Dryer Exhaust Vent Requirements

Photo of how a dryer vent should be

You should use only 4 inch (10.2 cm) diameter (minimum) rigid aluminum or flexible metal duct and an approved vent hood which has a swing-out damper that opens when the dryer is in operation. When the dryer stops, the dampers automatically close to prevent drafts and the entrance of insects and critters. To avoid restricting the outlet, maintain a minimum of 12 inches (30.5 cm) clearance between the vent hood and the ground or any other obstruction. Do not use galvanized pipe because the humidity in the airflow will cause the inside of the pipe to corrode.

The following are specific requirements for proper and safe operation of your dryer. Failure to follow these instructions can create excessive drying times and fire hazards.

If your dryer takes too long to dry clothes make sure that your dryer vent was installed correctly and is not restricted.

Do not use plastic flexible duct to exhaust the dryer. Excessive lint can build up inside the exhaust system and create a fire hazard and restrict air flow. Restricted air flow will increase dryer times. If your present system is made up of plastic duct or metal foil duct, you should replace it with a rigid or flexible metal duct.

Risk of Fire - A clothes dryer produces combustible lint. If the dryer is not exhausted outdoors, some fine lint will be expelled into the laundry area. An accumulation of lint in any area of the home can create a health and fire hazard. The dryer must be connected to an exhaust outdoors. Regularly inspect the outdoor exhaust opening and remove any accumulation of lint around the outdoor exhaust opening and in the surrounding area example: clothing, draperies/curtains, paper to come in contact with exhaust system.

The dryer MUST NOT be exhausted into a chimney, a wall, a ceiling, or any concealed space of a building which can accumulate lint, resulting in a fire hazard.

Exceeding the length of duct pipe or number of elbows allowed in the "MAXIMUM LENGTH" charts can cause an accumulation of lint in the exhaust system. Plugging the system could create a fire hazard, as well as increase drying times. Do not screen the exhaust ends of the vent system, nor use any screws or rivets to assemble the exhaust system. Lint can become caught in the screen, on the screws or rivets, clogging the duct work and creating a fire hazard as well as increasing drying times.

Use an approved vent hood to terminate the duct outdoors, and seal all joints with duct tape. All male duct pipe fittings MUST be installed downstream with the flow of air. Explosion hazard. Do not install the dryer where gasoline or other flammables are kept or stored. If the dryer is installed in a garage, it must be a minimum of 18 inches (45.7 cm) above the floor. Failure to do so can result in death, explosion, fire or burns.