ASHRAE-DC waterside economizer.pdf

© 2009, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (). Published in ASHRAE Transactions 2009, vol. 115, part 2. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE’s prior written permission. LO-09-015 Waterside Economizing in Data Centers: Design and Control Considerations Jeff Stein, PE Member ASHRAE ABSTRACT energy savings from airside economizing are significantly reduced but can still be substantial1. However, if adiabatic Free cooling was not common in data centers in the past humidification (direct evaporation) is used then the savings for a variety of reasons including the philosophy that data can be even greater than airside economizing without center cooling should be designed for maximum reliability and humidification2. Furthermore, more and more data center not for energy efficiency. Recently times have changed. Energy managers are realizing that humidity control has little if any and sustainability are more important to many data center impact on data center operations and therefore more and more owners now and sophisticated owners and designers know that data centers are relaxing or eliminating humidity control. free cooling can provide a good return on investment while still