Heat Pumps

Understanding the big picture about heat pumps will help you make the best home comfort choice for your household.

heat pumpsOver the years, the demand for heat pumps has increased, and for certain scenarios, we can see why. In some cases, heat pumps are a great option—particularly in places with mild, dry weather. A heat pump will turn on and off less often than a gas furnace. Older models used to blow cold air through a home’s vents when the system temporarily switched into reverse to defrost the coil. This is not something homeowners need to worry about with newer models. Still, heat pumps are simply not ideal for climates like ours.

Overall, heat pumps have not typically been popular in places with climates like the Northeast. In Maine, most homeowners would need to supplement their heat pumps with an oil or propane furnace during the winter months.

Is a Heat Pump a “Greener” Option?

Heat pumps sometimes have a reputation for being a green home heating option. It’s important to note, however, that the electricity required to effectively run a heat pump is typically generated by the burning of fossil fuels, rendering them no greener than the furnace in your basement.

Heat pump technology has advanced in recent years—and this includes some models that stand up to the coldest New England weather—but most homeowners can’t rely on heat pumps as their only source unless their house is extremely well insulated.

How Do Heat Pumps Work?

Highly efficient between 20°F and 80°F, a heat pump is a mechanical-compression cycle refrigeration system that runs on electricity and can either heat or cool a space. Here’s how it works:

  • An indoor unit called an air handler is installed, and a unit similar to a central air conditioner (referred to as a heat pump) is mounted outside.
  • A compressor moves refrigerant inside and outside between these two units, absorbing or releasing heat.
  • When it’s cold outside, a heat pump extracts outside heat and moves it indoors.
  • When it’s hot outside, the process is reversed and the heat pump performs like an air conditioner, moving heat from indoors outside.

Drawbacks to Consider

Heat pumps include some little-known drawbacks that are important to factor in if you’re considering having one installed in your home. Small wall-mounted cassettes within a heat pump system deliver reduced temperature uniformity in the home. This is comparable to air conditioning being at only one end of the house, and increases the potential for frozen and broken pipes. It’s also important to keep in mind that heat pump backup service can lead to strong efficiency degradation.

In addition, keep in mind that the outside cabinet of air-source heat pumps requires attention. You have to continually check to ensure nothing blocks free airflow. Any debris, including leaves, snow or ice can cause issues, whereas a furnace and boiler are completely protected inside the home.

If you are considering purchasing a heat pump, request a home energy audit to learn what will work best for you and to confirm that it is the right move.