Travelling by car for work or leisure can be very stressful when the weather is hot. According to various studies, the driver’s reactions are 20% slower when the temperature in the passenger compartment exceeds 35° C compared to 25° C. That is like having a blood alcohol level of 0.5 grams of alcohol per litre. Not to mention that the temperature inside the car can spike up to 60° C when it is parked in the sun. That is why a good air conditioning system is certainly useful but it is advisable to follow a few simple rules to make the best use of it. You need to beware of an insidious enemy, one that acts silently at first and then makes itself felt after a distance, even after a few hours, because you could catch a chill that exposes you to several risks, from a simple sore throat to conjunctivitis, colds, bronchitis and even pneumonia. Not to mention annoying muscle troubles (typical stiff neck), joint and abdominal pain, intestinal problems and headaches.
EASY DOES IT
The first thing to do is to turn up the system gradually and not set it immediately to maximum cooling (16/17° C) as you could be tempted to do when the car is overheated after being parked in the sun. The best thing to do is to open the doors and windows for a minute or so before turning on the engine and A/C. This will reduce the air temperature in the passenger compartment. The second thing to remember is to keep the air recirculation function off. It is a common fallacy that preventing warm air from entering from outside will help to lower temperatures. However, by doing so, the air inside the passenger compartment becomes less healthy and the passenger compartment will become saturated with dirty air.
Another misconception is that the air conditioning should never be switched on if the outside temperature is not high. Even in summer, humidity can be very high in the morning and switching the A/C on eliminates the risk of fogging up the windows. In general, setting the A/C to 22-24° C is sufficient for travelling comfortably. Importantly, do not direct the air vents towards your face, chest or stomach. It is recommended to point it towards the windscreen, windows and (without overdoing it) the feet. The aim is to achieve a uniform temperature so it makes sense to leave it to the system by activating the “auto” function, if available. Finally, air must not be stagnant. When travelling, roll down the windows for a few minutes every hour.
Never forget that the A/C takes air from outside and introduces it after it has been dehumidified, cooled and filtered. For the system to work properly, have the filters replaced every year or 15,000 km. Condensation can accumulate in the system and bacteria can prosper in hot weather. This is not hygienic and responsible for unpleasant air odours. A good rule of thumb is to switch the A/C off a few minutes before arriving at your destination, leaving the fan on to partly remove any moisture. If the bad smell persists, disinfectant sprays are needed to defeat the bacteria. You will find them easily in car accessory shops and they must be sprayed in the radiator or the air vents. The vehicle passenger compartment must be well ventilated immediately after application.