How (and why) to clean your dryer vent

Dryer maintenance doesn't stop at the lint trap. You are cleaning your lint trap—right?

Maintaining a clean dryer vent is an underappreciated household task. Not only will ensuring smooth airflow between your machine and the great outdoors help your clothes dry faster, but it will also reduce your fire risk. Trust us: a couple hours of your time (at most) is a small price to pay for avoiding a lint-fueled blaze.

When to clean your dryer vent

Guidance varies on how often you need to clear out the ol’ dust pipes, but most recommendations fall between every three months and at least once a year. You’ll probably need to do it more if you do lots of laundry, and less if you live alone.

But if your clothes are taking increasingly longer to dry, your machine gets surprisingly hot to the touch, or (red alert) you notice a burning smell when the dryer is on, you should clean the vent and ducts immediately. There are about 3,000 dryer fires each year and neglected cleanings are the leading cause, the US Fire Administration says.

What you’ll need

At minimum, you’ll need a vacuum with a hose or otherwise tubular attachment. Depending on the length of your dryer duct, your desired cleanliness level, and how everything is connected, you may also want a long-handled brush, a face covering, a power drill, and/or a screwdriver.

You can buy dryer vent cleaning kits with super-long brushes, but you can also improvise with a balled-up rag strapped to a stick. If you DIY your own cleaner, you should be careful not to damage the ductwork and ensure your makeshift swab doesn’t get stuck, or fall apart and block the duct. And of course, if you’re unsure about what you’re doing at any point, you can call a professional dryer cleaning service.

How to clean your dryer vent

  1. Unplug your dryer. Disconnecting the power supply should be the first thing you do when working on any electrical appliance, and your dryer is no different. If you have a gas-fueled machine, find the supply line and turn the gas off too.
  2. Locate both ends of the dryer vent. This should be relatively easy: one end is at the back of your dryer and the other is on the outside of your home.
    • Note: If you live in multi-family housing, you may not have access to the exit vent, so check with your property manager or landlord to see if they or you are responsible for cleaning the vent.
  3. Remove your exterior vent cover. This cover prevents animals and debris from entering your home, and taking it off will make cleaning easier. It may be fastened with screws or it might slip on and off.
  4. Move your dryer away from the wall. Give yourself enough space to access the vent connection in the back so you don’t bend or damage the ducts. If you have a gas line, be extremely careful not to bend or break it. You absolutely do not want a gas leak.
  5. Disconnect the duct from the back of your dryer. Fasteners vary, so you may see tape, a screw-tightened steel hose clamp, or some kind of clip. When your machine is free of all restraints (unless you have a gas connection), you can move it to wherever is comfortable for the rest of the job. 
  6. Clean the dryer. If you haven’t done so already, take the lint trap out and clean it. You should be doing this after every load anyway—it’ll reduce the amount of lint that makes it into your duct, keeping it cleaner for longer. Then brush and vacuum out the lint trap area. Next, brush and vacuum out the vent in the back of the dryer.
  7. Disconnect the duct where it enters your wall. You might not be able to do this, but if you can, it will make cleaning easier. It likely connects to the outside-bound ductwork the same way it fastened to the back of your dryer.
  8. Brush out the duct. Remove what lint you can by hand, and carefully vacuum inside—you don’t want to damage the pipe. For longer ducts, you can use a long-handled brush and rotate it as you move it back and forth (the ones included in cleaning kits often connect to power drills so you can spin them easily inside the duct). You might want to cover your face during this step to avoid inhaling dust and lint.
    • Pro tip: If one end of your duct is higher than the other, clean from that side if possible. This will ensure that debris does not fall onto you while you work, and tumbling dirt might loosen up other grime as it falls.
    • Note: If you’ve been cleaning your lint trap or have a short distance between your dryer and the outside, you might not have to do much, but this can also be a dirty job. Flexible ducts, for example, are more likely to bend and clog.
  9. Clean up. Vacuum or sweep up any dust and debris that’s on the floor or piled up outside where the vent exits the house. Any lint left behind the dryer may be sucked into the machine when it turns on. If you removed your exterior vent cover, don’t forget to put it back on—you don’t want a bird or small mammal moving into your dryer duct.
  10. Reconnect your dryer. As you put everything back together, make sure nothing got damaged during the cleaning process. Put it back in place, plug it in and (if necessary) turn the gas back on.
    • Pro tip: If you’re taping your duct, use foil tape instead of standard duct tape. Foil tape won’t dry up and fall off.
    • Warning: Do not fasten ducts with screws or other sharp fasteners. They can puncture the ductwork, causing leaks and catching lint.
  11. Test the dryer. To ensure there are no air leaks and your setup works smoothly, run the empty dryer for about 15 minutes on a low setting.

How to prevent lint buildup

Future cleanings will be easier and your dryer will work better if you make it hard for lint to build up in the first place.

  • Clean the lint trap. We mentioned this above, but it bears repeating: make sure this removable screen is clear of lint before and after every load. Dryer sheet residue can also get stuck in the mesh, so try putting some water on it. If it doesn’t flow through, clean it with a brush and warm soapy water, then dry it with a towel.
  • Regularly clean around your dryer. Simply put, the less dust your machine can suck up from its environment, the better.
  • Hang heavier items out to dry. The heavier your dryer load, the harder your machine works. Stick that bulky duvet cover outside if you can, and your machine will thank you.
  • Consider replacing your duct. Because flexible ducts are more likely to clog than solid metal ones, they are also more fire-prone. They may also be against building code in your area. If you have one, check with your local building code office to see if it’s OK. Even if it is, straight ducts are easier to clean.
John Kennedy

John Kennedyis PopSci's DIY editor. He previously covered legal news for Law360 and, before that, local news at the Journal Inquirer in Connecticut. He has also built and remodeled houses, worked as a fencing coach, and shelved books at a library. When he's not taking things apart or putting them back together, he's playing sports, cooking, baking, or immersed in a video game. Contact the author here.