Section 322.43. Duct and plenum sealing.

 

(1)  Duct systems with joints not located entirely within the conditioned space or with joints located on the unconditioned side of stud bays, joist cavities and similar spaces, shall be sealed in accordance with this section.

(2)  Sealing shall be accomplished using welds, gaskets, mastics, mastic-plus-embedded-fabric systems or tapes installed in accordance with the manufacturer's instructions.

(3)  Insulation that provides a continuous air barrier may be used in lieu of sealing metal ducts.

(4)  Tapes and mastics used with rigid fibrous glass ducts shall be listed and labeled as complying with UL 181A.

(5)  Tapes and mastics used with flexible air ducts shall be listed and labeled as complying with UL 181B.

(6)  Tapes with rubber-based adhesives may not be used.

(7)  Except where exempted as indicated in sub. (8) , duct tightness shall be verified by either of the following:

(a) Postconstruction test: Leakage to outdoors shall be less than or equal to 8 cfm per 100 ft 2 of conditioned floor area or a total leakage less than or equal to 12 cfm per 100 ft 2 of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the entire system, including the manufacturer's air handler enclosure. All register boots shall be taped or otherwise sealed during the test.

(b) Rough-in test: Total leakage shall be less than or equal to 6 cfm per 100 ft 2 of conditioned floor area when tested at a pressure differential of 0.1 inches w.c. (25 Pa) across the roughed in system, including the manufacturer's air handler enclosure. All register boots shall be taped or otherwise sealed during the test. If the air handler is not installed at the time of the test, total leakage shall be less than or equal to 4 cfm per 100 ft 2 of conditioned floor area.

(8)  A duct tightness test is not required if the air handler and all ducts are located within conditioned space.

CR 08-043 : cr. Register March 2009 No. 639 , eff. 4-1-09; CR 15-041 : cr. (7), (8) Register December 2015 No. 720 , eff. 1-1-16; numbering correction in (7) made under s. 13.92 (4) (b) 1. , Stats., and correction in (7) (intro.), (b) made under s. 35.17 , Stats., Register December 720 , eff. 1-1-16.

Note

Standard duct tape or "duck tape" has a rubber-based adhesive and does not comply with the requirements of this section. Microsoft Windows NT 6.1.7601 Service Pack 1