Hi Quilter, just a few other suggestions. I had my bedroom thoroughly cleaned, got all new hypo-allergenic bedding and the best dust mite covers for everything, espescially the mattress at they really collect there. The other thing I did was get an air purifier for my room. This is not a humidifier or dehumidifier. It filters the air in the room and removes all the dust, mold and offending particles. It might be worth looking into. Also, when I cough a lot I drink tea with honey. I have found honey to be very calming and seems to help quiet the cough. But I am also on a new med for my asthma called symbicort and it cleared me up the first day I used it. I haven't used my rescue inhaler in a week. And I am breathiing very freely now. So I just wanted to give you a few ideas and see if anything will work for you. Also, you should probably change your furnace filters at least once a month. That is what my heating company tells me and it is true they are all dusty after a month. You can get some at the hardware store for very cheap and they work as well as others. The 3 month ones I was told do not last that long so is a waste of money. Let us know how you are gettiing along.Take care.