Ground source, or geothermal, heat pumps are similar to ordinary heat pumps, but instead of transferring heat to or from outside air, they rely on the stable, even temperature of the earth to provide heating and air conditioning. Many regions experience seasonal temperature extremes, which would require large-capacity heating and cooling equipment to heat or cool buildings. For example, a conventional heat pump system used to heat a building in Montana's −70 °F (−57 °C) low temperature or cool a building in the highest temperature ever recorded in the US—134 °F (57 °C) in Death Valley, California, in 1913 would require a large amount of energy due to the extreme difference between inside and outside air temperatures. A few feet below the earth's surface, however, the ground remains at a relatively constant temperature. Utilizing this large source of relatively moderate temperature earth, a heating or cooling system's capacity can often be significantly reduced. Although ground temperatures vary according to latitude, at 6 feet (1.8 m) underground, temperatures generally only range from 45 to 75 °F (7 to 24 °C).

The blower assembly is located between your main furnace and the cold air return. The blower is responsible for pulling air from your home and then sending it through the furnace and the heat exchanger. The air gets circulated throughout the home via the duct work. The furnace’s air filter is contained within the blower compartment. Regular-style filters should be replaced or cleaned each month.

Cleaning the debris that builds up on your filters will aid with the flow of air. When your air filter is clogged, your air handler must work harder to compensate for the blockage of air flow. In addition to driving up your utility bill, the reduced air flow through your heating and cooling system can cause your heat exchanger to overheat and shut off too quickly.