A geothermal air conditioning system works in any climate. The United States Department of Energy explains that more than 50% of new geothermal heat pump installations are located in areas with extreme weather conditions. They can be used anywhere because the Earth's temperature six feet below the ground surface is remarkably constant. It has a temperate temperature of 50 to 55 degrees throughout the year, regardless of whether the air temperature is 0 or 100 degrees.
The system's pump transfers heat between your home and the Earth, taking advantage of the constant moderate temperature. As any homeowner can tell you, a traditional heating system that burns fuel, natural gas, or propane will generate high heating bills in exchange for a warm home in winter. The average lifespan of an air-source heat pump is 12 years, so a geothermal system lasts two to four times longer than an air source system. It contains a liquid (water or a mixture of water and antifreeze) that absorbs heat in winter or dissipates it in summer.
A geothermal system offers the best of both worlds; it doesn't burn fossil fuels to heat your home and the system also works the other way around, providing efficient central air conditioning in summer. The heat pump would then distribute that heat throughout the house through an air conditioning system, just like a traditional heating system would. Open circuit systems, as in Figure 2, extract water from the subsurface (groundwater) and then return the water to the ground (colder water, with the heat extracted), using the heat from the water to heat the living space. Another big misconception about geothermal energy is that it's expensive, but in the long run it's actually the most cost-effective heating system.
Ground-based heat pumps literally pump heat from the floor into a space, often someone's home. For every hour your geothermal heat pump runs, it emits a pound less carbon compared to a furnace or air conditioning system. The federal government recently extended federal tax credits for residential renewable energy products, such as geothermal heat pumps, until December 31. The heat pump, which replaces the boiler or furnace, uses a compressor and a heat exchanger to increase that floor temperature by 55 degrees to whatever you want. Heat pumps work much like refrigerators, which cool down a cool place (the inside of the refrigerator) by transferring heat to a relatively warm place (the surrounding room), making it warmer.
Most closed-loop geothermal heat pumps circulate an antifreeze solution through a closed circuit, usually made of a high-density plastic tube that is buried in the ground or submerged in water. This allows a geothermal system to use BTU to efficiently heat homes even on the coldest days of the year.
