Why the Material, Bends & Distance of a Dryer Vent Matter

Most people are familiar with the flexible, ribbed metal vent for the dryer. And even though you keep up with removing the lint from the dryer trap after every load, some still gets through to the vent pipe itself. Overtime, these bits turn into balls or even clogs. This is what leads to a potential fire hazard. 

As the heat builds up from the dryer running, the clog is unable to allow the vent to function. Therefore, the perfect dry and hot conditions are just waiting for the spark to ignite in the confined space. To help prevent the crevices for lint to get caught in the vent pipe, a rigid metal vent is recommended to be used. The use of screws or anything that will penetrate the pipe is not recommended when installing them as lint can also get caught on these.

So, why are the distance the vent pipe travels as well as the bends it takes important? The maximum length of 35 feet is the furthest distance most dryers are capable of pushing out the exhaust. Otherwise, you’ve got a pipe full of lint once again.

Next, are how 45-90 degree bends and vertical climbs can have an effect on exhaust capabilities and lint trapping as well. By standards, for every 45° angle, the distance the pipe can be from the dryer is shortened by 2.5 feet. For every 90° bend, the length is shortened by 5 feet. So, if you have one 45 and two 90’s, your distance can only be a maximum of 22.5 feet from the dryer to the exterior of the structure. As for the vertical climb, lint is not lighter than air…

Oh, and please do not put screens over the exhaust point because, once again, this will trap lint.