On Wed, 20 Apr 2005, Wayne Stallwood wrote:
It gets worse in climates where Air Conditioning is used in most office spaces. 100% of the energy a CPU uses is turned into heat output...heat which in turn has to be removed by running the Air Con harder and longer.
True, and true for all equipment, including the office desk fan.
Air conditioning is not 100% efficient so for every 50 Watts of power you pump into a CPU you waste another 50 Watts plus trying to cool the office.
NOT true. Air conditioning functions by pumping heat from the office to the outside. To remove one watt's worth of heat requires much less than one watt input power to the air conditioning plant. How much less depends on the difference between the temperature at which the heat is rejected and the room temperature, as well as the efficiency of the a/c plant. The ratio of the heat rejected to the input power is the co-efficient of performance and ratios of 4:1 are typical.
The point that is made is sound, but the figures are wrong.
Leon Stedman IEng. ACIBSE.