8" x 25' Silver Jacket Flex Duct, R4.2

Product Overview

The JP Lamborn MHP25B-08 Flexible Air Duct is an R-4.2 insulated duct assembly engineered for residential and light commercial HVAC applications. Constructed with a reinforced inner core, fiberglass insulation, and a durable silver vapor-barrier jacket, this duct provides efficient airflow with dependable thermal and acoustic performance. It is suitable for both supply and return air systems and is designed to meet mechanical and energy code requirements for flexible air distribution systems.

Technical Specifications

• Model: MHP25B-08
• Manufacturer: JP Lamborn (Hart & Cooley)
• Series: Residential
• Product Type: Insulated Flexible Air Duct
• Inside Diameter: 8 inches
• Length: 25 feet
• Insulation Value: R-4.2
• Outer Jacket: Silver vapor-barrier jacket for moisture resistance and mechanical protection
• Air Velocity Rating: 5000 fpm (maximum)
• Temperature Range: -20°F to 140°F (-29°C to 60°C)
• Core Construction: Helically wound, wire-reinforced inner core
• Insulation Type: Fiberglass blanket insulation with polyethylene vapor barrier
• Application: Supply and return air distribution for residential and light commercial HVAC systems
• Compliance: UL 181 Class 1 Air Duct; conforms to NFPA 90A and NFPA 90B standards
• Installation: Approved for use in both conditioned and unconditioned spaces per mechanical code requirements

Professional Notes

Install in accordance with JP Lamborn and SMACNA flexible duct construction standards. Fully extend duct lengths to maintain designed airflow capacity and minimize static pressure loss. Support ducts at regular intervals to prevent sagging and insulation compression. Seal all joints and terminations using UL 181-approved tape or mastic for air-tight system performance. Avoid excessive bending, compression, or mechanical stress to preserve insulation value and maintain airflow efficiency.

Summary

The JP Lamborn MHP25B-08 Flexible Air Duct is an 8-inch diameter, 25-foot R-4.2 insulated duct with a silver vapor-barrier jacket. Rated for 5000 fpm and -20°F to 140°F operation, it provides durable, thermally efficient, and code-compliant air distribution for professional residential and light commercial HVAC installations.