Where mini-splits fit
No ducts
Homes heated by wall or baseboard heaters with no central AC.
Hot rooms
Bonus rooms over garages and west-facing rooms the central system can't keep cool.
Additions
New space where extending ducts is impractical.
ADUs
Detached or garage-conversion ADUs that need their own heating and cooling.
Single-zone vs multi-zone
| Single-zone | Multi-zone | |
|---|---|---|
| Setup | One outdoor unit, one indoor head | One outdoor unit, two to five or more heads |
| Best for | One room, an addition, a small ADU | Several rooms or a whole home without ducts |
| Control | One thermostat | Each head set separately |
| Bay Area cost | $6,500–$10,000+ | $12,000–$25,000+ (3–4 zones) |
Cost source: Galaxy Heating & Air, Feb 2026 (contractor).
Indoor head types
Wall-mounted
The most common and least expensive head. Mounted high on an outside wall when possible to keep the line set short.
Ceiling cassette
Recessed into the ceiling, distributing air in four directions. Needs attic or joist space above.
Ducted (concealed)
A slim air handler hidden in an attic or soffit with short ducts to one or more rooms. Quietest look, more labor.
Line sets and outdoor unit placement
Each indoor head connects to the outdoor unit with a refrigerant line set, a condensate drain and a control wire, usually run through a 3-inch hole and covered with a paintable line-set cover outside. The manufacturer's manual limits line length and height difference. The outdoor unit sits on a pad or wall bracket; city setback and noise rules apply, and HOAs in places such as Blackhawk and Rossmoor review outdoor equipment.
- Shortest practical line set from head to outdoor unit
- Condensate drain that falls to daylight or a pump
- Outdoor unit clear of bedroom windows and property lines per city rules
- A dedicated circuit for the outdoor unit
Permits and licensed installation
Mini-splits need a building permit and a contractor holding a CSLB C-20 license. California requires a license for jobs of $1,000 or more in labor and materials (CSLB AB 2622 bulletin), and refrigerant handling requires EPA Section 608 certification. Check the license at cslb.ca.gov. More: choosing a contractor.
Refrigerant
Most new mini-splits use R-454B or R-32 after EPA's January 1, 2026 GWP-700 limit. The refrigerant guide explains what that means for repairs and new installs.
Cost
Ranges, the factors behind them and how to compare bids are on the cost page.
Rebates as of Oct 2026: MCE customers can get up to $400 per 500 sq ft for heat pump heating and cooling and up to $675 for a heat pump water heater; most other programs are closed or ended. See the dated rebate table.
Mini-split questions
Is R-410A still allowed in California?
Existing R-410A systems can still be serviced. For new systems, EPA's GWP-700 limit took effect January 1, 2026, and most new mini-splits use R-454B or R-32. A May 2026 EPA rule change allows leftover R-410A equipment made before 2025 to be installed, but California's Air Resources Board has its own refrigerant rules, so ask the installer to confirm the equipment is allowed here. See the refrigerant guide.
Can a handyman install a mini-split?
Not legally for a typical job. In California, work of $1,000 or more in labor and materials needs a CSLB license, and mini-split installation is C-20 (HVAC) work. It also needs a building permit, and anyone handling refrigerant needs EPA Section 608 certification.
What mini-split brands should I stay away from?
Judge the installer and the support, not a brand list. Look for equipment with parts available locally, a warranty that is registered in your name, and an installer who has set up that line before. A well-installed mid-range unit outperforms a premium unit with a poorly run line set.
How much does a mini-split cost?
Galaxy's 2026 Bay Area figures: $6,500–$10,000+ for a single zone and $12,000–$25,000+ for three to four zones. The cost guide has more ranges and the price drivers.