins that attach to the rods. As I've learned, it's common for the rod-to-manifold connection to oxidize and they simply don't come out....so instead the outside assembly (tubs and fins) can slide off...but not the rod. A common problem and one of the reasons why evacuated tubes have gone out of fashion. 

My primary question here is how to deal with a common problem with used evacuated tube systems. One seasoned solar thermal person told me that once an evacuated tube system goes up it doesn't come down the way it's supposed to. The system I'm looking into is only four years old. The used flat plate collectors I've used with great success are upwards to thirty years old and work like a charm. 

Companies that used to sell and install evacuated tube systems no longer do so and now I know why. But, there's still potential with the system in question and I love to tinker. So anyone who's grappled with them please chime in.

------------------------------
Dan Antonioli
Owner
Going Green
Dryden NY
solardan26@gmail.com
------------------------------

Original Message:
Sent: 10-18-2022 02:21 PM
From: Henry Vandermark
Subject: Salvaging a used evacuated tube system

Dan:
If you are being offered a great deal, does that mean you are being paid to removed system?
Perhaps photos might better define "bad shape". Sometimes bad shape means it was not installed correctly, but removing glass tubes should not be too difficult. I am not sure what you mean by "rods". Do you mean a structural parts, water pipe in/out of glass tube or the heat-pipe inside the evacuated tube that transfers heat to the manifold/header? The heat-pipe type panels use some heat transfer paste that can harden, making removal difficult/tedious. 
So. depending upon models/generation of panels/system answers might be a little different. Find the model number and get an installation manual on the Sunmaxx website that match. Then if you can identify questions more I might be able to help, but since the Sunmaxx has/had an address in Bainbridge, NY they too might have some answers/parts if needed.
Good luck,
Henry

------------------------------
Henry Vandermark
Solar Wave Energy, Inc.
Cambridge MA
hkv@solarwave.com

Original Message:
Sent: 10-18-2022 04:49 AM
From: Dan Antonioli
Subject: Salvaging a used evacuated tube system

I have extensive experience with solar thermal systems, all of them using flat plate collectors. I'm being offered a presumably great deal on a four year old evacuated tube system (SunMaxx) that is in bad shape. Many of the tubes didn't come out of the manifolds properly and the soft copper rods are stuck in the manifolds. Our first step is to figure out how to remove the rods without damaging them, and if we do wind up damaging them: 1) how to salvage them, and; 2) how to remove all the contents of rod inside the manifold opening so we can install a new one. 

Anyone here have experience with evacuated tube systems?

------------------------------
Dan Antonioli
Owner
Going Green
Dryden NY
solardan26@gmail.com
------------------------------

Dan:
Yes , they do not have a good reputation, except for burning bridge, but they are a company with a history of business practices not a technology.
It sounds like the "rod" if there is just one per evacuated tube you are speaking about is a heat-pipe. I would guess the heat transfer paste they used was not rated for high temperature and hardened like cement. you might try rubbing alcohol to soften the hardened paste. If that works clean both bulb and socket, then use high temp. version.
While Sunmaxx may have "0" support, there are manuals online, but you need the model number to match as there are various models.
1. manual will only help, plus any specs. for your specific collectors
2. one common problem your mention, heat pipe to manifold connection: clean old and find either high temp paste for high temp lub to connect in sockets. If nothing, then use water to lub, leaving copper to copper for heat transfer.
3. What you colleague mentioned ".....t once an evacuated tube system goes up it doesn't come down the way it's supposed to. ..." while vague, it might be in reference to heat-pipe failure from stagnating at high temperature. Note: one of the issues about evacuated tube collectors with heat-pipes is that you can not tell if the heat pipe has failed by looking at it. A heat-pipe is an evacuated tube with a little water inside and wick. water boils from the evacuated tube part (lower section) to the top (bulb in manifold) condenses and returns to the bottom. The wick help water to go back down. some wick are or include metal powder covering the full length of the tube. Collector stagnation can mess up that distribution.
So, sometime shaking the heat-pipe end to end will re-distribute the dust/wick so the heat-pipe work better.  For some heat-pipes this shaking might work for ever but without monitoring performance in at least some simple way it is hard to tell.
Best of luck
Henry
SP.
Basically I am a flat plate person.
Flat-plates generally collect more yearly per area, but good quality evacuated tube panels have there place, higher temperature during cold weather.


------------------------------
Henry Vandermark
Solar Wave Energy, Inc.
Cambridge MA
hkv@solarwave.com
------------------------------

Original Message:
Sent: 10-18-2022 04:22 PM
From: Dan Antonioli
Subject: Salvaging a used evacuated tube system

Henry, 

The SunMaxx system was installed properly and the SunMaxx Bainbridge office is just down the road from the site where this system lived. SunMaxx customer service is virtually non-existent, unless you regard virtual people who have no technical information to offer customer service. They have offered zero information and have a bad rap in the solar thermal community. 

Evacuated tubes have a copper rod that attaches into the heat manifold....the rods are at the center of the tube assembly and heat up and transfer that heat to the manifold where the water passing through is heated. If you take apart a tube there are the evacuated tubes, the rods, and the heat fins that attach to the rods. As I've learned, it's common for the rod-to-manifold connection to oxidize and they simply don't come out....so instead the outside assembly (tubs and fins) can slide off...but not the rod. A common problem and one of the reasons why evacuated tubes have gone out of fashion. 

My primary question here is how to deal with a common problem with used evacuated tube systems. One seasoned solar thermal person told me that once an evacuated tube system goes up it doesn't come down the way it's supposed to. The system I'm looking into is only four years old. The used flat plate collectors I've used with great success are upwards to thirty years old and work like a charm. 

Companies that used to sell and install evacuated tube systems no longer do so and now I know why. But, there's still potential with the system in question and I love to tinker. So anyone who's grappled with them please chime in.

------------------------------
Dan Antonioli
Owner
Going Green
Dryden NY
solardan26@gmail.com

Original Message:
Sent: 10-18-2022 02:21 PM
From: Henry Vandermark
Subject: Salvaging a used evacuated tube system

Dan:
If you are being offered a great deal, does that mean you are being paid to removed system?
Perhaps photos might better define "bad shape". Sometimes bad shape means it was not installed correctly, but removing glass tubes should not be too difficult. I am not sure what you mean by "rods". Do you mean a structural parts, water pipe in/out of glass tube or the heat-pipe inside the evacuated tube that transfers heat to the manifold/header? The heat-pipe type panels use some heat transfer paste that can harden, making removal difficult/tedious. 
So. depending upon models/generation of panels/system answers might be a little different. Find the model number and get an installation manual on the Sunmaxx website that match. Then if you can identify questions more I might be able to help, but since the Sunmaxx has/had an address in Bainbridge, NY they too might have some answers/parts if needed.
Good luck,
Henry

------------------------------
Henry Vandermark
Solar Wave Energy, Inc.
Cambridge MA
hkv@solarwave.com

Original Message:
Sent: 10-18-2022 04:49 AM
From: Dan Antonioli
Subject: Salvaging a used evacuated tube system

I have extensive experience with solar thermal systems, all of them using flat plate collectors. I'm being offered a presumably great deal on a four year old evacuated tube system (SunMaxx) that is in bad shape. Many of the tubes didn't come out of the manifolds properly and the soft copper rods are stuck in the manifolds. Our first step is to figure out how to remove the rods without damaging them, and if we do wind up damaging them: 1) how to salvage them, and; 2) how to remove all the contents of rod inside the manifold opening so we can install a new one. 

Anyone here have experience with evacuated tube systems?

------------------------------
Dan Antonioli
Owner
Going Green
Dryden NY
solardan26@gmail.com
------------------------------

The rod/pipe is made of very soft copper, bends easily when out of the tube, and flattens when gripped with channel locks. Finding a way to grip the rod/pipe so you can turn it and loosen the point of insertion is the biggest issue here. But I've got a couple of ideas for a grip that distributes the connection and hopefully allows for loosening it from the manifold. If we can do that then we'll be able to salvage the system.
Was hoping SunMaxx would have a tool or a tip here, but the two people I've talked to about this with evac tube experience say that it's usually a lost cause...once the connection oxidizes and "welds" together then it won't come out....but I've got a couple of ideas about that as well. Will report back.

------------------------------
Dan Antonioli
Owner
Going Green
Dryden NY
solardan26@gmail.com
------------------------------

Original Message:
Sent: 10-18-2022 06:05 PM
From: Henry Vandermark
Subject: Salvaging a used evacuated tube system

Dan:
Yes , they do not have a good reputation, except for burning bridge, but they are a company with a history of business practices not a technology.
It sounds like the "rod" if there is just one per evacuated tube you are speaking about is a heat-pipe. I would guess the heat transfer paste they used was not rated for high temperature and hardened like cement. you might try rubbing alcohol to soften the hardened paste. If that works clean both bulb and socket, then use high temp. version.
While Sunmaxx may have "0" support, there are manuals online, but you need the model number to match as there are various models.
1. manual will only help, plus any specs. for your specific collectors
2. one common problem your mention, heat pipe to manifold connection: clean old and find either high temp paste for high temp lub to connect in sockets. If nothing, then use water to lub, leaving copper to copper for heat transfer.
3. What you colleague mentioned ".....t once an evacuated tube system goes up it doesn't come down the way it's supposed to. ..." while vague, it might be in reference to heat-pipe failure from stagnating at high temperature. Note: one of the issues about evacuated tube collectors with heat-pipes is that you can not tell if the heat pipe has failed by looking at it. A heat-pipe is an evacuated tube with a little water inside and wick. water boils from the evacuated tube part (lower section) to the top (bulb in manifold) condenses and returns to the bottom. The wick help water to go back down. some wick are or include metal powder covering the full length of the tube. Collector stagnation can mess up that distribution.
So, sometime shaking the heat-pipe end to end will re-distribute the dust/wick so the heat-pipe work better.  For some heat-pipes this shaking might work for ever but without monitoring performance in at least some simple way it is hard to tell.
Best of luck
Henry
SP.
Basically I am a flat plate person.
Flat-plates generally collect more yearly per area, but good quality evacuated tube panels have there place, higher temperature during cold weather.


------------------------------
Henry Vandermark
Solar Wave Energy, Inc.
Cambridge MA
hkv@solarwave.com

Original Message:
Sent: 10-18-2022 04:22 PM
From: Dan Antonioli
Subject: Salvaging a used evacuated tube system

Henry, 

The SunMaxx system was installed properly and the SunMaxx Bainbridge office is just down the road from the site where this system lived. SunMaxx customer service is virtually non-existent, unless you regard virtual people who have no technical information to offer customer service. They have offered zero information and have a bad rap in the solar thermal community. 

Evacuated tubes have a copper rod that attaches into the heat manifold....the rods are at the center of the tube assembly and heat up and transfer that heat to the manifold where the water passing through is heated. If you take apart a tube there are the evacuated tubes, the rods, and the heat fins that attach to the rods. As I've learned, it's common for the rod-to-manifold connection to oxidize and they simply don't come out....so instead the outside assembly (tubs and fins) can slide off...but not the rod. A common problem and one of the reasons why evacuated tubes have gone out of fashion. 

My primary question here is how to deal with a common problem with used evacuated tube systems. One seasoned solar thermal person told me that once an evacuated tube system goes up it doesn't come down the way it's supposed to. The system I'm looking into is only four years old. The used flat plate collectors I've used with great success are upwards to thirty years old and work like a charm. 

Companies that used to sell and install evacuated tube systems no longer do so and now I know why. But, there's still potential with the system in question and I love to tinker. So anyone who's grappled with them please chime in.

------------------------------
Dan Antonioli
Owner
Going Green
Dryden NY
solardan26@gmail.com

Original Message:
Sent: 10-18-2022 02:21 PM
From: Henry Vandermark
Subject: Salvaging a used evacuated tube system

Dan:
If you are being offered a great deal, does that mean you are being paid to removed system?
Perhaps photos might better define "bad shape". Sometimes bad shape means it was not installed correctly, but removing glass tubes should not be too difficult. I am not sure what you mean by "rods". Do you mean a structural parts, water pipe in/out of glass tube or the heat-pipe inside the evacuated tube that transfers heat to the manifold/header? The heat-pipe type panels use some heat transfer paste that can harden, making removal difficult/tedious. 
So. depending upon models/generation of panels/system answers might be a little different. Find the model number and get an installation manual on the Sunmaxx website that match. Then if you can identify questions more I might be able to help, but since the Sunmaxx has/had an address in Bainbridge, NY they too might have some answers/parts if needed.
Good luck,
Henry

------------------------------
Henry Vandermark
Solar Wave Energy, Inc.
Cambridge MA
hkv@solarwave.com

Original Message:
Sent: 10-18-2022 04:49 AM
From: Dan Antonioli
Subject: Salvaging a used evacuated tube system

I have extensive experience with solar thermal systems, all of them using flat plate collectors. I'm being offered a presumably great deal on a four year old evacuated tube system (SunMaxx) that is in bad shape. Many of the tubes didn't come out of the manifolds properly and the soft copper rods are stuck in the manifolds. Our first step is to figure out how to remove the rods without damaging them, and if we do wind up damaging them: 1) how to salvage them, and; 2) how to remove all the contents of rod inside the manifold opening so we can install a new one. 

Anyone here have experience with evacuated tube systems?

------------------------------
Dan Antonioli
Owner
Going Green
Dryden NY
solardan26@gmail.com
------------------------------