The fourth edition of SMACNA’s flagship “HVAC Duct Construction Standards-Metal & Flexible” is now available for 45-day public review.
Continuing to build on the history of the duct construction standards, this new edition represents the state-of-the-art in sheet metal duct fabrication and installation. Comments must be received by Nov. 9, 2017 at 5 p.m. (EST).
Significant changes from the third edition include:
- Tables for spiral flat oval duct for positive and negative pressure applications
- Options for internal supports for flat oval duct
- Information on spray and aerosolized duct sealants
- Updated liner requirements to include non-fiberglass liner types
- Added information for lined round duct
- Added details for hangers to better illustrate where hangers are required
- Updated requirements for flex duct hanger spacing and hanger width
- Additional information for spiral fittings.
To provide input, visit the Papers and Guidelines section on SMACNA’s Technical Resources webpage, www.smacna.org/technical.