Experimental study on direct evaporative cooling for free cooling of data centers.

With the cold-fog direct evaporative cooling (CDEC) technology, which uses the natural cooling sources, the cooling energy consumption of data centers can be reduced, and thus the cooling cost can be decreased significantly. There are only a few studies on the application of CDEC in data centers. In this paper, CDEC technology is proposed to provide cooling sources for a data center after cooling the high-temperature fresh air and circulated air from the data center. According to the results of experiments, it can be concluded that only when the relative humidity of high-temperature fresh air is lower than 40 %, the treated air meets the air supply requirements of the data center. otherwise, the circulated air need be treated by CDEC in order to ensure that the air temperature can be reduced to below 30 °C and the relative humidity be less than 80 %. Compared with general evaporative cooling, the efficiency can be improved by 2.07 %–28.50 % with CDEC. Besides, according to the orthogonal experiment, the sequence of various influencing factors on the CDEC is: air speed > spray flow rate > spray angle, which provides guidance for the optimization of application of CDEC in data centers. • Applying cold-fog direct evaporative cooling (CDEC) technology to data centers. • A cooling scheme for data center under a high-temperature climate is proposed. • FDEC can improve the utilization of natural cold sources in data centers. • FDEC is 2.07 %–28.5 % more efficient than general evaporative cooling. • This contributes to achieving free cooling for data centers throughout one year. [ABSTRACT FROM AUTHOR]