The answer to how a heat pump heats is simple: It moves heat instead of making it. On any winter’s day when the temperature is above about 30 degrees, sufficient latent heat exists in the outdoor air to warm your home. It only has to be extracted and concentrated, then moved indoors and dispersed through the house. When a heat pump’s operating within its outdoor temperature specs, no gas burners or electrical resistance coils are required. That’s how a heat pump heats more efficiently: The only energy expended is in extracting and moving heat – not making heat. Under the ideal outdoor temperature conditions, a heat pump can produce up to four units of heat for every one unit of electricity it uses.
But what about when outdoor temps aren’t ideal? Once the temperature drops below a certain minimum – around freezing for most standard heat pumps – the system can’t harvest sufficient heat and automatically defaults to supplemental heating, usually built-in electric coils. However, in a dual-fuel heat pump system, a gas furnace provides the backup heating at a lower cost than the electric coils. The temperature at which supplemental heat kicks in is known as the “balance point.”
Since this sort of direct electric heat is less efficient than the heat exchange process in a heat pump, the correct balance point setting is vital. Your HVAC contractor can perform calculations to determine the optimum balance point. Also, installing a programmable thermostat helps ensure that you exploit the full extent of the heat pump’s efficiency. Other factors affect the balance point, too, including the overall efficiency of your home. By adding insulation and sealing air leaks, a homeowner may lower the balance point without upgrading to a more efficient heat pump.
Heat pump capacity is improving steadily. Today, high-efficiency heat pumps can continue to produce heat in outdoor temperatures down to the low 20s without activating supplemental heating. In addition, other heat pump alternatives are available. To warm individual rooms or limited areas in a house, a ductless mini-split heat pump mounts a compact air handler directly in the room, eliminating the efficiency losses of ductwork.
Have more questions about how a heat pump heats so efficiently? Paitson Bros. Heating and Air Conditioning has the answers. We’ve served homeowners in the Wabash Valley since 1922.
Our goal is to help educate our customers in Terre Haute, Indiana about energy and home comfort issues (specific to HVAC systems). For more information about heat pumps and other HVAC topics, download our free Home Comfort Resource guide.
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Paitson Bros
1 (812) 232-2347
Serving the Wabash Valley, IN Area Since 1922