| Data centers are becoming one of the largest industrial energy users consuming approximately 61 billion KW of power, which is almost 2 percent of the electrical usage, in the US. Some data centers have reported that about thirty percent of their total energy is consumed by data center cooling resources. In recent years, more effort is being made on the improvement of the "power usage effectiveness (PUE)" through use of the air-side economization, also known as "free cooling". Air-side economizers bring in large amounts of ambient air to cool the internal heat loads when weather conditions are favorable and result in substantial monitoring savings that drives the cooling resources. However, if ambient air properties are not suitable to cool the information technology (IT) equipment directly, ambient air needs to be conditioned before entering the IT equipment. One method of conditioning outside air is to use direct evaporative cooling which sprays atomized water as air passes through an evaporative cooling zone. Atomized water vaporizes and conditions the air passing through the cooling zone by adding moisture and reducing its temperature. In this study, computational fluid dynamics (CFD) analysis is performed using a commercially available CFD tool, Fluent, to determine performance of direct evaporative cooling in an air-side economizer. Many factors that affect performance of evaporative cooling, such as particle sizes of atomized water, ambient air temperature and humidity, water temperature are investigated in this work. |
