Auxiliary heat systems in heat pumps are designed to supplement the primary heating source when outdoor conditions compromise its efficiency. A critical parameter for these systems is the maximum external temperature at which the auxiliary heating element engages. This threshold represents the point where the heat pump can no longer efficiently extract sufficient warmth from the outside air to meet the thermostat’s set point. For example, if the set point is 70F and the heat pump can only raise the indoor temperature to 65F with the compressor alone, the auxiliary heat engages to bridge the 5F difference. This temperature setting is crucial for optimizing energy usage and preventing unnecessary reliance on the typically less efficient auxiliary heat source.
Setting an appropriate activation point offers several advantages. It can significantly reduce energy consumption by minimizing the runtime of the auxiliary heat, which often uses electric resistance and consumes more power than the heat pump compressor. Historically, these systems were designed with less sophisticated controls, leading to frequent and sometimes unnecessary activation of the supplemental heat, resulting in higher energy bills. Modern systems incorporate intelligent algorithms that consider factors such as temperature trends, heat loss rates, and the performance of the heat pump compressor to determine the optimal engagement of the supplemental heat. This leads to both cost savings and reduced strain on the auxiliary heating components, potentially extending their lifespan.
