Construction, Working Principle, Types and Troubleshooting of Wall Mounted Split Air Conditioner
Wall mounted split air conditioners are widely used in residential and commercial applications due to their efficient performance, quiet operation, and aesthetic design. In the ITI Refrigeration and Air Conditioning (RAC) trade, it is essential to understand their construction, working principle, types, and troubleshooting methods for proper installation and maintenance.
Construction of Wall Mounted Split AC
A wall mounted split air conditioner consists of two main units: the indoor unit and the outdoor unit. These units are connected by refrigerant piping, electrical wiring, and a condensate drain line.
Indoor Unit
- Evaporator Coil: Made of copper tubes with aluminum fins, it absorbs heat from indoor air.
- Blower Fan: Circulates air over the evaporator coil and supplies cooled air into the room.
- Air Filter: Removes dust and impurities from air.
- Drain Tray and Pipe: Collects and removes condensate water.
- Control Panel (PCB): Controls operation using sensors and remote signals.
Outdoor Unit
- Compressor: Compresses refrigerant and circulates it through the system.
- Condenser Coil: Releases heat to the outside air.
- Condenser Fan: Improves heat dissipation.
- Expansion Device: Usually capillary tube or expansion valve.
- Casing: Protects components from weather conditions.
Connecting Components
- Suction Line: Carries low-pressure vapor refrigerant.
- Liquid Line: Carries high-pressure liquid refrigerant.
- Insulation: Prevents heat gain/loss in pipes.
Working Principle
The working of a wall mounted split AC is based on the vapor compression refrigeration cycle:
- Evaporation: The evaporator absorbs heat from indoor air, cooling the room. Refrigerant changes from liquid to vapor.
- Compression: The compressor compresses low-pressure vapor into high-pressure, high-temperature vapor.
- Condensation: The condenser releases heat to the outdoor air, converting refrigerant into liquid.
- Expansion: The expansion device reduces pressure and temperature of refrigerant before entering evaporator.
This cycle repeats continuously to maintain the desired indoor temperature.
Types of Wall Mounted Split AC
Non-Inverter Split AC
- Compressor runs at constant speed
- Turns ON/OFF based on thermostat
- Lower initial cost
Inverter Split AC
- Compressor speed varies as per load
- Energy efficient and quieter
- Maintains constant temperature
Hot and Cold Split AC
- Provides both cooling and heating
- Uses reverse cycle operation
Smart Split AC
- Wi-Fi enabled control
- Remote operation via mobile apps
Troubleshooting of Wall Mounted Split AC
Troubleshooting is essential to identify and fix faults in the system. Common problems and their causes are explained below:
1. AC Not Cooling Properly
- Low refrigerant charge
- Dirty air filters or coils
- Faulty compressor
2. AC Not Starting
- Power supply issues
- Faulty capacitor or relay
- PCB malfunction
3. Water Leakage from Indoor Unit
- Blocked drain pipe
- Improper installation angle
- Dirty evaporator coil
4. Unusual Noise
- Loose components
- Fan imbalance
- Compressor issues
5. Ice Formation on Evaporator
- Low refrigerant
- Poor airflow
- Faulty thermostat
6. Compressor Not Running
- Overload protection activated
- Faulty wiring
- Defective compressor
General Maintenance Tips
- Clean filters regularly
- Check refrigerant pressure
- Inspect electrical connections
- Clean condenser and evaporator coils
Conclusion
Understanding the construction, working principle, types, and troubleshooting of wall mounted split air conditioners is essential for RAC technicians. It helps in proper installation, efficient operation, and quick fault diagnosis.
With increasing use of split AC systems, technical knowledge and practical skills are important for maintaining performance, energy efficiency, and long service life. Proper troubleshooting ensures reliable operation and customer satisfaction.