• Welcome to The Building Code Forum

    Your premier resource for building code knowledge.

    This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.

    Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.

    Ready to upgrade? Log in and upgrade now.

flexible duct or flexible connector

BSSTG

Gold Member
Joined
Nov 30, 2009
Messages
729
Location
Seadrift, Tx.
Greetings all,

Could somebody tell me what the difference is between the 2. They are both referenced in 603 of the "06 IMC. They are obviously something different since they have different length limitations.

Byron
 
They are both listed under UL 181. You will have to check whether the product is listed as air duct or an air connector. What I have seen is the insulated flex is listed as duct, and the foil uninsulated flex is listed as an air connector (if listed at all). In either case, the product needs to be Ul 181 approved in order to be used.
 
UL181 includes about 16 tests, including corrosion resistance, mold growth and humidity, high and low temperature, puncture, impact, erosion, positive and negative pressure, and leakage, as well as flammability examinations, including surface burning characteristics, flame penetration and burning.

http://ulstandardsinfonet.ul.com/tocs/tocs.asp?doc=s&fn=0181.toc

I believe that the flexible connector doesn't have to pass as many of these tests, and it is limited to 14 ft. length.
 
Back
Top