Ducted air conditioning

A single indoor unit is tucked into a ceiling void or loft. Rather than blowing air directly into one room, it pushes conditioned air through a network of insulated ducts to discreet grilles in each room it serves. Many ducted systems are zoned, so different areas can be set to different temperatures or switched off independently. See how air conditioning works.

One large unit, zoned with dampers (e.g. Daikin’s Easyzone). A single, powerful ducted unit — a high-static unit, meaning it can push air through a whole network of ducts — sits on one outdoor unit. This is a single system, not a multi-split. Conditioned air travels to every room, and motorised dampers in the ductwork open and close to send it to the rooms calling for it. Because it’s one unit, this is usually the simpler and more economical way to do a whole home, and a single larger unit gives plenty of capacity. The trade-off: every room shares that one unit and its single coil, so they share one mode (all heating or all cooling) and one air temperature — each room’s thermostat controls how much air it gets, rather than setting a truly independent temperature.

One unit per room, on a multi-split. Instead of one big unit, each room has its own smaller ducted unit — a medium-static unit, sized for shorter runs — all connected to a single multi-split outdoor unit. Now each room has its own coil, so control is genuinely independent room to room. The trade-offs are cost and complexity: more indoor units and more pipework make it dearer to buy and install, and — like any standard multi-split — all the units still share the same mode at once.

Which is right for you? For most whole-home installs the single zoned unit is the cost-effective default, and modern damper zoning gives good room-by-room control of airflow. The per-room approach earns its extra cost where rooms genuinely need to run independently. A good installer should walk you through both for your layout — and it’s a useful thing to raise yourself.

Pros: by far the most discreet option — no visible indoor units, just grilles; conditions multiple rooms or a whole home from one system; zoning gives room-by-room control; a clean, integrated, premium finish.

Cons: the most expensive option to buy and install; needs enough void space for the unit and ducts; much easier and cheaper to install during a build or major renovation than to retrofit into a finished home; servicing access needs planning in.

Ideal for new builds, major renovations and premium projects where a near-invisible whole-home system is the goal and there’s void space for ducts. Less suitable as a quick retrofit into a finished property, or for a single room — where a wall-mounted or ceiling cassette unit is simpler and cheaper.

Ducted systems are sized to the total area and number of rooms served, so capacities start higher (commonly from around 5 kW / 18,000 BTU) and rise well beyond that for whole homes and commercial spaces. Careful design of both the capacity and the ductwork is essential — see how to size a system or, for larger projects, commercial heat-load.

The highest of the system types — around £5,000–£15,000+ for a whole home as a 2026 guide price, reflecting the equipment, ductwork and installation involved, and notably more economical to install during construction than as a retrofit. See the full home cost guide for current prices and what moves them.