Air Recirculation

Some people mistake it for the ‘undo’ button, the ‘u-turn’ button or, our favourite, the ‘fish hook dispenser’ button.

What are we talking about? The recirculation button, which is fitted to all modern cars with air-conditioning. Like so many modern features, the recirculation button is often misunderstood and therefore not used correctly. So, we’re here to give you all the details on when you should use it and why.

What does it do?

The 'Recirculation' button, as it’s also known, performs a fairly simple function, instead of having the air conditioning drawing in fresh air from outside, it recirculates the air already in the cabin. It does this for several reasons, but the primary one is because it allows the air-con to quickly and efficiently cool the cabin; at least on warmer days.

When your air-con is taking in hot external air it takes more energy to cool it, whereas when the recirculation system is operating your air-conditioner is only having to keep the already-cooled air inside the car cold.

The eagle-eyed amongst you may have noticed that when you set your air-con to its maximum setting, the car automatically switches to recirculation as that’s the only way it can achieve its optimum cooling.

When should i use it?

During the hotter days of summer, it’s most beneficial to use the recirculation button because it will help to reduce the strain on your air-conditioning system. Not only will your car’s cabin cool more quickly, but you’ll also help your fuel economy. That’s because your air-con won’t need to work as hard and therefore reduce the load on the engine.

The trick to remember is that if you get into a car that has been sitting outside in the sun on a hot day, you’ll need to get rid of all the hot air from the car before you hit the button. So, you should wind down your windows and drive for a few minutes until the stale, hot air has been evacuated. Then you can hit the recirculation switch and dial up the maximum cooling effect.

Clearing the air

The other ideal time for using the recirculation button is when you’re stuck in traffic or a tunnel or enclosed space (such as a car park). Because your air conditioning is drawing in outside air from around your car, it’s also sucking in the exhaust gases from the other vehicles nearby.

Using the recirculation cuts off the feed of polluted air and allows you to breathe more clearly. A lot of modern tunnels around Australia will remind you to hit the button as you enter because even if the traffic is flowing smoothly and the tunnel’s circulation is working, there’s still a bigger build-up of polluted gases inside an enclosed space.

But while recirculation is best used in summer, the opposite is true in winter. That’s because with the colder outside air, using the button can trap moisture in the car and that will lead to foggy windows. In winter and on colder days, the air-con doesn’t need the extra help from the recirculation button so you can take in the fresh air instead.