Wednesday, August 11, 2010

Paul's DIY Solar Water Heating System

This is Paul's version of the "$1K Solar Water Heater".  While the design generally follows the $1K design, he has included several unique features:

- The collector housing (box) is made from metal instead of wood.

- A selective finish is applied to the absorber for better performance.

- A thermally conductive copper adhesive bond absorber fins to riser tubes.

- Fins are formed of heavy gage aluminum using a press.

- Barrel storage tank with PEX custom wound heat exchanger coil.

This is one of Paul's collector fins.  Very nicely formed using tools he built.
He used Permatex Copper Spray a Gasket to adhere and thermally bond the aluminum fin to the copper riser pipe.  This may give better thermal performance -- something I hope to test fairly soon.
The fins were painted by the moderately selective paint called Thermalox  -- this paint is available in easy to apply spray cans and gives a lower emissivity finish that should reduce collector heat loss and improve performance.

This is Paul's collector -- it uses a metal frame made from galvanized steel stud "rail" material.



To store the collected solar heat, Paul uses two barrels, each with a new version of the coil of PEX type of heat exchanger that uses two coils of small diameter PEX pipes in parallel to transfer heat from the solar storage to the potable water.  John Canivan's JC-SolarHomes website has quite a bit of material on using drums for solar heat storage.

Paul  worked out an innovative way to moving the fairly heavy collector up on to his high roof -- probably not OSHA approved, but it worked:

All the details on Paul's DIY Solar Water Heating System...

Other $1K Solar Water Heating System Examples...

More than you ever wanted to know about building a $1K Solar Water Heater...

Gary