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My 2nd floor dryer vents outside of house but into the small enclosure between the roof and ceiling of the attached porch overhang (see photo below). There is no vent coming out of the overhang.

enter image description here

isherwood
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Dave K
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  • If the dryer is located towards the middle could it be vented to the side of the porch on an angle? Or would vent have to be straight line out of the front of the porch overhang? Front does not have enough space plus gutter is in the way – Dave K Apr 25 '23 at 13:40
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    Are you sure the dryer vents into that space? Can you tell us, and show with better pictures please, where the vent goes into the wall? It would be strange for a dryer to be up against a front wall by in that location. And the pipe might go up the wall and vent out somewhere else. Please tell us more, and post better quality pictures! – jay613 Apr 25 '23 at 16:04
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    I'd dry a load on high, something with lots of moisture like towels. After about 10-20 minutes, inspect the outside of the house to see where the steam is coming out of the house. – rtaft Apr 25 '23 at 21:58
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    I checked the roof, no vent. I’ve checked under the porch below and no vent there either. So I placed my arm into the hole that vents from the laundry room and out the house. It’s a short hole that seems to stops inside the enclosed area of the covered porch. – Dave K Apr 26 '23 at 10:16
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    Is this space fully enclosed or is it open at the bottom? It wasn't clear from the picture. You called it an enclosure but I just want to make sure. – user253751 Apr 26 '23 at 14:35
  • Do you have a sketch of where your vent runs? Any chance you could extend the actual exit from "house structure" down through the soffit of the porch overhang? – Huesmann Apr 26 '23 at 14:38
  • Do you know if the porch was added on later? I can't really tell from the pictures. – Lio Elbammalf Apr 26 '23 at 14:52
  • No it was added when the house was built. – Dave K Apr 26 '23 at 15:00
  • Yeah I think the solution is extending pipe to the soffit of the porch. Or 90 degrees and out the side of the porch ceiling. – Dave K Apr 26 '23 at 15:28
  • It is a fully enclosed space. It’s the space between the ceiling and roof of the attached porch. There’s an enclosed space due to the roof having a pitch. – Dave K Apr 26 '23 at 15:59
  • @rtaft on a cold day would be even better, perhaps a quiet one as you might be able to hear something from outside – Chris H Apr 27 '23 at 07:52
  • If it's a gas dryer, you may have a carbon monoxide problem too depending on how that overhang is designed. – rtaft Apr 27 '23 at 09:43
  • It’s an electric dryer – Dave K Apr 27 '23 at 13:06
  • Please don't substantially change your question after you have answers. If you now want to know what to do about it, post a new question and provide views of the porch attic. – isherwood Apr 27 '23 at 13:42

4 Answers4

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Yes, that's a problem!

Depending how long it's been set up like that, you may already need to replace the whole porch roof, and hope it hasn't rotted the wall framing too much.

Dryer exhaust needs to vent ALL THE WAY OUT of the BUILDING. "Air shall not be exhausted into an attic, soffit, ridge vent, or crawl space." (2015 IRC M1501.1)

Or you need a ventless (heat-pump) dryer that just needs a drain for the water. But you still may need a new porch roof.

If someone other than you installed it this way, you may have recourse to sue them for the cost of the new porch roof.

The Current Thing
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Ecnerwal
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    I'd say it's a _potential_ problem, and that degree of rot is extremely unlikely. Let's not cause any heart conditions here. – isherwood Apr 26 '23 at 13:02
  • Thanks. I don’t get the sense there is extreme rot. But I certainly am looking to prevent any future damage going forward – Dave K Apr 26 '23 at 16:00
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    If it's in a dry climate it may not be a problem – Voltage Spike Apr 26 '23 at 18:35
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    Dryers also vent quite a bit of lint. Any closed space they vent into will be covered with lint pretty quickly. The lint is quite flammable, but there's not likely to be a source for ignition - just a big mess. – JPhi1618 Apr 26 '23 at 19:06
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    @DaveK rarely is any answer so unambiguously correct. It is not ok. I encourage you to accept this answer. – jay613 Apr 26 '23 at 19:51
  • Understood. I am looking for solutions. Not easy to vent considering it’s upstairs and at the front of the house – Dave K Apr 26 '23 at 20:48
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    If it's been like that for a very long time, the bad job might not have been the vent installation. The ceiling could have been added. Still a problem of course – Chris H Apr 27 '23 at 07:57
  • @DaveK if you are "looking for solutions" you appear to have left that **completely** out of your question. Simplest solution without a ventless dryer is to put a vent in the sidewall above the porch roof. Next would be vent through the porch roof. – Ecnerwal Apr 28 '23 at 00:23
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The whole point of a vent for a dryer is to take away the moisture contained in the air used to dry the wet/damp items in the dryer. That moist air will go to anywhere cooler than itself. So if it can't get straight out to atmosphere (fresh air), it will wander round inside the void - your roof space - until it finds somewhere suitable, on which to condense.

So, over time, the inside of that roof space will be damp every time you use the dryer. That will encourage rot and fungus there, increasing happily in secret. Until one day, you'll need to replace the timbers.

Solution: take the tube straight outside. If it goes through the roof space on its way, that's o.k., but its end must vent to outside. It will need some grille or flap to stop wildlife entering, and maybe will look a little ugly. Better than having to strip of at least part of the roof, though.

EDIT: With a little more info., like it's 12' to the side of that porch, I recommend taking the cladding off from above the front door, and putting a tube with an elbow between there and the dryer. Something like a sewer pipe may be an answer - not sure what diameter they are where you are. So now, the moist air (possibly gas if its a gas dryer) will travel from the back of the dryer, round 90 degrees, along the 12' to the left, with a bit of a slope, to a proper vent (flaps) out of the building above the door. Easy to take apart, easy to repair, and not unsightly. May help to take off a few tiles opposite the back of the dryer for easy access. Using non-flexi pipe means you'll be able to offer it through, and up to the hole where the dryer outlet is.

Tim
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  • What about venting on a 90 degree angle out the side of the porch roof? I say this because the dryer points out the front but the roof pitched so there’s no space to vent straight out the front. – Dave K Apr 26 '23 at 12:17
  • @DaveK A 90 degree bend is fine - just try and keep the pipe short. (Preferably with a smooth bore and a decent radius on the bend rather than a sharp angle, so there is a good airflow.) – Martin Bonner supports Monica Apr 26 '23 at 13:12
  • Unfortunately the laundry room is towards the middle of the house so the pipe would have to go about 10-12 feet to the left to get to the outside. – Dave K Apr 26 '23 at 13:15
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    what is with Americans' fear of condensing dryers? I heard they are even more energy-efficient since the heat is recycled. – user253751 Apr 26 '23 at 14:36
  • @user253751 I mean, it's not like they are objectively better. Vented, ventless, and heat pump dryers all have pros and cons. – Abion47 Apr 26 '23 at 17:05
  • @user253751 the reason I personally don’t plan on buying one is that they are slower than heat dryers. They are certainly more power-efficient, and it’s nice that they’re gentler on clothes. They’re also rarer, and more expensive, here. I often do all my family’s laundry in one big weekend day, rather than throughout the week, and I can’t as easily do that if the clothes-pipeline has a bottleneck on drying. – Jacob Krall Apr 26 '23 at 19:09
  • @user253751, price. The cheapest condensing dryer I could find was priced at $900 (the cheapest without wifi or a mandatory arbitration agreement was another $100). A comparable electric heated dryer would cost $400; at current electricity prices, the payback time for the condensing dryer would be about 50 years. – Mark Apr 26 '23 at 23:53
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Route the vent to the side of the roof using rigid metal ducting and terminate to a dryer vent hood like so:

enter image description here

enter image description here

Make sure to slope the ducting towards the vent hood so that any condensation flows towards the outdoors.

MonkeyZeus
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  • Use a sheet metal duct and make sure it slopes toward the wall vent. This is a long-ish run in exterior space and the steam will condense if it's cold out. You don't want it pooling inside the duct and dripping out inside that porch roof space. – aquaticapetheory Apr 27 '23 at 13:39
  • @aquaticapetheory Good call. Did OP mention where the current termination is? I didn't see anything in the comments. – MonkeyZeus Apr 27 '23 at 13:47
  • You mean horizontally? Comment above says 10-12 feet. – aquaticapetheory Apr 27 '23 at 13:50
  • Correct it is towards the middle of the front If the house. So 10 to 12 feet from the side. – Dave K Apr 27 '23 at 16:15
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Solution: Open that attic space, extend vent to and through side wall. Or down thru the porch ceiling, but that will be a problem if you ever want to enclose the porch

keshlam
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  • Not enclosing the porch so venting through porch ceiling seems like the solution – Dave K Apr 27 '23 at 13:05
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    @Dave This is not a good idea. The steam will rise then condense on the porch roof ceiling and adjacent wall even if it's not enclosed. That ceiling is probably not air tight so it'll get in there again too. You want it to have as clear a shot of getting away from the house as possible. Plus you probably want that porch to be usable space and now you've got a cloud of steam there. Going a few extra feet to a vent on the side of the porch overhang is the better way. – aquaticapetheory Apr 27 '23 at 13:59
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    Agreed, out the side seems worth the relatively small amount of extra effort even if it does mean having to patch the ceiling. – keshlam Apr 27 '23 at 15:25
  • The side of the porch is my preference. But that means a 90 degree vent pipe that goes an extra 10 to 12 feet to get to the side. So I’m not sure if this is too long or not. – Dave K Apr 27 '23 at 16:13
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    @Dave The old dryer in my basement is blowing through 8 feet (or probably more) of crappy flexible duct that's not routed in any organized way and it does just fine. 10-12 feet of smooth rigid duct with a single 90 deg elbow should not be a problem. If you're worried, you can insulate it and/or add a booster fan but it should not be necessary. – aquaticapetheory Apr 27 '23 at 16:53
  • @Dave Here is something a bit more solid for [dryer vent guidance](https://www.nachi.org/dryer-vent-safety.htm) – aquaticapetheory Apr 27 '23 at 16:57
  • I added a second picture in the main post that illustrates in a highlighted yellow line where the dryer is and how the vent would have to go 90 degrees to get to the side of the porch ceiling. – Dave K Apr 27 '23 at 18:36