Ceiling cassette air conditioning

The body of the unit sits hidden in the ceiling void, with only a flush grille visible from below. It draws air in through the centre of the grille and blows conditioned air out through vents on (typically) all four sides, giving an even spread across the room — which is why cassettes suit larger and open-plan spaces. It’s the same refrigerant split system as the other types; only the indoor unit’s location and shape differ. See how air conditioning works.

Pros: very discreet — nothing on the walls, just a ceiling grille; even, multi-directional air distribution well suited to bigger rooms; frees up wall and floor space; available from domestic capacities up to light commercial.

Cons: needs a suitable ceiling void, so it isn’t an option in every room; installation is more involved — and usually more expensive — than wall or floor units; harder to retrofit into a solid-ceiling room without building work.

Ideal for offices, shops, open-plan or larger rooms, and homes with a suspended ceiling or enough void above. Not suitable where there’s no ceiling void and one can’t be created — in which case a wall-mounted or ducted system may fit better.

Cassettes cover a wide range, roughly 3.5–14 kW (≈ 12,000–48,000 BTU), from a large domestic room to a sizeable commercial space. Larger rooms often use one well-placed cassette rather than several wall units. Size to the space — see how to size a system for homes, or commercial heat-load for business premises.

Higher than wall or floor units, both for the equipment and the more involved ceiling installation — so for a single room, above the £1,500–£3,000 wall-mounted range (a 2026 guide price), and more again at the larger sizes used in offices and shops. See the full home cost guide for the home price bands.