Evaporator Core—The a/c evaporator is like a small radiator but instead of containing hot antifreeze it contains cold Freon gas. The cold Freon gas passes through the evaporator thus making the evaporator very cold. The a/c blower fan is located behind the evaporator and blows air across it and that cold air travels through the dash duct work and out the vents inside the car. Consider the evaporator like a block of ice in your hand and when you blow across it like the blower fan you get cold air. The a/c water you see dripping from under the passenger side of the car is coming from condensation at the evaporator core.