By Bournemouth Air Conditioning. Published .
A single split system has one indoor unit and one outdoor unit. A multi split runs two or more indoor units from one outdoor unit. If you only need one room done, a single split is usually the answer. If you want several rooms and only have space for one outdoor unit, a multi split often makes more sense.
Here is how to weigh them up.
Single split: one room, one outdoor unit
The indoor unit sits on the wall of the room, and a pair of insulated refrigerant pipes, a drain and a cable run through the wall to the outdoor unit. It is the simplest arrangement and the quickest to install. Most single splits are a one-day job.
The advantages:
- Each system is independent, so a fault on one room does not affect another.
- Each outdoor unit is matched to its own room.
- You can do one room now and add another later without touching the first.
The downside is that every room needs its own outdoor unit and its own pipe route. On a terrace, a flat or a house with little outside wall space, that soon becomes a problem.
Multi split: several rooms, one outdoor unit
A multi split connects two or more indoor units, often of different sizes, to a single larger outdoor unit. Each room has its own controller and can be set to its own temperature. A multi split for two or three rooms usually takes two days to install.
The advantages are mostly about space and appearance. One outdoor unit instead of several matters in conservation areas, on small plots and wherever you want to keep the side or rear of the house tidy.
The trade-offs:
- If the outdoor unit fails, every room connected to it loses heating and cooling until it is fixed.
- The indoor units generally all run in the same mode, heating or cooling, at the same time. In a home that is rarely a problem.
- Pipe runs can be longer, because each indoor unit has its own pipes back to the outdoor unit.
- It needs planning at the start. Adding a room later only works if the outdoor unit has a spare connection and enough capacity.
Which suits your home?
- One bedroom, home office or loft room: a single split.
- Two or three bedrooms with one good spot for an outdoor unit: a multi split.
- A flat, a terrace or a period home where outdoor space or appearance is limited: a multi split is often the tidier answer.
- Rooms used at very different times that you want kept independent, such as a home office and a garden room: separate single splits.
Planning rules can decide it for you. Under the permitted development rules for heat pumps in England, a semi-detached or terraced house can have one outdoor unit and a detached house two, subject to other conditions. Our guide do you need planning permission for air conditioning sets out the details.
What about ducted systems?
Ducted and cassette systems hide the indoor unit in a ceiling void, with only a grille on show. They suit larger open-plan spaces and some high-end homes, but they need ceiling space and more building work. For most homes, wall-mounted single or multi splits are the practical choice.
Getting it right at the survey
The right answer depends on the rooms, the walls, where an outdoor unit can sit and what the electrics will take. At the free survey we look at all of that, then quote in writing for the arrangement that fits. If a single split will do the job, we will not sell you a multi split.
If you are thinking about heating as well as cooling, our guide to using air conditioning to heat your home in winter is worth a read first.
Book a survey or service
See air conditioning installation and home air conditioning for more, or the local pages for Wimborne and Bournemouth. Call 07910 686513 to book a free survey.
Related services: Air conditioning installation, Home air conditioning.