by Tim Reiher
In my more than a decade in the dryer vent industry, I’ve worked with or studied venting systems in 30 different states.
In all that I’ve seen and done, there are three elements of a dryer vent’s operation that raise the most concern because they create the most serious safety risks.
Transition duct material
This is the ductwork that connects your clothes dryer to your home’s venting system The transition duct material that most homeowners use is called flexible foil venting, but the problem is that this material does not meet code in 90 percent of cases.
The concern is that flexible foil is easily crushed by accidentally pushing the dryer too close against the wall. Crushed venting creates back pressure, a resistance to the outward air flow that leads to lint build-up. That build-up can easily ignite when it comes in contact with a dryer’s heating element.
The solution can be a simple fix. Make sure your transitional duct material is solid-rigid or semi-rigid ducting.
Venting length and layout
Most dryer manufacturers indicate an allowable venting length guideline in their owners’ manuals. The first important step is to know the length and layout of your venting to ensure its construction allows your appliance to work most efficiently.
Too many bends of 90 degrees in your venting can create back pressure, limiting efficiency and increasing the potential for fire.
If you’re not sure about the length and layout of your dryer venting, a CSIA Certified Dryer Exhaust Technician can identify weaknesses in your system and can remove or reduce the number of bends in it to improve safety.
Venting termination points
This is the spot where your venting reaches the outside of your home. The problem I most often encounter is that homeowners don’t keep these termination points free of debris.
The most common type of hood for dryer vent terminations is an angled metal piece with a damper, or flap, that opens in response to air pressure. While these can be useful, it’s crucial that the opening on such hoods is 4”. Using screens or bird cages can be a hazard and is often in violation of code because they lead to debris buildup.
Remember, an annual inspection by a CSIA Certified Dryer Exhaust Technician can ensure safer and more efficient venting by your dryer. It’s important to remove the lint from the filter after every load of laundry and occasionally hold the screen under running water to confirm it can pass through the screen easily.