Venting dryer downward/through floor
Because of the location of our laundry room (center of house/2d floor), it looks like the best route for dryer exhaust/vent is through floor to first floor ceiling joists, and then out the side of the house.
Are there any special precautions for this venting route, given that it's going down, rather than up? Is there any issue the fact that heat rises? Or that moisture that may collect on duct will not dribble back towards the dryer?