Experimental characterization of an energy efficient chiller-less data center test facility with warm water cooled servers

Typical data centers utilize approximately 50% of the total IT energy in cooling of the server racks. We present a chillerless data center where server-level cooling is achieved through a combination of warm water cooling hardware and re-circulated air; eventual heat rejection to ambient air is achieved using a closed secondary liquid loop to ambient-air heat exchanger (dry-cooler). Several experiments were carried out to characterize the individual pieces of equipment and data center thermal performance and energy consumption. A 22+ hour experimental run was also carried out with results indicating an average cooling energy use of 3.5% of the total IT energy use, with average ambient air temperatures of 23.8°C and average IT power use of 13.14 kW.