Ground-air heat exchange in ecosmart house
A REHAU ECOAIR ground-air heat exchange system will be the primary fresh air supply for the REHAU MONTANA ecosmart house. This geothermal system will also supply supplemental heating and cooling. Outdoor air will be drawn in through a 6 ft stainless steel air inlet tower equipped with electrostatic/HEPA filter. It will then travel underground around the perimeter of the house through 8 in. REHAU ECOAIR solid-walled PVC pipes with a silver particle-enabled antimicrobial inner surface. Upon entering the house, air will be ducted to individual zones via standard galvanized ducting, using automatic dampers to control zone flow. The individual zones may be fitted with room/zone air handlers to allow room air recirculation.
How ground-air heat exchange systems work
With today’s tight building envelopes, it is often necessary to bring in outdoor air to ensure good indoor air quality. Using geothermal energy to precondition incoming fresh air maximizes the building's energy efficiency.
Since ground temperatures 5 to 7 ft below the earth's surface remain relatively constant throughout the year, the incoming air that passes through ground-air heat exchange pipes is pre-warmed with ground heat in winter and pre-cooled with cooler ground temperatures in summer. By narrowing the gap between outdoor temperatures and comfortable indoor temperatures, ground-air heat exchange systems significantly reduce the amount of additional energy required to heat or cool a house.
Ground-air heat exchange systems require only a small amount of electrical power to operate an air intake fan and provide significant energy cost savings, especially when used in conjunction with heat or energy recovery ventilators (HRV or ERV). They can also allow downsizing of heating and cooling equipment particularly in larger buildings, and may replace the need for an air conditioning unit in residential buildings in some climates.