The house we rent has a small washer/dryer and the vent runs up and out through the ceiling. The dryer motor isn't strong enough to push all the lint up and out so we ran the ProFlex down to the floor and now the dryer works much better.The only issue is that on a warm day, the heat from the dryer stays in the house and can make it even warmer inside. On the upside, on a cold day we don't have to run the heat so much.