Window AC

A window air conditioner (often abbreviated as window AC or window unit) is a self-contained cooling system designed to be installed in a window or a slot in a wall. It is a popular choice for cooling individual rooms or small spaces, such as bedrooms, apartments, or offices.

A Window AC or any other AC working principle is same. All ACs are working on HVAC cycle. Window AC is basically installed in window or in gap of wall. It is very small AC as compared to other ACs. This AC don't have separate indoor & outdoor. Both indoor & outdoor section are placed in one location. This AC take small space for installation.

Working of Window AC:

As shown in above figure AC is installed in wall or in window. AC's front side is indoor which is inside the room & outdoor is outside the room. 

The working of Window is same but as mentioned in HVAC system. 

The compressor is compress the refrigerant gas at high temprature & high pressure after that refrigerant gas goes into condenser coil. In condenser coil heat is exchanged through outdoor fan (condenser fan) and the refrigerant gas become liquid with high pressure. This liquid state refrigerant is entered into expansion valve. Expansion valve spred liquid refrigerant in evaporator coil & then refrigerant is at liquid level with low pressure. When indoor blower blow air on evaporator coil then heat exchanging happens and cooled air enter into room. 

This blower also suck the return air from room which was hot air and blow this hot air again blow on evaporator coil & air temprature is get doen. This thing is continuously repeated. Once temprature maintained then AC will run on FAN mode. 

To maintain air quality in room AC take fresh air from outside through damper. This air damper is placed between indoor & outdoor. 

There are two controls in this AC:

1) Master Control:

It controls the compressor, compressor motor, evaporator & condenser fan motor. 

When switch is on cool mode then all motors & compressor is start and complete unit is work as air conditioning unit. 

When switch is on FAN mode then only evaporator fan motor is turn ON and complete unit is work as FAN. 

2) Thermostat Control:

Thermostat basically sense the temprature. It is placed in the path of return air. When the temprature of return air is same as set point then AC will be automatically switched OFF. 

Note: Either single motor is used for evaporator & condenser fan or seprate motor is used for evaporator & condenser fan. 

Maintenance of Windows AC: 

During maintenance of AC below points need to be check

1) Compressor:

• Check for any undue noise & vibration. 
• Anti - Vibration mounting to be checked. 
• Check the compressor current & voltage. 

2) Condenser & Evaporator:

• Condenser & Evaporator coils ro be washed with proper jet spray. 
• Condenser fan blade to be checked. 
• Evaporator blower to be checked. 
• Check fan & blower motor operation for free movement. 
• Check for any undue noise & vibration from motor. 
• Check outdoor anti vibration pads. 
• Check the current & voltage of both fans. 

3) Control or PCB:

• Check thermostat for proper operation. 
• Selector switch to be checked. 
• Supply air (temp) to be checked.

4) General:

• Check and tighten all terminal.
• Clean the air filter otherwise replace it if it damaged.
• Check the area around the AC unit and remove any leaves, branches, or other debris that may have accumulated. This ensures proper airflow and prevents blockages.
• Window ACs have a drainage system to remove condensation. Inspect the drainage channels or holes for any clogs and clean them if necessary. Ensure that water can flow freely without any obstruction.
• The seal between the window and the AC unit should be intact to prevent air leaks. Check for any gaps or cracks and use weatherstripping or caulk to seal them if needed. This improves energy efficiency.