Johns Manville Duct Insulation — 1-1/2 in x 24 in x 48 in Fiberglass Board

Product highlights

Meet the Johns Manville Duct Insulation, a fiberglass board designed to fit standard ductwork with a clean, silver finish. At 1-1/2 inches thick and 24 inches wide, this 4-foot panel is sized for straightforward cutting and installation in many HVAC runs.

Its 3 lb density and a practical R-value around 6.5 provide a reliable thermal barrier that helps reduce heat exchange during both heating and cooling seasons. The jacket is a Foil Scrim Kraft layer that shields the edges and contributes moisture management in typical duct environments. The faced and unfaced sides offer installation options depending on your duct configuration.

Key features at a glance

• Fiberglass insulation board with 1-1/2" thickness and 24" width (4 ft length).
• Density around 3 lbs per cubic foot, with a sturdy, lightweight profile.
• Approximate R-value of 6.5 for standard duct applications.
• Jacket: Foil Scrim Kraft, finished in a silver color for a clean, professional look.
• Wide temperature tolerance from -32°F to 450°F on the unfaced side; -32°F to 150°F on the faced side.

Practical uses and benefits

• Versatile for a range of blower and return duct configurations in residential or light commercial settings.
• Easy to cut and fit into existing duct runs, helping streamline installation projects.
• Durable outer jacket helps resist minor damage during handling in typical job sites.
• Standard-compliant with a broad set of industry specifications for safer, consistent performance.

Note: This product is suitable for board-style duct installations and is designed to meet common industry standards. For best results, match the thickness, width, and length to your duct dimensions and follow local codes and best practices.

Quality and compliance

Manufactured to meet or exceed widely used standards, including ASTM C612 and related Type I and III classifications, as well as fire and safety benchmarks.