Section 505 Domestic Cooking Exhaust Equipment
Where domestic cooking exhaust equipment is provided, it shall comply with the following as applicable:
- The fan for overhead range hoods and downdraft exhaust equipment not integral with the cooking appliance shall be listed and labeled in accordance with UL 507.
- Overhead range hoods and downdraft exhaust equipment with integral fans shall comply with UL 507.
- Domestic cooking appliances with integral downdraft exhaust equipment shall be listed and labeled in accordance with UL 858 or ANSI Z21.1.
- Microwave ovens with integral exhaust for installation over the cooking surface shall be listed and labeled in accordance with UL 923.
Domestic cooking exhaust equipment shall discharge to the outdoors through sheet metal ducts constructed of galvanized steel, stainless steel, aluminum or copper. Such ducts shall have smooth inner walls, shall be air tight, shall be equipped with a backdraft damper, and shall be independent of all other exhaust systems. Installations in Group I-1 and I-2 occupancies shall be in accordance with the Building Code of New York State and Section 904.13 of the Fire Code of New York State.
- In other than Groups I-1 and I-2, where installed in accordance with the manufacturer's instructions and where mechanical or natural ventilation is otherwise provided in accordance with Chapter 4, listed and labeled ductless range hoods shall not be required to discharge to the outdoors.
- 2.1. The duct shall be installed under a concrete slab poured on grade.
- 2.2. The underfloor trench in which the duct is installed shall be completely backfilled with sand or gravel.
- 2.3. The PVC duct shall extend not more than 1 inch (25 mm) above the indoor concrete floor surface.
- 2.4. The PVC duct shall extend not more than 1 inch (25 mm) above grade outside of the building.
- 2.5. The PVC ducts shall be solvent cemented.
Where a common multistory duct system is designed and installed to convey exhaust from multiple domestic kitchen exhaust systems, the construction of the system shall be in accordance with all of the following:
- The shaft in which the duct is installed shall be constructed and fire-resistance rated as required by the Building Code of New York State.
- Dampers shall be prohibited in the exhaust duct, except as specified in Section 505.3. Penetrations of the shaft and ductwork shall be protected in accordance with Section 607.5.5, Exception 2.
- Rigid metal ductwork shall be installed within the shaft to convey the exhaust. The ductwork shall be constructed of sheet steel having a minimum thickness of 0.0187 inch (0.4712 mm) (No. 26 gage) and in accordance with SMACNA Duct Construction Standards.
- The ductwork within the shaft shall be designed and installed without offsets.
- The exhaust fan motor design shall be in accordance with Section 503.2.
- The exhaust fan motor shall be located outside of the airstream.
- The exhaust fan shall run continuously, and shall be connected to a standby power source.
- Exhaust fan operation shall be monitored in an approved location and shall initiate an audible or visual signal when the fan is not in operation.
- Where the exhaust rate for an individual kitchen exceeds 400 cfm (0.19 m3/s) makeup air shall be provided in accordance with Section 505.4.
- A cleanout opening shall be located at the base of the shaft to provide access to the duct to allow for cleanout and inspection. The finished openings shall be not less than 12 inches by 12 inches (305 mm by 305 mm).
- Screens shall not be installed at the termination.
- The common multistory duct system shall serve only kitchen exhaust and shall be independent of other exhaust systems.