All automatic dry-cleaning machines must be provided with an exhaust system capable of maintaining a minimum air flow of 100 feet per minute face velocity in through the loading door whenever the door is open. In the case of attendant-operated units in which the exhaust system is an integral part of the whole unit assembly, and exhaust is not necessarily through the doors of the cleaning machines, the face velocity through the open portion of the complete machine unit shall be 25 feet per minute. In this case, the cleaning and drying units shall be inoperative if the ventilation system is not functioning. Duct-work connections from this system must be sealed (soldered or taped) and the discharge stack extended to a minimum height of 5 feet above the roof peak. The discharge stack shall be extended 5 feet above the top of any window located within 25 feet of the opening, and shall be located horizontally as far as possible from any air intakes. All exhaust from the maintenance area shall have a separate duct system and discharge to the atmosphere as outlined in this section.
('69 Code, § 5-22)