Underwriters Laboratories standards 560 and 2158 for clothes dryers require that all dryers listed must specify all metal dryer venting unless otherwise tested. A UL 181 label does not apply to dryer venting. Underwriters Laboratories Inc., an independent testing agency that helps set national safety standards, requires that dryer manufacturers
"include explicit instructions specifying that only rigid or flexible metal duct should be used for exhausting, unless the appliance has been investigated for use with nonmetallic duct."
Maytag and other major dryer manufacturers recommend against the use of plastic flexible duct.
Although plastic flexible duct (cheap and easy to install) might seem like just the thing for exhausting a dryer, it isn’t. This type of exhaust duct, which resembles a plastic-covered slinky toy, is not recommended for several reasons.
The Consumer Products Safety Commission estimates there are 24,000 clothes dryer fires each year in the United States, amounting to $96,000,000 in estimated property damage. Lack of maintenance is the leading cause of dryer fires, and [FONT=Arial]LINT is the leading material to ignite. These fires can be caused by failure of mechanical and/or electrical parts within the dryer itself, improper materials being put into the dryer, and insufficient airflow as a result of improper installation.[/FONT]
Clothes dryers can be a source of home fires. Be sure to check your dryer vent and vent hose regularly for lint accumulation. Lint is an excellent source of ignition for a fire. Vents should be made of rigid metal, because flexible vents can be damaged by heat, age and contact with other objects. All vents need to discharge directly to the home’s exterior.
SAFE USE OF HOUSEHOLD CLOTHES DRYERS
- North American-style household clothes dryers are required by manufacturers to be vented to the outdoors using a short length of rigid or flexible metal ducting. Manufacturers recommend that the maximum length of the metal ducting, which varies depending on the number of bends, should not be exceeded. This is clearly stated in the manufacturers installation instructions and the appliances are certified according to this requirement.
*]It is strongly recommended that plastic ducting not be used. Plastic ducts often collapse causing blockage and lint build up within the dryer. This type of plastic ducting can ignite or melt and will not contain a fire within the dryer