Double Deflection Grille

Double deflection grilles — the premium supply air grille, with two rows of individually adjustable blades (one horizontal, one vertical) giving full control over both the direction and spread of the airstream. They are the standard specification for comfort-critical supply air in offices, meeting rooms, retail and hospitality, where the outlet must deliver air into the occupied zone without draughts.

Stocked squares or made to measure

The square sizes in stock cover 9 sizes from 150mm x 150mm to 550mm x 550mm, each listed with its face size (neck plus 45mm each way). For rectangles and non-standard dimensions, the custom size double deflection grille is manufactured to your exact width and height, priced instantly on the product page — and a custom version with an integral damper is available when you want to balance airflow at the grille face rather than in the duct.

Why two rows of blades?

The front row steers air left-to-right, the rear row up-and-down. Together they let you throw supply air along a ceiling, drop it into an occupied zone, or spread it wide — and adjust the pattern after installation as the room use changes, which is why double deflection remains the default supply grille on commercial fit-outs. For simpler duties one row may do: see single deflection grilles. For extract, the eggcrate grille is usually the better fit. Mount onto a grille box to connect round ductwork to the rectangular neck. Stocked sizes despatch next day when ordered by 3pm, with free UK mainland delivery on orders over £400 ex VAT.