Mini Split Installation Guide: Step-by-Step for HVAC Professionals

Site Preparation

Location Selection - Indoor Unit

• Minimum 6-8 feet from floor (wall mount)
• No obstructions to airflow
• Away from heat sources and direct sunlight
• Accessible for maintenance and filter cleaning
• Consider condensate drainage path

Location Selection - Outdoor Unit

• Level surface with adequate support
• Minimum clearances per manufacturer specs
• Protected from snow/debris accumulation
• Away from bedroom windows (noise)
• Accessible for service

Indoor Unit Installation

1. Mark and drill mounting plate holes using level
2. Install mounting plate with appropriate anchors
3. Cut 3" hole through wall for line set
4. Slope hole slightly downward to exterior
5. Install line set, drain, and control wire through wall
6. Connect refrigerant lines with flare connections
7. Connect condensate drain
8. Connect control wire to terminal block
9. Hang unit on mounting plate

Outdoor Unit Installation

1. Set unit on mounting pad or brackets (level)
2. Connect refrigerant lines with flare connections
3. Connect control wire
4. Install electrical whip and disconnect
5. Verify line set routing doesn't trap oil

Refrigerant Line Installation

Flare Connection Tips

• Cut tubing square with tubing cutter
• Deburr inside and outside
• Use proper flaring tool for refrigerant tubing
• Apply refrigerant oil to flare surface
• Torque to specification with torque wrench

Vacuum & Startup Procedures

System Evacuation

1. Connect vacuum pump and micron gauge
2. Evacuate to 500 microns or below
3. Perform standing vacuum test (should hold under 500)
4. If pressure rises, check for leaks

Opening Valves & Startup

1. Remove vacuum pump (system under vacuum)
2. Open liquid line service valve slowly
3. Open suction line service valve
4. Replace valve caps with torque
5. Power on and verify operation
6. Check superheat and subcooling