Heritage Restoration, Inc.

Dryer Vents

We take dryer vents for granted. The venting concept is simple enough; allowing moist, hot air a direct path to the exterior of the house. Putting a vent in correctly can be tricky, but if you do it successfully you will only have to clean it annually. The vent can be a source for many problems and dangers, often times to unsuspecting homeowners.

According to the National Fire Protection Association, from 2006-2010, dryers and washing machines were involved in one out of every 22 home fires, with over 16,800 in 2010 alone. Clothes dryers accounted for 92% of the fires, washing machines 4%, and combined washer and dryers accounted for the remaining 4%. Failure to clean the units accounted for 32% of fires, mechanical failure or malfunction at 22% and 8% from electrical failure or malfunction.

Clothes dryer vents need to be unobstructed for efficiency and safety. The accumulation of lint or pest nests can clog a vent, or if the vent is crimped, flattened, or has too many hard angles can make a dryer vent improperly, causing excessive condensation, wasting energy, or worse, a fire. Also, a dryer working too hard can cause frequent repairs or premature replacement.

The exterior dryer vent ‘s function is also critical to your dryer’s performance. The vent is designed to allow the exhaust to flow freely when operating, while also preventing back drafts when the dryer is not operating. They also protect the house’s wall cavity and interior from wind and weather.

In essence, the dryer vent needs to function well to protect you, the building, and save energy. Yet we tend to neglect the functioning parts until they don’t, and a dryer vent is high on the list. Here are some things to look for:

  • Inspect how the dryer vent runs to the exterior. The vent should be a 4” smooth round hard metal, not bunched up corrugated plastic or vinyl tubes or the rectagular. There are several gauges of galvanized or aluminum hard duct metal. Building Code requires a 016-inch-thick metal, where many are too thin. The duct should not exceed a straight 25 feet, while reducing 2.5 feet for each 45-degree bend and 5 feet for each 90-degree bend. Do not use screws to attach each section, rather use real foil duct tape for the seams.
  • The exterior damper should be clear and functional. The flapper should move from open to closed freely, and not be clogged. If the vent is not functioning, you can install a new vent. There are many styles out there, although the ones that are easiest to clean are best. There are the plastic with three louvers, the metal hood type with one damper, or even a style called the Dryer Vent Seal that provides a good air seal and has a top that is removable for cleaning.
  • When cleaning the dryer vent, start by pulling the dryer from the wall and disconnect from the dryer. Pull out any lint that has collected in the vent opening as well as in the dryer outlet. Leave the vent disconnected. Go outside and unscrew the cover from the vent outlet. Pull all the lint you can reach. Use a dryer vent brush to loosen any built up lint. Vacuum the lint from both ends of the vent line. Push the vacuum hose into the vent line as far as it will go. Screw the dryer vent cap back onto the vent outlet and reconnect the vent line to the dryer when you are sure the vents are clear.


Having a clear direct dryer vent saves money, time, and potentially your house. Don’t make laundry harder than it needs to be.

The vent was damaged and inoperable.  There were gaps around the edges allowing air to come in.

The vent was damaged and inoperable. There were gaps around the edges allowing air to come in.

A Better solution.  At least it closes the gaps and is not restricted by the cast iron vent pipe.

A Better solution. At least it closes the gaps and is not restricted by the cast iron vent pipe.