Geothermal Heat Pump Systems to Save Energy!

One of the technologies that is prevalent is the use of Geothermal Heat Pump Systems (GHPS) which is a way of obtaining heat from the ground with an incremental input of electrical power or conversely, obtaining air conditioning and rejecting heat to the ground. There are a number of systems to be designed depending on the application: open loop, closed loop, well, horizontal laid in place piping or even piping into lakes and ponds. The goal is to be able to bring in a relatively consistent temperature water to the heat pump system such that it is not affected by the season of he year or outside temperature. We design our GHPS to be closed loop so that there is no reason to consider any cross contamination. In addition, a closed loop allows us to know precisely what we are dealing with regarding flows, temperatures and capacilities.

If we consider a well type GHPS, then we need enough well depth to take care of the heating of the building. Multiple wells are often needed to provide enough length so that the system will function as proposed. The IGSHPA has set forth guidelines for the depth, the contact length, optimum length for pumping circuits and similar design guidelines. We have taken our first GHPS design course in 1978 from IGSHPA and would suggest that you contact their web page at Heat Spring at http://www.heatspring.com/  for additional information.

Of course, the geothermal design for a home, a small commercial building and a large commercial or institutional building are all treated differently and uniquely designed. Care needs to be taken when considering soil type, heat transfer coefficients and other factors when the design is completed for a particular building.

The benefit of the GHPS is that although the capital cost is higher for the initial installation, the operating cost is significantly lower over the length of the building system Typically, we see energy savings in the 30 to 50% range with this type of heat pump system when it is properly designed. Therefore, the Life Cycle Cost is relatively short for a system such as this one when done for a project of any size. In addition this is a sustainable energy solution so from a High Performance Building, LEED, Green Globes or Energy Star approach this provides additional incentives.

In addition a geothermal heat pump system can be coupled to other sustainable technologies easily such as solar, CHP and some other inelligent energy solutions to further enhance efficiencies. Certainly call on us should you have any questions that you believe we can assist with!