dryer exhaust question

I am not sure whether I am referring to this correctly, but…I just bought a house where the owner had the silver dryer duct/exhaust/thingie attached to a white box on the floor rather than to a wall so the steam goes outside. There is a switch near the dryer that turns a fan near the basement window on. This seems to pull some of the heat and steam out, but not all. Is this common/ok?

By Cantaffordcarroll | 01/01/2009 9:21 AM