There are two buttons on a car’s air conditioner. One is the “recirculation” button, and the other is the “fresh air mode” button.
How to use these buttons is one of the things commonly reported as unknown by vehicle owners, so here I will tell you about their distinctions.
What is “recirculation mode”?
Recirculation is used is to circulate the air inside the car.
Selecting this button closes an air duct in the front of the car so that the air from outside the car does not enter the car.
What is “fresh air mode”?
Selecting this button introduces outside air into the car by opening an air duct in the front of the vehicle.
Which to use, recirculation or fresh air mode?
When it is better to use recirculation mode.
It is better to use recirculation in the following cases.
You want to make the air conditioner work quickly
Compared to fresh air mode, using the air conditioner in recirculation mode improves efficiency and the air conditioner works more quickly.
This is the same using air conditioners in the room of a building with the doors and windows closed.
If you do not close the room, the air from the air conditioner will escape, it will not get cold or warm up easily.
Also, air conditioning will be stronger in recirculation mode than fresh air mode.
You do not want dirty air or unpleasant odours inside the car
When driving in a tunnel, or behind a large truck etc. with the windows of the car open, dirty air and exhaust gas comes in. This is very unpleasant.
In these scenarios, it is best switch to recirculation mode, to block the entry of unclean outside air.
When it is better to use fresh air mode
To defog the windscreen quickly
Foggy windscreens are due to the temperature difference between the inside and the outside of the vehicle.
It is necessary to eliminate this temperature difference in order to defog the window.
In fresh air mode, it is possible to eliminate the temperature difference between the inside and the outside of the vehicle, so that the window can be defogged. In this case, choose the windscreen defroster in fresh air mode, so that outside air blows out around the window.
If you want to get defog as soon as the front window becomes cloudy, using the air conditioner at the same time will be faster.
You want to ventilate the vehicle
When you smoke a cigarette or eat food in the car, it can become full of unpleasant odours.
In such a case, switch to fresh air mode to ventilate the car by bringing in fresh air from outside.
What is the manufacturer's recommendation?
When looking at instruction manuals and explanations on the websites of automobile manufacturers, most say that fresh air mode should be the default for normal use.
The reason for this is that not only the windows become foggy if left in recirculation mode for a long time, the air inside the car also becomes unclean and short of oxygen, which can result in sleepiness.
For this reason, it is best to use "fresh air mode" usually and to select "recirculation mode" only when it is better to recycle the inside air.