The term "heat pump" is frequently used in reference to a heating and air-conditioning system, but not every homeowner is familiar with what a heat pump is, or what it does. In the simplest definition, a heat pump is an air conditioner that can reverse its operation to move heat into the house, instead of out.

The movement of heat

Most everyone is familiar with what an air conditioner does. It creates cool air, which is then circulated through a house's ductwork by the furnace or air handler. But strictly speaking, an air conditioner doesn't "make cold," it "gets rid of heat."

The refrigerant that a dealer puts into an air-conditioning system circulates back and forth between the air conditioner outside, and the coil inside, gathering heat as it goes. Once that heat gets outside the home, the air conditioner disperses it.

Standing next to an air conditioner, you can feel a steady stream of warm air coming off of it. This heat isn't generated by the air conditioner's motor or fan; it's the heat that was previously in the house, being vented into the atmosphere.

The heat pump difference

When a heat pump operates during warm weather, it performs exactly like an air conditioner. It gathers the heat that's inside the house, and vents it outside.

When cold weather arrives, however, the heat pump is able to reverse its operation. It gathers heat from the outside air and moves it inside to warm the house. Because even when the outside air feels cold on the skin, it still contains enough heat for the heat pump to gather and move inside.

Why select a heat pump?

The decision to choose a heat pump or a furnace for a home has to do with the climate in which the home is located. Heat pumps typically work better in warmer southern climates where winters aren't too harsh. Since the air doesn't get very cold, a heat pump can gather enough heat during cool weather or cold snaps to keep the home comfortable.

In northern climates that have colder winter weather, there is usually not much heat present in the air for a heat pump to collect. And even if there is some heat present in the outside air, it may cost a lot of electricity for the heat pump to run long and fast enough to collect it.

For that reason, homes in northern climates typically elect to use a gas furnace or oil-burning furnace for warmth.

Dual-fuel systems

For homes located in mild or moderate climates, a heat pump can be paired with a gas furnace to create a dual-fuel system. In this configuration, you enjoy the best possible balance between comfort and energy efficiency.

In cool weather, when the seasons transition from summer to fall, the heat pump in a dual-fuel system keeps the home warm. Because electricity is typically cheaper than gas, this means more energy-efficient comfort.

When winter arrives and the weather becomes colder, it would take substantially more electricity to draw in enough heat to keep the home warm. So the dual-fuel system switches from the heat pump to the gas furnace to provide warmth.

The most energy-efficient warmth, every time

The system will continue to switch back and forth automatically between the electric heat pump and the gas furnace, based on whichever is most energy-efficient for the current weather.

The switching point is preprogrammed by the dealer when the system is installed. Since the switch point is based on prices of electricity and gas in the area in which the home is located, this allows customized energy savings.

To get the energy-conscious advantages of a heat pump in your home, or to discuss the year-round advantages of a dual-fuel system, please contact your local Lennox dealer.