Performance of Indirect Evaporative and Hybrid Cooling Equipment: Findings from Laboratory and Field Testing

Several manufacturers have recently introduced hybrid vapor-compression/evaporative cooling solutions that incorporate the advantages of multiple cooling components into variable speed, multi-mode equipment. These technologies may utilize indirect evaporative cooling, exhaust air heat recovery, desiccant dehumidification (or other components) in combination with vapor compression. This presentation summarizes findings from several laboratory tests, and more than 30 monitored installations of different hybrid air conditioning solutions. It focuses on practical issues in design and commissioning that help ensure performance in operation. In most cases these strategies can reduce full-load cooling demand by more than 40%. Some systems deliver annual savings of 65% or more.