What is the car’s air recirculator and how to use it to make it a solution and not a problem.
It used to be a wheel, now it is a button that all modern cars have on their dashboard. It closes the air intake from the outside and reuses the air that is circulating in the passenger compartment. But just as it is useful for certain moments, it has to be disconnected in other circumstances.
The cars of the 70s and 80s regulated the hot and cold air, or the exit point on the floor or on the windshield through lever-type commands.
Advances in the design of climate control systems for automobiles have meant that what 50 years ago was a lateral lever that went from cold to hot, and from the feet to the windshield, has become a complex interior installation on the dashboard of cars, which is controlled by pressing a virtual button on a digital screen or a physical one on the central console.
Today, the air conditioning system in a passenger compartment not only heats or cools the environment, but also ensures that the windows do not fog up and that the air entering from the outside reaches the passengers as clean as possible. That is why today’s cars have a pollen filter and a button that many users do not fully understand what it is for: the air recirculator.
Often located in the central part of the dashboard, it is usually identified with the drawing of the silhouette of a car with an arrow rotating 180° inside, which effectively represents that the air is the same and does not come from the outside. Although most of them appeal to this almost universal scheme, there are brands that have decided to signal the recirculation system with a wheel composed of three or four arrows, more similar to the recycling symbol, but which can be understood without major difficulties.
The main function of this command is to isolate the passenger compartment of odors or impurities from the outside, so it is often used when driving or stopped behind a car that emits exhaust gases out of the ordinary, either by oil consumption or burning raw fuel, which often irritates the airways and eyesight of those who are exposed to these toxic fumes.
The second advantage, especially in summer, when the air conditioning is used to cool the interior with the air conditioner, is that the recirculator does not bring air from outside with the outside ambient temperature, and therefore less fuel will be consumed because the cooling will be faster. As is well known, the air conditioning equipment in automobiles requires energy that increases gasoline consumption.
The third benefit is related to the previous point. And is that, both in winter and summer, by closing the access of air from outside the passenger compartment, the air conditioning that we have selected will act more quickly, because the air that takes the system to forward it through the ducts is the same that is already inside, and therefore, is already at a temperature more suitable to what is required by the user. The gain is then double, in time and in consumption economy.
In any case, this effect is brief, because when the air is recirculated, its humidity is also recirculated, and then, in a few minutes, while the interior air conditioning is achieved, the windows of the car also fog up, especially in winter, when the temperature difference between the interior and the exterior is very large and the change of state of the air is generated, when it condenses.
So, if the fogging has already started, what to do is to turn on the air conditioning in winter, regulating the temperature towards heat values between 22° C and 24° C, and disconnect the recirculator in summer, so that the air begins to enter from the outside.
Regardless of whether the windows are fogged or not, and whether they are defrosted as mentioned above or by switching on the electric windshield and window defrosters, the air recirculation should not be used for more than ten minutes. It is very important that in a reduced environment, especially if there are more than two people, the air is renewed periodically, in order to maintain a purity for breathing.
The human being, when breathing, inhales oxygen and exhales carbon dioxide, therefore, after several minutes of keeping the recirculator connected, the air will start to become “rarefied”, heavy, and possibly cause drowsiness and headache, and beyond feeling more or less comfortable, it is dangerous for long trips, especially on the road. If this happens, the first thing to do is to open the front and rear windows to let the air circulate more quickly, in addition to disconnecting the recirculator.