Check Your Dryer Exhaust Vents

[GoingMyWay]

On Saturday I noticed that the dryer was taking an extremely long time to dry the clothes.  Normally the dryer finishes around the same time as the washing machine.  The washing machine said 14 minutes left, but the dryer said 1 hour 10 minutes!  I think the full dryer cycle is normally just under 1 hour.  I asked my wife if she ran a different dryer cycle by mistake, but she did not so I feared that there might be something wrong with the dryer itself.  I could see a lot of humidity inside of the dryer, but I kinda assumed it was because it was also a little humid outside.  The house had a slight fragrance of Tide detergent - normally you can smell when someone else is doing laundry when you're outside walking.  The clothes were eventually coming out dry, just taking an extremely long time to finish.  The lint trap also had zero lint attached to it after running 2-3 loads.

I decided to pull the flexible exhaust vent off the back of the dryer while it was still running.  I was immediately hit with warm moist air so that ruled out any blockage or problem with the dryer itself.  I stuck my arm down the exhaust pipe and discovered it was completely filled with water!  The flexible vent had bent down just like a P trap under the sink!  No wonder the dryer wasn't able to exhaust properly!

This is the nasty water that was stuck inside of the pipe.

[attachimg=1]

The dryer vents out through the roof so I climbed up there to see what might have allowed the water to get into the dryer vent in the first place.  The vent was closed in the down position, but there was this caked on lint that was able to catch and hold the vent open.

[attachimg=2]

My guess is that the vent must have gotten stuck open last week when doing laundry.  We had about 3 days of bad storms so the rain must have somehow been driven down into the open vent.  I'm still a little skeptical how that much water got down there, but wind driven rain does make it feel almost like it's raining sideways.  Water could have also slowly infiltrated over time and just this last week was enough water to completely block the vent.

I know you're supposed to routinely check the dryer exhaust venting and actually clean it out anyway, but I wonder how many people actually bother to do that.

 

[RKA]

Good detective work!

 

[GoingMyWay]

Thanks Raj!  I'm most happy that I don't have to buy a new dryer.

 

[Sparktrician]

I'm glad you didn't have a fire resulting from the blockage!  [scared]

 

[six-point socket II]

Glad you found the culprit!

Kind regards,
Oliver

 

[peter halle]

My dryer vent goes down and was installed with the crappy aluminize flexible pipe.  Before I discovered the sagging issue my dryer would cause audible bubbles.

By the way, dryer vents should be cleaned at least every couple of years.  And if you use excessive amounts of fabric softener so that Snuggles can live in your home - more often.  That stuff helps glue lint.

Peter

 

[JimD]

Reminds me of my dryer vent.  I live in a 50 year old house located on a large lake (lot almost worth more than house).  There were a lot of things I presume the former owner did because I hope no "professional" did them.  Like a staircase with over 3 inch variation in the rise (I rebuilt it).  The dryer was vented into an empty flue of the fireplace.  That doesn't work.  The flue was roughly 25 feet tall.  The dryer couldn't push air that far, especially through a 8 inch square flue.  So the flue was full of lint and dead birds.  I think the birds went into the flue to get the lint for their nests and then couldn't get out.

My dryer now vents through the wall of the crawl space through a rigid metal duct.  Works a lot better. 

 

[GoingMyWay]

I'm glad you didn't have a fire resulting from the blockage!  [scared]

That would have been a disaster!

Glad you found the culprit!

Kind regards,
Oliver

Me too.  When I first peaked behind the dryer I did think the venting looked a little odd (not how I vaguely remembered it looking from the last time I looked back there), but had no idea at the time it was filled with water.

My dryer vent goes down and was installed with the crappy aluminize flexible pipe.  Before I discovered the sagging issue my dryer would cause audible bubbles.

By the way, dryer vents should be cleaned at least every couple of years.  And if you use excessive amounts of fabric softener so that Snuggles can live in your home - more often.  That stuff helps glue lint.

Peter

The drying times should be reduced after the vents get a good cleaning since there will be much less air resistance.  I remembering cleaning the straight vent out in my parent's house.  I couldn't believe how much lint was inside of the pipe!  It's just such a pain to clean.  Our dryer is stacked on top of the washer, which is all sitting inside of a drain pan.  I still feel kinda bad for the installers from Best Buy who had to pick both units up to lift over the lip of the drain pan (the wall is directly to the left of the units too).  I struggled a fair bit to get the flexible vent to go back over the exhaust pipe on the back of the dryer.

I used to have a housemate and I think he might have used liquid fabric softener.  I've only ever used the sheets.  I used to buy the Costco Kirkland brand, but discovered that it left what appeared to be oil spots on some of our clothes.  We now only use Bounce Dryer Sheets.  Do the sheets also gum things up?

Reminds me of my dryer vent.  I live in a 50 year old house located on a large lake (lot almost worth more than house).  There were a lot of things I presume the former owner did because I hope no "professional" did them.  Like a staircase with over 3 inch variation in the rise (I rebuilt it).  The dryer was vented into an empty flue of the fireplace.  That doesn't work.  The flue was roughly 25 feet tall.  The dryer couldn't push air that far, especially through a 8 inch square flue.  So the flue was full of lint and dead birds.  I think the birds went into the flue to get the lint for their nests and then couldn't get out.

My dryer now vents through the wall of the crawl space through a rigid metal duct.  Works a lot better. 

Our laundry room is on the 4th floor of our townhouse so coming out through the roof is a very short trip.  My friend's parents had their laundry room in the basement and the dryer vented out just above ground level.  Unfortunately, a rat managed to find its way into the dryer vent and went all the way into the dryer.  The dryer (rat and all) caught on fire so it had to be completely replaced.

 

[DeformedTree]

Reminds me of my dryer vent.  ... The dryer was vented into an empty flue of the fireplace.  That doesn't work. 

Sure it does, when the fire happens it is conveniently in the chimney.  [tongue]

This is why I don't like these vents going up thru roofs, hard to access/clean, and increased chance of water getting in like this.  What amazes me is how there are more restriction on what can be used for HVAC ducts than dryer duct material, HVAC air is general not combustible.  So much garbage is sold for them, from various flex material, pipe things with the flow qualities of a maze just so it fits in a 2x4 wall.  They really need to get to some regs making near straight shots out walls code.  Something that can be cleaned easily, but even if not cleaned is no likely to get clogged up.  Worse is code requires you to have the exit 3 ft from any opening.  Which just causes builders to do more convoluted routing.  Because we know how toxic dryer vent air is.  Can't have them someplace where people might notice issues before they become a big issue.

 

[GoingMyWay]

Accessibility is a very good point!

Climbing up on the roof is a pain, especially when you're scared of heights like me.

I seem to recall seeing some dryer vent cleanout access panels with a built in secondary filter.  I don't remember where I was when I saw that now, but it seemed like a brilliant idea as soon as I noticed it.

 

[RJNeal]

This kinda reminds me of a job at an assist living place. They had like 6-8 washer dryer sets. Used the heck out of them. Most of the link traps were worked out lots of holes. There laundry room was in a bottom floor most the vent were routed though the mechanical area. There was lint everywhere in the mechanical area. I suggested that replace the traps and educate the housekeeping on the do’s and don’t.
Rick

 

[DeformedTree]

Accessibility is a very good point!

Climbing up on the roof is a pain, especially when you're scared of heights like me.

I seem to recall seeing some dryer vent cleanout access panels with a built in secondary filter.  I don't remember where I was when I saw that now, but it seemed like a brilliant idea as soon as I noticed it.

I think someone made a box that goes in the pipe with a second screen and a clear door, you mount it eye height so folks could see it and clean it out.  Of course it doesn't work if it's hid behind a double stack or shelves.  The more insane thing is they sell in stores a similar thing to "recover moisture/heat" into the space.  Yeah, blow the stuff you are trying to remove right back in the space.

 

[Cheese]

I'm glad you didn't have a fire resulting from the blockage!  [scared]

That's a more common situation than you'd think.  [eek]

Like Peter said, clean the vent/pipe/duct every couple of years. Use one of these, a 4" brush that chucks up in a drill and has 3' long screw-in extensions.

[attachimg=1]

Avoid using dryer sheets, they produce a sticky residue. Pull out the dryer lint screen and take a look at it. You'll likely see that some of the lint screen holes are plugging, that's from the dryer sheets. We no longer use dryer sheets.

Use regular steel or aluminum ducting for venting the dryer. Avoid the plastic spiral wrap duct and the aluminum flexible duct. Both can collapse and restrict, besides you can't clean the stuff with the brush shown above.

I used this to come out of the bottom of the dryer and then you can attach the sheet metal ducting directly to it.

[attachimg=2]

If you need to turn 90º, consider using 2 each 45º elbows instead, they're a lot less restrictive.

[attachimg=3]

 

[Rick Herrick]

Avoid using dryer sheets, they produce a sticky residue. Pull out the dryer lint screen and take a look at it. You'll likely see that some of the lint screen holes are plugging, that's from the dryer sheets. We no longer use dryer sheets.

Do you not have an issue with static electricity on your clothes?  Its really bad on these performance/wicking type of work out shirts.  My sons work shirts are similar and with out the dryer sheets, it drives us nuts.

 

[GoingMyWay]

Avoid using dryer sheets, they produce a sticky residue. Pull out the dryer lint screen and take a look at it. You'll likely see that some of the lint screen holes are plugging, that's from the dryer sheets. We no longer use dryer sheets.

I thought our lint screen looked pretty clean, but I just checked and you're right!  There is a swath of clogged holes!  I should look into replacing the flexible duct.

I do have the Lint Lizard to help clean out the lint that collects in the dryer behind the screen.

Avoid using dryer sheets, they produce a sticky residue. Pull out the dryer lint screen and take a look at it. You'll likely see that some of the lint screen holes are plugging, that's from the dryer sheets. We no longer use dryer sheets.

Do you not have an issue with static electricity on your clothes?  Its really bad on these performance/wicking type of work out shirts.  My sons work shirts are similar and with out the dryer sheets, it drives us nuts.

Static electricity is one of the main reasons why we use dryer sheets.  It also makes the clothes smell nice.  I think I might have forgotten to throw a dryer sheet in one time during winter.  My dress pant leg clung to my leg for the entire day.  It was so annoying!  I've seen some anti-static sprays, but I have no idea if they actually work.

 

[Bob D.]

Good advice from Cheese.

Above all read the manual that comes with your dryer. Most Mechanical Codes will say to follow the manufacturers recommendations on installing the vent. But they may add additional restrictions over those from the manufacturer.

The manual will tell you how long of a run the dryer can support including how many bends, it varies from one dryer to the next so don't make assumptions. Bends and other restrictions get counted for more than their actual length. This is to allow for the restriction they add over a straight length of pipe. And it should be obvious but NEVER reduce the pipe size.

 

[leakyroof]

I'm glad you didn't have a fire resulting from the blockage!  [scared]

That's a more common situation than you'd think.  [eek]

Like Peter said, clean the vent/pipe/duct every couple of years. Use one of these, a 4" brush that chucks up in a drill and has 3' long screw-in extensions.

[attachimg=1]

Avoid using dryer sheets, they produce a sticky residue. Pull out the dryer lint screen and take a look at it. You'll likely see that some of the lint screen holes are plugging, that's from the dryer sheets. We no longer use dryer sheets.

Use regular steel or aluminum ducting for venting the dryer. Avoid the plastic spiral wrap duct and the aluminum flexible duct. Both can collapse and restrict, besides you can't clean the stuff with the brush shown above.

I used this to come out of the bottom of the dryer and then you can attach the sheet metal ducting directly to it.

[attachimg=2]

If you need to turn 90º, consider using 2 each 45º elbows instead, they're a lot less restrictive.

[attachimg=3]

  I bought this kit to clean out our metal 4" round ducts in the basement, where both dryers live, and exhaust right above ground level outside the house
Even with short metal smooth runs, it is amazing how it builds up over time. Those brush heads do a great job of getting it off the sides of the metal ductwork.    [cool] [cool] [cool]

 

[jellyroll]

Check your local building codes or better yet latest International Building Code for ideas on fire maximum safety. Use aluminum (not steel which can eventually rust through due to the very high humidity and possible condensation) 26 ga or thicker in case there is a fire, not the c*#p at big box stores, no screws, they can cause blockages, instead use aluminum duct tape to prevent leaks and join sections, inner part of duct joint points away from dryer. There is a maximum allowable computed length (subtract length for each elbow, etc.) Check out 2 products: Magvent for easily removing and reinstalling the dryer during cleaning, and if needed, Dryer-ell to provide 90 degree bends without appreciable airflow loss. Both are pricy, but I use both and think they are worth while. Don't forget to inspect and clean lint from the outside damper as needed based on our dryer usage, I do that every 3 months... there is more lint there in the winter due to winter vs summer clothing plus minor condensation at the vent in winter.

 

[lawhoo]

I just used a Magvent to connect my new dryer to the wall vent. The dryer is under a fixed countertop, so access and visibility are limited. Your wall vent needs to align pretty closely with your dryer opening, if you use the straight Magvent (the 180), but it worked great. If your dryer doesn’t align closely enough, Magvent has a couple of alternatives. It’s clever—one of those “why didn’t I think of that?” products.

 

[Joelm]

We don't have to worry about venting anymore.

We switched to a Miele heat pump dryer which is super efficient. All it does is create moisture. You can use either a water reservoir or drip hose that comes with the unit. No need for vents.