Heat Pumps

Heat pumps have been used in nearly all parts of the U.S. as a way to heat and cool homes. They are not as common in areas that experience extended periods of sub-freezing weather, such as the Midwest; however, technology is advancing, and some heat pumps may offer an alternative way to heat your home. 

It is important to make sure your home is well insulated and air-tight prior to installing a heat pump to maximize the energy savings. Heat pumps are a good alternative for homes that are heated with an electric furnace or electric baseboard heat, propane, wood or fuel oil.

What is a heat pump?

Heat normally flows from hot to cold just as water flows downhill from high to low. Heat pumps move heat "uphill" against this normal flow.

  • A refrigerator is a heat pump. It moves heat from inside the fridge to the surrounding room so food stays cold.
  • Air conditioners also are heat pumps, moving heat from indoors to outdoors.

Air-source heat pumps

An air-source heat pump is able to heat or cool a home by moving heat to and from the air through ductwork connected to a single indoor unit that distributes the heated or cooled air throughout the house. There also are ductless versions available consisting of an outdoor compressor that connects to an indoor unit.

Heat Pump Summer Illustration
Heat Pump Winter Illustration

The heat pump’s refrigeration system consists of a compressor and two coils made of copper tubing surrounded by aluminum to aid heat transfer. To heat, liquid refrigerant in the outside coils extracts heat from the air and evaporates into gas. The indoor coils release heat from the refrigerant as it condenses back into a liquid. A reversing valve near the compressor changes the direction of the refrigerant flow. Heat pumps are more energy efficient as they concentrate and transfer heat rather than generate it. 
 

Geothermal or ground-source heat pumps 

A geothermal or ground-source heat pump heats or cools your home by moving heat to and from the ground through a series of buried loops. A "desuperheater" can be added to a geothermal heat pump to provide water heating.


Ground loop (vertical and horizontal) configurations

 











Heat pump comparisons

  Air-Source Ducted Air-Source Ductless Ground-Source/Geothermal
Configuration Connects to a single unit that distributes air through a series of ducts within the home. An outdoor compressor that connects to an indoor unit to distribute heat or cool air through the home. Extracts heat from the ground through an underground piping system and distributes throughout the home.
Benefits
  • Lower price point as long as home has installed ductwork.
  • Heats and cools 2 to 4 times more efficiently as opposed to conventional HVAC system.
  • Safer due to no combustion (eliminates carbon monoxide).
  • Reduced environmental impact.
  • Customizable room temperature control.
  • Heats and cools 2 to 4 times more efficiently as opposed to conventional HVAC system.
  • Safer due to no combustion (eliminates carbon monoxide).
  • Low maintenance.
  • Reduced environmental impact.
  • Acts as one system to heat and cool home and heat water.
  • Low noise - no outdoor equipment above ground.
  • Provides consistent output.
  • Saves between 30 – 60% on heating and 20 – 50% on cooling costs over conventional HVAC system.
  • Safer due to no combustion (eliminates carbon monoxide).
  • Low maintenance.
  • Reduced environmental impact.






 

Heat pump considerations  

  • Heat pumps have a higher installed cost than traditional heating systems; however, tax credits and Focus on Energy may offer cash-back reward incentives, which can reduce cost.
  • Evaluate potential energy cost savings before you install a heat pump.
Heat pump technology has evolved in recent years, enabling this equipment to perform well in cold climates. However, in some cases, a backup heat source may be required.  


Before you buy a heat pump

  • For ground-source heat pumps, contact the Wisconsin Geothermal Association for a list of experienced professionals.
  • For air-source heat pumps, contact a heating and cooling professional.
  • Make sure your home is well insulated and air sealed with good ventilation regardless of the type of heating system you choose. If your new home doesn't require much heat, the type of heating system you choose becomes less important.
  • If the building is new, see MGE's New Home Planner for recommendations.