What affects the cost of air conditioning
Installation and running costs explained, so you know what to look for in every quote.
Free, no obligation
Standard or pre-charged systems
The cost of air conditioning depends on the system type, how many rooms, the size of each unit, the pipe run between the units, the electrical work and access. Running cost depends on the unit's power input, how long you use it and your electricity tariff. Comparing quotes for the same rooms from several local installers is the most reliable way to see a fair price.
What affects the installation price
System type
Standard or pre-charged, and wall-mounted, floor console, cassette or ducted indoor units.
Number of rooms
One room, or several rooms from a multi-split outdoor unit.
Unit size
The cooling and heating output each room needs, from about 2.5 kW to 7 kW and above.
Pipe run and walls
How far apart the indoor and outdoor units are, and what the pipework passes through.
Electrics
Whether a new dedicated circuit is needed from your consumer unit, and how far it runs.
Access and position
Upstairs rooms, wall brackets or a ground stand for the outdoor unit, and access equipment.
Working out running costs
Running cost depends on the unit, your tariff and how you use it. You can estimate it like this:
Find the unit's power input in kW in the specification (not its cooling output).
Multiply by the hours you expect to use it.
Multiply by your electricity unit rate from your bill.
Inverter units often run below their rated input once the room is at temperature, so real costs are usually lower.
Keeping costs down
- Choose the right size, not the biggest
- Compare energy ratings and seasonal efficiency in every quote
- Set a sensible temperature and use timers
- Close doors and blinds on hot days
- Keep filters clean and service the system
- Use heat mode instead of plug-in heaters in winter
What should be in every quote
- Make, model, output and energy rating of each unit
- Pipe length included and the price for extra
- Electrical work and certification
- Trunking, making good and waste removal
- Warranty terms and servicing needed to keep them
- Lead time and how long the install takes
Why compare quotes
Prices for the same rooms can differ a lot between installers, because of equipment, pipe routes and how busy they are. Asking several local installers to quote for the same job is the most reliable way to see a fair price.
Three steps to your quotes
Tell us about your rooms
Home or business, how many rooms and the system type you would like.
We match local installers
Only installers who cover your postcode and fit your system type.
Compare your quotes
Weigh up prices, equipment and warranties, then choose, if you want to.
Air conditioning terms explained
Split system
An air conditioner with an indoor unit in the room and an outdoor unit outside, joined by refrigerant pipes and a cable.
kW and BTU
Units of cooling or heating output. 1 kW is about 3,412 BTU per hour. Units are sold in sizes such as 2.5 kW (9,000 BTU) and 3.5 kW (12,000 BTU).
Inverter
A compressor that speeds up and slows down to hold the temperature, rather than switching fully on and off. Quieter and more efficient.
SEER and SCOP
Seasonal efficiency ratings for cooling (SEER) and heating (SCOP). Higher numbers mean less electricity for the same comfort.
F-Gas certification
The qualification needed to install and work on equipment containing fluorinated refrigerants, which most standard systems use.
Pre-charged system
A split system sealed at the factory with a non-fluorinated refrigerant and a pre-flared pipe kit, so a typical install needs no F-Gas engineer.
Multi-split
One outdoor unit serving two or more indoor units in different rooms.
Condensate
Water removed from the air while cooling, carried outside by a drain pipe or pump.
Air-to-air heat pump
Another name for a reversible air conditioner: it moves heat from outside air into the room in winter.
Air conditioning costs: common questions
Why do air conditioning quotes vary so much?
Equipment, unit sizes, pipe runs, electrical work, access and how busy the installer is all change the price. Compare quotes for the same rooms and system.
Is a pre-charged system cheaper to install?
It can be quicker to fit, but the right choice depends on the room and the house. Compare quotes for both for the same job.
What does it cost to run?
Multiply the unit's power input in kW by the hours of use and your electricity unit rate. Inverter units often draw less once the room is at temperature.
Are there extra costs to watch for?
Longer pipe runs, a new electrical circuit, condensate pumps, wall brackets, access equipment and making good can all add to the price. Check what each quote includes.
How do I get quotes?
Enter your postcode, tell us about your rooms and compare quotes from local installers.
General information only, not technical, legal or planning advice. Installers confirm system size, siting and any permissions for your property. Updated October 2026.
Sources: The Fluorinated Greenhouse Gases Regulations (GB) and GOV.UK guidance on F-gas; Approved Document P (electrical safety) and the Building Regulations for England and Wales; the Energy Performance of Buildings Regulations (air conditioning inspections); manufacturer installation guidance for split systems.