CLASS 0 Uninsulated Flexible Duct and Method Of Use
An uninsulated flexible duct includes a core made of a polymer material and including a helical wire as a part thereof, the polymer material core having inner and outer surfaces and including a first adhesive. The duct also includes a fire resistant barrier material surrounding the outer surface of the polymer material core, the fire resistant barrier material including a seam running longitudinally along the length of the uninsulated flexible duct, the longitudinal seam having an overlap zone that contains at least one second adhesive to maintain an integrity of the longitudinal seam. The uninsulated flexible duct is one that is free of any vapor barrier and has a flame spread index and smoke developed index of zero (0) as defined in the UL 181 standard. Component parts of the duct are controlled in terms of composition, amount, and/or configuration to achieve the Class 0 rating.
1 . An uninsulated flexible duct comprising:
a core made of a polymer material and including a helical wire as a part thereof, the polymer material core having inner and outer surfaces and including a first adhesive;
a fire resistant barrier material surrounding the outer surface of the polymer material core, the fire resistant barrier material including a seam running longitudinally along the length of the uninsulated flexible duct, the longitudinal seam having an overlap zone that contains at least one second adhesive to maintain an integrity of the longitudinal seam,
the uninsulated flexible duct being free of any vapor barrier;
the uninsulated flexible duct being a vapor barrier-free uninsulated flexible duct that has a flame spread index and smoke developed index of zero (0) as defined in the UL 181 standard and having one or more of the following features:
a) if the fire resistant barrier material is a woven material, the weave of the woven material is such that the uninsulated flexible duct meets the flame spread index and smoke developed index of zero (0);
b) using an effective amount of the polymer material in the core so that the uninsulated flexible duct meets the flame spread index and smoke developed index of zero (0);
c) including an effective amount of a fire retardant in the polymer material so that the uninsulated flexible duct meets the flame spread index and smoke developed index of zero (0);
d) wherein the polymer material core is a fire retardant containing-film so that the uninsulated flexible duct meets the flame spread index and smoke developed index of zero (0);
e) the first adhesive includes a fire retardant in an effective amount so that the uninsulated flexible duct meets the flame spread index and smoke developed index of zero (0); and
f) the second adhesive includes a fire retardant in an effective amount so that the uninsulated flexible duct meets the flame spread index and smoke developed index of zero (0).
2 . The duct of claim 1 , wherein the fire retardant is a non-halogenated type or a halogenated type.
3 . The duct of claim 2 , wherein the fire retardant is a non-halogenated type.
4 . The duct of claim 1 , wherein the fire retardant is selected from the group consisting of a molybdenum-based flame retardant, a zinc-based fire retardant, aluminum trihydrate (ATH)—with antimony trioxide, aluminum hydroxide, and a phosphorous-containing fire retardant.
5 . The duct of claim 1 , including the fire retardant containing film as the polymer material core.
6 . The duct of claim 1 , wherein the polymer material core includes a pair of films with the helical wire disposed therebetween the gauge of the films being 0.0004 inches or less.
7 . The duct of claim 1 , wherein the polymer material core includes a single film the gauge of the single film being 0.0004 inches or less.
8 . The duct of claim 1 , wherein the polymer material core is a spirally wound core and an extent of overlap in a spiral winding of the core is such that the uninsulated flexible duct meets the flame spread index and smoke developed index of zero (0).
9 . The duct of claim 1 , wherein the polymer material core is a spirally wound core and a pitch of the helical wire is controlled to minimize overlap along a length of the uninsulated flexible duct so that the uninsulated flexible duct meets the flame spread index and smoke developed index of zero (0).
10 . The duct of claim 1 , wherein the vapor barrier free and fire resistant barrier material-containing duct includes one or both of the fire retardant-containing first and second adhesives.
11 . In a method of supplying conditioned or unconditioned air to a space using a flexible insulated duct, the improvement comprising using the flexible uninsulated duct of claim 1 for said supplying.