You may have a restricted or very dirty evaporator core/box. after a while the restrictions will ice up and you will get no air flow. when you turn the air off and it melts, it will work fine again until it ices up again. you may require a a/c evap cleaner spray, kool-it 96030 for example, and spray it up into the 1" drain on the passenger side of the engine compartment.

 

I was in my wife's Edge today and it was about 93 and the humidity up there too and I was sweating bullets. I could hear the fan blowing but nothing much coming out of vents. Brought down glove box and wouldn't you know it. My wife has apparently been stuffing a ton of napkins in glove and the went over the top and were docked into the recirculate vent. I would check in there make sure you do not have anything obstructing that vent, it's behind the glove box.

 

Did the OP ever find a solution to the problem? My recirculation vent is all clear so that is not the issue.

 

I have not identified a solution yet. I have not had time to take the truck somewhere and get it checked out like I want to. The air has been working great even with the 100+ degree days we've been having, so that is partly why I haven't yet made this a priority to get checked out further. I even had to make a 3 hr drive to OK and back last week and did not have any issues... but I did stop for about 15 - 20 minutes so it wasn't a continuous 3 hr drive.

 

It could be that the high heat won't let the ice form. See if it comes back once it cools down a bit and let us know.