Need constructive critique on my idea for a solar hot water panel , please

ilbebauck · 2011-07-08T16:11:34+00:00

Some background : I live alone and want to totally eliminate the needto run my 40 gallon electric water heater, and since i live in sunnyFlorida I believe I can do so given my low requirement for hot water.Im going to be building my solar collector very soon when all thematerials are gathered. My requirement for hot water usage is to takea relatively quick shower of 5-10 minutes using 100 f. hot water andbelieve the following plan will handle at least that :I want to use 3/4"x300' coiled red Pex Tubing which measures 32"diameter x 7" high . I will set this in a box which i will constructout of wooden 2x12's with a 1/2" thick plywood on the backside(treated) for a 36"x36" od Box. . I will lay 4" of dense pinkFoamboard in the bottom . A 32" square sheetmetal plate painted withflat high temp. low gloss Black paint (primed first) will be layed ontop of the bottom Foamboard . The coiled Pex tubing will be wrapped inheavy duty tin foil sheet to prevent UV light from seeing the Pex ,and this foil will be pulled tight around the coil of Pex and alsopainted high temp flat black. ... then the coil will sit inside thebox in direct contact with the sheetmetal plate. A double pane windowin frame measuring 36" sq. od (without any inside bars) will befastened on top of the box for a greenhouse effect. The box will sitagainst the southside of the house on the ground at a 30 degree anglefrom vertical in a location where where it will recieve full sun. Iwill cut the hot water CPVC pipe above the water heater and route tothe Solar Panel using 3/4" CPVC (insulated) connecting to the 3/4" Pextubing stubbed out of the side of the Box using Pex compressionfittings . The return CPVC pipe (insulated) will run back to the topof the water heaters hot water supply pipe. (Since my hot waterreqirements are very minimal, I opted not to heat the entire waterheater) .Since stagnation temps/pressure in the box are of concern, i plan onsecuring a section of shiny sheetmetal over the face of the Box...