Inventors:
Terence C. Honikman - Santa Barbara CA
International Classification:
F24J 302, F24D 300
Abstract:
Solar energy is utilized to augment the heater of a water heating system, such as a domestic hot water system, having a water storage and heating tank by conducting water to the tank through a solar energy storage tank and circulating a heat transport liquid through a solar collector and selectively through the solar tank and water tank in response to the collector temperature, the solar tank temperature, and the water tank temperature, in a manner such that heat transport liquid flow occurs in a normal solar energy storage mode through the collector and the solar tank under a first set of temperature conditions, and cascade fashion through the collector, the water tank, and then the solar tank in a cascade solar energy storage mode under a second set of temperature conditions and in a maximum solar energy storage mode under a third set of temperature conditions. Heat transport liquid flow may occur through the solar collector and solar tank in response to a preset low collector temperature to prevent freezing of liquid in the collector, and the water tank heater may be shut off in response to a high collector and water temperature condition to conserve energy. The invention also provides novel solar collector and tank heat exchanger structures for the heating system.