Multi Leaf Volume Control Damper

Multi leaf volume control dampers (VCDs) are the standard way to balance and regulate airflow in ducted heating, ventilation and air conditioning systems. Multiple opposed-action blades give accurate, progressive control from fully open to fully closed, letting commissioning engineers set each branch of a system to exactly the right air volume. This range covers made-to-measure rectangular VCDs, heavy duty VCDs for high-velocity systems, and fixed-size circular multi leaf dampers to suit standard duct diameters from 100mm to 1000mm — stocked in ten popular diameters — 100, 125, 150, 200, 250, 315, 355, 400, 450 and 500mm — for next-day despatch; other diameters (including 160mm, 180mm and 224mm) and all rectangular units are made to measure.

Made-to-Measure Volume Control Dampers

Our core rectangular VCD is made to order to your exact width × height in 1mm increments, from 100mm up to 1000mm, with the price calculated instantly on the product page. It features 50mm roll-formed steel blades with opposed blade action, nylon spindles, and a drive linkage mounted out of the airflow to minimise turbulence and noise. Construction is DW144 compliant, with case leakage designed to Classes A, B and C to DW144 2016, Eurovent 2/2 and BS EN 1751, for duct pressures up to 1000Pa. Choose a Flangefit (65mm deep, 30mm flanges) or Spigotfit (85mm fully welded) casing, in galvanised or 430-grade stainless steel, with your preferred control: lockable hand quadrant, extended spindle for motorisation by others, or a factory-fitted 24V or 230V actuator.

Heavy Duty VCDs for High Velocity Systems

For larger ducts and higher duties, the heavy duty VCD uses aerodynamic 100mm airfoil blades and a fully enclosed drive mechanism, rated for velocities up to 20 m/s and duct pressures up to 2000Pa. It is made to measure in sizes up to 2400mm × 2000mm, DW144 compliant with Class A–C case leakage, and offers the same Flangefit/Spigotfit, galvanised/stainless and hand-quadrant/spindle/actuator options — with on-site conversion between manual and motorised control.

Need a simple shut-off instead? See blast gate dampers or single blade dampers. For fire-rated applications, always use a certified fire damper or fire & smoke damper. Made-to-order lead times are shown per product; free UK mainland delivery over £400 ex VAT.