The Dirt on Geothermal Heat Pumps
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It takes a lot of energy to heat or cool enough air to make your home comfortable and with most conventional heating and air conditioning systems, you see that on your energy bills.
Space heating and cooling make up the biggest portion of a typical home's energy usage at a whopping 48 percent. Geothermal heat pumps (GHPs) can provide some welcome relief from the heat at just a fraction of the energy use.
GHPs use the constant mild temperature a few feet below the Earth's surface to transfer heat into or out of the air as it heats or cools your home. In horizontal systems, coiled plastic piping is placed in wide trenches at least four feet deep, depending on climate, soil and other factors. Vertical piping costs more money because it requires digging much deeper.
Horizontal or vertical; both systems work on the same basic principles. A liquid runs in the loop from the heat pump under the Earth's surface.
In the summer, the heat pump refrigerant loop pulls the heat out of your home's air and runs it through the pipe system. The heat is transferred to the ground, reducing the liquid temperature to near that of the ground temperature. The cooled liquid then comes back inside and receives more heat that was taken out of the air, cooling down the home.
In the winter, the liquid is warmed close to the ground temperature. The warm liquid provides heat to the indoor refrigerant loop, transferring heat to the indoor air to help your house reach its set temperature.
GHPs are up to 72 percent more efficient than standard air conditioners and 44 percent more efficient than standard heat pumps. But GHPs have more to offer than just savings. They also improve indoor humidity, keeping it at a near constant 50 percent. They're quieter and they tend to have a long service life, often with underground piping warranties lasting 25 to 50 years.
The initial cost of GHPs is certainly higher. However, the next time you hear that old air conditioning unit cranking away and you think about how high your energy bill is going to be, think about how cool it would be to have a geothermal heat pump in your home.