Specifies minimum requirements for the design, installation, commissioning, operation, and maintenance of air-handling systems and water systems in buildings, to assist in the control of micro-organisms, particularly those associated with Legionnaires disease, Pontiac fever, humidifier fever, and hypersensitivity pneumonitis. It does not apply to sole occupancy dwellings, nor is it intended for the control of the wide range of discomfort symptoms which may afflict the occupants of some buildings.