This button helps your car cool faster, save fuel
What's the story
The air recirculation button on your car's dashboard, often overlooked by drivers, is more important than you think. The button, which looks like a car outline with a curved arrow inside, plays an essential role in the functioning of your vehicle's air conditioning system. When activated, it prevents outside air from entering and instead recirculates the cabin air for cooling. This not only cools the cabin faster but also reduces engine load and improves fuel efficiency.
Mechanism
How does it work?
The air recirculation button works by closing the external vents of your car's AC system and preventing it from drawing in outside air. Instead, it pulls in air from inside the cabin, usually from the footwells, and runs it through the system. This may seem like a small change but has a major impact on how quickly your cabin cools down.
Efficiency
It cools your cabin faster
Your car's AC doesn't produce cold air; it removes heat from the air it takes in. In fresh air mode, if the outside temperature is 35 degree Celsius, the system continuously works against that temperature. But when you switch to recirculation, once the cabin temperature drops to 25 degree Celsius, it starts working with this lower temperature. Each cycle begins at a lower temperature, making the cabin reach your desired setting much faster than before.
Savings
It also saves fuel
The AC compressor, a mechanical pump driven by the engine via a belt, works harder when cooling hot outside air. This puts maximum load on the engine and costs fuel. However, when recirculation brings down intake air temperature progressively, the compressor doesn't have to work as hard. Modern variable-displacement compressors throttle back when thermal load drops, reducing mechanical drag on the engine and saving fuel in the process.
Usage tips
When to use it?
The air recirculation mode should be activated as soon as you get into a hot car and want it to cool quickly. In bumper-to-bumper traffic, this feature also prevents the exhaust fumes from entering the cabin. However, avoid using it for long periods with multiple passengers in a closed car, as CO2 levels may rise and the air could become stale.