The air removed by every mechanical ventilating exhaust system shall be discharged outside at a point where it will not cause a nuisance, and from which it cannot again be readily drawn in by a ventilating system.
Exceptions:
1. Air which will not cause a nuisance may be discharged into a boiler room in such quantity as is required to supply the needs of combustion.
2. Air which will not cause a nuisance may be discharged into a garage used for active storage of only five or more cars, provided the garage is separately ventilated during all hours of occupancy, in accordance with the provisions of Section 18-28-403.3.
2.1 Provisions shall be made in cases as described above so that when an air system is used for smoke exhaust, the smoke shall be automatically discharged to the outside and the secondary use of the air is automatically dampered off.