Installing a Ground Loop Heat Pump
The evolution of heat-pump technology has been in process for some time now gradually progressing with science and innovation, the old methods used the temperature differential of air from inside and outside the home to heat or cool it during the winter and summer months. Using the same principles, a ground-loop heat pump utilizes the base temperatures of the subsurface ground as a sort of heat sink to heat and cool the home according to the time of year. The majority of money saving is due to the absence of natural gas or the reduced demand on electricity to heat or cool the air. At a depth of about six feet under Earth’s surface it maintains a relatively constant temperature, usually varying between 45 to 75 degrees throughout most of the planet surface and throughout most of the year. Using geothermal heat pumps heat can be captured from the warmer Earth and transferred into your home in the winter time, during the summer months heat can be taken from your home and discharged into the cooler ground. Using a closed loop system a continuous network of pipes containing an antifreeze solution absorbs heat and passes it through a heat exchange system where it is concentrated and distributed through the home using ducts. These systems are generally low maintenance and use little energy to power the compressor and heat pump, as a result, use of this system reflects a monthly cost reduction of 25 to 50 percent in energy bills.
Ground loop heat pumps do require a substantial amount of piping in order to work efficiently, and are more immediately cost effective for properties that have sufficient horizontal space in their yard. If your property lacks horizontal space in the yard then the piping can be buried vertically by drilling holes to depths up to several hundred feet depending on your needs. Although the energy saving will be the same, vertical installation will be more costly than its horizontal counterpart which means the monetary payback would be spread over a longer period of time. Heat pumps of any type require correct sizing and the size of the unit will vary with the climate and the energy efficiency of the home it will be servicing. In a horizontal installation several hundred feet of trenches will need to be dug up using a back hoe or a trencher, the piping is then laid in the trench and the trench is filled. The ground piping can be run in straight lines or in a modified “slinky” layout which are becoming the standard in residential systems due to the fact that the slinky-coil loops are more economic both financially and geometrically. They save space because the coils overlap in the bottom of the trench. In order to reduce the risk of leaks in the system pipes up to 500 feet long can be employed, the joints are heat-fused and pressure tested and you can get a closed loop system that includes a 50 year warranty.