Exhaust through direct openings or ducts.
Municipal Code of Chicago § 18-28-403.9
in effect18-28-403.9 Exhaust through direct openings or ducts.
If a mechanical ventilating exhaust system is required in any room, air may be exhausted to corridors or uninhabited rooms through direct openings or horizontal ducts not to exceed 5 feet (1525 mm) in length if all of the following requirements are met:
1. The room being supplied does not contain dangerous or noxious fumes, odor or dust; and
2. Adequate relief openings for mechanical exhaust exist in such corridors or uninhabited rooms.
Source: City of Chicago, Municipal Code of Chicago (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/chicago/latest/chicago_il/0-0-0-2686958Fetched: 10/24/2026