A better way to think about data center cooling is to forget the notion of adding ‘cold’ to a room. Rather, think about air conditioning as removing heat from the room. To that end, there are two components that make up any effective cooling solution. They are first, the Heat Removal section, often referred to as the CRAC, CRAH, or the evaporator, and the second, the Heat Rejection section which is named according to the cooling approach executed and referred to as the condenser, dry-cooler, fluid-cooler, cooling tower, etc.
As such, the first step in selecting an appropriate data center cooling solution always starts with establishing suitable design criteria. Further, selecting the optimal cooling solution involves a deep understanding and comparison between the performance characteristics, capital expense (CAPEX), and operational expense (OPEX) of each potential configuration.