Geothermal heat pumps are the most energy efficient, environmentally
clean, and cost effective space conditioning systems available according
to the Environmental Protection Agency in the United States of America.
Ground Source Geothermal heating and cooling is a renewable resource,
using the earths energy storage capability.
The earth absorbs 47% of the suns energy amounting to 500 times more energy
than mankind needs every year.
The closed loop portion of a ground source heat pump system consists of polyethylene pipe buried in the ground and charged with a water/antifreeze solution. Thermal energy is transferred from the earth to the fluid in the pipe, and is upgraded by passing to a water source heat pump. One 100 metre vertical closed loop borehole will typically deliver 14000 KWh of useful heating energy and 11000 KWh of useful cooling energy every year for life. For a typical commercial building early trials indicate annual HVAC energy consumption in the order of 75 kWh/m² compared with 156 kWh/m² ‘good practice target’, and 316 kWh/m² typical consumptions published by the Department of the Environment in Energy Consumption Guide No.19. Low energy consumption means associated lower CO2 emissions than from conventional systems.
Energy savings of 40% compared with air source heat pumps and by over 70% compared to electric resistance heating are being achieved, and CO2 emissions are reduced to 40 kg/m², less than half that associated with DoE typical HVAC design. With the heat source buried in the ground, the system is both invisible and silent. There is no need for boiler, flue, cooling tower, water treatment or associated plant rooms, and the total building resource content is reduced. At a depth of 7 to 7.5 metres the earths temperature will be constant at a temperature equal to the average mean ambient temperature throughout the year in any location meaning temperature in winter higher than the air temperature, and in summer lower than air temperature thereby providing higher efficiencies in both heating and cooling modes and ensuring a lower peak load throughout the year.
Features include: Lower Utility Bills, Less Maintenance, No Visible Outdoor Plant, Reduction in Emissions, Versatility of System.