Multi-room air conditioning cost in Essex: a homeowner's price guide

If you want to cool and heat more than one room, the price works differently from a single-room job. A single wall-mounted unit has a fixed price on our list. A multi-room system has to be designed around your home: how many rooms, how big each one is, and how the pipework gets from each room to the outdoor unit.

This guide explains what drives the multi-room air conditioning cost, how a multi-split compares with separate single-split systems, and how to use our fixed single-room prices to get a rough idea before we visit.

There are two ways to air condition several rooms:

• A multi-split system. One outdoor unit connects to two or more indoor units. Each room has its own indoor unit and its own controls.
• Separate single-split systems. Each room gets its own indoor unit and its own outdoor unit.

Both let you set each room to a different temperature, or switch rooms off when no one is using them. The main differences are on the outside of the house and in how the job is priced.

A multi-split often suits homes with limited outside wall space, or where you want two to four rooms done at the same time. Separate single splits can suit rooms on different sides of the house, or rooms you plan to add one at a time. Our multi-room air conditioning page explains how multi-split systems work in more detail.

Multi-split systems are not on our fixed price list. We quote them individually, because the right outdoor unit and the amount of pipework change from home to home.

Our fixed single-room prices still give you a useful starting point. As an example, here is what a standard bedroom and a living room would cost as two separate single-split systems on our recommended Gold package, the Mitsubishi Heavy Industries Premium ZS White:

These are single-split prices for each room, taken from our fixed list. They are not a multi-split price, and a multi-split for the same two rooms will be quoted separately after a survey. You can see every package and size on our prices page.

Several things move the price of a multi-room system up or down:

1. The number of rooms. Each room needs its own indoor unit, so more rooms means more hardware and more fitting time.
2. The size of each indoor unit. Our size guide puts a standard bedroom (up to 25m²) at 2.5kW, a large bedroom or standard living room (up to 35m²) at 3.5kW, and a large living room or open space (up to 50m²) at 5kW. Our guide to choosing the right size covers this room by room.
3. The outdoor unit's capacity. The outdoor unit must be big enough for all the indoor units connected to it.
4. Pipe run lengths and routes. A bedroom with an outside wall near the outdoor unit is a short run. A room on the other side of the house means longer pipework and more time to route it neatly.
5. Wall construction. Some walls take longer to drill and make good than others.
6. Electrics. The system needs a safe, dedicated supply. We check your consumer unit at survey.
7. Condensate drainage. Every indoor unit produces water as it cools. If a unit is not on or next to an outside wall, it needs a condensate pump, which adds £200 for that unit.

Hardware: units and materials

The hardware is the indoor units, the outdoor unit, and the materials that connect them: copper refrigerant pipework, insulation, cabling, trunking and brackets. Indoor units on the same outdoor unit generally need to come from a compatible range, so your engineer will talk you through which combinations work. A quote that looks low can sometimes mean cheaper materials, so it is worth asking what is included.

Labour and installation complexity

Labour depends on how much work it takes to get each indoor unit connected. On a multi-split, every room is piped back to one outdoor unit, so the routes can be longer and more involved than on a single split. Pipes may need to run through a loft, a floor void or along an outside wall. Working at height, such as an upstairs wall that needs scaffolding, also adds time. We agree all of this with you before work starts.

Every home is different, so there is no standard package. Some common setups we are asked about are:

• Two or three bedrooms upstairs. Often one outdoor unit serving the main bedroom and one or two smaller rooms.
• A bedroom and a living room. One indoor unit upstairs for sleeping and one downstairs for the evenings.
• A loft conversion and a bedroom. Loft rooms often need a condensate pump, as the unit may not sit on an outside wall with an easy drain route.
• An open-plan extension plus another room. Large glazed spaces may need a bigger indoor unit, or two. Our open-plan living guide explains why.

We work out which rooms suit one outdoor unit, and which might be better as a separate single split, at your free survey.

A multi-room job means more pipework, so planning the routes matters. We look for the neatest path from each indoor unit to the outdoor unit. Where we can, the pipes go straight through the wall behind the indoor unit. Where they have to run on a surface, we use neat trunking. Routes through lofts or floor voids can hide pipework completely, but they take longer, so we talk through the options with you at survey.

The outdoor unit needs a spot that is easy to reach for servicing, with space around it for air to flow. One outdoor unit instead of three is one of the main reasons people choose a multi-split.

Running costs depend on how many rooms are in use at once, the size of each room, how long you run the system and whether you are cooling or heating. That is why we do not give one monthly figure for a multi-room system. Modern systems use inverter technology, which lets the outdoor unit speed up or slow down to match what the rooms need, rather than switching fully on and off.

One advantage of separate room control is that you only pay to cool or heat the rooms you are using. Our guide to air conditioning heating and running costs shows how to work out the cost using current UK energy prices.

Heating with air conditioning

Every system we fit is an air-to-air heat pump, so each indoor unit heats as well as cools. Many people use their system to warm a home office or bedroom on cold mornings without heating the whole house.

You can only add another indoor unit to a multi-split if the outdoor unit has spare capacity for it. We check this at survey. If you think you might want another room covered in future, tell us at the start, so we can plan for it or suggest a separate single split later.

The refrigerant in air conditioning is a fluorinated gas, so anyone installing it for someone else must be F-Gas certified by law. With several indoor units and longer pipe runs, careful pressure testing and commissioning matter even more. We are F-Gas registered with REFCOM (REF1022701) and NAPIT registered (64714) for electrical work. The team is led by Oliver, who has over 20 years of trade experience, and we fit, service and repair systems for homes and businesses. Our air conditioning installation page covers what happens from survey to commissioning.

To get a rough idea per room, see your fixed price for each room you want covered. Our air conditioning cost guide explains what is included in every price. For a full multi-room quote, contact us or call 01268 264002 to book a free survey, and we will design a system around the rooms you want to cool and heat.