What is the primary factor that affects the performance of electric heat pumps?

The primary factor that affects the performance of electric heat pumps is outdoor temperature. Electric heat pumps operate by transferring heat from outside the home into the interior. As the outdoor temperature decreases, the heat pump must work harder to extract sufficient heat from the outside air. This means that the efficiency of the heat pump can significantly decline in colder temperatures, leading to reduced heating output.

Understanding how outdoor temperature impacts the system is crucial for assessing heat pump performance, especially in regions that experience significant winter temperatures. While other factors like indoor humidity, heating unit age, and voltage levels can influence overall system performance, the outdoor temperature plays a more direct role in the heating capacity and efficiency of electric heat pumps. In cold climates, the effectiveness of the heat pump can drop, potentially requiring supplemental heating to maintain comfortable indoor conditions.