What to expect on mini split installation day, step by step

By install day the decisions are already made: the estimate visit fixed the head locations, the condenser placement, the line-set route, and the written price. Your job before the crew arrives is small — clear a working area under each indoor head location, make sure we can reach the electrical panel, and secure pets somewhere calm. If an HOA or historic-district approval applied, that paperwork was handled before scheduling.

1. Walkthrough and protection. The lead installer confirms placements with you, then drop cloths and floor protection go down along every path we'll work.
2. Mounting the indoor head. The bracket levels onto the wall, and a roughly three-inch hole is drilled through the exterior wall behind or beside the head — that one penetration carries the refrigerant lines, condensate drain, and control wiring.
3. Setting the outdoor unit. The condenser sits on a pad or wall brackets at the location we agreed — clear of bedrooms, out of sight lines where possible.
4. Running and connecting the line set. The insulated refrigerant lines route from head to condenser, in paintable line-hide when they run along a wall. Electrical connects to a dedicated circuit.
5. Vacuum and pressure test. Before any refrigerant flows, the lines pull down to a deep vacuum and hold — this is the step that separates a factory-spec install from a shortcut, because moisture or leaks left in the lines quietly kill compressors.
6. Commissioning. Refrigerant releases, the system runs through heating and cooling, temperatures verify at the head, and drainage confirms.
7. Walkthrough and cleanup. You get the remote tour — modes, schedules, filter care — the workspace resets, and the paperwork (registration, warranty, any CPS Energy rebate filing) starts.

A straightforward single-zone install is one working day — often done by mid-afternoon. Multi-zone systems run one to two days depending on head count and routing. What stretches a job: long or complex line-set routes, panel work when a new circuit is needed, masonry walls, and second-story head placements. None of these are surprises — they're identified at the estimate and priced into the written quote.

Less than people expect. The wall penetration is a three-inch hole per line set, drilled once, sleeved and sealed. There's no duct chase, no ceiling opening, no plaster demolition — this is exactly why ductless wins in older Alamo Heights and Monte Vista homes. Dust control and drop cloths are standard, and the crew's last task is a cleanup walkthrough with you. That's our clean-install guarantee, and we mean it literally: your home looks like we were never there.

Run the system normally from day one. Expect the first utility cycle to reflect how you use the zones — the wins come from conditioning the rooms you're in, not the whole envelope. Filters rinse clean in minutes every few weeks in heavy season. And if anything sounds, drips, or behaves oddly in the first weeks, call us — commissioning issues are rare and covered, and catching them early is always the right move.