These geothermal heat pumps seems like a great way to heat and cool homes. Basicly they use the soil as the place to dump hot air and as a place to suck up warm air in the winter. As opposed to a normal heat pump which uses the outside air to either heat your home in the winter or dump the heat from your home into during the summer to cool it.
Geothermal pumps cut costs year-round
September 2, 2007
Geothermal heating (heat pump) is extremely energy efficient and generally yields the lowest utility bills of any residential system. In effect, it uses renewable energy from the sun's rays that get stored in the ground. Geothermal heat pumps also provide the most energy-efficient cooling during summer. Some models also can be combined with solar systems.
In the heating mode, a geothermal heat pump can produce up to five dollars worth of heat for each dollar on your electric bills. Unlike standard heat pumps that lose efficiency and maximum heat output as the outdoor temperature drops, the efficiency and heat output from a geothermal heat pump remain relatively constant.
During summer, a regular heat pump or central air conditioner loses efficiency and cooling output when it is hotter outdoors. Unfortunately, this is when your house requires the greatest cooling capacity. Cooling efficiencies are as high as 30 EER (energy efficiency ratio). A standard heat pump or central air conditioner is typically less than half as efficient.
Another summertime advantage is free hot water when the geothermal heat pump is cooling your house. Instead of exhausting the heat to the outdoor air through outdoor condenser coils, this waste heat is diverted to your water heater. This device is called a desuperheater, and it is included as a standard or optional feature on geothermal heat pumps.
A geothermal heat pump operates like a standard heat pump except it exchanges heat with the ground instead of the outdoor air. The temperature of the outdoor air can vary 30 degrees from day to night and more than 100 degrees from the coldest winter night to the hottest summer day. In contrast, the temperature several feet below the ground surface varies relatively little.
In order to capture the heat energy from the ground in winter or exhaust the heat during summer, a long pipe is usually buried in the ground. An antifreeze-water solution, running through the pipe, acts as the heat transfer medium. If there is a pond or wells can be dug, this water can run through the heat pump's heat exchangers. Many new models use earth-friendly R410A refrigerant instead of Freon.
Since no outdoor condenser coils and fans are needed, the entire heat pump and all mechanical components are located in an indoor unit. It operates quietly and, with no outdoor fan or compressor, there is no noise to bother neighbors or your family at night. This also reduces wear and tear from constant exposure to outdoor weather and playing children.
Write for (or instantly download at www.dulley.com) Update Bulletin No. 723, a buyer's guide of 2007 geothermal heat pump models listing stages, efficiencies, outputs, features, Freon/R410A, cost comparison chart and ground loop details. Please include $3 and a business-size self-addressed, stamped envelope.
Send questions to JAMES DULLEY, c/o Detroit Free Press, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit www.dulley.com.