Passive solar water heater

[David Lechman]

Hi All.

I'm building a passive solar hot water system.It's composed of an
insulated box with a 30 degree angle.I'm using a glass door for
the lid.The lid is on hinges (my only way of regulating the temp.)
I live in Arizona,where the daytime temp. can exceed 110 degrees
for months.(overnight temps. "plummet" to 85-95).My box will be
totally in the shade from mid May thru mid September. Is there
a way to calculate how hot the water will be during those months?
A plumber told me that the pressure relief valve goes off at
158 degrees.Will my water be getting that hot? I plan on
leaving the lid open during the hot months,but I am still
wondering if the water will still get too hot.
Does anyone have a passive solar water heater in my area?
Any ideas?

Thank You.

[Steven Fahey]

Hi David,

I don't live near Arizona, but I do have a home-built solar water heater. I don't imagine you will have the difficulties that I have - mine is to prevent the water troughs for my horses from freezing in the winter. My box was built around an open water trough, with a window on the sunny side to heat the water. It saves quite a bit of electricity that the floating heater doesn't have to use.

For dozens of home-made projects using solar energy, you want to see the site called "build-it-solar"

http://www.builditsolar.com/index.htm

Good luck!