How much does air conditioning cost to install and run?
By the A.C. Wilgar air conditioning team · Last updated October 2026
Quick answer: indicative prices for a fully installed home air conditioning system are £3,000–£4,000 for one room, £5,000–£8,000 for two rooms and £7,000–£10,000 for three rooms, with four or more rooms typically from £10,000. Running a 2.5 kW unit at full cooling output costs around 18p an hour, and less once the room reaches temperature (see our cost assumptions below). Supply and installation is currently zero-rated for VAT.
Air conditioning installation prices
These are the indicative ranges for the systems we install across Bromley, Beckenham, Orpington and Sevenoaks. They include the equipment, installation, commissioning and all relevant taxes.
| System | Rooms | Indicative installed price |
|---|---|---|
| Single split | 1 room | £3,000 – £4,000 |
| Multi-split | 2 rooms | £5,000 – £8,000 |
| Multi-split | 3 rooms | £7,000 – £10,000 |
| Multi-split or multiple systems | 4 rooms or more | £10,000+ |
What affects the price
- Cooling capacity: larger rooms, sunny rooms, lofts and conservatories need bigger units. See what size air conditioner you need.
- Number of rooms: a multi-split serves several rooms from one outdoor unit, which costs less than separate systems.
- Model and brand: premium models add features such as advanced air purification, quieter operation or design finishes.
- Pipe run: the distance between indoor and outdoor units, the route the pipework takes and the type of wall it passes through.
- Outdoor unit position: a ground-level stand is usually simplest; high wall brackets and flat roofs take more work.
- Electrical work: some homes need a new dedicated circuit from the consumer unit.
Is there VAT on air conditioning?
Not at the moment, for most homes. Air conditioning that heats as well as cools is classed as an air source heat pump, so supply and installation in a home in Great Britain is zero-rated for VAT until 31 March 2027. The rate is due to rise to 5% from 1 April 2027. Our prices include all relevant taxes.
How much does air conditioning cost to run?
Running costs depend on the size of the unit, how hot it is outside, how well the room is insulated and how long you run it. At the Ofgem price cap rate for October to December 2026 (26.32p per kWh for electricity), typical costs at full cooling output are:
| Unit size (cooling) | Typical power use at full output | Approximate cost per hour |
|---|---|---|
| 2.0 kW | 0.55 kW | 14p |
| 2.5 kW | 0.7 kW | 18p |
| 3.5 kW | 1.0 kW | 26p |
| 5.0 kW | 1.5 kW | 39p |
Inverter units throttle back once the room reaches the set temperature, so the real cost per hour is usually lower. Example: a 2.5 kW bedroom unit running 6 hours a day for 60 summer days, averaging 0.4 kW, uses about 144 kWh. That is roughly £38 for the whole summer.
For heating, a good unit delivers 3 to 4.5 kWh of heat for every kWh of electricity. See can air conditioning heat your home? for a cost comparison with gas and electric heaters.
Running cost assumptions: these figures are illustrative estimates, not a quote or a guarantee. They assume the Ofgem price cap average direct debit electricity unit rate for 1 October to 31 December 2026 (26.32p per kWh), exclude standing charges, and use typical power draw at full cooling output for each unit size as shown. The summer example assumes a 2.5 kW unit running 6 hours a day for 60 days at an average of 0.4 kW. Your actual costs will depend on your energy tariff, the model installed, the size and insulation of the room, the weather, your settings and how you use the system. Installation prices are indicative ranges and your quote will be based on your home.
Servicing costs
We recommend an annual service to keep your system efficient, clean and within the manufacturer’s warranty terms. Have your air conditioning and boiler serviced at the same time and your boiler service is half price.
How to keep running costs down
- Choose the right size of unit for the room.
- Set a sensible temperature. Around 24–25°C is comfortable for cooling and uses far less energy than 18°C.
- Close curtains or blinds on sunny windows during the day.
- Keep doors and windows closed while the unit is running.
- Clean the filters every two to four weeks when in regular use. See air conditioning filters explained.
- Use the timer, eco mode or app control so the unit only runs when you need it.
- Book an annual service.
Fixed air conditioning vs portable units
Portable air conditioners cost less to buy, but they are noisier, less efficient and vent hot air through a hose in an open window, which lets warm air back in. A fixed split system is quieter, cools more effectively, uses less electricity for the same cooling and also heats your room in winter.
Get expert advice for your home
We install air conditioning across Bromley, Beckenham, Orpington, Sevenoaks and the surrounding areas. Get an instant estimate online, or book a free home survey and one of our F-gas certified engineers will recommend the right system for your rooms.
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