Why Clean Dryer Vents?
Hopefully, whenever you use your dryer, you clean the lint trap. It is good practice to do so as it helps the dryer do its job more efficiently and uses less energy. Air must flow through the dryer to remove water from the washed clothes. Most of the lint from the clothes is caught by the dryer vent, but a small percentage of it goes out the dryer vent. Over time over many dryer cycles, the lint builds up on the walls of the dryer vents causing inefficiency of air flow and drying time, decreasing the longevity of your dryer, as well as creating a potential hazards to your home.
Luckily we clean dryer vents to keep drying time low, increasing the lifetime of your dryer, and keeping your home safe.
To understand why dryer vent cleaning is important, let’s look at how a dryer works. Here is an illustration from the Consumer Product Safety Division from their study on dryer vent safety in 1999.
As you can see from the illustration, the blower pulls air from the front, then gets heated, then distributed to the drum where the wet clothes are, then out the exhaust vent. The lint trap catches what it can, but it cannot catch all of the small fibers from clothes. The vents eventually build up lint on the walls narrowing vent space restricting air flow. Curves or elbows in the vent and runs longer than 10 feet can increase potential for lint build up in the vent.
The first indication of building up of lint on the walls of the dryer vents is increased drying time. Clothes might also be hotter than normal at the end of drying cycle as well as the outside of dryer being hot. With a poor exhaust and air flow, moisture cannot leave the dryer as readily. This means it takes longer for your clothes to dry, possibly even two cycles. This increases energy usage and consumption.
The other thing that happens with this restricted airflow is that the dryer is working harder to keep the air warm. Many modern dryers have humidity or moisture sensors that can regulate the amount of heat needed to dry clothes. Since the clothes are not drying efficiently, the dryer is now working harder to dry a load of clothes. This not only wastes energy, but shortens the life of the dryer itself.
Energy costs and dryer longevity are important points to consider, but there is a safety issue with clogged dryer vents as well. The lint that builds up on the walls is quite flammable. With the heat produced by the dryer exhaust may reach temperatures hot enough to cause a catastrophic fire. The U.S. Consumer Product Safety Commission estimated there were 15,500 fires in 1996 associated with clothes dryers. The commission also concluded that the most frequent location of where the fire originated was in the duct or venting system. Evidence found where fires began at the motor, electrical system, and thermostat could have been caused by lack of proper exhaust airflow.
In the case of natural gas or propane heaters, a carbon monoxide safety hazard also exists with a restricted airflow dryer vent. Carbon monoxide is a non-flammable, but very dangerous colorless and odorless gas that needs to be vented outside the home with any gas appliance. If the vent is restricted, this toxic carbon monoxide can find its way back into the home.
It’s important to have your dryer vent inspected and cleaned on a regular basis to keep you, your dryer, and your home operating safe and efficiently.