In this article, we discuss the best installation products and techniques to prevent dryer vent fire hazards.
According to the NFPA (National Fire Protection Agency), there are around 16,000 clothes appliance-related fires each year in the US, with most of them caused by clothes dryers. Most fires are caused by clogged ducts, filters, and vents due to maintenance neglect and improper installation.
How to Prevent Dryer Vent Fires
1. Clean the lint tray after every use
2. Make sure the dryer duct and vent are professionally installed
3. Have your dryer duct and vent professionally cleaned and inspected annually
How Dryer Vents Should Always Be Installed
Standard Dryer Vents should always exit to the outside
Dryer Vents should not exit into ‘bucket’ systems (see photo below), crawl spaces, basements, attics, or other indoor areas. Dryer vents should always exit to the outside. See more about Condensing dryers that do not require vents below.
Note on Condensing Dryers (that do not require a vent)
Condensing dryers are becoming increasing common and have been sold in Europe for decades. Condensing dryers do not need a vent and may be safer than a traditional dryer- however because they produce condensate or water, it is recommended to install a hose directly to the washer drain (rather than having to empty out a bucket). Condensing dryers may take longer and consume more electricity than a standard dryer and some people complain that they don’t dry clothes as well. Condensing dryers may not accommodate the larger loads that a standard dryer can. If you are considering putting a dryer in a location without a vent we recommend consulting an HVAC contractor about installing one before opting for the condensing dryer.
All Dryer Vents Hoods should always have a functioning damper
Dampers prevent pests from entering the duct and causing fire hazards and other issues.
Dryer Vent Hoods should never have screens
Screens are not allowed on the dryer vent hoods because they allow the accumulation of lint. Luckily these screens are easily removed. If screens are present and lint debris has accumulated it is recommended to have the entire duct professionally cleaned.
Dryer Vents Should always be 4″ smooth metal from the laundry room to the outside
Flexible ductwork should only be used between the dryer and the wall connection- these are called ‘transition ducts’ because they transition from the appliance to the vent. Flexible ductwork should never be used through or beyond floors and walls.
Dryer Vents should never be longer than 35 feet
The 4″ smooth metal pipe between the laundry room and the outside should never be longer than 35′. 5′ should be subtracted from the 35′ number each time a 90-degree elbow is used.
Only Metal Professional Flame-Resistant connectors should be used – no Plastic connectors!
Plastic connectors, even though they are marketed and sold for dryer connections, should not be used. Only metal flame-resistant connectors should be used.
Best Practice Dryer Vent Connection (behind the dryer)
The best dryer vent connection is a recessed metal vent box like the one shown which helps protect the connection from damage. When it is not possible to install a recessed dryer vent box, other low-profile flame-resistant connectors can be used to protect the flexible transition ducts from damage or from disconnecting. Ideally, the dryer exits through the wall and not the floor- floor connections are more prone to damage. It is also recommended to build a ‘stop’ to prevent washers and dryers from crushing the ducts.
Best Practice Transition Duct between the dryer and the wall
Flexible ducts or ‘transition’ ducts should never be longer than 8′ and should only be made of flame-resistant metal (see photographs). The first product is preferred over the second and third.
Regularly Inspect Your Dryer Duct connection for damage or leaks
Washers and dryers often move during operation. Check behind your washer and dryer every couple of months for damage or leaks. Also, check your 4″ smooth metal exhaust vent (where accessible) and the exit (vent hood) for damage or other issues. If you observe any plastic parts or damaged or disconnected areas, contact an HVAC contractor for repairs to prevent possible fires and condensation issues.
Appliance and Vent Inspections in Asheville and WNC
Our Company, Builder Buddy Inspections & Testing, evaluates (when accessible) the dryer ducts, connections, and vents as part of our Home Inspections, Pre-sale Inspections, Commercial Inspections, and Annual Maintenance Inspections. Dangerous fire hazards are widespread and can be prevented as part of our Annual Inspection Program. If you are within 40 miles of Asheville, call us today to set up an appointment or schedule here.