GEOTHERMAL HEAT PUMPS – YES

On the Level: Geothermal Heat Pumps and Energy Efficiency
Jim Rooney, September 26, 2010 (The Capital)

"…[It is wise to be wary [about the efficiency and reliability of geothermal heat pumps but] I have inspected these heat pumps as part of performing home inspections and have attended all-day seminars…[and] I can tell you that the simple answer is yes - they are mechanically reliable IF they are designed and installed properly…

"…The track record is good, but they tended not to have been installed in homes at any great rate due to simple parameters, mostly surrounding initial price and site conditions. When I first began looking at them they were most advisable for owner-operated buildings of 10,000 square feet or more…schools, municipal buildings, health facilities and the like…Ground zero for geothermal heating - also known as ground source heat - in the U.S. was out in the Midwest…"

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"The basic energy exchange mechanism [for geothermal heast pumps] is via buried lines, either through trenches dug to a specific depth or vertical wells into which sealed plastic pipes are filled with a liquid - like anti-freeze - running through them to affect the thermal exchange. In some instances the lines can be placed into a water source such as a large pond if the depth is enough…[S]ystem design is very dependent upon site conditions…

"The move toward energy efficiency at all levels has begun to make them more attractive to homeowners. I have read that geothermal systems have even been employed in some Habitat for Humanity homes…Ikea is installing a [130 500 ft. deep] geothermal system in a new 450,000 sq. ft. building in Colorado and claims of efficiency are nothing short of astounding over traditional heating and cooling…"

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"I have begun to see TV spots for geothermal installation…If we still see the ads after a long stretch of time then that's a good indication they are selling…[The spots also indicate] there is now a population of folks who know how to work on them…[but my] sense is the heart of the system, the heat pump, will last longer than a common air-medium employing system.

"I can't give you an exact payback period for a geothermal heating and cooling system over the traditional air exchange heat pump, but I know they use less energy so they'll lower electric bills and you can get tax credits for putting one in…I've seen claims by the International Ground Source Heat Pump Association that some payback periods are as short as three years. I [dubiously] considered the source of that claim…"