ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers) recommends an intake temperature of 18 to 27°C for most IT equipment, with an expanded allowable range of 15 to 32°C for equipment rated to handle wider conditions. In practice, most Australian data centres target 20 to 24°C supply air temperature. CRAC units maintain these setpoints continuously. Standard air conditioning cannot do so reliably.