Section 325.17709. Ventilation exhaust ducts and deodorizing vents; size; sealing; discharge height.

(1) Ventilation exhaust ducts and deodorizing vents in dry cleaning establishments shall be sized to maintain the required air flow. The joints of the ducts shall be effectively sealed, soldered, or taped. The ducts shall extend to a minimum height of 5 feet above the roofline and a minimum of 25 feet from any air intake unit or opening and shall extend above any adjacent parapet wall or above adjacent buildings, whichever is higher. The ducts shall be equipped with a vertical discharge cap.

(2)      Where deodorizing vents are connected to a common duct, the  main duct shall be sized to maintain rated airflow from all  the  dry   cleaning machines and shall be extended as required by subrule (1) of this rule. Backdraft dampers in individual deodorizing stacks may be required by the department.

(3)     The exit location of ventilation  ducts   and    deodorizing   system vents  shall be  installed  so  as  to  prevent  the  entry    of solvent-contaminated  air into the make-up air supply or other air intakes or combustion air systems in the dry cleaning establishment.

History: 1981 AACS; 2004 AACS.