Venting Clothes Dryer Into Roof

The international residential code allows you to run a dryer vent through the attic but you can t terminate it there.

Venting clothes dryer into roof.

Be careful you don t cut through any studs electrical wires or pipes in the process. For dryer efficiency and safety the shortest and straightest ducting route is always best. Every turn increases friction loss unless you use non restrictive elbows. Dryer vent specialists will tell you that a vertical approach to installing a dryer vent is inefficient and creates a fire risk for a home if it goes unchecked.

It is not advisable to vent a dryer through the roof. Air velocity reduction from friction loss promotes lint build up and makes the dryer work harder to completely dry each load. After the snow melts below the vent it ll probably freeze again farther down on the roof. Venting the dryer outside in cold weather wastes a lot of heat.

To make the dyer more efficient you can buy an inexpensive heat diverter and install it in the exhaust duct of electric dryers only not gas dryers you ll save about 50 worth of heat per load in the winter. Doing so would fill your attic with warm moist air that could rot the framing. If venting outside isn t an option you can vent the dryer out of the attic through the roof using a special roof vent to keep rain out. But we don t recommend it for two reasons.