After spend 3 weeks in our new BH 3160 we decided to clean all the saw dust out of the unit. The worst was in the return ducts of both ACs. The one over the TV was 1/3 blocked with wood chips and dust. Under the bed was another bad area. Our 2010 BH was the same. I would think Heartland could afford a couple of air hoses to eliminate this problem. LOVE our new BH