How geothermal heating systems work
With a geothermal heating and cooling system, you could save a lot of money over the duration of your home ownership. While the installation costs associated with geothermal heating systems do tend to be higher than those seen in conventional alternatives, geothermal heating costs are much lower once the system is operational. This is because geothermal heating and cooling uses abundant, naturally occurring local resources which are very inexpensive to extract and apply.
The advantages of residential geothermal heating include not only cost savings over the life of the system, but also superior efficiency when compared to conventional oil furnaces. Geothermal energy is also very clean, producing very low amounts of pollution, or none at all. However, geothermal residential heating systems require either a large yard (for horizontally oriented installation) or the complete absence of ground bedrock (for vertical installation). It may not be possible for you to install a geothermal system if your lot is small and rocky beneath the surface.
How Geothermal Heating and Cooling Works
Residential geothermal heating systems have three main components: a ground loop, a heat pump or furnace, and a means of distributing heat. Essentially, here's how it works:
- Polyethylene pipes are built into a ground loop, which can be horizontally or vertically oriented. These pipes must penetrate deeper than the frost line, where the internal temperature is both warm and constant. If you want to heat your home, these pipes extract heat from the soil. If you want to cool your home, they are used to return the heat extracted from your house back to the ground.
- Your heat pump/furnace system, which is located inside your house, takes the heat delivered by the ground loop and transfers it to the distribution system.
- The distribution system, which can either be comprised of ductwork or radiant floor heating coils, delivers heat to the interior of your home. You use a thermostat to set the desired heat level, just as you would with a regular propane furnace.
If you want to cool your house instead, simply set the thermostat to the desired level and the entire system will operate in reverse. The distribution system will extract heat from the air, send it back down through the furnace and into the ground loop, where it is returned to the ground.