This is a very interesting $1K style system from Bill with quite a few interesting design variations. Among the unique features:
- Closed loop rather than drain back for freeze protection
- Glazed with dual wall polycarbonate glazing.
- A unique collector frame that uses EPDM rubber roofing for weather protection.
- Using a custom made PVC tank liner instead of the usual folded EPDM liner.
- Lots of detail on roof mounting the collector, including the site made collector hoist shown just below.
- A unique design approach to handing differential expansion issues in the absorber design.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEituvZcWBsPx2b9LW4ZfzVbOhu4501wZ_88_n67BQBEkgcW8hlgCpjL6moxx4d4ZmY3bvvyXW9omC4MJm8yD8FjBgtqJg7P4wes5TWicDriwhHIy4uHZa3NIdgVWCxvhxlsGDcIT9plz_g6/s320/BillClosedLoopOV.jpg) |
Bill's system with the first collector in place |
Bill used a closed loop system because he was not able to maintain a good slope on the plumbing to and from the the collector. This requires adding a 2nd heat exchanger to the tank that transfers heat from the collector circuit (which has antifreeze) to the storage tank which is plain water -- this is Bill's heat exchanger arrangement:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEju8QammNOuA5zz6xp1VrxStzKDJrcTmHTPQuTWhAKgZhVXtrH-9Z5OXbw7pNvRyS_nM0QWdHmUbbgNP8koOc3jXw3AwtxXb97wRvQHU0mfmRyH3mb6fJOAxDav0DrNLDMDZ6DQgtAhafQ5/s320/BillClosedLoopHX.jpg) |
The collector loop and domestic hot water heat exchangers in the storage tank. |
Another unique feature of the system is the that Bill used a custom made PVC liner instead of the folded EPDM liner. This is a picture of the liner:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEje3QqlkSBlR25VvbgLOWV6SHWbKzlWj9qAmE6EP8wFs2_gaTLbCQD6Cq4_G75Y4KdEhWEKwNhVmyNTy4qFZyrh-Tcl-NDo5GvWm84_UFDURgyuekZmuzgAEJm8gc95DbVkDHnaR8BgppuO/s320/BillClosedLoopLiner.jpg) |
Custom PVC tank liner |
This seems like a good way to go if you can get a competitive price on the liner.
I also like the special hoist that Bill made to get the collector up on the roof:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0XI0RBBp_YhZpbOlnM94hSjjj26c5FEdBy3kEcGbhukSzjndLOW82aZ7O-rBL95xT5uwk8K5xW1hQkEYndJ9KZ0oFE4FLTynPHYes0zYj6XAh46DKu6ya4d6WN7X_HtkoRcBReWfQq9he/s320/BillClosedLoopHoist.jpg) |
Custom made hoist to lift collector to roof. |
These collectors are heavy, and Bill has several of them to get up on the roof -- the hoist will save a lot of work and be safer.
Go here for all the details on Bill's system....
Go here for the details on a hundred or so other solar water heating systems...
Gary