Condensation in an air conditioner refers to the process by which water vapor in the air changes into liquid water. This occurs when warm, humid air comes into contact with a cold surface, such as the evaporator coil of an air conditioning unit.
The condensation process happens as follows:
Air Circulation: The air conditioner draws warm air from the room through a return air grille and passes it over the evaporator coil.
Cooling Process: The evaporator coil contains a refrigerant, which absorbs heat from the warm air as it passes over the coil. This heat transfer cools down the air, lowering its temperature.
Moisture Removal: As the air cools, its ability to hold moisture decreases. The moisture in the air condenses on the cold surface of the evaporator coil, turning into liquid water droplets.
Drainage: The liquid water collects in a condensate pan located beneath the evaporator coil. It is then drained out of the air conditioner through a condensate drain line or pumped out using a condensate pump.
Now, let's move on to why condensation occurs after switching off the compressor inside an air conditioning unit:
The compressor is a vital component of an air conditioner that circulates refrigerant, pressurizing and propelling it through the cooling system. When the compressor is operating, it maintains the evaporator coil's surface temperature at a level below the dew point of the air passing over it, causing condensation to occur.
However, once the compressor is switched off, the refrigerant circulation stops, and the evaporator coil begins to warm up. As a result, the surface temperature of the coil rises above the dew point, preventing further condensation from taking place.
However, the air in the room may still contain a significant amount of moisture. When the air conditioner is turned off, the cooling effect on the room air ceases, and the temperature of the evaporator coil gradually increases to match the surrounding room temperature. This temperature rise causes the moisture remaining in the air to re-evaporate, rather than condense, since the surface of the evaporator coil is no longer cold enough to facilitate condensation.
In summary, condensation occurs during normal air conditioning operation when warm, humid air comes into contact with a cold evaporator coil. After switching off the compressor, the evaporator coil warms up, preventing further condensation and causing any remaining moisture in the air to re-evaporate.