过去，免费冷却在数据中心并不常见，原因有很多，包括数据中心冷却应设计为最大可靠性，而不是能效。最近时代变了。如今，能源和可持续性对许多数据中心所有者来说更为重要，老练的所有者和设计师都知道，免费冷却可以在保持足够可靠性的同时提供良好的投资回报。许多数据中心正在设计或改造空侧省煤器、水侧省煤器，甚至“湿球”省煤器（直接蒸发冷却器）。 本文简要比较了空侧和水侧省煤器，然后简要比较了两种类型的水侧省煤器（CRAC和冷水机组），然后重点介绍了冷水机组水侧省煤器服务于数据中心的设计和控制考虑。单位:I-PCitation:ASHRAE Transactions，第115卷，pt。2、路易斯维尔2009

Free cooling was not common in data centers in the past for a variety of reasons including the philosophy that data center cooling should be designed for maximum reliability and not for energy efficiency. Recently times have changed. Energy and sustainability are more important to many data center owners now and sophisticated owners and designers know that free cooling can provide a good return on investment while still maintaining adequate reliability. Many data centers are being designed or retrofitted with airside economizers, waterside economizers, and even "wet bulb" economizers (direct evaporative coolers). This paper briefly compares airside and waterside economizers, then briefly compares the two types of waterside economizers (CRAC and chiller plant) and then focuses on design and control considerations for chiller plant waterside economizers serving data centers.Units: I-P