How Does an Air Source Heat Pump Work in Winter?

Air source heat pumps are relatively easy and inexpensive to install and have historically been the most widely used type of heat pump. These pumps are a great alternative to other heating systems because they use relatively little electricity to run.

For those who live in areas that can get very cold, like Minnesota or Massachusetts in the US (12℉/ ~ 11℃, 24℉/ ~ 4℃), you might want to know these How the pump runs all winter. We'll answer this question and more in upcoming articles.

First, it's important to understand that air source heat pumps do require a small amount of electricity. This is because they need to extract thermal energy from the surrounding environment and into a heat exchanger (sometimes called an evaporator).

Heat is absorbed by the refrigerant in the heat exchanger and evaporated into gas.

Additional information: Refrigerants absorb heat even at extremely low temperatures of -20℃. That's why heat pumps can work in cold weather.

The gas is then compressed, further increasing the temperature. In doing so, the gas can transfer its heat to your home's central heating system.

The refrigerant then gradually cools until it condenses and becomes liquid again. This process takes place in the second heat exchanger (condenser). In this condenser, cooler water from the central heating system continuously absorbs heat, which is then delivered to your home through radiators or underfloor heating.

Finally, the cooler refrigerant passes through the expansion valve.

Inside the condenser, the cooler water from the central heating system can continue to absorb any heat, which is then delivered to your home through any radiators or underfloor heating. Alternatively, it can be used to supply hot water to your faucet through the cylinder. 

Finally, the cooler refrigerant passes through the expansion valve. The pressure drops, the refrigerant returns to the evaporator, and the whole process starts all over again.

While an air source heat pump can withstand cold winter temperatures, it does come to a point where extreme outdoor temperatures inhibit its ability to operate effectively.

Between 25℉ ~ 40℉ (-3.8℃ ~ 4.4℃) they start to lose efficiency and consume more energy to get the job done.

But to answer the practical question at hand - an air source heat pump doesn't suddenly stop working. Instead, the pump works overtime, bringing heat from the outside environment into your home. But at this point, your heat pump will use emergency heat to supplement the heat needed for heating.

Side note: If you're concerned or have had this problem, a hybrid heating system can help. This helps solve this problem by using a heat pump most of the time and a natural gas furnace when the temperature is below a certain threshold.

The above describes the operation steps of the air source heat pump in winter in detail. If you have any questions or want to buy an air source heat pump, please contact us.

SUOHER is a professional custom heat pump manufacturer. We have a team with extensive experience in heat pump design, processing, quality control, and controller function development. Our target is global, including Europe, South America, South Africa, and Asia. Our team has had extensive experience in the heat pump field since 2006.