Aluminium Double Deflection Grille -

Double Deflection Grille


  • Excellent all-purpose supply air grille
  • Air throw adjustable in both horizontal and vertical planes
  • Suitable for wall, ceiling or duct mounting
  • Extruded aluminium construction
  • Optional rear damper can be added to control air volumes
  • 70% Free Area (Approx)
  • 32mm flat frame with countersunk screw holes

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All prices include VAT (where applicable)

Product Overview

Double Deflection Grilles have two sets of individually adjustable blades – a front set of horizontal blades and a second set of vertical blades set at 90 degrees to each other.

Gaps between the blades are sufficient to allow easy adjustment of blades, enabling the user to create custom blow patterns. Whether these be targeted towards one area, or fanned out to affect a wider area is entirely your choice.

As noise generation and pressure drops are slightly higher than with a single deflection grille, the double deflection grille is better suited to supply air applications.

All square sizes from 150sq – 550sq rising in 50mm increments are held in stock. Standard stocked grilles are powder coated to RAL 9010 (Pure White). Rectangular grilles and anodized finishes are made-to-order, usually within 5 working days.

Opposed blade dampers can be factory fitted to your double deflection grille. Adjustable through the grille blades with a screwdriver, opposed blade dampers allow easy volume control.

The Double Deflection Grille can also be made-to-order in sizes other than the standard sizes listed.

The smallest dimensions available are: 100mm x 100mm (W x H).

The largest dimensions available are: 2900mm x 2900mm (W x H).

For blade lengths above 570mm mullions will be used.


Double Deflection grilles are better suited for use as supply air outlets in a variety of settings including ceilings, walls and ducts.

Having a second row of blades reduces the free area by around 10%, therefore we do not recommend using a DD for extract purposes.


Fabricated entirely from extruded aluminium. Two rows of adjustable blades set within a frame. Blades held in place with high tensile spring wire and starlock washers.

For overall size including flange, add 48mm to width and height.

CVDDG - Sizing

In order to calculate the exact overall face dimensions of the grille +48m must be added to the nominal dimensions.

Nominal Dimensions = Opening Size.

This is the number shown in the part codes e.g. CVDD-150

For example:

CVDDG-150: The nominal opening size is 150mm x 150mm. The overall size including frame is 198mm x 198mm.

Actual Neck Size: For clearance within the aperture a standard tolerance of 5mm (2.5mm each side) is deducted from the nominal opening size for grilles sizes 150mm sq - 550mm sq (above 550mm sq the tolerance increases to -15mm)

For example:

CVDDG-150: The nominal opening size is 150mm x 150mm. The actual neck size is 145mm x 145mm.


Standard finish for this product is PPC RAL9010 Pure white

Double Deflection Grilles are also available in:

Satin Anodised

BS/RAL powder coated colours - please call for pricing.


Galvanised Steel Plenum Boxes complete with circular spigot to suit spiral ducting or flexible duct.

Rear control damper can be added to regulate volumes.

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