Bean dust, along with a lot of other stuff, makes me sneeze, not bad, just enough to be annoying. Also produces a lot of sinus drainage. I used to clean out the old JD 4400 cab when getting ready for harvest. Also cleaned the cab filter (no A/C, just a blower). I would have that cab spotless with all the holes plugged. Run the blower to keep the cab pressurized. Get to the end of the row and while I'm turning Dad would hop up on the step and ride a round just to make sure I was doing a good job. It would never fail. He would reach up and pop the door open to tell me what I needed to correct (run the header a bit lower, even though it's already on the ground, speed up the reel, slow down the reel, drive a little slower/faster, etc.). But when he popped that door open all my cleaning was for naught. "Dad, I'm trying to keep the bean dust out of here!" His reply, "Ah, a little dust won't hurt you. We didn't used to have cabs on anything." "True, but now we do. Why not take advantage of it?"