Environmental control and air conditioning [IT systems]

Most current day computers and IT systems will operate satisfactorily in a wide range of extreme conditions, it is no longer necessary to control to a strict dry bulb temperature within a very close tolerance, the only thing the computer objects to is a wide fluctuation in conditions over a short time-scale. Now you can operate in a wide range of room ambients and provided the temperature fluctuation is restricted to say /spl plusmn/5/spl deg/C you will have no problems, humidity is not a real concern, although care should be taken to avoid condensation or excess static. So the computer is no longer the problem. The environmental engineers biggest concern now is operator comfort, providing a comfortable workplace where the operator can work at optimum efficiency. With the small to medium sized IT systems this can often be achieved by natural or mechanical ventilation systems providing a cheap and reasonably energy efficient solution. But there are still a number of IT applications where a basic ventilation plant is inadequate and mechanical cooling must be introduced to remove the excess heat generated by the IT equipment and keep the environment within tolerably comfortable conditions. The author looks at several examples of where mechanical cooling is required: the mainframe computer for which indirect or direct cooling can be used; telecommunications; hospital body scanners; and office based PC systems. A case study of building society is discussed.