What is the air conditioning system/what does it do?

A car's air conditioning system conditions the air, which means while cooling the air in the car down, it also helps to ensure there isn't too much moisture in the car, so it stops the air getting too humid.  A further function of a car's air conditioning system is to clean the air in the car by filtering the dust and other particles from the air inside the car.

Getting into the details of the air conditioning system

An air conditioning system consists of several main components which work together, such as an aircon compressor, aircon condenser, aircon controller unit, pollen filter, aircon evaporator and aircon radiator.

The main features of an air conditioning system main are evaporation and condensation, and compression and expansion. At the heart of the car's air conditioning system, powered by a serpentine belt which is attached to the crankshaft of the car's engine, is the aircon compressor. Its role is similar to that of a heart, in that it pumps the refrigerant gas around the closed loop air conditioning system to the aircon condenser. The aircon compressor has a vital part to play and if it is damaged or faulty the entire air conditioning system will suffer. As the air in the car begins to warm up, the aircon compressor uses the heat from this warm air to begin the air conditioning process. The warm air is taken from inside the car, compressed in the aircon compressor and then this hot, compressed air is pumped into the aircon condenser. This hot air is then cooled in the aircon condenser and turns into liquid. This really cold liquid then flows from the aircon condenser into the aircon evaporator. As this is happening, warm air is blown through the evaporator and the warmth from this air is absorbed by the cold liquid travelling through the aircon evaporator, which makes the air being blown through the aircon evaporator really cold at the point it flows into the car. This whole process is then repeated over and again.

The pollen filter is an important part of the air conditioning system, which cleans and filters the air coming into the car and gets rid of allergens, essential for those who have allergies or suffer with respiratory difficulties. Having clean, filtered air in the car is also said to help avoid problems such as headaches, fatigue and nausea. The pollen filter catches pollen, dust, bacteria, exhaust fumes and stops any other particles, as well as leaves, dirt, twigs, insects and general road debris before they can enter the car's heating and ventilation and air conditioning systems.   A clogged up pollen filter can cause the air in the car to be contaminated with fumes and other unwanted particles, and because you are in an enclosed space this contamination is concentrated and therefore toxic. A blocked pollen filter can also inhibit air flow in the air conditioning and heating and ventilation system which could cause problems with the heating and cooling functions of these systems. It's worth ensuring you change the pollen filter before any problems like clogging, due to dirt build up, arise, particularly for the health benefits that having clean, filtered air provides. 

It is worth bearing in mind that using an air conditioning system in a car significantly reduces the number of miles per gallon the car can achieve. Energy is consumed in removing the heat and moisture from the air in the car, and this uses extra fuel because of the extra drain on the engine. But the health benefits of using an air conditioning system while travelling in the car are high and considered worth investing in by many people.

What if something goes wrong with the air conditioning system?

Air conditioning systems can fail for a number of reasons. For example, the air conditioning system can suffer from damage caused by an accident; the build up of mud and road debris can cause a blockage in the condenser; or corrosion can cause components to fail. A common cause of failure is a loss of refrigerant. This can be due to natural leakage over time or as a result of damage to components.