How Does a Heat Pump Work in Winter?

Many homeowners across Maryland use heat pump systems for efficient cooling over the summer months. When winter comes, these versatile HVAC systems can also be used for home heating! Grove Heating & Cooling answers how does a heat pump work in winter so you can better understand the capabilities of this HVAC equipment option.

How Do Heat Pumps Work in Summer?

Let’s run through how a heat pump works in the summer, then it will be simple to understand how a heat pump works in winter! Warm air from the home circulates back to the indoor unit which contains a coil  – as refrigerant cycles through the coil, it absorbs heat from the air to lower air temperature. 

Cooled air then circulates back into the home via the blower while the refrigerant travels to the outdoor unit. The compressor pressurizes the refrigerant and increases its temperature before it moves to the outdoor coil. Within the condenser coil in the outdoor unit, the refrigerant releases heat into the air outdoors. This process repeats as needed to keep the home at a comfortable, cool temperature.

How Do Heat Pumps Work in Winter?

Before we explain how a heat pump works in the winter, let’s first discuss the basics of heat pump operation. A heat pump is an appliance that transfers heat from one source to another. Unlike fuel-burning furnaces and boilers, a heat pump doesn’t generate heat. Because it is merely transferring heat between two sources, this HVAC unit has the ability to both heat and cool a space.

Heat pump systems are split systems. For air-source heat pump systems that transfer heat between indoor air and outdoor air, the heat pump unit sits outdoors, which can be paired with an air handler or even a furnace indoors. The two units are connected by refrigerant lines that run through an exterior wall of the home. Geothermal systems exchange heat between the indoor air and the ground, using a ground loop buried in the ground and a heat pump that is typically installed indoors.

To act as heating systems during the winter months, a heat pump will work in reverse to provide a home with heat. A component called the reversing valve redirects the flow of refrigerant so that heat is absorbed from the outdoor air by the outdoor coil. Heated refrigerant cycles through the indoor coil, releasing heat energy into the air circulating through the unit to raise the air temperature. This process repeats as needed to provide enough warmth for comfortable indoor conditions.

Can Heat Pumps Work When It’s Cold Outside?

If you’re just learning about how a heat pump works in winter, the process may seem hard to believe – is there really enough heat in the air to keep a whole house warm when it feels chilly outside? Believe it or not, yes! Though it may not feel warm to you, there is plenty of heat energy in the outdoor air for sufficient indoor warmth, depending on the outdoor temperature.

Conventional heat pumps offer very efficient heat up to a certain point, as far as outdoor temperatures go. Once outdoor temperatures fall around 40 degrees Fahrenheit, a heat pump will lose some energy efficiency. When temperatures hit about 25 degrees and below, a heat pump is no longer going to be the most efficient source of heat for a home. It may struggle to keep your home at your preferred temperature and it is best to use a backup heating system at this point, if you have one installed. There are newer cold weather heat pump units that are better equipped for operating in cold temperatures, which can be installed to avoid this winter problem.

Heat Pumps for Maryland Homes

A heat pump in the winter doesn’t differ much from summertime cooling operation – the HVAC system simply runs in reverse! Learn more about these versatile heating and air conditioning systems and receive an estimate for the installation of a new heat pump in your home – contact Grove Heating & Cooling today!