Heat Pumps & Geothermals

What is a Heat Pump?

A Heat pump is a heating and cooling system for your home. Heat pumps:

  • Use a basic refrigeration cycle—evaporation, compression, condensation, and expansion—to capture and pump heat from one area to another
  • Eliminate noisy outdoor compressors and fans
  • Reduce greenhouse gas emissions by the equivalent of planting 750 trees or taking 2 cars off the road

Check out what rebates SCI REMC offers for members installing heat pumps.

2 Types of Electric Heat Pumps

Air-Source Heat Pump

  • Air-source heat pumps look similar to an outdoor air conditioner
  • To heat a house, it gathers heat from the outside air, and moves that heat inside a house to keep it warm
  • To cool the home, it gathers the heat from inside and gets rid of it by sending it outside
  • In the winter (when temps go below 32º F), air-source heat pumps can have trouble gathering heat from the cold winter air, and in the summer, sending warm air out into warm air

Ground-Source (Geothermal) Heat Pump

  • Super-efficient geothermal heat pumps provide clean, quiet heating and cooling while cutting utility bills by up to 70%
  • A ground-source or geothermal, heat pump functions like a conventional heat pump, moving heat between indoors and out
  • The difference is that geothermal heat pumps transfer heat to and from the ground, via long loops of liquid-filled pipe buried in the ground
  • The temperature underground stays around 50º F no matter how hot or cold it gets outside
  • An air-source heat pump struggles to scavenge heat from freezing winter air or to dump it into the summer swelter
  • A ground-source heat pump has the comparatively easy job of extracting and disbursing heat through the 50º F liquid circulating in its ground loop
  • Geothermal systems are twice as efficient as the top-rated air conditioners and almost 50% more efficient than the best gas furnaces

What it Costs

Geothermal Closed-Loop Heat Pump (Geothermal System)

There are 2 main components to the geothermal system:

  • The buried closed-loop (a loop of pipe buried in the ground)
  • The indoor unit which is tied into a proper ductwork system
  • There is no outdoor unit used with this system as you would find with an air-source heat pump system
Buried Closed-Loop
  • Heat is exchanged with the earth by using a buried earth loop and a small circulating pump
  • Only 2 types of pipe are acceptable for the earth loop – polybutylene and high-density polyethylene pipe
  • This earth loop must be installed by a certified contractor
  • The loop is carefully assembled on location using “heat fusion” to join the pipes where necessary
  • Once assembled, the loop system becomes “one piece” of pipe with parallel circuits
  • The integrity of this loop is such that a virtual lifetime of trouble-free use can be expected
  • Installation by any other means may cause a failure of the pipe because of the unique conditions below the ground
Heating Mode
  • Water, with an antifreeze solution, is circulated through the earth loop
  • In the heating mode, the indoor unit extracts heat from the solution in the loop, and with a refrigeration process, intensifies that heat and delivers it through the duct system at temperatures ranging from 95 to 105º F
  • Since heat is being transferred – not produced – the geothermal system is delivering over 3 units of energy for every unit of energy it consumes
  • This is possible due to the fact that it takes advantage of below-ground temperatures that are warmer in the winter and cooler in the summer than the outdoor air
  • Since the earth loop is buried in the ground, where temperatures are constant, the outdoor temperature does not adversely affect the high efficiency of the geothermal system
Cooling Mode
  • In the cooling mode, the indoor unit extracts heat from the air inside the home, and transfers that heat into the solution circulating through the loop
  • The heat is then rejected to the earth
  • It is much easier to transfer heat into the cooler earth than trying to transfer it into the 90º F to 100º F outdoor air

Domestic Hot Water (Desuperheater)

  • Most manufacturers offer an option that produces a large percentage of the annual hot water requirements
  • A “Desuperheater” is installed with a small circulating pump between the existing water heater and the geothermal system
  • “Desuperheaters” are becoming a standard
  • During the winter, when the geothermal system is operating in the heating mode, hot water is being produced at the same high efficiency
  • In the summer, the heat that is being rejected by the geothermal system is transferred to the water heater at little or no cost

Rebates & Credits

Geothermal Heat Pumps

Geothermal rebate icon

New construction or replacing gas or electric

Mini-Split Heat Pump

Mini-split heat pump icon

Single room or whole home installations

Air Source or Dual Fuel Heat Pump

Air-source or dual fuel heat pump icon

Heat pump replacing gas, existing A/C or heat pump, new construction, or replacing 100% electric resistance heat.

HVAC Tune-Up

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Air source, geothermal heat pumps, and central air conditioning systems

Visit our Rebates & Credits page for more information.