| Abstract |
Properly designed geothermal heating and cooling systems are simple, reliable, affordable, and 300 to 500 percent efficient, relative to electricity consumed. Keys to effective design include small and localized mechanical components, conceptual simplicity, adequate flushing and purging access for water loops, low-tech controls and thermally “tight” building construction. Advanced design practices include integration of simultaneous heating and cooling loads, use of Heat Recovery Ventilators to pre-condition fresh make-up air, and systematic recycling and re-use of existing British Thermal Units (Btu) in already conditioned air. Risks and unknowns for mechanical system designers lie mainly in sizing design of the ground-coupled heat exchanger and circulating pumps. Integration of accurate data for the building load, soil conditions, climate and heat pump performance specification results in a “right-sized’ system that optimizes efficiency for up to 30 years of reliable service. |