Founded in Houston in 1976, Quietflex Manufacturing Co., LP makes flexible ductwork and fiberglass products, with four manufacturing facilities in Houston, Phoenix, Groveland and Pittston. The company says it began producing fiberglass in 1997 and serves HVAC-related applications as well as niche markets such as LNG tank insulation.
GREENGUARD Certified
UL Listed/Approved
HUD Standards for Outdoor Use with Mobile Homes
Compliance program
UL
Quality certification
Hranec CorpFounded by Steve Hranec in 1995, Uniontown-based Hranec Corp. combines mechanical construction services with large-scale HVAC manufacturing, including custom ductwork and roof products. Its manufacturing operation has expanded from a 2008 fabrication facility to a 40,000-square-foot roof-product shop and a 200,000-square-foot building completed in 2026. Hranec also stands apart with specialized offerings such as outdoor Tuff Duct and its patented Spiral Graphix, which turns exposed spiral ductwork into customized visual displays.UNIONTOWN, PA
Hennemuth Metal FabricatorsHennemuth Metal Fabricators is a family-owned and operated ductwork manufacturer and distributor founded in 1954 by Gordon Hennemuth. Based in Oakdale, Pennsylvania, the company fabricates custom duct and fittings for commercial and residential HVAC contractors, with in-house spiral and rectangular duct production. Its 60,000-square-foot fabrication shop opened in 2018, and the business reports more than 100 years of combined staff experience.OAKDALE, PA
Varflex CorporationFounded in Rome in 1924 by two brothers and their brother-in-law, Varflex Corporation is a century-old manufacturer whose early work helped establish fiberglass sleeving in the United States. The company grew from a small operation into a 150-plus-employee manufacturer with more than 200,000 square feet of facilities, while its Griffin family legacy continues through a policy of donating 100% of profits to charity. Varflex is ISO 9001:2015 registered.ROME, NY