The Consumer Product Safety Commission estimates that over 24,000 clothes dryer fires occur each year in the United States. Lint that collects in your vents is very combustible. Over time, your dryer vent has the propensity to fill with lint that gets past the dryer's filter. As the lint builds up, this can cause over-heating - which can lead to a fire as well.
Clothes dryers evaporate the water from wet clothing by blowing hot air past them while they tumble inside a spinning drum. Heat is provided by an electrical heating element or gas burner. Some heavy garment loads can contain more than a full gallon of water which, during the drying process, will become airborne water vapor and leave the dryer and home through an exhaust duct (more commonly known as a dryer vent).
The clogging of the dryer vents prevents the adequate removal of air and moisture from the dryer, and a typical 45 minute cycle turns into an hour and 45 minute cycle, resulting in a waste of energy, additional clothes fibers lost and the frightening possibility of a fire. This leaves some scratching their head, frustrated and confused they just throw some additional time on the dryer to finish the job perpetuating a very dangerous problem. Clothes dryers are one of the most expensive appliances in your home to operate. The longer they run, the more money they cost you.
Problems from clogged dryer vents can be prevented with by regularly checking the inside of the dryer and the dryer exhaust system vents.
If your dryer vents the exhaust moist air to the home's exterior, it has a number of requirements:
1.) It should be connected. The connection is usually behind the dryer but may be beneath it. Look carefully to make sure it’s actually connected.
2.) It should not be restricted. 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. This is often a problem since dryers tend to be tucked away into small areas with little room to work. Vent hardware is available which is designed to turn 90° in a limited space without restricting the flow of exhaust air. Restrictions should be noted in the inspector's report. Airflow restrictions are a potential fire hazard.
3.) One of the reasons that restrictions are a potential fire hazard is that, along with water vapor evaporated out of wet clothes, the exhaust stream carries lint – highly flammable particles of clothing made of cotton and polyester. Lint can accumulate in an exhaust duct, reducing the dryer’s ability to expel heated water vapor, which then accumulates as heat energy within the machine. As the dryer overheats, mechanical failures can trigger sparks, which can cause lint trapped in the dryer vent to burst into flames. This condition can cause the whole house to burst into flames. Fires generally originate within the dryer but spread by escaping through the ventilation duct, incinerating trapped lint, and following its path into the building wall.