What to Expect on Your AC Installation Day

Booking a new air conditioning or heat pump system can feel like a leap into the unknown if you've never had one fitted before. The reassuring part: a typical domestic installation is completed in a single day, with far less mess and disruption than most people expect. Here's exactly what happens, from arrival to handover.

1. The Site Survey and Final Plan

Before installation day, an engineer visits the property to agree the best position for the indoor and outdoor units, plan the pipework route, and confirm the electrical supply is adequate. This is also when we talk through any awkward runs — a pipe through a listed building's wall, or an outdoor unit that needs to sit somewhere discreet — so there are no surprises when the install team arrives.

2. Fitting the Indoor Unit

On the day itself, the team protects your floors and furniture before doing anything else. The indoor wall unit is mounted, and a small, neat core hole is drilled through the wall for the pipework. Most homeowners are surprised at how tidy this stage is — a well-run install leaves barely a trace of dust.

3. Outdoor Unit and Pipework

The outdoor condenser is mounted on a wall bracket or ground stand, then connected to the indoor unit with insulated refrigerant pipework, condensate drainage and control cabling. Before any refrigerant is released, the whole system is vacuum-tested and pressure-checked to confirm there are no leaks — a step that's easy to skip and impossible to verify later, which is exactly why it matters who does your installation.

4. Commissioning and Handover

Finally, the engineer powers up the system, tests both cooling and heating modes, and walks you through the remote control, timers and energy-saving settings. You'll receive your warranty paperwork and a note of when the first annual service is due. For most single-room domestic systems, the whole process — start to finish — takes around 6–8 hours. Larger multi-room or commercial installations are scheduled over two to three days, agreed in advance during the survey.