Dryer fires are amongst the leading causes of home fires in North America, accounting for over 14,000 reported disasters each year. The leading cause of these dryer fires is failure to clean; in other words, the majority of dryer fires are avoidable with regular maintenance. In fact, dryer lint is so flammable that the Boy Scout's Manual suggests using dryer lint as tinder to quickly start a camp fire. Once a spark touches dryer lint, the flame ignites and carries through the transition duct and into the concealed parts of the home. Even with cleaning the lint screen after each cycle, particulate still gets through the dryer's exhaust duct and creates blockages which restrict airflow. Dryer venting efficiency can be improved by various ways other than cleaning the lint screen and having the exhaust duct serviced on a regular basis.
Practically every home with a tumble dryer uses some type of flexible transition duct to connect the appliance to the wall. Most homes, however, have grandfathered in older materials that are not only inefficient, but flammable too. White vinyl and "slinky" foil ducts feature a plastic Mylar coating which goes up in flames and quickly spreads throughout the duct run. The owner's manual in most modern dryers require using "flexible metal vents" instead of foil vents. When white vinyl or "slinky" foil is used, the appliance warranty may be voided due to the vulnerability of using these dangerous transition materials. Beyond the flammability of these older options, the foil-based material collapses within the 4" opening, creating an abrasive 3.25" space that results in numerous points for lint to catch.
The International Mechanical and Residential Building Codes specify UL2158A Listed materials to be considered as code compliant. Underwriter's Laboratory created the UL2158A Standard in 2006 which focused on "Clothes Dryer Transition Duct" that is listed on products which meet/exceed flame burning tests of at least 430 degrees Fahrenheit. Combining building code requirements along with manufacture's recommendations, it's evident that only flexible metal vents can be used as transition ducts.
Today, only two types of flexible metal vents meet the strict building code requirements and are UL2158A Class 0 Listed materials. (Class 0 refers to materials being tested to exhibit zero flame and zero smoke attributes during specific laboratory burn tests.) Most semi-rigid aluminum ducts are Class 0 along with DryerFlex™ as well. While semi-rigid aluminum is airflow efficient, it crushes easily and is tough to bend in tight areas. DryerFlex can be bent into tight turns without sacrificing airflow efficiency. Simply put—DryerFlex combines the flexibility of old foil materials with the efficiency and fire ratings that modern appliances and buildings codes require.
When looking for the best material to connect the dryer to the wall, DryerFlex is the clearly your only premium option. Vent cleaning professionals, appliance installers, and home builders are exclusively installing Dryerflex every day, nationwide. Aside from replacing your transition duct with DryerFlex, here are some other helpful tips to ensure your dryer is operating as safe and efficient as possible.