What feature may a high-efficiency heat pump have for low ambient conditions below 10°F?

A high-efficiency heat pump designed to operate effectively in low ambient conditions, particularly below 10°F, may incorporate two outdoor coils. The presence of two outdoor coils can significantly enhance the heat pump's ability to extract heat from the outdoor air, even when the temperatures drop. This design allows for more efficient heat exchange, leading to improved performance in cold weather.

In low-temperature conditions, the capacity of a heat pump can diminish, making it crucial to have features that maintain efficiency and heating output. By employing two coils, the heat pump can increase the surface area for heat absorption, enhance airflow, and improve overall heat transfer. This innovation supports consistent heating performance and helps mitigate issues associated with frost buildup on the coils.

Other components, such as a single-stage compressor or fixed speed fan, might not provide the same level of efficiency in extreme cold. Standard insulation, while helpful for minimizing heat loss, does not directly contribute to the heat pump's efficiency in extracting heat from colder air. Thus, the dual-coil design stands out as a vital feature for high-efficiency heat pumps operating in low ambient temperatures.