What Is a Heat Pump and How Does It Work?

If you live in a climate where the temperature can fluctuate wildly, you know that heat pumps are one of the best ways to keep your home comfortable during winter and summer. The only problem is that there are many misconceptions about how they work. This article will take you through exactly what a heat pump is and what it does.

What Is a Heat Pump?

It’s helpful to consider what they are to understand how heat pumps work. Heat pumps use an evaporator and a condenser to transfer heat between two different home areas. They are frequently used in homes in hot climates where air conditioning may not be an option. A conventional heat pump uses a refrigerant that absorbs and releases heat as it changes from liquid to gas.

A Basic Overview of How a Heat Pump Works

The outdoor unit of your heat pump uses the compressor to transfer refrigerant throughout the system. The refrigerant is piped into the indoor evaporator, which is connected to the indoor blower of your heating system. As it passes through your indoor coil, the refrigerant gives off its heat to your home’s air. It then goes through an expansion valve device, which converts it back into a liquid as it suddenly reduces its pressure and temperature. It is returned to the outdoor unit via a pipe in your home’s crawl space or attic. In the compressor, it warms up and starts its cycle over again.

How a Heat Pump Works When Cooling Your Home

The outdoor unit sends refrigerant to the indoor evaporator through a pipe in your home. The evaporator is connected to a fan. Air passes over the evaporator coils, where a refrigerant picks up heat from the indoor air and becomes warm. The blower sends back that cool air throughout your home. The refrigerant heats up and evaporates into gas form.

The refrigerant then passes to a compressor, where it is pressurized and then sent to an outdoor unit. Outdoor air is blown over condenser coils using a fan. Heat is transferred from the refrigerant to the air.

The refrigerant condenses back to a liquid in this process. The warm refrigerant is then pumped back to an expansion valve in the indoor unit. In the indoor unit of your heat pump, the expansion valve cools it as it reduces its pressure significantly.

Outdoor Unit

The outdoor unit of your heat pump contains a fan and a coil. It gets air from the outside and passes it through the evaporator in heating mode or a condenser in cooling mode. The refrigerant that moves through the system is a liquid that warms up when it’s doing its job. A fan is used to blow air through the coils.

Indoor Unit

The indoor unit of your heat pump contains a fan and coil. Air moves through the evaporator and is cooled as it goes through a condenser in heating mode and an evaporator in cooling mode. A fan moves air through a condenser or an evaporator coil and your home’s ducts in a heat pump.


The refrigerant in your heat pump is a specially formulated coolant that gives off heat as it changes from liquid to gas and back again. As air passes through the evaporator, the refrigerant picks up heat. The condenser absorbs heat from the refrigerant and transfers it to outdoor air or a room. Most modern heat pumps use an environmentally friendly refrigerant known as R-410A.


The compressor in your heat pump is the key to everything that happens during the operation of your heat pump. The compressor takes refrigerant from the outdoor unit and sends it back into your home’s indoor unit. It also pressurizes the refrigerant when it passes through it.

Reversing Valve

The reversing valve is another essential part of your heat pump. As the refrigerant passes through the evaporator, it absorbs heat from the air and gives it off to your home’s indoor coil. The reversing valve opens when your heat pump is cooling and closes when heating. It lets refrigerant take off its heat from the condenser and pass it on into your home to give off its heat to the outside air and start its cycle over again.

Expansion Valve

The expansion valve regulates the refrigerant flow through the heat pump so that it doesn’t overheat or freeze. It also turns off and on to keep things running smoothly as your heat pump switches from heating to cooling. As the refrigerant moves through the outdoor and indoor coil, it changes back into a liquid as the pressure and temperature are reduced.

How a Heat Pump Works When Heating Your Home

When your heat pump starts heating your home, it does the reverse of cooling. The indoor coil is connected to the indoor heat pump blower. As your heat pump moves from cooling to heating, the reversing valve will open as the fan starts blowing warm air into your home. The warm air makes its way through your home’s duct system.

The refrigerant is sent out to the indoor unit, where it gives off heat. As the refrigerant gives off heat to the indoor air, it becomes liquid. The warm refrigerant is cooled as it moves through the expansion valve and then sent back to your outdoor unit. The cycle continues.

Benefits of Heat Pumps

1. Heat pumps are more efficient than air conditioners. A heat pump can use about 50% less fuel energy than an air conditioner of the same size.

2. They can be used year-round. This makes heat pumps an excellent choice for homes when it’s too cold for air conditioning.

3. They have a high-reliability rating. Since heat pumps are so energy efficient and require less maintenance than a typical air conditioner, you can use them for years without worrying about replacing them.

4. They are eco-friendly. A heat pump can maintain a comfortable indoor temperature with minimal electricity usage. Since the unit is so energy efficient, you’ll help contribute to reducing global warming.

5. They improve air quality. Since heat pumps filter the air and dehumidify your home, they help reduce the amount of dust and germs in your home. By eliminating excess moisture and improving airflow, your family will enjoy fresher, cleaner air.

6. They add value to your home. If you’re looking to sell your home, heat pumps offer a practical and desirable feature. Homebuyers will want to know that they can depend on the comfort of their new homes. A heat pump is also appealing because it’s an energy-efficient addition to any home.

7. They operate quietly. Since they are so energy-efficient, heat pumps don’t produce any noise. Your neighbors will be able to enjoy their quiet nights as they sleep.

In conclusion, heat pumps can provide you with a convenient, comfortable, and reliable way to help reduce the cost of heating your home while preserving your quality of life indoors. We at Green Energy Mechanical Inc will help you with installing and maintaining your heat pump. We offer cooling, heating, and plumbing services in Canton, MA. Contact Green Energy Mechanical Inc today for more information!

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