Lambro Industries 251 Aluminum Vent Decreaser 4x3 in

Product Description

The LAMBRO INDUSTRIES 251 is an aluminum vent decreaser designed to transition dryer or exhaust vent ducting from a 4-inch diameter to a 3-inch diameter connection. This fitting is used when duct runs require a reduction in size between sections, allowing installers to adapt vent lines to equipment outlets, wall caps, or termination points that differ in diameter. Fabricated from aluminum, the 251 offers corrosion resistance and durability in both interior and exterior vent applications. HVAC technicians and appliance installers handle this type of fitting as a standard part of duct fabrication and layout work.

This decreaser is suited for residential and light commercial ventilation installations where a 4-inch to 3-inch duct transition is required. Typical applications include dryer exhaust venting, bathroom exhaust fans, and range hood duct runs where the outlet or termination fitting does not match the primary duct diameter. The fitting is sold individually as a single unit.

Key Features

• Reduces duct diameter from 4 inches to 3 inches in a single fitting
• Aluminum construction resists corrosion in exhaust and ventilation applications
• Compact, lightweight design at 1.2 pounds for easy handling during installation
• Suitable for dryer exhaust, bath fan, and range hood vent runs

Compatibility

Designed as a standard duct transition fitting for residential and light commercial ventilation systems requiring a 4-inch to 3-inch diameter reduction.

Installation Notes

This fitting is typically installed by HVAC technicians or appliance installers as part of a dryer or exhaust vent duct assembly. Disconnect power to any associated appliance before beginning duct work. Secure the decreaser to adjoining duct sections using approved foil tape or sheet metal screws as required by local mechanical codes. Avoid using this fitting in applications where a diameter reduction would restrict airflow below the minimum required by the connected appliance manufacturer.

Technical Specifications

• Inlet Diameter: 4 inches
• Outlet Diameter: 3 inches
• Material: Aluminum
• Weight: 1.2 pounds
• Unit of Measure: Each
• Package Quantity: 12

Standard Information

• Brand: LAMBRO INDUSTRIES
• Manufacturer Part Number: 251