Thermosiphon Passive Solar Water Heater

Two 4’ x 5’ panels with an 80 gallon storage tank are installed on the roof, typically facing South. The panels contain food grade glycol, which, when heated by the sun, rises up to circulate through the insulated ceramic lined water tank, heating the water.

The system can act as a stand alone water heater, as the tank contains its own heating element, or the system can act as a non-electric pre-heater to a standard electric or gas water heater in the home. Savings in water heating cost exceed 90 percent in Florida, saving over 20 percent of the typical electric bill. This system does not freeze, and corrosive water will not damage the collector stainless steel tubes, as only the glycol comes into contact with the stainless steel.

How it works Food grade glycol is heated by the sun in the collector area, boiling it, causing it to rise up and circulate through the insulated, ceramic lined water tank, heating the water. Giving off its heat, the glycol condenses, falling back into the collector area. No pumps or sensors are involved.