Discover how a heat pump can heat and cool your home and how well these systems perform in ultra-cold climates.

As utility costs rise, many homeowners who seek long-term savings are installing heat pumps. The efficiency of these systems is impressive: an air-source heat pump can deliver up to three times more heat energy than the electrical energy it consumes. Even though heat pumps are gaining in use, they’re not well understood. Here’s a quick overview of how they work.

How heat pumps work

Heat pumps are powerful yet efficient multitaskers that can both heat and cool your home. It’s not magic; it’s taking advantage of thermodynamics. In nature, heat always flows from warmer areas to colder ones. Heat pumps take advantage of this by using a refrigerant to move heat either indoors or outdoors. There are a variety of refrigerants that can be used. Heat pump systems designed for cold climates can operate down to -30°F.

In addition to the law that heat moves from hot to cold, here are a few science basics before we go further:

• Heat energy exists even in cold air. Air that’s 18°F has slightly more heat in air that’s 10°F. Even small amounts of heat can be drawn inside to heat a home.
• When a gas is compressed, its pressure and temperature rise.
• When a gas expands, its pressure and temperature drop.

Before we look at how the system works, let’s get familiar with its main parts. These include:

• Compressor – circulates refrigerant and raises its pressure and temperature
• Outdoor coil – absorbs or releases heat depending on mode
• Indoor coil – absorbs or releases heat depending on mode
• Expansion valve – reduces refrigerant pressure, which lowers its temperature
• Reversing valve – switches the system between heating and cooling modes
• Lines of copper tubing – carry refrigerant between components
• Fan – moves air across the coils (in most ducted systems)

Cooling and heating modes

With the parts above in mind, here’s how they work in each mode.
The reversing valve switches the flow direction depending on whether you want to cool off or warm up.

When you want to cool your house, the heat pump moves refrigerant through the expansion valve. This lowers its pressure and temperature, causing the refrigerant to absorb heat from indoor air as it flows through the indoor coil. The refrigerant then carries that heat to the outdoor coil, where it is released.

To heat your home, the process works in reverse. Cold refrigerant flows through the outdoor coil, absorbing heat from outside air (even when it’s cold). The refrigerant is then compressed which raises its pressure and temperature. The hot refrigerant flows through the indoor coil, where a fan distributes the heat through your ductwork.

Whether cooling or heating, these cycles repeat continuously, keeping your home at the temperature you desire.

If you’re a visual learner, an excellent demonstration of how heat pumps work is this video from This Old House.

Heat pumps work in really cold climates

There has been long-standing doubt about the effectiveness of heat pumps in cold climates. However, there’s no longer any reason to dismiss the technology. Heat pump use is growing in the coldest places on earth, like Finland, Norway and Canada. If the systems are up to the task in Nordic and Arctic climates, they’ll keep us toasty warm here in the Midwest.

How much heat pump systems cost

A ducted heat pump system will run $4,500 to $8,000. The price is driven by system performance, efficiency, labor and the complexity of the install, according to CNET.

If a $4,500 system saves $650 on utilities annually, you’ll reach the break-even point in 6.9 years. ($4,500 ÷ $650 = 6.9)

A home equity loan is a convenient way to finance a heat pump system to keep your home comfortably cool and warm as needed.

 

 All loans subject to approval. Rates, terms, and conditions are subject to change may vary based on credit worthiness, qualifications and collateral conditions.