How does air conditioning system works in a car?

During hot days, many people find refuge in their cars. This is because apart from shade, cars also provide a cool environment in which occupants don’t have to bear the heat. This wouldn’t be possible if a car doesn’t have an air conditioning system. Perhaps, during one of those hot days sitting in a car, you have wondered how an air conditioning system works.

So, how does a car air condition system work?

As you may have noticed, an air conditioning system doesn’t just involve a cooling fan. While a fan may cool down air inside a car, it can’t bring the temperature much lower. On the other hand, an air conditioning also cools down the air inside a car, just like a fan, but with a greater effect. Furthermore, an air conditioning does more than that.

Simply put, an air conditioning system conditions the air inside a car. So, this means that the system does more than cooling the air inside the car. An air conditioning system also reduces the humidity level – or the amount of moisture in the air – in the car. By lowering the air temperature and reducing the amount of moisture from the air, car occupant would feel more comfortable.

Air conditioning, whether in car, a room or a building, works by employing four basic principles: Evaporation, Condensation, Compression and Expansion. An air conditioning system is fitted with a number of parts that fulfill these principles: Compressor, Condenser, Expansion Valve, Receiver Drier and Evaporator.

As soon as the air conditioning system is turned on, a cooling fluid called refrigerant enters the compressor. The compressor squeezes (compression) the refrigerant, packing the molecules together. This process usually results in high temperature, and the refrigerant becomes a high-pressure vapor. Then this vapor is pumped to the condenser.

The condenser now changes the high-pressure vapor into high-pressure liquid. Looking very similar to a radiator, the condenser packs (condensation) the molecules in the vapor, thereby transforming the refrigerant into its liquid state. The process also generates heat, which in turn is removed by air flowing through the condenser.

Then, the now liquid refrigerant flows to the expansion valve, also called as orifice tube. This valve removes pressure from the refrigerant, allowing it to expand (Expansion) and becomes cold vapor. Since some moisture might still be carried with the refrigerant vapor, this moisture is removed through a desiccant in the receiver drier.

Now free from moisture, the cold refrigerant vapor moves into the evaporator, which looks similar to a radiator and is installed in the cabin or passenger compartment. As the cold refrigerant vapor passes through the evaporator, it vaporizes (Evaporation) and absorbs heat from the air sucked from the cabin. Air in the cabin is sucked by an air intake and is blown through the evaporator. This air becomes cold and enters the passenger compartment.

From the evaporator, the refrigerant is sent to the compressor to continue the air conditioning process.