The Acorn Sunwave Energy Systems water solar collector, was installed in ~1979. This six section unit totalling 400 sq. ft., is mounted on south roof exposure. Water is pumped through the heat exchanger from a 2,000+ gallon wooden insulated storage tank mounted in a basement mechanical room. The tank is capable of holding 400,000 BTUs or more of warm water for both heating and domestic hot water use.

Water for house heating use uses a dedicated circulation pump and a heating water coil mounted in the return air to the furnace. Solar water is the first stage of heating.

A separate 30 gallon stainless steel heat exchanger is mounted within the tank to pre-heat domestic hot water before entering the electric hot water heater. Domestic hot water is continually available through the use of a separate circulation pump that moves water throughout the house. A separate (third) hot water return line maintains warm water at the faucets.

The Sunwave system warms water throughout the year using collected sun energy. For Indianapolis this represents ~55% of the year.