Are you planning to install a new split-system air conditioner? Understanding the boundary between Homeowner Preparation (Partial DIY) and Professional Commissioning can save you significant money on installation labor while keeping your manufacturer warranty fully intact.

This guide breaks down the step-by-step process and compares four major brands: Alliance (FOUS/FOUSI), JVC, Samsung, and Comfee.

 

 

The 2-Phase Installation Process

A standard midwall split installation is split into two distinct phases. Homeowners can safely complete Phase 1 to cut down on contractor hours, but a licensed HVAC specialist must complete Phase 2.

 

Phase 1: Structural & Mounting (Safe for DIY)

• Indoor Head Unit: Secure the metal backing plate to an interior wall, ensuring a minimum 15 cm clearance from the ceiling for air intake. Use a spirit level to guarantee it is completely flat.

• Core Drilling: Drill a 65 mm hole through the wall. Crucial: The hole must slope downward at a 5° angle toward the outside so condensation drains via gravity.

• Pipe Bundling: Straighten the copper lines gently on the floor. Bundle the insulated copper pipes, communication cables, and the ribbed drain hose together using vinyl tape. Always position the drain hose at the absolute bottom of the cluster to prevent indoor flooding.

• Outdoor Compressor: Anchor the outdoor condenser unit onto heavy-duty rubber feet on a level ground pad or mount it securely to cantilever wall brackets. Ensure 30 cm of clearance behind the unit and 50 cm in front of the fan.

 

Phase 2: Technical Commissioning (Licensed Technician Required)

• Flaring & Connection: Cutting, deburring, and expanding the copper pipe ends using a precision flaring tool to mate with the brass outdoor valves.

• Vacuum Evacuation: Connecting a vacuum pump and manifold gauges to pull the entire closed system down below 500 microns. This removes hidden pockets of atmospheric moisture that react with compressor oil to form damaging acids.

• Gas Commissioning & Testing: Checking joints for pressure drops, opening the service valves with an Allen key to release pre-charged refrigerant (R32/R410A), and running system diagnostic test cycles.