I seemed to have this problem with the heat in my apartment. Now keep in mind that a few months ago I lived in a different house and that heat also gave me problems, so it's not just this heater. Before it was central heating, now it's forced heat. Whenever it kicks on I start coughing like crazy. When I wake up in the morning I have, I'm guessing but a few ounces of mucous in my lungs, but come 4 or 5 at night, none, I'm totally fine. I tried turning on my ceiling fan to circulate some of the air some, it helped a little, but I still have much mucous. One night I woke up coughing, so I opened my window and it helped, but it's way too cold to keep the window open now. Note I'm only like this in the winter, in the summer, for the most part I'm quiet. I spoke to my doc about this and he said it's just the changing of the seasons; I think it's a bit more then that.