2 to 5 rooms One outdoor unit, separate control in every room
Multi-Split Air Conditioning for Two to Five Rooms
Aircova fits multi-split air conditioning in homes across London and the South East, from £3,995 for two rooms, fitted with VAT included. One outdoor unit runs up to five indoor units, each with its own temperature, and the whole system heats your home in winter too.
- F-Gas certified engineers
- Fixed price with VAT, in writing
- Two or three rooms fitted in 2 to 3 days
Prices last checked: October 2026
One outdoor unit, several rooms
How does multi-split air conditioning work?
Multi-split air conditioning links two to five indoor units to a single outdoor unit, so several rooms are cooled or heated from one condenser outside. Each room has its own remote and temperature. Aircova supplies and fits these systems in homes across London and the South East at fixed prices.
The outdoor unit holds the compressor, which is the part that does the hard work. It pumps R32 refrigerant through a pair of insulated copper pipes to each indoor unit in turn. Inside every room, a fan blows air across a coil. The refrigerant takes heat out of the air in summer or adds heat in winter.
Each indoor unit has its own pipe run back to the outdoor unit, plus a power and signal cable and a condensate drain. The outdoor unit has a separate connection port for every room. A three room system has three sets of pipes arriving at the back of the house.
Why the inverter matters
An inverter compressor speeds up and slows down to match how many rooms are calling for cooling. If only the bedroom is on at night, the compressor runs gently. When every room is on during a heatwave afternoon, it ramps up. That is why one outdoor unit can serve a small study and a large lounge without wasting power.
The outdoor unit is sized for the total load of all the rooms, not for each room on its own. A typical model for two rooms might be rated around 4 to 5kW, while one for four or five rooms is larger. We check the combined size against the manufacturer’s tables, because each brand allows a set range of indoor units on each outdoor model.
What each room controls
Every indoor unit has its own remote, its own set temperature, and its own timer. You can keep a bedroom at 19°C overnight and leave the spare room switched off. Most systems we fit also come with Wi-Fi control, so you can switch rooms on from your phone on the way home.
Fixed-price packages
Multi-split prices for 2, 3, 4 and 5 rooms
Our multi-split cost starts from £3,995 for two rooms and rises by about £1,500 for each extra room. That makes the cost per room lower as the system grows. Every price below is fitted, includes VAT, and is confirmed in writing after a free survey.
Air conditioning for 2 rooms
Two indoor units on one outdoor unit, often a main bedroom and a lounge.
from£3,995
Fitted, VAT included
- Two indoor units, a shared outdoor unit
- Up to 3m of pipe per indoor unit
- Usually fitted in two days
- Separate remote in each room
Air conditioning for 3 rooms
Three indoor units, enough for the bedrooms on a typical upper floor.
from£5,495
Fitted, VAT included
- Three indoor units, a shared outdoor unit
- Up to 3m of pipe per indoor unit
- Usually fitted in two to three days
- Wi-Fi control from your phone
Four rooms
Bedrooms plus a living space, all from the same condenser.
from£6,995
Fitted, VAT included
- Four indoor units, a shared outdoor unit
- Up to 3m of pipe per indoor unit
- Fitting days confirmed at survey
- Wi-Fi control from your phone
Five rooms
The largest home system on one outdoor unit, for most of a house.
from£8,495
Fitted, VAT included
- Five indoor units, a shared outdoor unit
- Up to 3m of pipe per indoor unit
- Fitting days confirmed at survey
- Wi-Fi control from your phone
Prices include the indoor and outdoor units, up to 3 metres of pipework per indoor unit, a bracket for the outdoor unit, electrical connection, commissioning and VAT. Longer pipe runs, scaffolding or tower access, a consumer unit upgrade and internal wall chasing are priced at the survey. Our air conditioning cost guide explains each extra with real figures.
For context, UK guides put two to three room systems at roughly £2,800 to £5,750, with London homes at the upper end. Our figures include VAT and named brands, and nothing is added after you agree. You can also get an instant quote online in about two minutes.
Compare your options
Multi-split or several single splits?
If you want three rooms cooled, there are two ways to do it. You can fit one multi-split with three indoor units, or three separate single splits, each with its own outdoor unit. Both work well. The right choice depends on your outside space, your budget and how much you mind one fault affecting every room.
Outdoor space is often the deciding factor in London. A Victorian terrace with a narrow side return rarely has room for three condensers on the back wall. A single larger outdoor unit is easier to place, tidier to look at, and keeps one source of noise rather than three near the neighbours.
Single splits win on resilience. If one outdoor unit fails, only one room loses cooling. On a multi-split, a fault in the outdoor unit stops every room until it is fixed. For a home office that must stay cool, some owners keep that room on its own single split for this reason.
| Point | One multi-split | Three single splits |
|---|---|---|
| Outdoor units | A single larger unit | Three smaller units |
| Aircova price from | £5,495 | About £6,585 (3 x £2,195) |
| Outside wall space | One bracket or ground stand | Three positions needed |
| If an outdoor unit fails | All three rooms stop | Only one room stops |
| Pipe runs | Longer, all back to one point | Short, one per room |
| Adding rooms later | Only if a spare port was planned | Add another single split |
Pros and cons at a glance
Neither option is better in every home. This is how they compare once the units are on the wall.
- One fault affects one room
- Shortest pipe runs
- Easy to add a room later
- Needs space for every condenser
- One outdoor unit to place
- Lower price for three or more rooms
- Tidier outside the house
- One fault can stop every room
When one room is enough
If only one bedroom or office overheats, a single split is quicker and cheaper. It is usually fitted in a day, from £2,195. See our guide to wall-mounted air conditioning for the 2.5kW and 3.5kW options.
For nothing on the walls at all, a ducted system hides the indoor unit in the loft or ceiling. It feeds slim grilles in each room. Read about ducted air conditioning to see if your ceiling void is deep enough.
Indoor units and sizing
Mixing indoor unit types and sizing each room
A multi-split does not have to use the same unit in every room. Most brands let you mix styles on a single condenser, as long as the combination sits inside the maker’s approved list.
Wall-mounted
Best for bedrooms and lounges
The most common indoor unit and the lowest price per room. It sits high on the wall and spreads air across the ceiling.
Included as standard in every package above.
Floor console
Best under windows and in lofts
A low unit that sits where a radiator might go. It suits loft rooms with sloped ceilings and rooms with no clear high wall.
Priced at survey as a swap for a wall unit.
Ceiling cassette
Best for open plan kitchens
Fits flush into a ceiling and blows air in four directions. It needs a ceiling void above, so it suits extensions and renovations.
Ceiling depth checked at the survey.
Ducted head
Best for a hidden finish
A slim unit hidden in the loft or ceiling feeds one or two rooms through grilles. Only the grille shows in the room.
Needs about 25 to 30cm of ceiling void.
How we size each room
Every indoor unit is sized for its own room. A bedroom up to about 20m² usually needs 2.5kW. A lounge or a sunny room often needs 3.5kW, and an open plan kitchen and dining space can need 5kW or more.
Room size is only the start. South and west facing glass, roof windows, a flat roof above, and the number of people in the room all add heat. A loft bedroom under a slate roof can need more power than a larger ground floor room. You can work out a starting figure with our BTU calculator, and 1kW is about 3,412 BTU per hour.
The outdoor unit is then matched to the total. Makers allow the indoor units to add up to a little more than the outdoor rating, because rooms rarely all need full power at once. We stay inside the approved range for each brand, so the warranty stays valid.
Planning a loft or flat? Pipe routes and consent are the two things to sort first. Our pages on loft conversions and air conditioning for flats cover both.
Fitting days
Multi-split installation: steps and timing
A two or three room multi-split installation usually takes two to three days. The extra time compared with a single room comes from the pipe runs. Each indoor unit needs its own route back to the outdoor unit.
- Survey. We measure each room, plan every pipe route and check your consumer unit.
- Written quote. You get the models, room sizes, total price and fitting dates in writing.
- Day one. We protect floors, core drill each wall and mount the indoor units and brackets.
- Day two. Pipes, cables and drains are run in trunking or hidden routes back to the outdoor unit.
- Commissioning. We pressure test with nitrogen, vacuum each circuit, release the refrigerant and test every room.
- Handover. We show you each remote and the app, then register the manufacturer warranty.
Refrigerant work is regulated. Anyone who installs or services these systems needs an F gas qualification. The company also needs F gas certification, as the GOV.UK guidance on F gas explains. Every engineer on an Aircova job is certified, and we share their registration number before the first day.
Pipe routing in UK homes
Pipe routes are what make or break a tidy job. In a terrace, we often run the pipes for upstairs rooms through the loft and down the back wall in one neat trunking run. In a semi, the side wall usually gives a clear route from front bedrooms to the outdoor unit.
Flats are different. The outdoor unit usually goes on a balcony or a flat roof. Pipes may need to cross internal walls or run inside a boxed ceiling. Lease terms often require the freeholder’s written consent first. Where the outdoor unit changes how a building looks, check our planning permission guide and speak to your council, especially in conservation areas.
Where you are renovating, the best time to fit is before plastering. We can run pipework inside stud walls and floors, which leaves only the indoor units on show.
Typical homes we plan for
Two bedrooms in a Victorian terrace
The main bedroom faces the street, and the back bedroom overlooks the garden. We run the front pipes through the loft and down the rear wall, so nothing crosses the front of the house. One outdoor unit sits on a bracket above the side return. This is a typical two day job.
Three rooms in a 1930s semi
Two bedrooms and a home office share one outdoor unit on the side wall. The side wall gives a short, straight route to all three rooms. Brick cavity walls drill quickly, and the job usually runs over two to three days with the units tested on the last afternoon.
Bedroom and lounge in a mansion flat
The outdoor unit goes on the rear balcony on rubber feet, out of sight from the street. Pipes run inside a boxed section along the hallway ceiling. We supply the noise figures and spec sheets your managing agent will ask for before the work is booked.
Heating, brands and servicing
Heating, brands and servicing for multi-room systems
Every multi-split we fit is an air-to-air heat pump. In winter the outdoor unit runs in reverse, pulling warmth from the outside air and moving it into each room. That makes it a practical form of whole house air conditioning that also does the heating in the rooms it serves.
One point to know: on most home systems, all the indoor units run in the same mode at once. You can set different temperatures, but one room cannot cool while another heats. A heat pump also warms the air in each room only, not radiators or hot water.
The Ofgem Boiler Upgrade Scheme gives £2,500 off air-to-air heat pumps in England and Wales. The heat pump has to fully replace your existing fossil fuel or electric heating and cover all of your home’s space heating. You can check the heat pump grant rules before you book.
The scheme also requires an MCS certified installer, so raise the grant at your survey. On efficiency, look for the SEER figure for cooling and the SCOP figure for heating on each model. Higher is better for both, and modern inverter systems reach a SCOP of around 4.
Brands we fit
We fit multi-split ranges from Daikin, Mitsubishi Electric, Fujitsu, Toshiba and Panasonic, with Samsung, LG and Hitachi on request. Compare the options on our pages for Daikin air conditioning installation, Mitsubishi Electric and Fujitsu. Mixing brands on one system is not possible, so the indoor units always match the outdoor unit.
Servicing a multi-split
A multi-split should be serviced once a year, and every indoor unit is cleaned on the same visit. Most makers ask for yearly servicing to keep warranties of up to 5 years, and longer on some ranges. Book an air conditioning service with us and we check the refrigerant, coils, drains and filters in every room.
Why Aircova
A fixed price for several rooms, before anything is booked
Larger systems are where vague quotes cause the most trouble, so we price every multi-split room by room. Your written quote lists each indoor unit, its size, the outdoor model and any extras. If you want whole house air conditioning later, we can plan a spare port now. A fourth or fifth room can then be added without changing the outdoor unit.
We are a London based company that handles air conditioning installation for homes across London, Surrey, Kent, Essex and Hertfordshire. Every job is done by F-Gas certified engineers. You get the same fixed price in spring or in the middle of a heatwave.
- Each room sized and shown on your written quote
- Pipe routes agreed with you before drilling
- Nitrogen pressure test and deep vacuum on every circuit
- Warranty registered in your name, with paperwork left behind
FAQs
Multi-split air conditioning FAQs
How many rooms can one multi-split outdoor unit run?
Most home multi-split outdoor units run between two and five indoor units. The exact number depends on the model and on the combined size of the rooms. A two port outdoor unit suits a pair of bedrooms, while a five port model can cover most of a family house. We pick the outdoor unit from the maker’s approved combinations, so every room gets enough cooling and heating and the warranty stays valid.
Is a multi-split cheaper than separate single splits?
For three or more rooms, a multi-split is usually cheaper. At Aircova three rooms start from £5,495 on one outdoor unit, while three single splits start from about £6,585. For two rooms the gap is small. The choice often comes down to outdoor space and how you feel about one fault affecting both rooms. We price both options at the survey if you ask.
What happens if the outdoor unit breaks down?
If the outdoor unit develops a fault, every room on that system stops cooling or heating until it is repaired. A fault in one indoor unit usually affects only that room. Yearly servicing catches most problems early, such as a blocked drain or low refrigerant. If one room must never lose cooling, such as a home office, we can put it on its own single split.
Can I run just one room on a multi-split?
Yes, you can run one room on its own and leave the others switched off. The inverter compressor slows down to match the smaller load, so you are not paying to cool empty rooms. Each indoor unit has its own remote and timer, and most systems can also be switched room by room from a phone app.
Can one room heat while another room cools?
No, not on most home multi-split systems. All the indoor units share one outdoor unit, which runs in either cooling or heating mode at a time. You can still set a different temperature in each room. In the UK this is rarely a problem, because rooms in the same house usually need the same mode on any given day.
Can I add another indoor unit later?
Only if the outdoor unit has a spare port and enough spare capacity. Many people add a room after a loft conversion or an extension, so we ask about future plans at the survey. If you might want an extra room later, we can fit a larger outdoor unit now. We leave a capped connection ready for the extra pipe run.
How far can the indoor units be from the outdoor unit?
Each maker sets a maximum pipe length per room and for the whole system, and they vary by model. Our prices include up to 3 metres of pipe per indoor unit, which covers many back bedrooms and ground floor rooms. Longer runs, such as front bedrooms in a terrace, are measured and priced at the survey before you agree to anything.
Does a multi-split need planning permission?
Often not, but it depends on your home. In England, most small outdoor units on houses do not need planning permission if the appearance of the building is not materially affected. Flats, listed buildings and conservation areas often need consent. One outdoor unit instead of several usually makes approval easier, but always check with your council first.
Get your fixed price
Tell us how many rooms you want to cool and heat. We will call you with a fixed price for your multi-room system. No pressure and no obligation.
- Reply within one working day
- Free home survey
- Price confirmed in writing
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