What Is a Heat Pump and How Does It Work?

Looking for a new and efficient way to heat and cool your home? A heat pump may be just what you need. For those unfamiliar with this handy appliance, heat pumps are electrically powered residential HVAC systems that efficiently move heat from one area of the home to another.

Especially effective in moderate climates, heat pumps can heat and cool a home by extracting heat energy from the surrounding environment. Compared to other popular electronic heating devices, heat pumps are extremely cost-effective and allow homeowners a reliable temperature control system throughout the year.

How does a heat pump work?

In the cold of winter, a heat pump extracts heat from the outdoor air and moves it inside to provide warmth. While that might not seem possible, there actually is heat circulating in winter air. During summer months, the pump transfers heat energy from air inside the home to outside, subsequently cooling the home’s interior. These are known as air source heat pumps. Ground source (or geothermal) heat pumps are also available and they operate by transferring interior air to the ground outside.

Keep in mind that heat pumps do not generate “new” heat; they simply move it from Point A to B. Interestingly, when in its cooling mode, a heat pump is functionally identical to a traditional air conditioner by absorbing warm indoor heat and releasing it through the outdoor unit.

How to choose the right system

If you’re in the market for a heat pump system, be sure to consider key factors such as the size of your home, regional climate variations, and individual heating and cooling needs. To that end, it is important to become familiar with the components of a heat pump system, starting with the outdoor and indoor units:

Outdoor unit

Within the outdoor unit is a coil and fan combination that condenses (cooling) or evaporates (heating) air and the fan then blows outside air over the coil.

Indoor unit

Also called air handler units, this component acts similarly to the outdoor unit but in reverse order, with the fan moving air throughout ducts in the home.

Other elements in a heat pump system include a refrigerant that absorbs or rejects heat; a compressor to pressurize and move the refrigerant; a reversing valve that reverses refrigerant flow to switch between heating and cooling; and expansion valve that regulates refrigerant flow and pressure as it passes through the system.