An Integrated Ventilation, Vapor Compression and Indirect Evaporative Cooling Systme

This proposal addresses environmental problems associated with indoor air quality (IAQ) and energy consumption in residential buildings. As building envelopes become increasingly tight to satisfy energy efficiency requirements, health conditions that are correlated with indoor air quality - 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 develop 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 (GWP) of refrigerants, which is orders of magnitude greater than CO2 per pound. The amount of refrigerant leaked form a 14 SEER 3 ton air conditioning system charged with R410A is estimated to have a heat trapping effect equivalent to 1800 pound of CO2 over its expected lifetime. The technology described in this proposal 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, we expect that the technology will cost no more than alternative equipment and will eliminate the need for on-site refrigerant charging. The combination of improve IAQ, reduced operating costs and little to no incremental first cost five 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 over 30% in Midwest and Northeast climates and 80 to 90% 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.