Summer is just around the corner. As we all know, a good car air-conditioning system can cool the car down quickly and ensure a comfortable drive, but we often don’t really know how to use the air-con properly or how to maintain and look after the system. We often find ourselves in this situation: when we switch on the car’s air conditioning in sweltering, blazing heat, we discover that the system is malfunctioning, which can be quite a worry. To address these issues, we’ll provide a detailed guide on the correct use of your car’s air conditioning system and the key points to bear in mind during its maintenance and upkeep.

Turning on a car’s air conditioning system may seem like a straightforward task, but in reality, it is easy to overlook the correct methods and precautions. Whilst we do not need to fully understand how the entire system works or its complete structure, it is essential to know the correct way to use it and how to maintain it properly. Understanding these points not only improves the efficiency and durability of your car’s air conditioning but also ensures the system remains in good working order, as its condition directly affects our health.

Turn on the car air conditioning regularly

Firstly, the cool air blown out of the car’s vents passes through the blower fan, the evaporator in the air-conditioning system, the small reservoir in the heating system, and the air ducts. Over time, these systems accumulate significant amounts of dust and moisture; if not used or maintained properly, this can lead to mould growth and encourage the proliferation of bacteria, the harm to our health being self-evident.

When using the car’s air conditioning system for the first time after a change of season, you should open the car doors, switch to the external air circulation mode and set the fan to high. You should then step out of the vehicle, leave the system running for at least two minutes, switch it off, and clean the seats and carpets inside the car. This is done to expel as much bacteria and dirt as possible from the air conditioning system, which has been left unused for a long period, thereby preventing any adverse effects on the quality of the air inside the vehicle and reducing potential harm to the driver and passengers.

During other seasons when the air conditioning is not required for cooling, you should still switch it on at least once a month. Leave it running for just 30 seconds before switching it off. This ensures that the compressor and all the pipes remain well-lubricated, prevents leaks and the deterioration of hoses, and enhances the durability of the air conditioning system.

In direct sunlight, let the air heat up first before switching to cooling

When a car is left parked in direct sunlight, the temperature inside can reach 50°C or even higher. This makes getting into the car a real ordeal for the driver. Even with the air conditioning switched on, it is difficult to bring the temperature down quickly enough. At best, one might feel a slight coolness from the vents, whilst the seat and backrest remain unbearably hot.

In fact, before getting into the car, open all the windows or doors to let the hot air out. Switch on the fan and the fresh air mode (without turning on the cooling function just yet) to speed up air circulation and quickly dispel the heat from inside the car. Only then should you get in, close the windows and doors, and switch on the cooling function. Doing this will naturally improve the cooling performance and efficiency of the air conditioning.

Avoid leaving it switched on for long periods

Some motorists, for the sake of convenience, leave the air conditioning running continuously during the summer. However, when a vehicle is cold-started, neither the lubrication provided by the engine oil nor the operating temperature of the cylinders is at an optimal level. Under these conditions, the load on the engine and the resulting wear are the most severe of all operating conditions. Furthermore, running the air conditioning compressor and blower fan simultaneously increases the load on both the engine and the electrical system, causing unnecessary wear to the engine whilst also resulting in suboptimal cooling performance. Therefore, the air conditioning system should be switched off when starting the vehicle.

However, during the cooling process, car air conditioning systems accumulate a significant amount of moisture inside. If the engine is switched off immediately, this trapped moisture cannot be expelled quickly enough; over time, this leads to mould forming inside the air conditioning ducts, thereby fostering the growth of bacteria that are harmful to our health. If you notice a sour, musty odour whilst using the air conditioning, this is typically the result of prolonged improper use. To address this issue, three minutes before reaching your destination, switch off the cooling function and set the system to fresh air mode. This allows as much moisture as possible to be expelled from the system, thereby reducing the likelihood of mould growth inside the unit.

The operating time should not be too long

Many drivers set their air conditioning to the lowest temperature and leave it on for long periods to combat the sweltering heat of summer. However, this is actually very detrimental to one’s health. Due to the significant temperature difference between the inside and outside of the vehicle, excessively low temperatures inside the car can easily cause passengers who have just stepped in from a hot environment to develop heat-related colds or flu-like symptoms. Furthermore, prolonged exposure to a cold air-conditioned environment increases the risk of developing ‘air-conditioning sickness’. For air conditioning systems with automatic climate control, we recommend setting the temperature between 22°C and 26°C.

Finally, it is crucial to note that many drivers often leave their cars parked in garages with the air conditioning running whilst they rest. This practice carries a high risk of carbon monoxide poisoning. In enclosed spaces, carbon monoxide from vehicle exhaust fumes accumulates and is drawn into the cabin through the air conditioning system’s air intake, causing carbon monoxide levels to rise. This can lead to poisoning and, in severe cases, even death. Therefore, when a vehicle is in a relatively enclosed environment, the air conditioning should be switched off and the engine turned off.

When using the air conditioning in recirculation mode for extended periods whilst parked outdoors, the lack of air circulation causes the air inside the vehicle to become stale. Driving for long periods in such an environment can lead to dizziness and a foggy head, which may affect the health of both the driver and passengers. It is therefore not advisable to use the recirculation mode with the windows closed for long periods. During long journeys, you should switch to fresh air mode frequently and stop to rest at appropriate intervals to alleviate fatigue. Furthermore, in older vehicle models with poor heat dissipation, leaving the air conditioning running for an extended period after parking may cause the coolant temperature to rise excessively, which in severe cases could result in engine damage.