Hawaii Administrative Rules
Title 11 - DEPARTMENT OF HEALTH
Subtitle 1 - GENERAL DEPARTMENTAL PROVISIONS
Chapter 39 - AIR CONDITIONING AND VENTILATING
Section 11-39-13 - Garage ventilation
Current through February, 2024
Ventilation for enclosed automobile parking garages shall be guided by the following:
(1) Each story or level of a parking garage shall be mechanically ventilated unless all of the following requirements are met:
(2) Mechanical ventilation for parking garages shall require a minimum of one and five tenths cfm per square foot (seven and five tenths liters per second per square metre) over the entire floor area requiring ventilation. At locations where traffic is such that congestion can occur, for example at an exit, the air distribution shall be adjusted to provide more air.
(3) Ventilation may be by supply or exhaust, but shall be arranged for reasonably even air distribution.
(4) An engineered system may be employed, using the equation: Q = Kn/C, where Q = exhaust ventilation rate, cfm; K = 1,380,000 (a constant); n = number of cars running at one instant; C = allowable carbon monoxide concentration, parts per million. For residential parking garages, n = 1.18 per cent of total parking spaces. For other parking garages, n may be higher. For engineered systems C shall be selected with regard to threshold limit CO and as approved by the director.