Multi-Split Air Conditioning — Two to Four Rooms from One Outdoor Unit
A multi-split air conditioning system uses a single outdoor unit to serve two, three or four indoor units — each in a different room. It is a popular choice for homeowners who want multiple rooms air conditioned while keeping the exterior of their property clean and uncluttered. Forge Air designs and installs multi-split systems across the South West, from straightforward two-room systems to complex four-room configurations.
What's included
- System design for 2, 3 or 4 indoor units
- Leading multi-split outdoor units: Mitsubishi Electric MXZ, Daikin MXM, Panasonic CU, Fujitsu AOYG, Hitachi RAS
- Mix of indoor unit types — wall-mounted, ceiling cassette or floor units
- Full combination table compliance (manufacturer-approved configurations)
- Pipework design and routing for multiple circuits
- Independent controls per room — each unit is individually adjustable
- F-Gas certification for the complete system
- Manufacturer warranty registration
How it works
Free home survey
We assess all rooms, measure heat loads, review pipe routing options and identify the most practical outdoor unit location.
System design
We design a system within the manufacturer's approved combination tables, ensuring every indoor unit will receive its rated capacity.
Installation
Multi-split systems typically require one to two days depending on the number of rooms and complexity of pipe routing.
Commissioning
Each indoor unit is independently commissioned and balanced. F-Gas certification covers the complete system.
The Forge Air standard
Frequently asked questions
What is the difference between a multi-split and individual single splits?
A multi-split uses one shared outdoor unit for multiple rooms; individual single splits give each room its own dedicated outdoor unit. Multi-splits have a cleaner exterior but create a single point of failure — if the outdoor unit fails, all rooms are affected. See our comparison guide.
Can I mix different indoor unit sizes on the same multi-split?
Yes — most manufacturers allow mixed capacities on the same outdoor unit, within their approved combination tables. For example, a 2.5kW bedroom unit and a 5.0kW living room unit can share the same outdoor unit.
How many rooms can one outdoor unit serve?
Most domestic multi-split outdoor units serve 2–5 indoor units. The maximum depends on the outdoor unit model and the total connected indoor capacity. We design within manufacturer-approved limits.
Are multi-split systems more expensive than individual single splits?
The total installed cost is often similar. Multi-split outdoor units cost more than single-split equivalents, but the shared installation costs can offset this. We provide both options at the survey stage for comparison.
Related services
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