Linear Slot Diffusers

Linear slot diffusers — the narrow-slot ceiling and high-wall outlets that turn supply air into a discreet architectural line. Available from 1 slot up to 8 slots wide, made to the length your design calls for, in standard or plaster-in frames, with a matching configurable plenum box to connect the ductwork behind the finished surface.

One to eight slots, made to length

Slot count sets both capacity and visual weight: a single-slot diffuser draws a fine line across a ceiling, while multi-slot versions move serious air along atriums, meeting rooms and open-plan spaces. Every diffuser — 1, 2, 3, 4, 5, 6, 7 or 8 slots — is manufactured to your specified length, so continuous runs and precise bay-by-bay layouts are straightforward. Choose the standard frame for conventional mounting, or the plaster-in frame that beds into the plasterboard for a shadow-gap finish with no visible surround.

The Linear Slot Box

Behind the diffuser goes the Linear Slot Box — our configurable plenum, sized online to match your diffuser’s slot count and length, with spigot options for connecting round ductwork. Configure it on the product page and the drawing updates live as you type; it can even match itself to a slot diffuser already in your basket so the pairing is right first time.

Every diffuser is made to order, with the lead time shown on the product page before you buy, and UK mainland delivery is free on orders over £400 ex VAT. For linear outlets in walls, sills and joinery, see our made-to-measure linear bar grilles.