Quietflex 1440 Flexible Foil Air Duct 14 in 25 Ft R4.2

Product Description

The QUIETFLEX 1440 is a rip-stop flexible foil air duct designed for residential and light commercial HVAC distribution systems. Built with a metalized polyester vapor barrier and fiberglass insulation, it carries an R-4.2 thermal rating and handles a continuous temperature range of -20 to 180 degrees F. At 14 inches in diameter and 25 feet in length, it suits trunk-to-register runs where a single section needs to cover extended distances without joints. Licensed HVAC technicians and sheet metal installers are the primary trade for this product.

This flexible duct is suited for supply air distribution in forced-air heating and cooling systems. The 14-inch diameter accommodates higher-volume branch or main runs in residential systems and smaller commercial applications. It is rated for a maximum air velocity of 6000 feet per minute (fpm), making it compatible with higher-output air handlers and variable-speed systems where airflow demands exceed what smaller flex duct can handle. The 25-foot coil reduces the need for mid-run connections in longer duct paths.

Key Features

• R-4.2 fiberglass insulation with metalized polyester vapor barrier reduces condensation and heat loss
• Rip-stop construction improves tear resistance during handling and installation
• 14-inch diameter supports high-volume supply runs at up to 6000 fpm velocity
• Positive pressure rating of 10 inches water column (in-WC) handles demanding system pressures
• Continuous operating range of -20 to 180 degrees F with intermittent tolerance to 200 degrees F
• 25-foot length minimizes splices and reduces potential leak points in longer runs

Compatibility

Designed as an OEM-style flexible duct section for residential and light commercial forced-air HVAC systems using standard 14-inch round duct fittings, collars, and takeoffs.

Installation Notes

Installation should be performed by a licensed HVAC technician in accordance with SMACNA flexible duct installation standards and local mechanical codes. The duct must be fully extended and supported at intervals recommended by the manufacturer to prevent excessive sag, which reduces airflow and increases static pressure. Seal all connections at collars and takeoffs with listed duct mastic or UL 181B-listed tape — do not use standard cloth duct tape. Shut down the air handler and confirm zero system pressure before cutting or connecting sections.

Technical Specifications

• Diameter: 14 inches
• Length: 25 feet
• R-Value: R4.2
• Velocity Rating: 6000 fpm
• Positive Pressure Rating: 10 in-WC
• Negative Pressure Rating: 0.5 in-WC
• Temperature Rating (Continuous): -20 to 180 degrees F
• Temperature Rating (Intermittent): -20 to 200 degrees F
• Material: Metalized Polyester Vapor Barrier and Fiberglass Insulation
• Color: Silver

Standard Information

• Brand: QUIETFLEX
• Manufacturer Part Number: 1440