makeup air ducts

[BSSTG]

Greetings all,

I can't seem to find any special requirements for Type I kitchen hood makeup air ducts. Are there any? I was walking through a kitchen remodel the other day and I noticed flex ducts being connected for makeup air and it just didn't look right. Last night I was going through my code book and could not find any specifics.

thanks folks

Byron

 

[globe trekker]

See Section 510.8 - Duct Construction in the 2006 IMC.

"Ducts utilized to convey hazardous exhaust shall be constructed of

approved G90 galvanized sheet steel, with a minimum nominal thickness as

specified in Table 510.8.

Nonmetallic ducts utilized in systems exhausting nonflammable corrosive

fumes or vapors shall be listed and labeled. Nonmetallic duct shall have a

flame spread index of 25 or less and a smoke-developed index of 50 or less,

when tested in accordance with ASTM E 84. Ducts shall be approved for

installation in such an exhaust system."

.

 

[mtlogcabin]

506.3.1.2 Makeup air ducts.

Makeup air ducts connecting to or within 18 inches (457 mm) of a Type I hood shall be constructed and installed in accordance with Sections 603.1, 603.3, 603.4, 603.9, 603.10 and 603.12. Duct insulation installed within 18 inches (457 mm) of a Type I hood shall be noncombustible or shall be listed for the application.

 

[BSSTG]

thanks,

I should have spotted that but didn't. It sure is great to have you folks for advice. I'm just a one man shootin match around here with no one to bounce this stuff off of.

thanks again

Byron