SOLAR ( sort of )

[Anonymous]

We get LOTS of sunshine in Southern Arizona.

Without getting too elaborate, here's my idea;

Loop about 100' of plastic pipe in the rooftop. Connect FROM cold inlet TO my water heater.

During the daytime, ( which is when we use hot water ) Water would be solar-preheated before going to the water heater.

No need for any "controls" except to disconnect it in the wintertime. ( temps do dip to freezing at nite in mid-winter )

Opinions ??? What kind of pipe ? Would I need to fasten it to the rooftop ??

[Bob F]

You could make a simple batch pre-heater out of an old water heater tank.

Bob

[Old Boat]

It will work. When I was in college and living in a mobile home, I made a solar water heater. It consisted of a 4 x 8 x 8" box insulated with 1" foam that had aluminum on it. The top was covered with 2 layers of heavy clear plastic with a 1" space between them. Inside I put in 500 feet of 1/2" Poly pipe coiled. I hooked the input of the box to the cold water line at a tee so that the water could go either to the tank or the heater. The output of the box went to a tee at the TPR valve. The allowed the hot water to rise into the mobile home and push the colder water back into the coils. Kind of a self circulating pump. This worked very well for the summer, getting water that was 175 degrees out of it even on cloudy days. It eventually failed though because the pipe got a kink in it. Suffice it to say that the entire

500 foot roll of poly melted into a big blob in the box. The concept was sound though. I later built one out of PVC pipe for our pool and hooked it in line with the pump and it did work to heat the pool. Depending on the climate where you live will dictate the method you use to make yours.

LJ

[buffalobill]

and in winter you use a geothermal ground loop. see your local plumbing permit office on requirements on both. the words anti-siphon and check valve come to mind. maybe ask some school/college science lab to come and design it for you.