Simply stated, a clogged dryer vent is caused by the build-up of lint in the dryer ventilation system. There are many reasons a clothes dryer vent may become clogged. First, the complex construction of new homes built today tends to have dryers located away from an outside wall. This means dryers tend to be vented longer distances creating more bends in the vent through the home. The additional length creates more places for lint to collect or for animals and birds to hide. Secondly, dryer vents are often made from flexible plastic or foil duct, which may be easily kinked or crushed where they exit the dryer and enter the wall or floor. Ducts made of this material are more likely to sag and let lint build up at low points than ridge metal or UL approved flexible metal ducts. Poorly connected internal ducts can also trap lint. Screens or cages at the duct termination are helpful to prevent animals from getting into the exhaust from the outside, but if they are not properly cleaned and maintained they can also become clogged and restrict air flow.
Lint and debris can build up in the clothes dryer vent blocking air flow and creating potentially hazardous conditions including the possibility for an exhaust fire or carbon monoxide intrusion (gas clothes dryers). “The U.S. Fire Administration, National Fire Data Center reports that there are over 12,700 home fires per year associated with clothes dryer fires resulting in 15 deaths and 300 injuries, and 88 million dollars in property loss.”*
Along with the water vapor evaporated from the wet clothes, the exhaust stream carries lint – highly flammable particles of clothing made of cotton and polyester – through the ventilation duct. Lint can accumulate in the exhaust duct, reducing the dryer’s ability to expel the heated water vapor, which then accumulates as heat energy within the machine. As the dryer overheats, mechanical failures (thermostat, limit switch, damaged screen, or crushed hose) can trigger sparks which cause the lint trapped in the dryer vent to burst into flames.
A restricted dryer vent reduces air flow and causes your dryer to run hotter and longer, substantially impacting energy efficiency. Excess heat created by poor air flow can ruin your clothes, add dollars to your home’s energy bill and increase the wear and tear on your appliance. If your dryer takes twice as long to dry clothes as it should, the number of loads that it will dry in its lifetime is substantially reduced. Having your dryer vent cleaned helps reduce energy consumption, operating costs and the possibility of a fire.
Dryer vents are often made from flexible plastic or metal duct, which may be easily kinked or crushed where they exit the dryer and enter the wall or floor. Ducts made of flexible plastic or foil are likely to sag and let lint build up at low points. Ridges can also trap lint. Screens may be present at the duct termination and can accumulate lint and restrict air flow.
A clogged dryer vent does not allow for the clothes dryer to exhaust properly. Gas clothes dryers that become clogged have the potential to cause Carbon Monoxide to back fill into your home. Carbon Monoxide poisoning is very dangerous and can be fatal with prolonged exposure.
The complex construction of new homes built today tends to have dryers located away from an outside wall. This means dryers tend to be vented longer distances creating more bends in the vent run to accommodate the extended path they must take through the home. The additional length create more places for lint to collect or for animals and birds to hide.