Solar Domestic Hot Water

Dream Farm

Solar Domestic Hot Water

Our Solar Domestic Hot Water System provides us with 120F-150F water most of the spring, all summer, and most of the fall. During winter it preheats our water so our propane hot water heater doesn't work as hard. This system will pay itself off the fastest. It cost us only $3500 (after the $3000 rebate from the State of Michigan) and has saved us at approximately $2000 in four years of operation.

Our Solar Collector array consists of three Heliodyne Gobi 3366 liquid solar collectors (27 square feet each) mounted on an outbuilding. These are among the most efficient thermal collectors made. The non-toxic propylene glycol coolant cycles in a closed loop to the house where it exchanges heat with our hot water tank.

Though much smaller than our solar PV array, our solar domestic hot water collector array can collect just as much energy, over 20 kWh per day (88,000 BTU/day).

We have an American Solar Electric Hot Water Heater in series with our propane hot water heater. (Though it has a 4500 watt electrical element, it is currently not connected to any electrical power,but may be in the future)

The rest of our Solar Domestic Hot Water System consists of a Grundfos UP 42F closed loop propylene glycol pump, a Taco Model 006 Cartidge Circulator, and a Heliotrope Thermal Delta-T Differential Temperature Thermostat

Energy and Dollar Savings From Solar Hot Water and Efficiency Measures

As shown by the graphs below, installing Solar Hot Water and implementing efficiency measures cuts our propane use by two thirds and saves us a thousand dollars per year.