Air Conditioning engaging when off

I have took the Dodge Caravan SE to one dealership and called another with this problem.

In the summer I noticed when the vent was on Floor with the AC button off the air was coming in like a refrigerator from the floor vent. A couple of times I noticed a large stream of water under the van flowing away when stopped.

The first dealership this will happen as the AC compressor will kick on when the humidity is high, the floor is wet or the coils are hot. The second dealership told me over the phone the compressor will never kick on if the button is not pressed (except for defrost). However that if you have temperature on cool all the way left and the air outside is 80 degrees the van would bring in the air at about 75 degrees cooling it. I said would it not eventually bring in 80 degrees since the van can not cool it? He said no there are things happening that would cool the air even though the compressor does not turn on.

it's not like when we had the vents we opened on the bottom and what came in is what came in. Its all new now.

So is the compressor kicking on? Does the van lower outside temperature without AC on? How can they check if the compressor is randomly turning on?