Are you referring to a specific car?. Most of the cars I've driven have an AC button, a Recirc button, a fan speed control and a temperature control. You can set the fan speed to max, the temperature to the coldest setting, and have the AC on cooling outside air. When you press recirc, it starts drawing air from inside the cabin.

The only cars I've driven that may have used the system you describe are fords and some chevys. I know that fords have an "ac" and a "max ac" setting on the knob, and the difference may well have been recirculation. It's been a while since I've driven one.