What does your car’s recirculation button actually do and should you use it?

When you’re flipping on your car’s air conditioning or heater -- you’ll be faced with a tough decision: fresh air or recirculation?

You may or may not know what the difference is -- maybe that’s why you clicked on this headline. Or maybe you’re here to tell me this is obvious information. Either way, we’re diving into it -- I cannot be stopped. We’ll keep it simple, don’t worry.

What’s the recirculation button do?

According to Main Street Mechanic, when you press the recirculation button, the air duct in the front of the car closes, so air from outside stops entering the car.

Instead, the existing air in the vehicle is, well, recirculated, and cooled or heated, based on which function you’re using.

If recirculation mode is off -- your air duct is open, and you’re pulling in air from outside the vehicle. Pretty standard info here.

So should you use recirculation or fresh air?

Experts say it’s best to use recirculation mode during the warmer months, while you’re using air conditioning, because your vehicle won’t have to cool down the air as much, since it’s coming from inside the car, and it’s already a cooler temperature.

Some newer models automatically switch modes based on air moisture levels.

You should try to avoid using recirculation in the winter, because it can trap humidity in the car, which could in turn fog up your windows. Your windows will de-fog faster when using fresh air in winter, too.

And during times of poor air quality, using the recirculation mode can help reduce pollution inside your vehicle, like when we have wildfire smoke in the air.