The automotive a/c evaporator core contains cold Freon gas unlike the radiator that contain hot antifreeze. While in the system, the cold r12 or r134a Freon gas passes through the evaporator causing the evaporator to become very cold. The a/c blower fan can be found behind the evaporator and blows air across evaporator core. The cold air travels through the dash ducts work its way into the the vents inside the vehicle. The a/c water you see dripping from under the passenger side of the car is coming from condensation at the evaporator core.