Before you buy equipment
Start with the full DIY mini-split project roadmap if you are sequencing size → wire → mount. DIY videos skip code and refrigerant law — verify what is legal in your jurisdiction before purchasing.
- Size the head with a BTU calculator — buy matched indoor/outdoor pair from same series
- Confirm electrical: 110V vs 220V, breaker size, wire gauge, outdoor disconnect location
- Plan line-set path length — pre-charged DIY kits have maximum line length; longer needs pro charge
- Check local code: permits, condenser setbacks, noise ordinances
Install sequence overview
Mount outdoor condenser on pad or bracket with clear airflow clearances. Mount indoor bracket level, drill wall penetration with slight outward slope for drainage.
Run line set, communication wire, and drain. Flare connections torqued to spec. Pre-charged systems open valves after leak-check; traditional installs need vacuum pump to 500 microns or below.
Open electrical, test heat and cool modes, and check drain flow. These steps are summaries — follow the manufacturer manual exactly.
When to hire a licensed HVAC tech
This guide is planning information only — not a step-by-step substitute for manufacturer instructions or professional advice.
- Line set longer than DIY kit rating — requires weighing refrigerant charge
- No comfort with flaring or vacuum procedure — leaks cost more than install labor
- Jurisdiction requires licensed refrigerant work
- Multi-zone systems with complex branch selectors
Tools and materials checklist
Confirm head size with the mini-split calculator before ordering — line-set kits are matched to specific BTU tiers on many DIY brands.
- Indoor bracket, level, stud finder, core bit for wall penetration
- Flaring tool, torque wrench, nitrogen or leak detector
- Vacuum pump and micron gauge (if not pre-charged kit)
- Outdoor pad or wall bracket, disconnect box, whip to breaker
- Line hide cover (optional), condensate drain hose and slope