Range hood ducts must be galvanized steel / stainless / copper (smooth, airtight, with backdraft damper)

Description

Range hood and downdraft cooking exhaust ducts must be constructed of galvanized steel, stainless steel, or copper. The duct must have a smooth interior, be airtight, equipped with a backdraft damper, and be independent of all other exhaust systems. Discharge must be to the outdoors (not attic / crawl space / interior). Exception: listed ductless range hoods are exempt when used per manufacturer instructions where mechanical or natural ventilation is otherwise provided. Downdraft systems may use Schedule 40 PVC under slab-on-grade with conditions.

Why this exists

Plastic flex duct for cooking exhaust is a fire risk and a code violation; smooth-wall metal is the architect's spec sheet default. Ductless / recirculating hoods are convenient but don't remove moisture or CO from gas cooking — for gas ranges, vent to the outdoors.

Categories

Applies to

• Jurisdiction: New York State

Source

Solver enforcement

Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.

Related directives

• Garage / dwelling fire separation · IRC R302.6
• Natural light in habitable rooms · IRC R303.1
• Habitable space minimum ceiling height · IRC R305.1
• Egress window net opening dimensions · IRC R310.2
• Stair riser, tread, and headroom · IRC R311.7