Patent ID: 7751990

Claim:
A method of detecting a fouled air filter in a computer equipment enclosure, the computer equipment enclosure comprising: an air filter, a supply plenum connecting the air filter and the computer equipment enclosure, a fan operating at a current fan speed, the fan providing airflow across computer equipment installed in the computer equipment enclosure, and a filter monitoring module connected for data communications to a management module, the management module capable of managing the computer equipment enclosure and computer equipment installed in the computer equipment enclosure, the method comprising: calculating, by the filter monitoring module, a pressure differential across the air filter, further comprising: determining, from a first pressure sensor located outside the computer equipment enclosure, air pressure outside the computer equipment enclosure; determining, from a second pressure sensor located inside the supply plenum, air pressure inside the supply plenum; and calculating the difference of the air pressure outside the computer equipment enclosure and the air pressure inside the supply plenum; determining, for the current fan speed by the filter monitoring module in dependence upon a pressure differential profile for the air filter, whether the calculated pressure differential across the air filter exceeds a predetermined threshold value; and if the calculated pressure differential across the air filter exceeds the predetermined threshold value, reporting, by the filter monitoring module to the management module, that the calculated pressure differential across the air filter exceeds the predetermined threshold value.