Furnish and install Johnson Controls VD-1250 low leakage all aluminum volume control dampers.
Frames are constructed of formed extruded aluminum with linkage concealed in the side channel to eliminate noise and friction. Compressible spring stainless steel side seals and self-lubricating bearings are also be provided.
Blades are constructed with extruded aluminum in airfoil shape. Damper blade width must not exceed 6 in. and includes seals. Blade pins are 1/2 in. plated steel hex. Blade operation is to be parallel or opposed as shown on the schedules.
Performance is designed for tight shutoff and tested in accordance with AMCA Standard 500. Leakage for a damper with seals must not exceed 3 cfm per square foot at a 1 in. w.g. The damper must be rated to operate over a temperature range of -72°F to 275°F (-58°C to 135°C).
Sizing is determined by the designer in accordance with accepted industry practices to ensure proper system performance. Blank off-plates and duct-to-damper transitions may be required.