Condensation in an air conditioner refers to the process of converting water vapor in the air into liquid water when it comes into contact with a cold surface. This phenomenon is essential for the proper functioning of an air conditioning unit as it helps to remove humidity from the indoor air, making the environment more comfortable.
Here's how condensation occurs in an air conditioner:
Cooling Process: Air conditioners work by circulating refrigerant through a closed loop system. The refrigerant absorbs heat from the indoor air and carries it to the outdoor unit, where it releases the heat to the outside environment. As a result, the air inside the air conditioner becomes cooler.
Dehumidification: When warm, humid air is blown over the cold evaporator coil of the air conditioner, the temperature difference causes the water vapor in the air to condense into droplets on the surface of the coil. These droplets collect and eventually form water.
Drainage: The condensed water drips down from the evaporator coil into a drainage pan or tray. From there, it is usually directed outside the building through a drain pipe or pumped out to prevent water leakage inside the room.
Now, regarding why condensation may happen after switching off the compressor inside an air conditioning unit:
The compressor is the central component responsible for the circulation of refrigerant and the cooling process in the air conditioner. When the compressor is running, it maintains a low temperature on the evaporator coil, leading to continuous condensation of water vapor in the air.
However, when the air conditioner is switched off, the compressor stops running, and the cooling process ceases. The evaporator coil, which was previously cold, starts to warm up slowly due to the ambient room temperature. Despite the compressor being off, the evaporator coil may still be colder than the surrounding air for a short period after the unit is switched off.
As a result, the warmer, humid air in the room can still come into contact with the relatively cold evaporator coil surface, causing condensation to occur even after the compressor has been turned off. This is why you might notice some water dripping or condensation forming on the evaporator coil after the air conditioner is switched off. Over time, as the coil warms up completely, the condensation process stops, and the coil returns to room temperature.