Despite the fact that these two buttons, the air intake in the cabin and the air recycling, have been in every car for decades, their use seems to keep the drivers' headaches.
So when do we use one and when the other? Whether you have a simple manual air conditioning system with a rotary switch or automatic and electronically controlled (even dual) air conditioning, the basic principles are the same here.
Air recycling remains the most common choice in the summer, but not in the winter. The recycling of cabin air will cool the indoor environment faster on a hot day, removing unnecessary hassle from the device's components. It is enough not to choose it recycling once you start, when the cabin is still hot that is!
However, we choose air recycling when the windows start to fade. In a cold winter day, that is, or in a sudden summer rain.
The basic idea here is that the car's air conditioning system should work like home air conditioners. Which recycle the room air by cooling it more and more, instead of introducing the hottest air from the outside environment. The same goes for its AC car.
So when it comes to making air conditioning work quickly and efficiently, air recycling is the only appropriate action. We do the same and when we don't want the bad odors of the outside to enter the cabin, we block the introduction of fresh air.
That's according to Tamotsu Todoroki, an air conditioning expert, despite the fact that what he says contradicts the manufacturers' manuals, which often suggest air intake as the most suitable way for the air conditioner to work.
The reason for this is not just that glazing of the windows, but also the fear of manufacturers for the cabin air, which is becoming increasingly unclean and low in oxygen, a situation that can lead to dangerous situations for passengers.
The well-known website How Stuff Works tells us, however, that this is a myth that has survived unjustly. The car is not a closed system, as air passes inside even with the air conditioner in the air recycling function. If you sit behind a garbage truck, the site tells us, in a little while you will be able to smell the stench that it emits even with the air recycling selected. And in any case, we always leave (even slightly open) a window.
The new generation of electronic air conditioners automatically switches between the two functions, taking care of the freshness of the air. In some recent models, the recycling button is even absent, as sensors that monitor temperature and humidity in the cabin operate fully autonomously here.