Dryer Vent Safety: Fire Risks & Dryer Efficiency

Dryer Vent Safety

Dryer vent safety and house fires are no joke. Fact: “2,900 home clothes dryer fires are reported each year and cause an estimated 5 deaths, 100 injuries, and $35 million in property loss.” Source.

So what can you do to protect your home from a possible fire?

Dryer Vent Safety – Common Questions

Ensure Proper Installation and Ventilation

When thinking about your dryer vent, this should be your first thought.

Where Should The Dryer Vent, Vent To?

The dryer vent should always vent to the exterior of your home. It can vent through exterior walls or through the roof. A dryer vent should NOT vent into a garage.

How Long Should A Dryer Vent Be?

A dryer vent should not exceed 35 feet in length. Furthermore, for every 45 degree turn of a dryer vent you should remove 2.5 feet in total allotted length. For every 90 degree turn, you should remove 5 feet in total allotted length.

M1502.6 Duct length.The maximum developed length of a clothes dryer exhaust duct shall not exceed 35 feet from the dryer location to the wall or roof termination. The maximum length of the duct shall be reduced 2.5 feet for each 45-degree (0.8 rad) bend, and 5 feet for each 90-degree (1.6 rad) bend. The maximum length of the exhaust duct does not include the transition duct.

What Should My Dryer Duct Be Made Out Of?

Use a smooth rigid metal duct. Joined ducts should be in the direction of lint travel to prevent lint being caught up at the joints and flowing out of the duct.

M1502.5 Duct construction.
Exhaust ducts shall be constructed of minimum 0.016-inch-thick (0.4 mm) rigid metal ducts, having smooth interior surfaces, with joints running in the direction of air flow. Exhaust ducts shall not be connected with sheet-metal screws or fastening means which extend into the duct.

Can You Use Flexible Metal Duct?

Flexible metal duct is not recommended for dryer venting. This will easily clog and need frequent cleaning.

This includes: flexible metal duct foil and flexible plastic!

flexible dryer duct
Do not use ^^^

Dryer Vent Safety Maintenance Tips

dryer vent safety and maintenance

Cleaning

You should clean your dryer duct every year. You can clean it by using this drill attachment which is basically a pipe cleaner. My personal recommendation is to clean from inside your home and push the brush to the outside.

Often times, a dryer vent could vent to your roof. If this is this case it can be difficult to clean from the roof without removing the gooseneck.

Here’s an example of what a dryer vent gooseneck looks like on your roof.

dryer vent gooseneck on roof

Screens Or Flaps?

Also, any screens (like the one in the featured image of the post) should be removed from the discharge of the dryer vent. Screens will easily clog lint and need frequent maintenance.

Instead, you should use a flap mechanism which is pushed out by hot air by the dryer.

Roof goosenecks often come with screens installed. You should check your roofers removed the screen from your dryer vent gooseneck.

Other Considerations for Dryer Vent Safety

Following the rules above will definitely help stop fires and help your dryer become more efficient.

Here are some other rules to follow:

M1502.3 Duct size.
The diameter of the exhaust duct shall be as required by the clothes dryer’s listing and the manufacturer’s installation instructions.

M1502.4 Transition ducts.
Transition ducts shall not be concealed within construction. Flexible transition ducts used to connect the dryer to the exhaust duct system shall be limited to single lengths not to exceed 8 feet, and shall be listed and labeled in accordance with UL 2158A.Required support for lengthy ducts is covered by the following section:

M1502.4.2 Duct installation.
Exhaust ducts shall be supported at intervals not to exceed 12 feet and shall be secured in place. The insert end of the duct shall extend into the adjoining duct or fitting in the direction of airflow. Exhaust duct joints shall be sealed in accordance with Section M1601.4.1 and shall be mechanically fastened. Ducts shall not be joined with screws or similar fasteners that protrude more than 1/8-inch into the inside of the duct
.

Concluding

Maintaining your dryer vent will stop fires and improve the efficiency of your dryer.

If you have any questions, be sure to comment down below!

You may also want to check out our home maintenance checklist.

Aaron Shishilla

Author Aaron Shishilla

Aaron Shishilla is the youngest registered professional inspector in Florida. Coming from a family-owned home inspection company and now the marketing manager at Waypoint.

More posts by Aaron Shishilla

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