In commercial buildings, space heating, cooling, and ventilation account for 34 percent of energy used on site and 31 percent of primary energy use, according to the U.S. Department of Energy. The Green Proving Ground program selected multiple innovative HVAC technologies to investigate their usefulness, effectiveness, and applicability across the GSA portfolio.
Preliminary Technology Assessments
High efficiency heating, ventilating, and air conditioning (HVAC) units are a new class of rooftop unit (RTU) that can reduce building energy needs by half without reducing HVAC effectiveness. Blowing conditioned air through central shafts and ceiling spaces, the new technology incorporates variable speed controls on the refrigerant compressor, valves, and fans to efficiently heat or cool designated spaces as desired. The high efficiency HVAC RTUs capture and reuse heat, cold, and humidity from a building’s exhaust air and utilize waste heat from the compressors to reheat air that has been purposely over-cooled.
Modular micro-channel absorption chillers are powered by readily available alternative or waste heat sources (excess solar thermal, heat exhaust, or cheaper natural gas) instead of electricity, and can directly replace legacy heating, ventilation, and air conditioning (HVAC) chillers. These modular absorption chillers provide an extremely efficient method of converting heat into cold, and represent a potentially revolutionary new type of HVAC system. In addition to air conditioning, this technology can also be dual-purposed for space heating.
The socially driven web-based thermostat is a heating, ventilation, and air conditioning (HVAC) control system that enables office building occupants to control their thermal environment through a mobile device or web page. The software collects and processes occupant preferences in a “social networking /gaming” environment; artificial intelligence technologies then calculate the most efficient way to satisfy those preferences using the building’s HVAC system.