According to the National Fire Protection Association (NFPA) It is estima,ted that annually over 15,000 house fires are attributed to clothes dryer fires, with seven deaths, 344 injuries, and 233 million dollars in direct property damage. Dryers cause 4% of house structure fires, with a rise in these types of fires during the fall and winter months peaking in January. What caused the majority of the fires? Lint and the type of dryer vent piping are used to impair the ability to expel the lint that the dryer lint screen doesn’t catch. It doesn’t help that most people install their dryers and never maintain the vent piping. Failure to clean the dryer (34 percent) is the leading cause of home clothes dryer fires.
Most of these fires can be attributed to the lack of maintenance.
Improperly installed dryer vents and the type of dryer vent material used to vent the dryer contribute to fires. A broad range of dryer vent ducts or piping is available, including – flexible aluminum foil ducts,semi-rigid aluminum ducts, rigid sheet metal ducts, and rigid right angle periscope type ducts. Let’s talk about each type, some of the components, recommended installation, and dryer maintenance.
Dryer Venting and Components:
Flexible vinyl duct should never be used for dryer venting! It is a fire hazard! The packaging is clearly labeled * NOT FOR USE IN DRYER VENTING * ONLY RECOMMENDED FOR BATHROOM FAN VENTING *Flexible aluminum foil duct with high tensile steel wire helix encapsulated with an aluminum foil type material, making it easy to connect to round and oval connections. However, the interior of the duct is not smooth, and the ribs, along with poorly supported areas that sag, are prone to collect lint that gets past the dryer lint screen. This type of duct is recommended to be used only for transition ducts as it may become a fire hazard. It also should not be used with gas dryers, and it is prone to damage when cleaning with a brush.
Semi-rigid aluminum ducts are corrugated, flexible, and can typically be stretched to an 8-foot length of pipe. Although this is much better than the foil flexible ducts, it is still not smooth and can present the same issues with the build-up of lint, thus potentially creating a fire hazard.
The rigid sheet metal duct has a smooth interior; sections should be connected together with foil duct tape as opposed to screws as they can catch lint. This is the best method for all dryer vent ducting and if space allows for a transitional duct. Care should be made in the design and installation to limit elbows and long runs to minimize the need for maintenance. When long runs are present there should be a cleanout tee. The cleanout tee should be installed in a manner that it won’t become a lint trap.
Periscope type duct is a quick, easy, and safe alternative for transitional vent duct, plus it reduces the space needed behind your dryer.
Exterior dryer exhaust vents typically have an integral hood damper system designed to prevent cold air, snow, or rain from entering the home. There are vent hoods with an attached damper, louvered vents, and ones with an attached pest guard. Dryer vents should never be covered with small gauge screening to prevent birds and rodents from entering; small gauge screen will get clogged quickly, possibly resulting in a vent pipe fire. They also need to be cleaned regularly.
These days we see a lot of laundry rooms adjacent to the garage or near the bedrooms, which can create long dryer vent runs with many turns. With long dryer venting runs and sharp turns, dryer venting maintenance is critical as more lint accumulates on the inside of a vent that is not located on an outside wall. So have your clothes dryer installed by a professional. Make sure an approved and proper vent pipe material is used, and make sure that any vertical runs have no sags. The vent should never be vented inside the living space, in the attic or crawl space, or in combination with any other type of vent, like a bathroom exhaust fan ventilation.
It is crucial to reducing the potential for a dryer fire! First and always read the manufacturer’s instructions and warnings. If the drying time is excessive for clothes to dry or they come out hotter than normal, you either have a maintenance or mechanical issue. Make sure the exterior vent is free and clear of any accumulated lint. Clean lint out of the vent pipe at a very minimum once a year. The correct electrical plug and outlet are used, and the dryer is connected properly. Clean the back and under the dryer with a dryer/refrigerator vent and coil brush every six months. If the dryer venting piping is visible, inspect it annually. Do not store combustibles near the dryer. If you have a gas dryer, have your HVAC contractor inspect the gas lines when they service your furnace. If your dryer isn’t operating properly or efficiently or you are unable to maintain it. Have both the dryer and venting system serviced by a qualified professional.