AC Infinity 4-Inch Flexible Rubber Noise-Reduction Duct Coupler

The AC Infinity AC-RCA4 is a heavy-duty rubber coupling designed to connect inline fans, carbon filters, silencers and rigid duct ports. Made from durable Nitrile Butadiene Rubber (NBR Grade 65A) with a matte black finish, it slips over solid duct flanges to absorb motor vibration, reduce sound transfer and help maintain efficient airflow in HVAC and indoor cultivation setups.

Two stainless steel worm-drive clamps sit in moulded exterior channels to provide a uniform, non-slip grip under continuous fan vibration. An internal centre lip keeps metal duct ports separated, helping to prevent metal-to-metal rattling and high-frequency turbulence noise.

Key Features

• Vibration and acoustic isolation: Thick NBR rubber helps dampen motor vibration and fan noise before it travels along rigid ducting.
• Airtight rubber seal: The flexible collar conforms around duct ports to help prevent odour bypass, pressure loss and air leaks.
• Internal separator lip: Keeps metal fan flanges and carbon-filter collars apart to reduce vibration transfer.
• Moulded clamp channels: Hold the two stainless steel worm-drive clamps securely in place.
• Tool-free slip-on connection: Fits over metal flanges, carbon-filter necks and inline fan ports for straightforward installation.
• Universal 4-inch fit: Designed for 4-inch inline fans, carbon filters, dampers and silencers.

Technical Specifications

Real-World Applications

• Indoor cultivation ventilation: Couples a 4-inch inline exhaust fan, such as a CLOUDLINE S4 or T4, to a 4-inch carbon filter without additional flexible ducting.
• Acoustic silencer and fan isolation: Mounts between exhaust fans and duct silencers to help reduce vibration transfer.
• Residential HVAC and workshop venting: Connects rigid metal ducting, range-hood spigots and bathroom exhaust ports while helping suppress motor hum.