HybridAir: An Integrated Ventilation, Vapor Compression, and Indirect Evaporative Cooling System

EPA Contract Number: EPD06039
Title: HybridAir: An Integrated Ventilation, Vapor Compression, and Indirect Evaporative Cooling System
Investigators: Bourne, Dick
Small Business: Davis Energy Group, Inc.
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2006 through August 31, 2006
Project Amount: $69,988
RFA: Small Business Innovation Research (SBIR) - Phase I (2006) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , SBIR - Green Buildings , Small Business Innovation Research (SBIR)


This Phase I SBIR project addresses environmental problems associated with indoor air quality (IAQ) and energy consumption in residential buildings. As building envelopes increasingly become tight to satisfy energy efficiency requirements, health conditions that are correlated with IAQ, such as asthma and allergic diseases, are on the rise. The most effective strategy to improve IAQ is ventilation with outside air.

Residential air conditioning energy consumption has doubled since 1978, and increased ventilation requirements will exacerbate this upward trend. This problem is unlikely to be addressed by improvements in conventional air conditioning equipment, as the technology is highly developed and faces diminishing returns for future improvements. High air conditioning electricity loads also correlate with poor outdoor air quality and force the operation of “peaker plants,” which are commonly dirtier than other plants.

Another environmental threat posed by vapor compression air conditioning is the global warming potential of refrigerants, which is orders of magnitude greater than CO2 per pound. The amount of refrigerant leaked from a 14 seasonal energy efficiency ratio (SEER) 3-ton air conditioning system charged with R410A is estimated to have a heat trapping effect equivalent to 1,800 pounds of CO2 over its expected lifetime.

The technology described in this project combines proven night ventilation and advanced evaporative cooling technologies with a downsized vapor compression system to more efficiently provide air conditioning in residential building and improve IAQ. Once fully developed, Davis Energy Group expects that the technology will cost no more than alternative equipment and will eliminate the need for onsite refrigerant charging. The combination of improved IAQ, reduced operating costs, and little to no incremental first cost, provides the technology potential to set a new standard in the residential air conditioning marketplace.

Relative to 13 SEER air cooled equipment, the technology holds the potential to reduce cooling energy consumption by more than 30 percent in Midwest and Northeast climates and 80-90 percent in Western and mountain climates. The proposed effort is structured to evaluate the feasibility of these cooling energy savings and assess the overall potential of the hybrid cooling strategy. To accomplish this, the Phase I project includes design, fabrication, and testing of a mockup, as well as refinement of operating modes and strategies. Test results will include ventilation rates, cooling capacity, and energy efficiency.

Supplemental Keywords:

small business, SBIR, indoor air quality, IAQ, air conditioning, energy, cooling, ventilation, refrigerant, advanced evaporative cooling, compression system, energy efficiency, asthma, global warming potential, EPA,, Scientific Discipline, Air, HUMAN HEALTH, Environmental Chemistry, Health Effects, indoor air, Environmental Engineering, asthma, electrically enhanced filtration, fresh air exchange, energy conservation, green building, ambient air, ventilation rates, building construction, allergic response, indoor air quality, evaporative cooliing technologies

Progress and Final Reports:

  • Final Report