The short answer
Installation is usually the largest single line in the bill: a single split is typically £1,500–£3,000 fitted, and a multi-split £3,000–£6,000 or more. That price bundles the unit, brackets and pipework, the electrical connection, mounting both units, vacuuming the system and commissioning it. By law the work must be done by an F-Gas-certified engineer, so installation labour is not optional.
Installation cost is where most of the money goes, and it is also where the biggest variation between quotes appears. This page explains what a fitting price actually covers, why two similar homes can be quoted very differently, and how to read a quote so you can tell a fair price from a thin one. All refrigerant installation must be carried out by an F-Gas-certified engineer working for an F-Gas-registered company.
Installation cost at a glance
- Single split fitted £1,500–£3,000
- Multi-split fitted £3,000–£6,000+
- Who may install F-Gas-certified engineer only
- Typical fitting time Often half a day to two days
- Key cost driver Pipe-run length and access
What the installation price covers
An installation quote is not just “fitting the box on the wall”. A proper fixed split install includes mounting the indoor head, siting and securing the outdoor condenser, running insulated refrigerant pipework and condensate drainage between them, making the electrical connection, then pressure-testing, vacuuming and charging the system before commissioning it. Each of those steps takes time and skill, which is why labour is the dominant part of the cost. The vacuuming stage in particular — removing moisture and air from the pipework before refrigerant is introduced — is essential to the unit working correctly and lasting, and it is one reason the job cannot be rushed or improvised.
- Mounting the indoor unit and outdoor condenser securely.
- Refrigerant pipework, insulation, brackets and condensate drain.
- Electrical connection to a suitable, protected circuit.
- Pressure test, vacuum, charge and commissioning.
Typical fitting costs in 2026
As a market guide, a single split fitted in a straightforward location is typically £1,500–£3,000 all-in, and a multi-split serving several rooms is £3,000–£6,000 or more. The unit hardware is only part of that; the rest is labour and materials. A self-contained portable needs no certified install at all, which is why it is so much cheaper to get going — but it trades that saving for lower efficiency and more noise in the room. The wide band within each range reflects how much the practicalities of your property move the figure.
| Job | Typical installed cost | Notes |
|---|---|---|
| One room, single split | £1,500–£3,000 | Short pipe run, easy access |
| Two or more rooms, multi-split | £3,000–£6,000+ | More heads, more pipework |
| Portable (DIY) | £300–£600 | No certified install needed |
Why quotes differ so much
The same room can be quoted at very different prices depending on the practicalities. Distance between the indoor and outdoor units, the routing of the pipe (concealed runs cost more than surface trunking), how the outdoor unit is mounted, and how easy it is to reach a power supply all move the figure. Conservation areas, listed buildings or tight permitted-development limits can also affect siting and add survey work — see planning permission for air con. A flat in a block with the only viable condenser position three floors up will cost more to fit than a ground-floor room with the outdoor unit just outside.
- Long, hidden or awkward pipe routes add labour and materials.
- High-level or roof-mounted outdoor units may need access equipment.
- Extra electrical work to reach a suitable circuit raises the cost.
How to read a quote
A good quote itemises the unit, the pipework and materials, the electrical work and the labour, and confirms the installer’s F-gas registration. It should also state the cooling capacity (kW) proposed for the room, because an oversized unit wastes money and an undersized one will struggle in a heatwave. Ask whether commissioning and a first service are included, and whether the price covers making good any holes or trunking. Comparing two quotes only works when both list the same items; a headline figure with no breakdown tells you little. For the broader picture see our total cost guide and installation explained.
This page is general information only and not a substitute for a site survey. Always obtain a written, itemised quote from an F-Gas-certified installer who has inspected your property.
Where the money actually goes
It helps to picture the split between hardware and labour. On a single-split job, the indoor and outdoor units are a meaningful slice of the total, but the certified labour, the refrigerant pipework and insulation, the brackets, the condensate drainage and the electrical work together usually make up the larger share. That is why two installers quoting the same unit can land far apart: one may be pricing a tidy half-day fit with a short pipe run, the other a full day with concealed pipework and a lifted outdoor unit. When you compare quotes, look past the unit model and at the labour and materials lines, because that is where the real difference sits. A fair quote will also confirm the system will be vacuumed and commissioned, not just connected and switched on, since skipping those steps stores up faults and shortens the unit’s working life.
Compare quotes the right way
Ask each installer to itemise units, pipework, electrics and labour, and to confirm F-gas registration, so you are comparing like with like.
Frequently asked questions
Why is installation the biggest part of the cost?
Because it is skilled, certified labour: mounting both units, running and insulating pipework, making the electrical connection, then vacuuming, charging and commissioning the system safely and legally.
Can I buy the unit and just pay for fitting?
Some installers will fit a supplied unit, but many prefer to supply their own so they can warranty the whole job. Either way the fitting labour itself is unavoidable and must be done by a certified engineer.
How long does a typical install take?
A simple single split is often completed in half a day to a day; a multi-split with several heads and long pipe runs can take two days or more.
Does the quote include the first service?
Not always — ask. Some installers include commissioning and a first service; others charge the £80–£150 annual service separately.
Sources & further reading
- gov.uk — the Fluorinated Greenhouse Gases Regulations 2015 (GB F-gas)
- REFCOM / the F-Gas Register — registered company requirements
- Energy Saving Trust — home cooling guidance
- Planning Portal — permitted development for air conditioning units
This guide is general information, not a site-specific survey or a substitute for a quote from an F-Gas-certified installer. Installation, servicing and refrigerant handling are legally restricted to F-Gas-certified engineers.