Systems, which are not properly commissioned, are out of balance or are failing to deliver appropriate levels of air flow/pressurization have a potential impact upon the working environment and personnel comfort. These system failings may not be noticed on a day-to-day basis, but unless rectified can have a negative effect on performance of both building and personnel. The carrying out of regular system surveys and integrity checks, as part of a planned maintenance routine, should be considered good practice and classified as high priority.