Most all vehicles have a re-circulation button with the AC controls in their cars. But many of us are unsure when to use it.
Well, the easy answer is to use it in the summer and turn it off in the winter.
The re-circulation button simply takes the air from inside the car and recirculates it in the cabin instead of pulling fresh air from outside. On days like today when it is miserably hot outside, if you do not recirculate the cooler air in the cabin, than your AC system is pulling hot air from outside and trying to cool it. Using the re-circulation feature will get your car cooler and will decrease the wear and tear on your AC system.
– Side note, if your car has been baking in the sun, its better to roll the windows down and turn recirculate off for the first minute or so to get rid of the super hot air inside the car before turning the recirculate on.