Before install day
A good contractor does a load calculation to size the system and confirms your electrical capacity (a 230V system usually needs its own breaker). You'll settle placement together - where the indoor head and outdoor unit go. Getting these right up front is what separates a smooth install from a problem one; see where to put a mini split and the sizing guide.
What happens on the day
A typical single-zone install runs roughly like this:
- Mount the indoor head. A bracket goes on the wall, high and level, and a ~3-inch hole is cored through the wall for the line set to pass outside.
- Set the outdoor unit. The condenser goes on a pad, bracket, or stand, level and clear, positioned for a short line-set run.
- Run the line set and drain. The insulated refrigerant lines, control wiring, and condensate drain route from the head, through the wall, to the outdoor unit - often tidied in a line-set cover.
- Electrical. A dedicated circuit and disconnect are wired to the outdoor unit. This is also when a surge protector makes sense.
- Evacuate and charge. The tech pulls a vacuum on the lines to remove air and moisture, then releases or adds refrigerant to spec. This step is where install quality is made or lost.
- Test and commission. Power up, run heating and cooling, check the temperatures and drainage, and confirm it's operating correctly.
Timeline
- Single zone: typically most of one day.
- Multi-zone: often a day and a half to two-plus days, depending on the number of heads and the runs involved.
After the install
Expect a walkthrough - how to run it, clean the filters, and what the remote does. Make sure the installer registers the warranty (or you do), since many brands require registration and reward it with longer coverage. Then set a simple maintenance routine, starting with the filters.
What it costs - and getting quotes
Install cost depends on the number of zones, the run length, and any electrical work. Know the going rate before you book with the installation cost guide and the cost estimator, and see how to find a good installer for vetting. When you're ready, request quotes from local installers below.
FAQ
How long does mini split installation take? A single-zone system is usually a one-day job; multi-zone setups take a day and a half to two or more, depending on the number of heads and the line-set runs.
What do I need to do before installation? Settle placement with your installer, confirm your electrical panel can support the system, and clear access to both the indoor and outdoor locations. The load calculation and sizing are the installer's job.
Is mini split installation messy? Minimally - the main disruption is coring a ~3-inch hole through the wall for the line set. A tidy crew cleans up and can add a line-set cover for a finished exterior look.
Do I need an electrician too? Usually the HVAC contractor handles the dedicated circuit and disconnect, but confirm it's included in the quote - some coordinate with an electrician for panel work.