| Abstract |
the most efficient and lowest Life Cycle Cost heating and cooling systems commercially available, according to U.S. Environmental Protection Agency and the Department of Energy. Public awareness and definition of “geothermal energy” are being reshaped by this commonly available source of renewable, earth heat. More than half of two million Geothermal Heat Pumps (“GHP”) installed world-wide now operate successfully in all 50 of the United States. Efficiencies and economics of GHPs are, literally, multiples or fractions of conventional Heating, Ventilation and Air Conditioning (“HVAC”) technologies. The primary reason is that GHPs collect ambient heat from soil mass within 400 feet of ground surface for concentration by vapor compression cycle and delivery into conditioned spaces. They reverse this process when in cooling mode. GHPs use external electric power to run only the appliance itself (compressor, loop circulating pump, air fan), not to combust or convert chemical energy to thermal energy. No fuel other than electricity is used. First-cost of small-scale (i.e. residential) installations may be two or three times those of conventional HVAC systems, just as custom fixtures and furnishings elsewhere in the home can be relatively expensive “upgrades”. First-cost of larger institutional and commercial systems, however, often totals within 20% (less or more) of standard mechanical systems. Operating and maintenance costs at both scales are routinely one-half to one-fourth those of conventional equipment, as are recurrent maintenance costs, while service lives of equipment are typically twice as long. Part of these economic advantages result from technology and part result from innovative design practices that recycle heat rather than waste and re-create it in endless, one-way processes. Financing mechanisms and investment criteria are similar to normal construction, with expanded variations based on unique savings’ potentials and value-sharing opportunities. Recovery (“Payback”) of incremental first-costs often occurs within the first 3 to 8 years of a 25- to 30-year service life. Accrued savings and salvage values over extended use of original equipment are scarcely comparable to normal HVAC costs. Life Cycle Cost advantages of GHP are multiples of 3 to 5 or more. Ground-coupled heat exchangers (the largest added First Cost) remain available for continuing use by replacement heat pumps. |