NATE Air Conditioning and Heat Pumps Practice Exam 2026 – All-in-One Guide to Master Your Certification!

The thermal balance point of a heat pump system is the outdoor air temperature at which the heat pump's output equals the heat loss of the home. At this specific temperature, the heat provided by the heat pump matches the amount of heat that is lost from the home to the outside environment, ensuring that the indoor temperature remains stable without the need for additional heating sources.

When the outdoor temperature drops below this balance point, the heat pump may struggle to maintain the desired indoor temperature because its efficiency decreases and its heating output is not sufficient to compensate for the increased heat loss. Conversely, if the outdoor temperature is above the balance point, the heat pump can efficiently maintain the indoor conditions, as it is capable of producing more heat than is lost.

This concept is particularly significant in dual-fuel systems, where coordination between the heat pump and a backup gas furnace comes into play, but the thermal balance point specifically relates to the heat pump’s performance alone.