Duct Liner Performance Starts with People

A manufacturer executive is writing about duct liner, the insulation lining inside the sheet metal air ducts that carry heated and cooled air through a building. His point is that this material affects more than just comfort once it's installed. It helps absorb noise from HVAC equipment and reduce sound traveling between rooms through the vents, and it helps keep air at the right temperature as it moves through ducts while reducing condensation.

For homeowners, the practical takeaway is about what goes into that insulation. Knauf's version, called Performance+ Duct Liner, uses a bio-based binder instead of the phenol-formaldehyde binders common in older fiberglass insulation, and is certified formaldehyde-free. It's also made with at least 50% recycled glass. The product has third-party certifications like GREENGUARD and GREENGUARD Gold, Verified Healthier Air, and Asthma & Allergy Friendly, which speak to indoor air quality and material safety rather than just thermal performance.

None of this requires immediate action on your part, but if you're ever replacing ductwork or having HVAC work done, it's worth knowing that duct liner materials vary in composition, not just in how well they muffle sound or hold temperature. Asking what liner material is being used, and whether it carries formaldehyde-free or indoor air quality certifications, is a reasonable question if indoor air quality matters to you.