CHANTILLY, Va. - The Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA) has announced that member company Walsh Mechanical Contractors, Abington, Mass., is the first to receive the Underwriters Laboratories (UL) third-party certification for the listing and labeling of sheet metal air duct under its new product category Sheet Metal Air Ducts.

Walsh principals, father and son, Paul LeBel Sr. and Jr., committed to participate in a pilot project under a partnership between the SMACNA Testing and Research Institute Inc. (STRI) and Underwriters Laboratories to work through the details of the new certification program.

The first step in the UL certification process for the sheet metal air duct contractor is to have its duct construction shop standards verified as compliant with the SMACNA “HVAC Duct Construction Standards-Metal and Flexible.” This ANSI-accredited standard is widely recognized throughout the nation’s model codes as the governing requirement for construction and installation of sheet metal ducts.

Next, the prospective sheet metal air duct contractor must develop a Quality Control Manual that documents the entire production process through clearly delineated steps and verifications. This documentation ranges from the conformance testing of the incoming raw materials to the finished product that is ultimately loaded for transport to the job site. While it is recognized that each contractor has unique practices and procedures, STRI offers assistance in providing a Quality Control manual template for this purpose.

At this point, contractors are ready to make their submittal to UL. Counterchecks are made relative to the validity of verified shop standards and documentation is prepared. Finally, UL field inspectors visit the contractor’s shop. Following UL compliance procedures and the duct contractor’s Quality Control Manual, the UL representative performs an audit to verify that the prospective contractor has a compliant process and product. If all the steps have been included and the verification forms are in place to ascertain that the sheet metal air duct is manufactured according to the STRI/UL Verified Shop Standards, UL authorizes the use of UL labels on each section of compliant duct manufactured. Under this program, these shop audits reoccur every six months.

According to SMACNA, the UL certification program offers the building industry a number of benefits:

• Assures that the fabrication of inferior duct systems does not occur.

• Provides a higher degree of confidence to the engineering/architectural community via an independent third party that duct is constructed to the industry standard.

• Provides a continuing education process for participating firms.

• Gives insight into the intricacies and flexibility inherent in SMACNA’s duct construction standards that ensure an efficient low leakage air distribution system is constructed.

• Provides a means for authorities having jurisdiction, engineers, and specifiers to identify sheet metal duct that is compliant with code.

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Publication date:06/22/2009