how does a heat pump work

How Does a Heat Pump Work: Advantages and Process

When most people think of an HVAC system, they think of air conditioning units. However, several kinds of systems exist, including heat pumps.

Eastern Shore Heating and Air Conditioning host some of the top heat pump service professionals in New Jersey. When you ask, “how does a heat pump work” among other questions, we have the answers.

1. What Is a Heat Pump?

A heat pump pulls heat from the outdoors and disperses it inside during colder months; it is a dual-unit heating and cooling system. Once it gets warmer, the pump does the opposite, absorbing heat from the indoor air and pushing it out. 

Electric heat pumps have many advantages over alternative air conditioning systems. Heat pumps do not burn coal or fossil fuels, unlike furnaces, making them more eco-friendly. Also, because they can heat and cool your home, you may not need an additional heating or cooling system.

2. How Does a Heat Pump Work?

Heat pumps consist of an indoor air handler and an outdoor unit. Each unit has a single coil—one that functions as an evaporator and another as a condenser—and a fan. Refrigerant, a substance that changes between liquid and gas forms, flows through the system using the components explained below.

For this example, we will use an air source unit during hot weather to explain how a heat pump works:

  1. The suction line takes in the refrigerant to start the process. It is also known as the low-pressure side.
  2. Vaporous refrigerant enters the compressor, which pressurizes it and helps it move through the entire system. The pressure superheats the refrigerant, making it exceptionally hot.
  3. A discharge line facilitates transport from the compressor to the condenser coil.
  4. The superhot vapor enters the condenser, which has a fan blowing indoor air over it to remove excess heat. In the summer, a fan sends the heat outdoors as the still-pressurized but cooled refrigerant keeps going. In this state, the refrigerant turns into a liquid.
  5. The refrigerant enters the liquid line to reach the expansion valve and the evaporator coil. The pressure in this line does not allow the liquid to turn back into a gas.
  6. The expansion valve, also called a metering device, has a high-pressure and low-pressure side. The liquid expands and can become partially gaseous but does not have enough heat energy to become fully gaseous.
  7. Partially gas and partially liquid refrigerant enters the evaporator coil. Vents suck indoor air over the coils, and the refrigerant absorbs the heat from the air to become fully gaseous. The cooled air blows back into the building through air ducts.
  8. The vaporous refrigerant, now cooled, returns to the compressor to start the cycle again.

Heat pumps also have a reversing valve that can switch the refrigerant flow. During this process, the coils switch functions, and the compressor sends hot gaseous refrigerant to the indoor unit. The superheated substance releases heat into the suctioned air blown over it during the reverse process.

3. What Kinds of Heat Pumps Are There?

The two kinds of heat pumps pull air from different sources. An air source heat pump transfers heat to and from the outdoor air. Alternatively, geothermal heat pumps, also known as “ground source,” transfer heat to and from the ground.

Both heat pumps take or reject heat from one place to another. However, geothermal heat pumps are more expensive due to technical requirements. Still, they have a higher consistency rate and lower operating costs because of how warm it is underground.

4. Can Heat Pumps Work with Other Systems?

Yes, a heat pump can function alongside other cooling or heating systems. 

For example, those living in colder climates can use a heat pump and furnace together in a dual-fuel system. These systems alternate between the furnace for colder weather and the heat pump for warmer weather. Homeowners can save money based on which unit works most effectively in the current weather conditions.

Heat pumps usually replace rather than work with air conditioning units because they are functionally similar to them in warmer climates. However, homeowners in hot climates that do not have cold days often enough usually have a dedicated air conditioner instead.

Call on Us for Your HVAC Needs

Eastern Shore Heating and Air Conditioning technicians have installed, repaired, and replaced HVAC systems since 1979. Our 24/7 availability and attention to detail ease homeowner struggles across central New Jersey. To receive a free quote or if you want to know more about our boiler services in NJ, call 732-800-9416.