Environmental Conditions

Temperature and humidity targets are major drivers of cooling energy use - and cost. Yet most data centers are overcooled and missing the mark on humidity control. Once operators address air management, they should consider operating at recommended temperatures and humidity.

High-Level Best Practices

Although most computer room air conditioners (CRACs) are controlled based on the return air temperature, air intake to IT equipment is the important specification to meet. 

  • At minimum, follow ASHRAE guidelines for data center temperature ranges recommended for reliable IT operations
  • Even better, operate at the maximum ASHRAE recommended temperature range (80.6°F)
  • Anticipate that servers will occasionally operate in a higher, but allowable, range (89.6°F)
  • Minimize or eliminate humidity control altogether

Many opportunities exist to reduce energy consumption of cooling equipment, including

  • Raising the chilled water temperature
  • Using air-, water- or refrigerant-based economizers
  • Installing variable-speed pumps and fans through the plant
  • Installing dry coolers
  • Installing rear door heat exchangers (RDHx) for high-density racks
  • Use a centralized cooling system instead of individual direct expansion (DX) systems

Featured Resources

Data Center Master List of Efficiency Actions 

This comprehensive list of recommended efficiency actions for data centers provides more information on the high-level operational best practices outlined above as well as a more detailed list of best practices related to cooling and air management.
Download the PDF

Thermal Guidelines and Temperature Measurements in Data Centers

This document initially develops a list of generalized thermal best practice recommendations as a first step towards temperature management and measurements in data centers, ultimately saving infrastructure energy as well as protecting electronic equipment.