Short of Heating your house with Solar and cooling your house with evaporated water, this is the closest thing we have right now to an environmentally sound system. Its advantage is that it heats and cools the house as one unit and the Earth becomes your heat sink.
Thanks to the good people of Econar for the Explanation:
ECONAR® GeoSource® Geothermal Heat Pumps
How Geothermal Works
Geothermal can be used to providing heating or cooling services. In each instance the process is similar.
In the heating mode, the water circulating in the earth loop is colder than the surrounding ground. This causes the water to absorb energy, in the form of heat, from the earth. The water carries this energy to the heat exchanger in the pump. In the heat exchanger, refrigerant absorbs the heat energy from the water. The water now leaves the heat exchanger at a colder temperature, and circulates through the earth loop to pick up more energy.
The refrigerant gas, which contains energy gained from the earth loop, travels from the heat exchanger to the compressor. In the compressor, the refrigerant temperature rises to 160°. From the compressor, the superheated refrigerant travels to the air heat exchanger. Here, the heat pump’s blower circulates air across the air coil, increasing the temperature of the air, which is blown through ductwork to heat the home. After refrigerant releases its heat energy to the air, it then flows to the earth loop heat exchanger to start the cycle again.
In the cooling mode, the water circulating in the earth loop is warmer than the surrounding ground. This causes the water to release energy, in the form of heat, into the earth. The water, now cooler from traveling through the ground now flows to the heat exchanger in the heat pump. In the heat exchanger, hot refrigerant gas from the compressor releases its heat into the water. This causes the water to increase temperature, which it releases to the ground.
The refrigerant, which has released its heat energy and became a cold liquid, now travels to the heat exchanger. Here the heat pump’s blower circulates warm, humid air across the cold air coil. The air is then blown through ductwork to cool the home. The refrigerant in the air coil picks up the heat energy from the air, and travels to the compressor. When the refrigerant leaves the compressor, it then flows to the earth loop heat exchanger to start the cycle again:}
Then there is Mr. Slim – The Japanese are always one step ahead:
Which does not explicitly say it can be hooked up to a geothermal loop but I am sure it can…I can’t copy Mitsubishi’s web page so you will have to look for yourself. Then self promoter Doug Rye:
Geothermal Heat Pumps (GHP’s) have been supplying homes and businesses with high efficiency heating and cooling for nearly 20 years.
If you’re planning to build a new house, office building, or school, or replace your heating and cooling system, you may want to consider a geothermal heat pump (GHP) system. Geothermal heat pump systems are also known as GeoExchangeSM, ground-source, water-source heat pumps (as opposed to air-source heat pumps), earth-coupled heat pump, heat pump ground-source, or ground-coupled heat pump. Regardless of what you call them, energy-efficient geothermal heat pumps are available today for both residential and commercial building applications.
Did you know? The average life span of a geothermal heat pump is 22 years. That’s a long time!
Geothermal heat pumps save money, reduce emissions, and are cost effective in replacing conventional heating and cooling technologies
People will even give you money for installing one:
What a deal!