A friend asked the other day, “What do you say to someone interested in a geothermal heat pump system.” I thought I’d use this space and tell you what I told him. My friend was asking about a residential system, but I’ll try to keep it general to both residential and commercial because most of the things to consider are the same even though they may have very different answers.
The energy savings potential of a properly designed geothermal system is quite impressive. A geothermal heat pump works very similar to a regular air conditioner by pumping heat out of the building. In the winter, it runs in reverse and pumps heat into the building. The main difference is that a geothermal system puts this heat into the ground during the summer and pulls it out in the winter. Since the ground temperatures (for example) in winter are much closer to the indoor temperature than the outside air, the heat pump doesn’t have to work near as hard to move the energy into the building.
Because of the increased efficiency, the building owner will get significant cost savings on their utility bills. Unfortunately, this comes at a price. Geothermal is expensive since the contractor must drill wells or dig trenches to install the underground piping, and this cost will vary greatly by the site geology (what they must drill or dig through). There are many different configurations for geothermal, each with unique configurations and constraints. Cost payback calculations will include these factors and more and be a primary driver of whether or not geothermal is a good investment.
Whatever configuration is best for you, one of the common key design considerations is to not install a system any bigger than you need (meaning less drilling would be required). This means that the building owner should have reduced their cooling/heating needs (by sealing the building, reducing lighting heat loads, etc.) before installing geothermal. This portion of the project is where we can help the most. As part of our energy auditing services, we take a look at your building and see what can be changes to save money by saving energy. If you are interested in a geothermal system, contact us today so that we can give you some recommendations that will lead you to a well designed geothermal system.
