Homemade solar hot water

[DickWilson]

Punamom; If your system is valved to allow a flow thru feed, convection heating should induce enough flow to circulate thru your hw storage tanks and thru the tubing, the only concern I would have would be whether the tubing would heat enough to generate enough head pressure to reach your roof if that is where you are putting your coil. You would need a bypass in the main hw supply line to allow flow thru the heating loop when there is no hw demand from the house. Cold water make-up will reduce your hw temperature rather dramaticaly at each use, but recovery should be fairly rapid with sufficient sunlight. Supply lines to and from the auxillary heating coil should be insulated to conserve water temp and minimize radiant heat loss. Residential TPR (temperature, pressure regulator) valves for home hw systems are rated at 150 psi for pressure and 210 deg. F for temp. I would not expect your system to exceed that and if it did, you would want the valve to vent the system to prevent damage or an explosion. Consult with your plumber for pump and pressure tank sizing to determine system static pressure.

dick wilson