Best practices Data Center Temperature

     The purpose of this article is to provide a basis of "Best practices Data Center Temperature" for data center management and infrastructure. Local business reasons, local governmental code or other circumstances may mitigate the implementation of these best practices.

Air Conditioning & Cooling (Air Handlers, CRAH or FCU units)

• Air handers should be equipped with filters. These filters should be checked weekly and changed as needed. Pleated filters should be equipped with pre-filters.
• The relative humidity should be set in the 55 – 60% RH range.
• Air handlers should be equipped with output thermostats. These thermostats should be tied into a master monitored console with trip point setup to activate an alarm.
• Air handlers should not be installed back to back. The resulting vortex effect on the discharge may actually reduce flow.
• Air handlers should not be located close to high heat load equipment. The static pressure in front of the air handlers is actually very low due to the high velocity of the air handler's discharge. The low static pressure may cause hot air above the raised floor to be sucked into the sub-floor. This problem may be pronounced with high-static-output air handlers.
• Air hander placement and the number of air handlers should be such that if any one air handler fails, the remaining units will provide sufficient pressure and flow to cool the equipment.
• The room's humidity and cooling should be checked on a semi-annual basis with independent measuring equipment for data centers that do not experience a high rate of change. For those data centers that experience constant change, this time frame should shrink.
• Any sub-floor impediments to proper airflow should be reviewed. Old cabling should be removed, and large cable bundles should be spread out.
• Air handlers should be checked on a regular basis for proper operation and unit performance. Sensors should be check against independent measurement devices.
• Spot temperature and relative humidity measurements should be made on a regular basis with calibrated independent instruments.
• The height of the raised floor contributes to adequate airflow. This coupled with the static output pressure from the air handlers will determine where physical hot spots may arise in the data center. With a two foot raised floor, under ideal conditions, a typical air handler will have enough static pressure for normal flow at 30 feet.
• The residual chilled water piping stubs that remain after de-installation of air handlers should be removed.
• The design of the equipment racks will contribute to adequate airflow. For racks that contain high heat loads, fully perforated front doors, or no doors, are preferential.
• Air handlers should be checked for excessive dehumidification caused by low coil temperatures. Excessive dehumidification will cause corrosion in the fan coil units. This can readily be checked if the coil units are wet
• Condensate drains under the air handlers should not drain into open floor drains
• Water piping for the humidifiers should be supported so that unintentional breakage of the lines do not occur
• The discharge area of the air handers should be kept clean so that dust, dirt and debris are not blown into equipment intakes
• An active biocide program should be initiated to prevent growth in the condensate drains for the CRAHs