Geothermal heat pumps, sometimes referred to as earth-coupled, ground-source, or water-source heat pumps, use underground piping and the earth’s natural temperature as the source for heat transfer (instead of outside air). Despite seasonal temperature changes, the ground a few feet below the earth’s surface remains at a relatively constant temperature of 45°F to 75°F – warmer than the outside air temperature during the winter and cooler during the summer. This makes the earth an ideal thermal “battery” for rejecting heat in the summer and absorbing heat in the winter.
There are three major components of a geothermal HVAC system:
- The underground piping system, which acts as the condenser water loop to reject or reclaim heat. This is typically polypropylene piping, installed in vertical wells spaced 15-20 feet apart for heat dispersion.
- The water source heat pump, which contains the fan, heat exchanger (coil), compressor(s), and reversing valve. This unit distributes the conditioned air, similar to a furnace in your home, except heat is discharged to the water loop instead of an air-cooled condensing unit sitting outside.
- The last essential element of the system is the water pump. The two most common solutions are dedicated pumps and centralized pumps.
To learn about the advantages and disadvantages of this system, and how we’ve put it to work for our clients, download our white paper.