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Heat Pumps
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Heat Pumps

ALL ABOUT HEAT PUMPS

Learn about the new technology making home comfort even more efficient with our video on Heat Pumps.

Heat Pump Basics

  • Air-source heat pumps transfer warm/cool air between the outdoors and your home to help warm your home.
  • Geothermal heat pumps use consistent ground temperatures to help heat and cool a home via buried, solution-filled or well water-filled pipes.


Air-Source Heat Pumps

Air-source heat pumps (ASHP) are most common. ASHPs operate very similarly to an air-conditioner, but in reverse.

  • Reversing valves allow the coils to either cool or warm homes by moving molecules from one space to another – in the winter, warmer air molecules transfer into your home from outside; in the summer, warm molecules are removed from the indoors, leaving only cold air molecules.
  • Much like traditional air-conditioners, most ASHPs are centralized, with ductwork distributing the conditioned air.
  • Some ductless room-unit/mini-split ASHPs connect to an outdoor heat-pump instead of a centralized unit to heat/cool rooms directly.
  • ASHP systems run most efficiently with an outdoor thermostat. This runs the HP first before automatically switching over to 2nd-stage heating (your furnace). If your home has an electric furnace, this reduces electricity costs in addition to keeping you comfy.
  • The outdoor thermostat system should be set between 35 and 40 degrees, which will let the system know when to let your furnace help maintain comfort.
  • ASHPs deliver heat energy more efficiently than electric or natural gas furnaces because they transfer heat instead of converting heat from fuel.
  • Some, but not all, newer ASHPs can operate in this region of the US without a backup/emergency heating source like a furnace. This, however, is uncommon.


Geothermal Heat Pumps

Instead of moving air to adjust the air temperature, geothermal heat pumps (GHPs) tap into the consistently cooler temperatures of underground soil or water sources like wells.

  • Most GHPs are ground-source (closed-loop geothermal pumps) units.
  • Water source units use a water mixture inside underground pipes, which is circulated to cool or heat indoor environments.
  • GHP’s indoor coils move heat out of the circulating water and into your home’s air.
  • Because they run at relatively lower temperatures than furnaces, GHPs work best in well-insulated, air-tight, energy-efficient homes.
  • GHPs are more efficient than ASHPs due to the temperate and consistent temperature of the ground soil, however, GHPs are much more expensive to buy/install compared to ASHPs.


Efficient doesn’t always mean “cheaper”! Energy efficiency relates to the efficiency in converting one form of energy to another when warming or cooling a space.


Electric furnaces produce heat at 100% efficiency (no energy is lost in the transfer of electricity to thermal energy) but the energy required to generate heat costs more than less-efficient (80-95%) natural-gas furnaces. Heat pumps may be designed more efficiently, but it may still be cheaper to heat your home with a natural gas furnace depending on the comparative fuel costs.