Although there are many peculiar kinds of clothes dryers, they all have a type of exhaust port in the back to vent out the hot air that exits the dryer. The complication is that if you opened this port to the inside of your house, it would be like running a section furnace every time your clothes dryer is turned on. Therefore, ventilation chutes are installed in homes and apartments to allow the hot air exiting your dryer to reach the outdoors. In some cases the dryer vent runs straight out horizontally from your laundry room to an external wall and has an opening a few feet above groundlevel. Other dryer vents run vertically up to the rooftop and open at a port just like a plumbing air vent. The complication with vertical vents is that you are typically actually working against the force of gravity. Since these vents eventually accumulate degrees of dust and lint over time, it’s inevitable that this lint will eventually need to exit the system. In horizontal vents, the only force holding the lint from getting out is any friction it has against the metal or potential partial blockages from existing lint buildups. Not only do you have all of this to cope with in a vertical setup, however now you are actually working your dryer with creating enough air new to keep this line clear while also pushing any particulate up as high as 20 feet or more against gravity itself. Even if fires were never a concern, this is a pressing load to put on your energy costs regardless of what your budget looks like. Therefore, if you have a choice, it’s typically smarter to go with a horizontal dryer vent over a vertical one.