Harvey Sachs is senior fellow, Buildings Program, with the American Council for an Energy-Efficient Economy (ACEEE). Wilson Lin is an assistant director with the Ministry of Environment and Water Resources, Singapore. For more information, see the ACEEE Emerging Technologies and Practices web page at www.aceee.org/topics/emerging-technologies-and-practices. Also, Sachs will be presenting a workshop on "Emerging HVACR Technologies and Practices" at the Air Conditioning Contractors of America (ACCA) Commercial Contracting Roundtable, being held Oct. 7-8, 2010 in Fort Worth, Texas. For more information, visit www.acca.org.
Ongoing
economic and indoor environmental concerns require HVAC innovation. New liquid desiccant air conditioning systems offer
substantial energy savings and greatly improved humidity control in
applications where latent loads (moisture) are very high relative to sensible
loads.
Smart HVAC equipment that recognizes when it is failing or has failed, or when conditions have drifted outside its optimum range, could save substantial amounts of energy if the equipment sent useful information to the building owner or contractor. This is referred to as automated fault detection and diagnostics (FDD).
Energy recovery ventilation (ERV) systems exchange heat (often both sensible heat and water vapor) between the outgoing exhaust air and the ventilation air being brought in. Under appropriate conditions, this allows reducing the capacity of the HVAC system and saves energy.
Advanced packaged rooftop units (RTUs) are emerging with higher efficiencies and additional features designed to save energy off-peak and improve reliability. Features include improved fans and economizers; better controls for the fan, refrigerant cycle, and economizer; and advanced monitoring and diagnostics.
Chilled beam systems provide savings by replacing fan energy with pump energy. They use pumped chilled water instead of blowing cold air. Water has much higher heat capacity, both by mass and volume. In typical pump and fan arrangements, this has been shown to translate into a reduction in fan energy by a factor of seven.