The ground heat exchanger in a GHP system is made up of a closed or open loop pipe system. Most common is the closed loop, in which high density polyethylene pipe is buried horizontally at 4-6 feet deep or vertically at 100 to 400 feet deep. These pipes are filled with an environmentally friendly antifreeze/water solution that acts as a heat exchanger.
There are four basic types of ground loop systems. Three of these — horizontal, vertical, and pond/lake — are closed-loop systems. The fourth type of system is the open-loop option. Which one of these is best depends on the climate, soil conditions, available land, and local installation costs at the site. All of these approaches can be used for residential and commercial building applications.
The installation of a GHP system is not for the do-it-yourselfer. Contact local utilities for references on licensed and experienced installers. In addition, many states have Heat Pump Councils which may provide additional referrals.
