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Geothermal heating and cooling, also known as a Ground Source Heat Pumps (GSHP), can be a fantastic option to provide both a renewable, energy efficient solution to heating and cooling as well as give valuable points to the NGBS.
The geothermal system has several ways of being a cost saving heating system by reducing annual out of pocket heating expenses by 60-80%. It also does not combust fossil fuels so the system does not need annual cleaning, as fossil fuel systems do. The maintenance required on a geothermal system can be done by the homeowner, savings thousands of dollars on an annual basis. GSHPs also operate at 450% efficiencies from the time it is installed through its average 30-40 year life expectancy. The payback on a geothermal in new construction is always 2-5 years, on retrofit homes sometimes it will take 10 years to see the payback but still well worth the investment!
From an environmental standpoint GSHPs provide healthy living within the house since there is not a chance of carbon monoxide, as there is with a fossil fuel system. Geothermal systems are endorsed by the EPA to be to most efficient, cleanest, and cost effective heating and cooling systems available.
At our house in Strafford we chose to install a vertical closed loop system which uses a series of four vertical boreholes connected with polypropylene pipe. This becomes the ground source to transfer the warmth in the winter and become a heat sink in the summer, while the house is in cooling mode. The amount of holes and depth of them needed are determined by the heat gain and loss on the home. This figures a BTU heat loss that than becomes the sizing means for the heat pumps. From there the ground source can be sized also.
The inside of the home is heated in the garage and basement by radiant pex tubing placed in the concrete slab. The main floor living space is heated and cooled by a water-to-air GSHP that allows air to flow through ducting. The radiant system does not provide cooling so the basement and garage is heated space only, whereas the main living space in the home is both heated and cooled.
Above: Skillings drills 6" holes for Above: 6" hole, cased and lined
closed loop installation with poly pipe for closed loop
Below: Radiant tubing stapled to Below: Nordic water-to-water
R-8 insulation to be covered with heat pump for basement and
concrete pour to create slab garage areas.
Below: Water-to-Air Geothermal Below: Steibel-Eltron domestic
for the main floor living space hot water heater w/preheat