Cooling Air / Air Management

In most cases, air distribution in data centers involves mixing of cooled air with air that has been heated by the IT equipment making it difficult to supply the cool air to where it is needed and resulting in inefficient heat transfer to the cooling system. 

Poor air management leads to more air being circulated than required, which leads to air mixing and short circuiting. It also results in recirculated hot air, which is the cause of most host spots.  


  • Install the Racks in Rows
  • Implement Hot and Cold Aisles
  • Preserve Any Hot-Aisle/Cold-Aisle Arrangements
  • Rearrange Perforated Floor Tiles, Locating Them Only in Cold Aisles and Matching the Tile Flow Rate with the IT Equipment Airflow Rate
  • Cover Openings Within and Between Racks
  • Evaluate the Air Path (Under the raised floor or in the ceiling space) and Rearrange the Cables, Wires, and Pipes to Address Possible Congestion in the Cooling Air Path
  • Seal the Remainder of the Cable Penetrations
  • Separate Cold Air and Hot Air
  • Shut Off Extra CRAC/CRAH/AHU
  • Reset Each CRAC/CRAH/AHU Chilled Water Valve Setpoint with the Highest Air Intake Temperature at the Racks in that Zone
  • Convert the Data Center CRAC/CRAH/AHU Air Temperature Control to the Rack Inlet Air Temperature Control
  • Use Modeling Tools such as CFD or Thermal Imaging Install Variable Frequency Drives (VFDs) on CRAC/CRAH/AHU Fans with Advanced Control


  • Demonstration: Portable Air Management Measurement Tools This report focuses on improving air management in small data centers due to the great potential for energy savings across the data center industry. To be able to implement air management, key environmental parameters such as IT equipment intake temperatures need to be monitored. This demonstration involves two inexpensive, portable measurement tools for assessing air management in small data centers on a limited, temporary basis. Access to simple, inexpensive toolds for implementing and tracking air management is imperative in such environments. Besides evaluating the accuracy of the temperature measurements, this report also includes an in-depth evaluation of the ease of use of the tools. 
  • Data Center Master List of Efficiency Actions provides more information on the high-level best practices outlined above as well as a more detailed list of best practices related to cooling air and air management.
  • The Data Center Air Management Tool was developed to accelerate energy savings in data centers without affecting the thermal IT equipment environment by assessing the data center air-management status. An accompanying Data Collection Guide is also available.
  • The NEW excel-based Data Center Air Management Estimator is a simplified version of the Air Management Tool that uses the same engine. The input options in this tool have been reduced in favor of increased clarity.