How is Geo Different than Traditional HVAC systems?


Geothermal heating and cooling systems are not new. 

They have been in use since the 1940s. Today, more than 50,000 systems are sold annually in homes around the country. While geothermal systems still only make up 1% of the total market for HVAC products, they have grown dramatically in the last 10 years. Upon learning of the substantial energy savings and the sustainability benefits of geothermal systems, more homeowners are determining that geothermal is the right choice for them.

Whether you have purchased an existing home or built a new home from the ground up, chances are that you have had an HVAC system in your home. The traditional systems below can use a variety of fuel sources including propane, fuel oil, electricity and natural gas. 

Traditionally, these systems include one of the following:

Gas Furnace coupled with an Electric Air Conditioner:

The furnace generates heat in the winter and distributes that heat through the house via a fan and duct work.  The air conditioner generates cool air in the summer and distributes that cold air in the same fashion. A thermostat controls the temperature in the home by activating the heating or cooling as needed and by controlling the fan that passes air through the furnace or over the air conditioners coil.

Conventional Heat Pump:

This system pulls heat from the home in the summer and ejects it outdoors, leaving the space cooler. The system reverses the cycle in the winter by pulling heat from the outdoor air and discharging it into the home.  The cool and warm air is dispersed through the house with a fan connected to duct work. A thermostat helps control the temperature in the home by running the fan and controlling the amount of heat that is moved into or out of the space.

A geothermal heat pump system operated the same as the typical heat pump system mentioned above.

There is one critically important difference.

While the conventional heat pump uses the outdoor air around the house to transfer heat, the geothermal heat pump uses the ground and its relatively constant temperature of 54◦F to either absorb or reject heat.  Equipment located inside the home or building will use water or refrigerant to collect or discharge the heat.  This will be coupled with a heat exchanger - a loop system which is typically buried beneath the ground - through which the fluid from indoors is carried to absorb or dispel the heat.  Warm or cool air is circulated around the home using a fan and duct work and is controlled by a thermostat. See more information on the types of loop systems below or go to our resources page for more information on the geothermal heat pump process (Buildopia.com or DOE.gov or smarterhouse.org)

So, what are the differences?

  • Uses natural gas, propane, fuel oil or electricity to generate heat or cooling
  • Indoor equipment requires regular/annual maintenance to keep it safe and efficient. (clean furnace, check ignitor and heat exchanger, no CO leaks, etc.)
  • Outdoor condensing unit annual inspection, leak checks, compressor and fan checks. Outdoor wear-tear on equipment, noise
  • Design life of 15-20 years for all components
  • Highest efficiency of 95% for Furnace and 26 SEER for Air Conditioner/Heat Pump
  • Typical 1 day installation
  • No water heating capabilities

  • Uses the earth’s constant temperature below ground as a renewable source of heat or cooling
  • An annual inspection of the indoor heat pump should happen, but the majority of the outdoor components are located underground and require no maintenance.
  • No outdoor equipment exposed to elements, no outdoor noise to disrupt outdoor living space.
  • Design life of 20+ years, with many components lasting much longer
  • Highest efficiency of EER
  • Typical outdoor installation lasts 2-3 weeks, due to need for a site survey and planning to determine the best location for the loop field and then completing the installation of the loops.
  • Indoor equipment can be installed and made operable in 1 day
  • Can be coupled with a water heater and/or radiant hydronic underfloor heater to generate warm water from the earth’s temperature – similar to how the system generates warm air