Multi-Split Air Conditioning
for Homes & Small Offices
Across Dorset & Hampshire

What it is

A multi-split system uses one larger outdoor condenser connected to between 2 and 5 (occasionally 6–8) indoor units in different rooms, each individually controlled. Refrigerant is distributed through dedicated pipework to each indoor head, and each room sets its own temperature independently.

Who it's for

Homeowners cooling 3–5 rooms (master bedroom, children's rooms, home office, lounge); small offices with 3–6 separate offices or meeting rooms; clinics, salons and retail with multiple zones; landlords future-proofing larger rentals or HMOs.

When you need it

During a renovation while walls are open, before next summer (booking from January–March avoids the May–August wait), when an existing collection of single splits is reaching end-of-life and replacement makes sense as one project, or when planning permission limits the number of outdoor units you can fit.

Why it matters

Compared to fitting 4 individual splits, a multi-split uses one outdoor unit (instead of four), is significantly quieter for neighbours, is materially cheaper to install across multiple rooms, and gives properly coordinated room-by-room control from a single app or wall controller.

Risks of waiting

• Outdoor unit under-sized for the total connected indoor load: rooms compete for capacity, none of them ever hits set-point on a hot afternoon.
• Pipe runs not pressure-tested in stages before being closed in: a leak found a year later means lifting floorboards or chasing out ceilings.
• Refrigerant charge not adjusted for total pipe length across all branches: system runs under-charged, ices, kills the compressor.
• Indoor heads mounted in wrong positions for airflow or against bedheads: cold draught, condensation, noise complaint from the partner who wanted air conditioning.
• Controls not commissioned properly: rooms turn each other off, schedules don't sync, you regret not paying for the centralised controller.

Common mistakes

• Picking a unit size by adding up room areas — multi-splits have diversity factors that need calculating properly.
• Trying to retrofit individual splits as 'a multi-split' by tying outdoor units together — they're different systems, it doesn't work.
• Skipping the centralised controller and then realising you can't sync schedules across rooms.
• Mixing brand A indoor heads with brand B outdoor unit — not how the manufacturer designed it, voids warranty, often won't even talk to each other.
• Booking the install in June and then waiting until September because every multi-split capable installer in Dorset is booked solid for the summer.

One outdoor unit for the whole job

Cleaner property exterior, quieter for neighbours, less planning friction than 4 separate outdoor units.

Individual room control

Each room sets its own temperature; one room cooling doesn't force the others to follow.

Cheaper than 4 separate splits

Materially less than installing 4 single-splits — one outdoor unit, one set of electrical, less commissioning labour.

Centralised app control

All rooms controlled from one phone app, with schedules, geofencing and energy reporting.

Whole-home heating in winter

Heat-pump mode across every room — efficient room-by-room heating without running the gas boiler for one cold space.

5–7 year warranty on the whole system

Single system, single warranty, single service contract — simpler than juggling 4 separate registrations.

Questions on this?

Talk to a specialist engineer direct.

01202 985241

Related services

Other things we look after.