An air conditioner (AC) works by removing heat from the indoor air, resulting in a cooling effect. While it may seem like the AC is "giving out cool air," it is actually absorbing heat from the room and expelling it outside. Let's explore the basic principles of how an AC operates:
Refrigerant: Air conditioners use a refrigerant, typically a chemical compound with low boiling and condensing points, such as hydrofluorocarbons (HFCs). The refrigerant circulates through a closed system of coils and tubes.
Evaporation: The AC system consists of two sets of coils: the evaporator coil and the condenser coil. The refrigerant starts in the evaporator coil, which is located indoors. The refrigerant is at low pressure, and as it enters the evaporator coil, it rapidly evaporates, absorbing heat from the indoor air in the process.
Heat Absorption: When the refrigerant evaporates, it changes from a liquid to a gas state. This phase change requires energy, which it extracts from the surrounding air. As a result, the indoor air loses heat, leading to a cooling effect in the room.
Compressor: After absorbing heat, the refrigerant in its gaseous state is then compressed by a compressor. The compressor raises the refrigerant's pressure, increasing its temperature as well.
Condensation: The high-pressure, high-temperature refrigerant gas now flows into the condenser coil, located outside the building. In the condenser coil, the refrigerant releases the heat it absorbed from the indoor air to the outdoor environment. As the refrigerant cools down, it changes back into a liquid state.
Heat Dissipation: The released heat is expelled into the outdoor air as the refrigerant condenses. The condenser coil, usually equipped with metal fins or a fan, facilitates the transfer of heat to the outside air.
Expansion Valve: The refrigerant, now in a liquid state, passes through an expansion valve or an orifice tube, which reduces its pressure. This pressure drop causes the refrigerant to cool further, preparing it for the evaporation stage in the indoor evaporator coil.
The process described above repeats cyclically to maintain a cool indoor environment. By continuously absorbing heat from the room and releasing it outside, the air conditioner creates a cooling effect.
It's worth noting that the air blown into the room by the AC is not inherently cool. Instead, it feels cool compared to the warmer air in the room because the AC has removed some of the heat from that air. The cooled air helps to lower the temperature and provide comfort to the occupants.