Mueller Streamline 180686 Flex Duct 12 Inch R-4.2 25 Foot

Product Description

The MUELLER STREAMLINE 180686 is a 12-inch diameter commercial flexible air distribution duct rated R-4.2, designed for supply and return air runs in commercial HVAC systems. The construction features a metalized outer jacket paired with an insulated inner core, providing vapor resistance and moderate thermal performance suited to commercial installation environments. At 25 feet per unit, this flex duct supports efficient routing through confined spaces and mechanical rooms where rigid ductwork is impractical. Licensed HVAC technicians and sheet metal contractors are the primary installers of this product type.

This flex duct is sized for commercial air distribution applications where a 12-inch diameter is required to move adequate airflow through supply and return trunk branches or extended runs. The R-4.2 insulation value meets moderate thermal requirements common in light commercial and larger commercial systems. The 25-foot length reduces the number of connections needed on longer runs, lowering labor time and potential leak points in the duct system. It is well suited for above-ceiling, plenum, and mechanical room routing in commercial construction and retrofit projects.

Key Features

• 12-inch inner diameter supports high-volume commercial supply and return airflow
• R-4.2 insulation rating provides moderate thermal and condensation resistance
• Metalized outer jacket delivers vapor resistance and added durability
• 25-foot length minimizes connection points and reduces installation labor
• Flexible construction allows routing around obstructions without rigid fittings

Compatibility

Designed as an OEM-style replacement and new-installation flex duct for commercial HVAC air distribution systems requiring a 12-inch diameter flexible duct with R-4.2 insulation and a metalized jacket.

Installation Notes

Installation should be performed by a licensed HVAC technician or qualified sheet metal contractor in accordance with SMACNA guidelines and applicable local mechanical codes. Disconnect and lock out the air handling unit before connecting or repositioning any duct sections. Support the flex duct at intervals specified by the applicable mechanical code to prevent sagging, which reduces airflow and increases static pressure. Avoid sharp bends or compression of the duct, as either condition significantly degrades system performance.

Technical Specifications

• Diameter: 12 inches
• Insulation R-Value: R-4.2
• Length: 25 feet
• Jacket Type: Metalized

Standard Information

• Brand: MUELLER STREAMLINE
• Manufacturer Part Number: 180686