Today, many consumers are in an excellent position to realize energy savings through the use of geothermal or ground-source heat pump systems. These systems are a wonderful source of “green” renewable energy which are useful in any geographic location but have been found to be particularly efﬁcient in areas that have large variation in seasonal outdoor air temperatures.
A closed loop geothermal heat pump system differs signiﬁcantly from an open loop system in that no ﬂuids present in the internal processes of the system are in contact with the environment. In a closed loop system all ﬂuids are pumped through a “closed” circuit of piping, and the ﬂuids never come into contact with the surrounding soil, rock, groundwater, or surface water body.An open loop system, however, utilizes a pumping well to supply water to the heat exchanger and, most commonly, the spent water is then returned to either another well, an injection well, or to the same well, which is called a standing column well. Other acceptable types of open loop systems exchange water with a surface water body.