Round duct reducer airRoxy 100/125 mm, model 02-496

Round duct reducer airRoxy 100/125 mm, model 02-496, is a metal fitting designed to adapt a 125 mm circular ventilation duct to a 100 mm duct. Intended for use in mechanical and natural ventilation systems, the reducer maintains airflow continuity when transitioning between different duct diameters. It is suitable for new installations, repairs and retrofits in residential and light commercial HVAC applications.

Advantages

The reducer provides a compact and durable connection between ducts of different diameters, ensuring minimal air leakage when properly fitted. Made of metal, it offers stable geometry and resistance to deformation under normal HVAC installation conditions. Its simple round-to-round design facilitates straightforward assembly with common duct clamps or sealants and helps preserve airflow characteristics across the transition.

Suitable for

• Residential ventilation systems where duct diameter changes are required
• Light commercial HVAC installations and ductwork retrofits
• Repairing or replacing sections of round ducting
• Connecting exhaust fans or appliances with differing outlet sizes

Key specifications

• Input diameter: 125 mm (round)
• Output diameter: 100 mm (round)
• Material: metal construction suitable for ventilation use
• Shape: straight concentric reducer for round ducts
• Application: interior HVAC duct transitions and repairs

How to use

Position the larger end of the reducer onto the 125 mm duct and the smaller end onto the 100 mm duct, ensuring a concentric fit. Secure both connections using appropriate duct clamps, spiral duct tape or an approved sealant to minimize air leakage. Ensure the reducer is installed in the correct airflow direction if system layout requires; avoid sharp bends immediately adjacent to the fitting to preserve airflow efficiency. After installation, check for leaks and mechanical stability, and make adjustments to clamps or sealing as needed.

Usage recommendations

For reliable performance, use corrosion-resistant clamps and HVAC-rated sealants, and install the reducer in accessible locations to allow periodic inspection. Match the reducer with compatible round duct profiles and avoid using the fitting in systems where rigid requirements for acoustic attenuation or specialized coatings are necessary.