The opposed blade damper is designed to clip on to the back of the grille. The maximum nominal size of one section is limited to a 450mm long x 450mm wide. Larger sizes are made up by a combination of units. If one dimension of the grille is longer than 450mm but the other one is 450mm or less, the dampers are just clipped to the grille in a line. If both the
dimensions are over 450mm, mullions are fitted to the back of the grille and the dampers clip on to the mullion. If it is necessary to fit more than one mullion, the dampers may be secured with rivets to ensure that they remain in place.
Code 0106. Opposed blade damper.
25mm increments on the nominal length from 100mm to 450mm and 12.5mm increments on the nominal height from 62.5mm to 450mm as single units. Multiple units in these increments can be made up to 1200mm x 1200mm by the use of mullions fitted to the back of a grille on diffuser.
Aluminium with die-cast aluminium alloy cam
operator, steel star lock washers and spring wire.
Mill finish aluminium.
The dampers are fixed to the back of the grille with a specially designed “Z” clip up to 450mm x 450mm nominal size of grille. If both dimensions are over 450mm, mullions are fitted to the back of the grille and the dampers clipped or rivetted to this.
Opposed blade dampers fitted to the back of a grille or
diffuser are not designed for balancing the basic ductwork system. This should be done with duct dampers in the
ductwork. The grille damper should only be used for fine tuning the required air volume at each terminal. An opposed blade damper does not start to operate effectively until it has been closed down by approximately 20%.
The noise generated by the damper will increase as it is closed beyond this point.This type of damper is not intended to provide complete shut off and consequently is not air tight when fully closed. Similarly, when they are banked together, the joints between the dampers are also not
Non standard sizes.
Any nominal length in 25mm increments and any nominal height from 100mm provided the nominal height does not exceed 450mm. If the nominal height, up to 450mm, is not an increment of 12.5mm then the product code will have a 9 as the prefix in place
of the 0.
The blades can be anodised matt black to reduce
reflectivity and to make the damper less obtrusive
from the face of the grille or diffuser. The damper
code becomes 0506 or 9506 if non standard height.
• The code for the basic product should have 13 digits.
See page 1.
• Please always give the length first and then the height.
• Add codes for alternatives/additions as suffixes.
An opposed blade damper for a 1000mm x 109mm grille with black blades would be coded