Method Statement for AC Ceiling Cassette Installation
1. Introduction
This method statement describes the systematic procedure for installing an air conditioning ceiling cassette unit in compliance with manufacturer guidelines and industry standards (ASHRAE, HVAC best practices).
2. Scope of Work
- Site preparation and ceiling assessment
- Mounting framework installation
- Refrigerant piping and electrical connections
- Drainage system setup
- Unit mounting and commissioning
3. Responsibilities
- HVAC Supervisor: Oversees technical compliance
- Installation Team: Executes physical installation
- Electrician: Handles electrical connections
- Safety Officer: Monitors compliance with PPE requirements
4. Tools & Equipment
- Ceiling cassette unit
- Mounting brackets & suspension rods
- Refrigerant piping kit
- Insulation materials
- Condensate drain pipe
- Laser level
- Core drill (for piping)
- Manifold gauge set
- Vacuum pump
- Electrical test meter
5. Installation Procedure
5.1 Pre-Installation
- Verify ceiling structural capacity (min. 50kg support)
- Confirm clearances (typically 30cm from walls)
- Mark refrigerant piping route to outdoor unit
5.2 Framework Installation
- Install suspension rods at 4 corners using M8 bolts
- Level mounting frame within ±2mm tolerance
- Secure with seismic restraints if required
5.3 Piping Works
- Run insulated copper pipes (flare connections)
- Install condensate drain with 1:100 slope
- Pressure test at 500psi for 24 hours
5.4 Electrical Connections
- Connect power cables (typically 220V/1Φ)
- Install dedicated circuit breaker
- Verify control wiring to thermostat
5.5 Unit Mounting
- Lift cassette using spreader bar
- Secure to mounting frame
- Connect refrigerant lines (torque to spec)
6. Testing & Commissioning
| Test | Procedure | Acceptance Criteria |
|---|---|---|
| Vacuum Test | Evacuate to 500 microns | Hold for 15 minutes |
| Drain Test | Pour 2L water in drain pan | Verify complete drainage |
| Operation Test | Run all modes for 1 hour | ±1°C of set temperature |
7. Safety Measures
- ▶️ Fall protection for ceiling work
- ▶️ Lockout/Tagout for electrical works
- ▶️ Refrigerant handling certification required
- ▶️ Fire extinguisher on-site
8. References
- ASHRAE 15 Safety Standard
- Manufacturer's installation manual
- Local mechanical codes
Prepared by: _________________________
Approved by: _________________________
Date: _____/_____/_________
Note: All installations require final inspection by licensed HVAC engineer.