Geothermal Heating & Cooling

While the name may sound a little "space-age," geothermal heat pumps are very "down to earth." To put it simply, you can use the natural warmth of the earth to heat and cool your home.

How it works

A geothermal system, also called a ground-source heat pump, works on a simple premise: the earth below a certain depth (the frost line, usually about four feet deep), is a constant temperature of about 50 degrees throughout the year.

Heat is taken from the ground and transferred to the air in your facility during the winter; the process is reversed during the summer.

The loops of piping are buried in the ground on your property, either vertically or horizontally. The ground loop is connected to a pumping module inside your building, where a mixture of water and liquid antifreeze is circulated through the system.

As the liquid moves through the underground pipes during winter months, it absorbs heat from the earth. When the heated liquid reaches the heat exchanger, it is converted through the refrigerant process to warm air and circulated through the building.

To cool your home in summer months, the system simply works in reverse with the flip of a switch.

The benefits

One system provides both heating and cooling. Because the equipment is self-contained and installed indoors, a geothermal system can have a life expectancy of up to 50 years; most are warranted for up to 25 years.

And that's not all:

• The liquid antifreeze is a non-toxic, non-polluting, biodegradable substance.
• The piping is specially designed to withstand extreme temperatures.
• The loops are joined by thermal fusion (melting them together), so there's virtually no chance of the liquid leaking out.
• There are no noisy "on" cycles with blasts of hot or cold air.
• No fluctuations in temperature from room to room.
• No flues to get clogged.
• No dangers of carbon monoxide poisoning.
• No noisy outdoor air conditioner.
• What more could a homeowner want?

How about lower energy bills? Heat from the ground is free, and the only electricity needed is for circulation.

According to the Geothermal Heat Pump Consortium, a geothermal system can lower your heating bills up to 50 percent and lower your cooling bills up to 30 percent, when compared to a conventional system.

And don't forget: ground-source heat is naturally renewable and non-polluting. No precious natural resources are wasted.

And for extra energy savings, you can add an attachment called a "desuperheater" that connects your heat pump to your water heater. When the energy from the heat pump isn't needed, it's diverted to your water heater so you'll be getting virtually free hot water.

Learn more

For all the facts about geothermal heat pumps, including the science behind the technology and how to find a contractor, visit the Alliant Energy Geothermal Web site.