I used to have something similar to this for my dryer. It vented into a little 'pot' that you were supposed to fill with water to catch the lint. My wife at the time never filled the little pot and we had lint EVERYWHERE. Mix lint with humidity in a damp basement and it's like glue. I had to use a wire brush to take it off the foundation walls. I have since moved the dryer and vented it out a window. My dog likes to sleep under it when it gets cold and I'm doing laundry, so I'm not really wasting the heat, am I?