pop the glove box door off, its got a few screws to a hinge under the door. then look up top of the dash area, theres a door there, when you hit recirculate that door closes, with the car on and running work the button, see if this door opens and closes. could be a vac line thats fallen off or cracked to it.

hitting recirculate should make it blow a bit harder, but not all that much. it should get colder as well.