A car air conditioning system consists of a compact version of the components of the normal air conditioner that has an evaporator, compressor, condenser, expansion device, and a fan which are fitted in a car to provide air condition inside the passenger’s compartment.
This air conditioning system takes power from the engine’s crankshaft and is operated
Why do we need an Automobile or an air conditioning system?
As we have already mentioned, the air conditioning system inside a cabin is required to provide a relaxed and fatigue-free atmosphere to the humans which in turn provides comfort which is essential for the health of a human being. But in a car, it is required due to the following reasons.
- When a vehicle is running, the passengers have to face lots of traffic that causes slow motion of vehicle due to which it is essential for a vehicle to be equipped with a system that can provide a comfort zone for the passengers.
- During summers there is lots of hot and humid air in the atmosphere which causes difficulty for a driver to drive and also for the passengers to travel, so during summer, an effective air conditioning system is required in a car which can provide a cool and humid free environment inside a passenger’s compartment.
- Air conditioning does not only condition the environment inside a passenger’s cabin but also provides filtered air which is very essential in cities like Dubai due to the very hazardous air pollution condition that can cause health issues to the passengers.
- In winters a vehicle faces a problem of fog or vapor formation over a front mirror which causes visibility problems and makes it difficult for a driver to drive a car, so it is essential for a vehicle to be equipped with a system that can fight with this problem.
How does automatic air conditioning work in a car?
High-Pressure Stage
Car air conditioning systems are constantly under pressure from a gas known as a refrigerant. In the past, a gas known as R-12, CFC-12, or its brand name Freon was used for decades until it was discovered that the gas was having a profound effect on the ozone layer. A chlorofluorocarbon, Freon is an organic compound that contains only carbon, chlorine and fluorine, and was produced as an erratic imitative substitute for methane, ethane, and propane. It was banned from production in the US and replacements called R-134a or HFC-134a were required in all vehicles produced after 1996.
The Compressor is in essence a pump that is powered by a belt connected to the engine’s crankshaft. When the shaft allows the refrigerant into the compressor, the belt drives the pump, putting the refrigerant under pressure. The system’s condenser acts just like a radiator wherein the pressurized gas is cooled by the expansion tubes that chill and turn the gas into a liquid. Next, the cooled refrigerant needs to be prepared for the evaporator and is sent through a tiny tank called the receiver or dryer. This reservoir contains discaants, a hygroscopic substance that helps liquids to sustain a state of dryness. These desiccants keep water away from the air – very similar to the packets of silica salt found in shoe boxes.
Low-Pressure Stage
After flowing through the dryer, the cooled liquid is put through expansion tubes were – you guessed it – it’s permitted to expand. This is the first stage of the low-pressure process where the refrigerant is allowed to relax before it is sent through the evaporator. This expansion valve is one of the more commonly serviced pieces of a vehicle’s A/C unit. The valves are moving parts that can easily wear out over time.
The evaporator is where the hard work of both the high-pressure stage and low-pressure stages comes to life. The evaporator is usually located underneath the dashboard within the cabin of the car. It functions to convert the cooled liquid back into a gas through a series of coils. The liquid boils the refrigerant to the point where it becomes gas and is then pushed out of the evaporator as a cold gas.
There are five essential parts to every vehicle AC unit you should know about:
- Compressor
- Condenser
- Expansion Tube
- Receiver/Dryer
- Evaporator
