| 6.6002.1a
Duct design and configuration | Ventilation ducts will be as short, straight, and smooth as possible Ventilation ducts will not be smaller than the connections to which they are attached | Effectively move the required volume of air |
| 6.6002.1b
Duct insulation | Ducts installed outside of the thermal
envelope
Envelope
The separation between the interior and exterior environments of a building that includes a combination of air and thermal barrier
will be insulated to a minimum of R-8 or equivalent to local codes | Prevent condensation from forming or collecting inside of the ductwork |
| 6.6002.1c
Duct support | Flexible and duct board ducts and plenums will be supported every 4' using a minimum of 1 ½" wide material Support materials will be applied in a way that does not crimp ductwork or cause the interior dimensions of the ductwork to be less than specified (e.g., ceiling, framing, strapping); duct support must be installed in accordance with authority having jurisdiction Metal ducts will be supported by 1/2" or wider 18-gauge strapping or 12 gauge or thicker galvanized wire no less than 10' apart | Effectively move the required volume of air Preserve the integrity of the duct system Eliminate falling and sagging |
| 6.6002.1d
Duct connections | Round metal-to-metal or metal-to-PVC will be fastened with a minimum of three equally spaced screws Other metal-to-metal or metal-to-PVC connections will be securely fastened and sealed with welds, gaskets, mastics (adhesives), mastic- plus-embedded-fabric systems, or tapes Flexible duct-to-metal or flexible duct-to-PVC will be fastened with tie bands using a
tie band
Tie band
A strap, often made of nylon, that mechanically squeezes a flexible duct to a fitting. Must have a minimum performance temperature rating of 165° (per UL 181A-type test) and a minimum tensile strength rating of 50 pounds
tensioning tool PVC-to-PVC materials will be fastened with approved PVC cement Other specialized duct fittings will be fastened in accordance with manufacturer specifications In addition to mechanical fasteners, duct connections will be sealed with
UL
UL
Underwriters Laboratories
181B or 181B-M listed material | Effectively move the required volume of air Preserve the integrity of the duct system |
| 6.6002.1e
Duct materials | Flexible materials will be
UL
UL
Underwriters Laboratories
181 listed or Air Diffusion Council approved The metal gauge of rigid kitchen fan ducting shall meet code requirements or the approval of the authority having jurisdiction. | Effectively move the required volume of air Preserve the integrity of the duct system |
