In existing data centers it is necessary to evaluate the following options:
- It may be economically feasible to add free air cooling if the center has access to an exterior wall or roof.
- Another option would be to investigate use of a water-side economizer. Many data centers were built without water side economizers, but this is an economical option that can gain many hours of free cooling annually with a rapid payback.
- Liquid cooling options such as rear door coolers that can function with higher temperature coolant can reduce chilled water requirements and instead operate with water produced by cooling towers or dry coolers.
Source: Guide to Minimizing Compressor-based Cooling in Data Centers by William Tschudi, Lawrence Berkeley National Laboratory