The core difference
A split system has a visible wall-mounted indoor unit in each room it serves. A ducted system has a concealed unit — typically in a loft or ceiling void — that distributes conditioned air through a network of ducts to vents in each room. Ducted systems are essentially invisible once installed; split systems have a visible unit on the wall.
Ducted air conditioning
Ducted systems are the preferred choice for new builds, full refurbishments or any property where maintaining an uncluttered interior aesthetic is a priority. The entire system is hidden, typically in a loft or ceiling space, with only the supply and return air grilles visible in each room.
Pros: Completely hidden, single outdoor unit, consistent temperature throughout the property, high-end appearance.
Cons: Higher installation cost, requires ceiling or loft space for the air handler and duct runs, more disruptive to install in an existing property.
Split system air conditioning
Split systems are the most widely installed type in the UK. They are faster and cheaper to install than ducted systems — typically a few hours per unit — and do not require void space or duct runs. Each room has its own indoor unit with independent controls.
Pros: Lower cost, faster to install, independent room-by-room control, easy to add units later, wide range of capacities and styles.
Cons: Visible indoor unit on the wall, multiple outdoor units for multi-room systems (unless multi-split).
Cost comparison
| System | Typical installed cost (3 rooms) |
|---|---|
| 3 × single split systems | £4,500 – £8,000 |
| 1 × multi-split (3 indoor units) | £4,000 – £7,500 |
| Ducted system (3–4 rooms) | £7,000 – £15,000+ |
Which should you choose?
For most UK homeowners, a split or multi-split system is the practical choice — lower cost, quicker installation, no structural work required. Ducted systems are worth the extra investment if you are building new, undertaking a full renovation, or if a visible wall unit would be unacceptable in the space.
Get quotes for both options
The best way to compare is to have an engineer survey your property and quote for the options that suit your building. Get free quotes from vetted local air conditioning engineers here.