How does the outdoor air temperature affect an air-source heat pump in heating mode?

The outdoor air temperature plays a significant role in the operation of an air-source heat pump, especially in heating mode. When the temperature of the outdoor air changes, it directly impacts the suction saturation temperature within the heat pump system. The heat pump extracts heat from the outside air to warm the interior of a building. As the outdoor temperature drops, the available heat in the air decreases, which causes a decline in the suction saturation temperature. This change affects the refrigerant's ability to absorb heat and can lead to reduced heating efficiency.

In heating mode, the heat pump relies on the thermal energy present in the outside air, so factors such as colder temperatures can reduce the system's overall efficiency. Therefore, a lower outdoor temperature corresponds to a lower suction saturation temperature, which can impact the performance and effectiveness of the heat pump in meeting the heating demands of the space.