Let’s Talk Dryer Ducts

dryer ductsDid you know that in 2010, the most current statistical data, an  estimated 16,800 home structure fires were reports that involved clothes dryers? Of this high number of fires, there were 51 deaths, 380 injuries and a whopping $236 million in direct property damage. (1)  The most common culprit?  Lint build up in the dryer ducts.

From 2006 to 2010, 81% home structure fires involving washers or dryers began in a laundry room or area.  92% of these home fires involved the clothes dryer.  The fire risk is equal whether the clothes dryer was gas fueled or electric powered. (1)

With this fire risk being quite high, Ed is going to be inspecting the clothes dryer connections even though it is not required in our standards.

Dryer Ducts: Materials

dryer ductsOne thing we have been seeing of late is a large number of dryers that are still using the outdated flexible vinyl or plastic.  Flexible vinyl was once popular as a ducting material, but now many codes prohibit it’s use as it is a fire hazard.  Foil is also prohibited in many regions as it crushes too easily obstructing the air flow and is also a fire hazard.

Ed recommends that all dryer ducts be switched over to aluminum flex ducting.
The main challenge with using any flexible ducting is that the ridging throughout the length of the duct is really good at catching lint.  When lint accumulates, it will block the air flow from the dryer to the vent.  Accumulated lint can ignite with just one spark.  To keep lint accumulation down, the flexible duct must be cleaned periodically, at least 2 times a year.

This ridging is not a problem with rigid aluminum ducts.  For this reason, rigid aluminum ducts, not flexible ones, should be used if the duct is to be enclosed in a wall or ceiling.

Dryer Ducts Disconnect

During a recent inspection, Ed was pleased to find aluminum flex ducting.  However, the dryer duct was disconnected from the back of the dryer rendering the duct useless.  In this situation, the lint discharged to the back of the dryer and onto the wall, where the electrical cord plugged into the wall was also covered in lint.  This is a fire hazard and requires immediate clean up.

All sections of dryer duct should be joined end to end with approved clamps.  Ed recommends using the type of clamp that is all metal and it looks like a large hose clamp. These clamps are available at home centers.

Maintenance of Dryer Ducts

All dryer ducts should be inspected and cleaned at least twice a year. This may require disconnecting a section or two so you can look inside and vacuum out lint accumulations.  To simplify vacuuming, consider using a special attachment to your vacuum, like the Lint Lizard.  Afterward, reassemble the sections.  Then check all the connections to make sure they are secure.

How to Clean Your Dryer Ducts

Safety Tips from the National Fire Protection Association

Maintain the Lint Filter

Clean the lint filter in a dryer before or after each use because accumulated dust and lint can be a fire hazard. If clothing is still damp at the end of a typical drying cycle or drying requires longer times than normal, this may be a sign that the lint screen or the exhaust duct is blocked.  Also, remove accumulated lint around the drum.  To be extra safe, consider a dryer duct safety alarm. Do not operate the dryer without a lint filter.

Remove Blockages

To remove a blockage in the exhaust path, it may be necessary to disconnect the exhaust duct from the dryer. Remember to reconnect the ducting to the dryer and outside vent before using the dryer again.
There are long, thin brushes one can buy to make it easier to reach and remove lint in the vent pipe and around the drum.  There are dryer lint removal kits.  You can even find dryer lint removal services. Have a qualified service person clean the interior of the dryer chassis periodically to minimize the amount of lint accumulation.

Use Appropriate Ducting

Replace plastic or foil, accordion-type ducting material with rigid or corrugated semi-rigid metal duct. Most manufacturers specify the use of a rigid or corrugated semi-rigid metal duct, which provides maximum airflow.  The flexible plastic or foil type duct can more easily trap lint and is more susceptible to kinks or crushing, which can greatly reduce the airflow.

Ensure Safe Electrical

Ensure that a dryer is plugged into an outlet suitable for its electrical needs. To help reduce electrical problems associated with washing machines and dryers, make sure the right plug and outlet are used and the machine is connected properly.  Washing machines and dryers should be properly grounded.

Turn Off When Out

Do not leave a dryer running if you leave the home, because if it malfunctions, no one will be there to avert possible disaster.

Installation and Maintenance

Have your dryer installed and serviced by a professional. It is important to keep dryers in good working order to avoid problems associated with lack of maintenance and part failures. Gas dryers should be inspected by a professional occasionally to ensure that the gas line and connection are intact and free of leaks.
Have a professional check the equipment if there are any doubts that it is running properly or safely.
Our next article will focus on Dryer Vents.


(1) Hall, John R., Jr. “Home Fires Involving Clothes Dryers and Washing Machines.” NFPA. N.p., Sept. 2012. Web. 02 Sept. 2016.