How Long Does Air Conditioning Installation Take?

Typical installation times

• Single wall-mounted split, straightforward access: usually one working day.
• Two-room multi-split: typically one to two days.
• Three to five room multi-split: typically two to four days.
• Ducted or concealed systems: several days, and usually best done alongside other building work.
• Small commercial cassette installation: one to two days per unit depending on ceiling access.

The full timeline, not just the fitting

The installation day is only part of the picture. A realistic end-to-end timeline runs: enquiry, survey (often within a week), quotation, equipment ordering (a few days to two weeks depending on model availability), then installation.

In practice, most straightforward domestic jobs complete two to four weeks after the initial enquiry outside peak season.

What slows things down

• Peak summer demand — June and July lead times can stretch to several weeks.
• Long pipe runs or difficult access requiring scaffolding or a platform.
• Electrical work, such as adding a dedicated circuit or upgrading a consumer unit.
• Landlord, freeholder or planning consent still outstanding.
• Specific model availability, particularly for higher-spec or low-noise units.

What happens on the day

• Indoor unit bracket positioned and core hole drilled through the wall.
• Refrigerant pipework, drain and interconnecting cable routed to the outdoor unit.
• Outdoor unit mounted on brackets or a floor stand and connected.
• System pressure tested and evacuated with a vacuum pump — this step takes time and shouldn't be rushed.
• Refrigerant released or charged, then commissioning, testing and a handover demonstration.

Planning around it

You'll need someone at the property for the day, access to the room and to the outdoor unit position, and a parking space for the installer's van. Drilling is noisy but brief, and most installers clear up thoroughly as they go.

If you want work done for summer, enquire in spring. Booking in April or May routinely gets a better lead time and a more considered survey than a July emergency call.