Ducted air conditioning

Ducted air conditioning hides the hardware. A single indoor fan-coil unit sits out of sight in a loft, bulkhead or ceiling void, and delivers cooled or heated air through concealed ducts to slim grilles in each room. One outdoor condenser serves the system. In the room, only the grilles are visible, which is why ducted is the choice for new builds, major renovations and design-led homes where a wall unit would spoil the look.

That invisibility comes at a price: ducted is the most expensive and most disruptive residential system to install, and it is far easier to fit while ceilings are open than to retrofit later. Current residential units from Daikin, Mitsubishi Electric, Fujitsu and Toshiba run on R32 and are reverse-cycle, so they heat as well as cool, and they are genuinely quiet because airflow is spread across several grilles.

Space and access. A concealed unit needs a void deep enough to hide it (around 240mm or more) and a serviceable location, such as a loft or an access panel, so filters stay reachable. Short, straight duct runs keep it quiet; poorly sized ducts cause air-rush noise.

Zoning. Motorised dampers and room thermostats let the system condition only the rooms in use, at different temperatures. Zoning unused rooms off is the main way to keep whole-home running costs down.

Cost and timing. Budget from about £6,000 to £15,000 or more for a whole home, with smaller single-zone work starting lower. Cost is driven by the number of rooms and grilles, duct complexity, whether ceilings are already open, and region (London and the South East add roughly 20 to 30%). A ducted install typically takes three to seven days against about a day for a single split, so the ideal time to fit it is during building work. For a finished home, a multi-split or wall-mounted split is usually simpler and cheaper.

Prices and running costs correct as of July 2026. The energy price cap changes quarterly, so check current rates before budgeting.