Thermaflex 53814000002 Flex-vent Insulated Flex Duct 14in X 25ft R-6

Product Description

The THERMAFLEX 53814000002 is a 14-inch diameter, 25-foot section of KM Flex-Vent insulated flexible air duct rated at R-6. The inner core is a smooth, airtight polyester film laminated over a heavy-gauge, corrosion-resistant steel wire helix. This construction supports a thick blanket of fiberglass insulation wrapped around the inner core, then enclosed by a bi-directional reinforced metallized outer vapor barrier that resists unraveling. The assembly is engineered for low- to medium-pressure HVAC distribution systems. Licensed HVAC technicians and sheet metal contractors install this product in residential and light commercial forced-air systems.

This flexible duct is suited for supply and return air distribution in residential and light commercial HVAC installations. The 14-inch inner diameter accommodates high-volume trunk runs and large branch connections off main plenums or wye fittings. It performs across a temperature range of -20 degrees F to 250 degrees F, making it appropriate for both heating and cooling applications. Maximum rated velocity is 5,000 FPM, supporting high-flow system designs without exceeding the structural limits of the inner core.

Key Features

• R-6 fiberglass insulation blanket reduces heat gain and loss along duct runs
• Smooth airtight polyester inner core minimizes airflow resistance in low- to medium-pressure systems
• Corrosion-resistant steel wire helix innercore maintains shape and resists collapse under negative pressure
• Bi-directional reinforced metallized outer vapor barrier prevents moisture intrusion and does not unravel
• Rated to 5,000 FPM air velocity for high-volume distribution runs
• Wide temperature range of -20 degrees F to 250 degrees F supports heating and cooling duty

Compatibility

Designed as an OEM-style flexible duct section for residential and light commercial forced-air HVAC distribution systems requiring a 14-inch inner diameter connection with R-6 insulation performance.

Installation Notes

Installation should be performed by a licensed HVAC technician or sheet metal contractor in accordance with SMACNA flexible duct installation standards and applicable local mechanical codes. Power down and lock out the air handler or furnace before connecting or repositioning duct sections. Secure both ends with approved draw bands and mastic or UL 181B-listed tape — do not use standard cloth duct tape. Avoid sharp bends and excessive compression of the duct body, as either condition significantly reduces effective airflow and insulation performance.