§ 27-456 Ventilation.
AC § 27-456
Public garages shall be ventilated in accordance with provisions of section 27-766 of article eight of subchapter twelve of this chapter and the following: (a) Garage spaces above or below grade except as provided in subdivision (e) of this section shall be provided with mechanical ventilation according to one of or a combination of the following methods: (1) Air exhaust at the rate of not less than one cfm per square foot of total floor area with properly designed means for air inflow.
(2)Air supply at the rate of not less than one cfm per square foot of total floor area with properly designed means for air outflow.
(3)Air exhaust or air supply at a rate sufficient to maintain an average concentration of carbon monoxide not to exceed one hundred parts per one million parts of air for periods longer than one hour and with a maximum concentration at any time not to exceed four hundred parts of carbon monoxide per one million parts of air. The concentration of carbon monoxide shall be determined by periodic tests taken between three and four feet from the floor by means of approved carbon monoxide detector tubes or other equivalent means. This method of mechanical ventilation may be used only if the overall design includes automatic ventilating fan control by means of approved carbon monoxide monitoring devices or by other approved means located so as to provide full protection for the occupancy.
(b)The provisions of section 27-766 of article eight of subchapter twelve of this chapter shall apply.
(c)Air supply shall be taken from an uncontaminated source. Exhaust outlets shall be located in accordance with the requirements of subchapter thirteen with one-half of them located six inches above floor level. In public garages where motor vehicles are parked by mechanical means, the ventilation requirements shall be one-half of those required above.
(d)No automotive service pits shall be installed in floors below the street floor. Pits shall have mechanical exhaust ventilation taken from near the bottom.
(e)Garage spaces above grade provided with natural ventilation having a free openable area of at least five per cent of the total floor area of the space and having adjustable openings measuring at least six inches by four inches located within six inches of the floor and at most sixteen feet apart on all outside and court walls need not be provided with mechanical ventilation.
