407.2 Outdoor Air Intakes and Exhaust Outlets.407.2.1 Outdoor Air Intakes.

Outdoor air intakes shall be located at least 25 feet (7.62 m) from exhaust outlets of ventilating systems, combustion equipment stacks, med- ical-surgical vacuum systems, cooling towers, and areas that may collect vehicular exhaust or other noxious fumes. Plumbing vents shall be located in relation to out- door air intakes per California Plumbing Code. The bot- tom of outdoor air intakes shall be located as high as practicable, but not less than 10 feet (3048 mm) above ground level. If installed above the roof, they shall be located 18 inches (457 mm) above roof level or 3 feet (914 mm) above a flat roof where heavy snowfall is anticipated. (1) Exceptions: These dimensions may be reduced if it is demon-

strated by the submission of details and calculations

(1) These dimensions may be reduced if it is demon-

strated by the submission of details and calculations that location of intakes with respect to exhausts and their orientation, or the use of special filters, pro- vides equal performance. (2) The requirements regarding the bottom of outdoor

air intakes and installation through the roof do not

(2) The requirements regarding the bottom of outdoor

air intakes and installation through the roof do not apply to skilled nursing facilities, intermediate-care facilities or nonsensitive areas in correctional treat- ment centers. 407.2.2 Exhaust Outlets. Exhaust outlets shall be located a minimum of 10 feet (3048 mm) above adjoining

407.4.1.1 Air supplied to operating rooms, cesarean operating rooms, cardiac catheterization labs, cys- toscopy rooms, delivery rooms, and nurseries shall be delivered at or near the ceiling of the area served. In these areas and in morgues and autopsy rooms all air removed from the area shall be removed near floor level. Exhaust or recirculation inlets shall be located not less than 3 inches (76 mm) nor more than 8 inches (203 mm) above the finished floor, except in morgues and autopsy rooms where all of the exhaust air is removed through an autopsy table designed for this purpose. At least two exhaust or recirculation air inlets of equal capacity shall be used in all cardiac catheterization labs, cystoscopy rooms, operating rooms, and delivery rooms and shall be located not less than 3 inches (76 mm) nor more than 8 inches (203 mm) above the finished floor. Exception: For airborne infection isolation rooms and protective environment rooms, see Sections 414.0 and 415.0. 407.4.1.2 Room supply air outlets and room recir- culation and exhaust air inlets installed in nonsensi- tive areas shall be located not less than 3 inches (76 mm) above the floor. Exception: For airborne infection isolation rooms and protective environment rooms, see Sections 414.0 and 415.0. 407.4.1.3 Corridors shall not be used to convey sup- ply, return, transfer or exhaust air to or from any room if the corridor is required to be fire resistive construction per the California Building Code. (1) Exceptions: Mechanically exhausted toilet rooms of 50

square feet (4.7 m ² ) or less and small rooms of

(1) Mechanically exhausted toilet rooms of 50

square feet (4.7 m ² ) or less and small rooms of 30 square feet (2.79 m ² ) or less such as janitor closets, housekeeping rooms, and electrical or telephone closets opening directly onto corridor. (2) Air transfer caused by pressure differentials in

rooms required to have a positive or negative

Air transfer caused by pressure differentials in

rooms required to have a positive or negative air balance by Table 4-A.

68 2019 CALIFORNIA MECHANICAL CODE

VENTILATION AIR

407.4.1.4 No space above a ceiling may be utilized as an outside-air, relief-air, supply-air, exhaust-air, or return-air plenum. Exception: Designs specifically approved by the enforcing agency. 407.4.1.5 Air from a patient room, exam room, treat- ment room shall not be transferred to another simi- lar room without first having passed through air filters as required by Table 4-B or Table 4-C. 407.4.1.6 Supply outlets and return and exhaust air inlets shall be located to prevent short-circuiting.