How Long Should Your Dryer Vent Line Be?
And How Does it Affect Your Clothes Drying Time?
A dryer vent line should be as short as possible. Long runs of vent line with multiple bends reduce the flow of air, often to the point where the dryer exhaust doesn't even reach the exhaust vent.
The International Residential Code (IRC) SECTION M1502 CLOTHES DRYER EXHAUST guidelines states that a dryer exhaust duct should not exceed 25 feet from the dryer to the exhaust vent in the wall or roof. However, that 25 ft. length is only if it's a straight line from the dryer to the exhaust, which it rarely ever is.
In any dryer vent line installation, there are always bends that restrict airflow. For every 45-degree bend, you have to deduct 2.5 feet from the total length. For every 90-degree bend, deduct 5 feet. (NOTE: the maximum length of the exhaust vent line doesn’t include the transition hose, the short length of duct that runs from the dryer to the wall).
What Happens If Your Dryer Exhaust Can’t Exhaust?
Clothes dryers need to have good airflow to work properly. When a vent line is too long, dryer exhaust ends up being stuck inside your vent line. You’ll notice it takes longer for your clothes to dry and the exterior of your dryer is hot. You’ll also have moisture in your home, which will show up as condensation on your windows or ceiling. Over time, this moisture can lead to mold growth on your walls and ceilings.
If you have a gas dryer, there’s even more for you to be concerned about. Carbon monoxide from the exhaust in your vent line can back up and infiltrate your laundry room. Unlike natural gas, which is scented so it can be detected, you won’t even know there’s carbon monoxide infiltrating your house.
What If You Can’t Get Your Total Dryer Vent Length Down To 25 Feet?
If there’s no way to get your dryer vent line down to 25 feet or less, you’ll need to install a booster fan on the line. These fans ensure dryer exhaust in the vent line actually makes it to exhaust vent. An automatic pressure switch starts the fan up when it detects the dryer is running.
Get Your Dryer Vent Line Problems Straightened Out With A Little Help From A Wizard
Besides cleaning out caked-on lint from dryer vent lines, Dryer Vent Wizard of Wisconsin will also install and reroute dryer vent lines for maximum efficiency and safety. If your dryer vent is more than 25 feet long, twisting and turning on its way to the exhaust vent, contact a Dryer Vent Wizard near you. We’ll either reroute it so it takes the shortest distance between your dryer and your exhaust vent or install a booster fan to ensure your dryer exhausts properly.
Contact the Dryer Vent Wizard of Wisconsin Nearest You:
Northeast Wisconsin: Fond du lac, Sheboygan, Manitowoc, Kewaunee and the Fox Valley Counties. 920-644-3797
North Milwaukee: All locations north of Highway 94 in Dane County, Waukesha, Milwaukee, Ozaukee, Washington and Dodge counties. 262-757-8368
Southeast Wisconsin: All locations south of Highway 94 in Dane County, Waukesha, Milwaukee, Walworth, Racine and Kenosha counties. 262-312-1991. For property managers and condo associations, call 262-501-5240.