How much does air conditioning cost in the UK?
The short version: a professionally installed single-room split system usually lands between £1,500 and £3,500 fully fitted. Multi-room systems run £3,500–£6,000+, whole-home ducted systems start around £5,000 and can pass £10,000, and a decent portable unit — the only option that needs no installation — costs £300–£600 off the shelf.
Installed prices by system type
| System | Typical installed price | Best for |
|---|---|---|
| Portable unit | £300–£600 (no install) | Renters, occasional use, one small room |
| Single split (1 room) | £1,500–£3,500 | Bedrooms, home offices, living rooms |
| Multi-split (2–4 rooms) | £3,500–£6,000+ | Cooling several rooms off one outdoor unit |
| Ducted (whole home) | £5,000–£10,000+ | New builds, renovations, invisible finish |
Each additional room on a multi-split typically adds roughly £700–£1,500, depending on pipe runs and access — though the per-room rate falls when everything is installed in one visit.
What's actually in the quote
A standard single-split installation should include the indoor and outdoor units, mounting brackets, refrigerant pipework and electrical connection, commissioning, and waste removal. Things that push the price up:
- Long pipe runs between indoor and outdoor units, or awkward access (high walls, scaffolding).
- Electrical work — AC needs a dedicated circuit, so a full consumer unit upgrade adds cost if yours has no spare capacity.
- Older or solid-wall properties where drilling and routing take longer.
- Season — summer installs can cost 10–20% more than the same job in winter or spring, and lead times stretch. If you can plan ahead, book in the colder months.
- Region — London and the South East price higher than the national average.
Rule of thumb for judging a quote: get at least three, make sure each itemises the unit model, pipework allowance and electrical work, and confirm the installer is F-Gas certified (legally required) with public liability insurance. A free pre-quote home survey is a good sign.
Running costs per hour
At current electricity prices (the July 2026 price cap puts electricity around 26p/kWh), typical costs look like this:
| System | Typical running cost |
|---|---|
| Modern inverter split (3.5 kW) | ~10–50p per hour — a typical unit draws about 1 kW, so ~26p/hr |
| Portable (8,000–9,000 BTU) | ~25–35p per hour |
| Multi-split, two rooms running | ~50–80p per hour |
Inverter models adjust their output to hold temperature rather than switching on and off, which can cut consumption by 30–40% versus non-inverter units. Splits also beat portables on efficiency because the heat-rejecting half of the machine sits outside your room instead of inside it.
The winter bonus most people miss
Nearly all modern split systems are reversible air-to-air heat pumps. The same unit that cools in July heats in January — and heating one room this way is usually cheaper than plug-in electric heaters. If you work from home, that can materially change the payback maths on a £2,000 install.
Ongoing costs
Budget £70–£120 per unit for an annual service. A well-maintained split system lasts 10–15 years; portables more like 5–10.
Ready for real numbers? Prices vary too much by property for any guide to be exact. Get up to three free quotes from F-Gas certified installers — or work out what size you need first.