How long does air conditioning installation take?

The short answer

Most single-room air conditioning installations take 4 to 8 hours. Multi-room systems take 1 to 3 days. Whole-home ducted systems can take 3 to 5 days.

In the UK, a standard single-split air conditioning installation typically takes between 4 to 8 hours to complete. That means many homeowners get cool air by the same evening.

How long does a single-room split system take?

A single-room split system is the quickest job. Most are finished within one working day.

A straightforward job takes 4 to 6 hours, or 6 to 8 hours if additional electrical work is required. Most single-room jobs wrap up well before evening if the engineer starts in the morning.

Expect your engineer on site for most of the day, with the system running before they leave.

How long do multi-room systems take?

Multi-room systems connect several indoor units to one outdoor condenser, which adds time for each extra room. Multi-splits typically take 1 to 2 days, with each additional indoor unit adding 2 to 3 hours.

• Day 1: outdoor unit positioning, wall drilling, first indoor unit fitted
• Day 2: remaining indoor units connected, electrical work, testing

How long does a ducted system take?

Ducted or whole-home systems take the longest. They involve more pipework and often ceiling or floor work, so usually take 3 to 5 days. Larger properties or systems with longer pipe runs can push towards the higher end.

That extra time isn't wasted. It goes into routing ductwork properly and keeping the finish neat.

What happens during a typical installation day?

Understanding the process helps explain why timing varies. Here's what a standard single-split day looks like — each stage matters, and skipping steps to save time often causes problems later.

• Setup and protection — dust sheets down, furniture moved, tools brought in
• Wall drilling — a standard cavity brick wall takes about 20 to 30 minutes per penetration
• Indoor unit fitting — backplate fixed, pipes routed, unit hung and levelled
• Outdoor unit installation — condenser mounted and connected
• Electrical and refrigerant connections — wiring completed, lines connected
• Testing and commissioning — system checked, settings explained

What factors can extend installation time?

Several things push jobs beyond the standard timeframe. Your installer should flag these during the survey, not on installation day itself.

• Pipe run length — longer distances between units need more materials and time
• Wall type — reinforced concrete or solid stone needs diamond drilling, over an hour per hole
• Electrical upgrades — older properties sometimes need new circuits
• Access difficulties — tight lofts, awkward gardens or upper floors slow things down
• Condensate drainage — long gravity runs or pumps add complexity in multi-storey buildings

How long does commercial air conditioning take?

Commercial installations generally take longer than domestic jobs, even for similar system types. For most commercial environments a standard split installation takes around two days, and many businesses prefer work outside normal hours to minimise disruption.

Larger projects such as full office or retail fit-outs can take anywhere from several days to several weeks, depending on the size of the building and complexity of the installation.

Can installation be completed in winter?

Yes, and it's often quicker. Installer diaries are less full outside summer months, so surveys and bookings tend to move faster. The actual on-site installation time doesn't change by season, but scheduling usually does.