This document describes how to estimate heat output from information technology (IT) equipment and other devices in a data center such as UPS, for purposes of sizing air conditioning systems. A number of common conversion factors and design guideline values are also included.
All electrical equipment produces heat, which must be removed to prevent the equipment temperature from rising to an unacceptable level. Most information technology equipment and other equipment found in a data center or network room is air-cooled. Sizing a cooling system requires an understanding of the amount of heat produced by the equipment contained in the enclosed space, along with the heat produced by the other heat sources typically encountered. Heat is energy and is commonly expressed in Joules, BTU, Tons, or Calories. Common measures of heat output rate for equipment are BTU per hour, Tons per day, and Joules per second (Joules per second is equal to Watts). There is no compelling reason why all of these different measures are used to express the same commodities, yet any and all of them might be used to express power or cooling capacities. The mixed use of these measures...