609.1 Air-Moving Systems and Smoke Detectors.

Air-moving systems supplying air in excess of 2000 cubic feet per minute (ft [3] /min) (0.9439 m [3] /s) to enclosed spaces within buildings shall be equipped with an automatic shutoff. Automatic shutoff shall be accomplished by interrupting the power source of the air-moving equipment upon detection of smoke in the main supply-air duct downstream of both the fan and filters served by such equipment.

Exceptions:

(1) Where all portions of the building served by air-moving equipment returning air in excess of 2,000 cubic feet per minute (ft [3] /min) (0.9439 m [3] /s) are protected by a total coverage smoke-detection system in accordance with NFPA 72 and the California Fire Code, interconnection to such system shall be permitted to be used to accom- plish the required return-air system shutoff.

(2) Automatic shutoff is not required where occupied rooms served by the air-handling equipment have direct exit to the exterior, and the travel distance does not exceed 100 feet (30 480 mm).

(3) Automatic shutoff is not required for Group R, Division 3 and Group U Occupancies.

(4) Automatic shutoff is not required for approved smokecontrol systems or where analysis demonstrates shutoff would create a greater hazard, such as shall be permitted to be encountered in air-moving equipment supplying specialized portions of Group H Occupancies. Such equipment shall be required to have smoke detection with remote indication and manual shutoff capability at an approved location.

(5) Smoke detectors that are factory installed in listed airmoving equipment shall be permitted to be used in lieu of smoke detectors installed in the main supply-air duct served by such equipment.

609.1.1 Duct Smoke Detectors. Duct smoke detec- tors shall comply with UL 268A, shall be labeled by an approved agency, approved and listed by California State Fire Marshal, and shall be installed in accordance with the manufacturer’s installation instructions. Such devices shall be compatible with the operating velocities, pres- sures, temperatures, and humidity’s of the system. Where fire-detection or alarm systems are provided for the building, the smoke detectors shall be supervised by such

DUCT SYSTEMS

systems in an approved manner and installed in accor- dance with NFPA 72 and the California Building and Fire Codes.

High-rise buildings having occupied floors located more than 75 feet (22 860 mm) above the lowest level of building access shall be provided with duct smoke detec- tion in accordance with Section 609.1 and the California Fire Code, Section 907.2.13.1.