GeoThermal Heat Pump

RainShine’s ground source heat pump system takes advantage of the steady state temperature of the earth for heating and cooling. In winter heat is extracted from the earth and delivered to the house. In summer heat is removed from the house and absorbed by the earth. Through the heat pump system the earth’s stored energy is accessed with minimal energy expenditure.

Well system: Because of the RainShine limited site area a closed vertical loop system was employed to access steady state temperatures. For the vertical system, 5 wells (approximately four inches in diameter) were drilled approximately 200 feet deep. Two high-density polyethylene pipes were installed in each of the holes and are connected at the bottom with a U-bend to form a loop. The vertical loops are connected with horizontal pipe (via a manifold), placed in trenches, connected to the heat pump in the basement and filled with an environmentally friendly antifreeze/water solution that acts as a heat exchanger. All joints were heat-fused and pressure-tested before and after installation. The majority of the depth of

RainShine’s wells were drilled through solid granite, an excellent conductor of heat thus positively impacting the efficiency of the system. The bores around the vertical loops in the wells were filled with bentonite clay.

Heating: In heating mode, the geothermal system uses the closed loop well system to extract heat from the ground. The heat pump takes heat from the loop and distributes warmed air through a conventional duct system.

Cooling: In cooling mode, ducted air is cooled by reversing the heating process. Instead of removing heat from the ground, the heat pump extracts heat from air flowing through the ducts and dumps it in the heat sink of the loop wells.

Hot Water: Desuperheaters transfer excess heat from the geothermal heat pump’s compressor to a hot water tank. In the summer cooling period, the heat that is taken from the house is used to heat the water for little cost. In the winter, water heating costs are reduced by about half.

Geothermal heat pumps save money in operating and maintenance costs. While the initial purchase price of a residential GHP system is often higher than that of a comparable gas-fired furnace and central air-conditioning system, it is more efficient, thereby saving money every month.

Unlike standard heat pump compressors that can only operate at full capacity, RainShine’s two-stage scroll compressors operate close to the heating or cooling capacity that is needed at any particular moment. This saves large amounts of electrical energy and reduces compressor wear. Two-stage heat pumps work well with RainShine’s zone control systems using automatic dampers to allow the heat pump to keep different rooms at different temperatures. RainShine’s heat pumps are equipped with variable-speed motors on their fans (blowers). The variable-speed controls for these fans keep air moving at a comfortable velocity, minimizing cool drafts and maximizing electrical savings. It also minimizes the noise from the blower running at full speed.

Rainshine’s geothermal system is eligible for a $2,000 state tax credit and a $2,000 federal tax credit.

Please see the simple diagram below taken from this informative website.

Ground-source (geothermal) eat pump in cooling mode.

Ground-source (geothermal) eat pump in heating mode.