Venting through interior wall, then outside?

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Bradcole1827

New Member
May 31, 2014
19
Graniteville, VT
I'm uploading a crude sketch of my home layout below. My problem is that, per code, I can't vent directly out my exterior wall because it is too close to the porch (2.5" would be clearance) .

No, I can't move the stove to another location. I need a solution from this location.

I can't go up because in order to get clearance over my porch roof, I'd have to go right through the middle of my upstairs bath vanity.

I drew what seems like the best venting option I can come up with. It requires an 18 inch run passing through an interior wall, then hang a 90 to the left and run 18 inches through the exterior wall and outside. The elbow in the bath would be inside a utility closet. Nothing combustible would be in there.

Questions are:
  • Is this crazy?
  • Is it a code violation?
  • I plan to use a standard thimble for the interior wall if this is acceptable.
  • Any other concern with this approach?
  • If this is reasonable, is an outside elbow upward to extend the vent 6ft up for draft advisable?
Thanks!

Brad
sketch1414966123267.png
 

bbfarm

Minister of Fire
Jan 2, 2012
708
wisconsin
Can you go straight out your wall then Veer right towards the bathroom outside then up

I would not put the vent like your drawing personally
 

bags

Minister of Fire
Oct 12, 2014
2,400
Kentucky
I'll agree with what bbfarm said. I don't think going thru the interior wall is wise and it will likely be frowned upon code wise if it is even legal there. Looking at your drawing it would be the same except outside instead of inside. A 45* to straight thru the wall to a 90* to a T then up.
 

johnny1720

Burning Hunk
Mar 6, 2007
240
The Great North East
That is not a good choice. If that is your only placement for the stove then maybe you shouldn't buy the stove.

Going directly out and up away from the porch would be ideal.
 

bags

Minister of Fire
Oct 12, 2014
2,400
Kentucky
Why couldn't you go right out next to the porch and then over? Looks like a clean an clear shot per the drawing. Yes you would see a little more pipe out there, but......
 

SmokeyTheBear

Minister of Fire
Nov 10, 2008
13,363
Standish, ME
Going out and then up above the roof line. Since you seem to have have foreclosed some of the other means.

This is not ideal either.

Those extra bends in the horizontal pipe and the other length would likely call for 4" venting and may exceed the maximum horizontal vent length recommended by the stove maker.

What about up inside and out the wall the porch is against?.
 

SmokeyTheBear

Minister of Fire
Nov 10, 2008
13,363
Standish, ME
While you can do what you propose you might want to consider making it impossible for any combustible to be inside that closet in the bathroom to get close to the vent.

Box the vent off at the clearance distances the vent makers gives for clearance to combustibles.

Then be certain that the stove makers recommendation on horizontal pipe lengths is followed because that is where the ash will pile up.
 

Bradcole1827

New Member
May 31, 2014
19
Graniteville, VT
Thanks for the many quick responses. There seems to be a wide agreement about going straight out, then running horizontally away from the porch.

Hey, I'm all for that! I was just (perhaps mistakenly) under the impression that a pipe could not run that close to a wall upon exit. But as I think about it, it runs close to the wall if it is going up vertical, correct? So why not have it come out, 90 to the right, then vent out.

Did I miss the common sense here:eek:? I saw in my install manual (CAB 50), where it listed a picture of all kinds of clearances. Maybe that's just for the actual end cap? Not all vent pipe period. I certainly would prefer this!

So here is an updated picture. I assume the red is what folks mean? So that's a 45, a 90 over, a 90 up, and a 90 out, on 3 inch pipe. Is that too much? Smokey mentioned that in regards to going to 4" I think. Better ideas after the 90 over?

Thanks again
Sketch20223636.png
 

bags

Minister of Fire
Oct 12, 2014
2,400
Kentucky
That should work fine. Just follow your suggested clearances in your manual. They also make holders for the pipe that screw onto the wall and secure the pipe. Might need a couple or few or those. See what others think about this too. I'm no pellet pro and am new myself. Good Luck!
 

chken

Minister of Fire
Dec 7, 2013
1,136
Maine
Thanks for the many quick responses. There seems to be a wide agreement about going straight out, then running horizontally away from the porch.

Hey, I'm all for that! I was just (perhaps mistakenly) under the impression that a pipe could not run that close to a wall upon exit. But as I think about it, it runs close to the wall if it is going up vertical, correct? So why not have it come out, 90 to the right, then vent out.

Did I miss the common sense here:eek:? I saw in my install manual (CAB 50), where it listed a picture of all kinds of clearances. Maybe that's just for the actual end cap? Not all vent pipe period. I certainly would prefer this!

So here is an updated picture. I assume the red is what folks mean? So that's a 45, a 90 over, a 90 up, and a 90 out, on 3 inch pipe. Is that too much? Smokey mentioned that in regards to going to 4" I think. Better ideas after the 90 over?

Thanks again
View attachment 143202
Seemed to me that you could do that with three 45s. All those 90s will likely put you into 4" pipe range. The first 45 is as you have it, the second 45 goes both away from the porch and up and away from the house. The third 45 allows you to straighten everything out for the termination cap. The 45s, though, don't give you a cleanout T, but I'd still prefer that to all the 90s you have planned.
 

SmokeyTheBear

Minister of Fire
Nov 10, 2008
13,363
Standish, ME
Thanks for the many quick responses. There seems to be a wide agreement about going straight out, then running horizontally away from the porch.

Hey, I'm all for that! I was just (perhaps mistakenly) under the impression that a pipe could not run that close to a wall upon exit. But as I think about it, it runs close to the wall if it is going up vertical, correct? So why not have it come out, 90 to the right, then vent out.

Did I miss the common sense here:eek:? I saw in my install manual (CAB 50), where it listed a picture of all kinds of clearances. Maybe that's just for the actual end cap? Not all vent pipe period. I certainly would prefer this!

So here is an updated picture. I assume the red is what folks mean? So that's a 45, a 90 over, a 90 up, and a 90 out, on 3 inch pipe. Is that too much? Smokey mentioned that in regards to going to 4" I think. Better ideas after the 90 over?

Thanks again
View attachment 143202

I would not run any horizontal along the outside at all.

Horizontal is bad enough inside that closet setup, it is worse outside because in addition to it being more restrictive of your combustion air flow a lot more ash will precipitate out in that kind of run due to the additional cooling off of the exhaust gases.

That 45, 90, 90, and 90 is over EVL for 3" pipe.

You want as few elbows as is absolutely required to get the exhaust outside and no more.

The goal is to exhaust the device and not add to the combustion blower's load, require additional cleaning, or prevent the stove from burning correctly.
 

CladMaster

Minister of Fire
Nov 20, 2012
677
Maine
Your idea in red is the best option.

You will need 3 45 bends, 1 cleanout tee and your straight pipes, and for the last part that runs up the wall with an end cap on the top, you will need at least 3 feet of rise to give the stove some natural draft in case of a power outage. If the EVL is over 15 feet in 3" pipe, you can change to 4" with an increaser off the last 45 bend then up in 4" pipe.
 

PelletGirl

Burning Hunk
Oct 25, 2014
180
Long Island, NY
Can someone explain to me why his original is not acceptable? Is it because it runs through a closet? Ours was just installed and set up in a similar fashion, except it does not go through a closet but our utility room. It then runs up about three feet and out. We had several installers come for estimates and they all told us it was our best option (and not against code). Info would be helpful because now I'm concerned. Thanks!
 

SmokeyTheBear

Minister of Fire
Nov 10, 2008
13,363
Standish, ME
The only issue with the interior run through the closet is one of proper burning if the vent is not sized to take into account the length, number of bends and most importantly keeping combustibles away from the vent (this would be a case of things falling or getting pushed against that vent, you can say all you want about it won't happen because I yadda, yadda, properly enclosed that can't happen ).

The sizing of vent is always a thing that you take into consideration (even though we have seen where "professionals" fall down on this matter).

The first part is a cause for additional cleaning, the second is a safety issue (never leave to chance that what can be prevented).

The first setup isn't ideal, it should pass code, it would be safer if the ability of things getting to the vent inside that closet was blocked.

We have plenty of cases on here of poor venting and the results and we always try to prevent mistakes that can lead to fires and the results thereof.
 
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PelletGirl

Burning Hunk
Oct 25, 2014
180
Long Island, NY
OK - I feel better now. Ours is through the wall into a utility room and we have the pipes blocked off from anything being able to fall on them or get near them. Just have to check to make sure the proper size venting was used. Thank you for the explanation.
 

bags

Minister of Fire
Oct 12, 2014
2,400
Kentucky
Sometimes ya just have to do what ya have to do. Doesn't make it ideal though. The easiest route is not always the best route although it is human nature to walk thru landscaping and mulch beds instead of using the walkways.
 
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PelletGirl

Burning Hunk
Oct 25, 2014
180
Long Island, NY
For us, this was the only route. I would have liked to avoid horizontals if we could, but we couldn't so we have one. My husband is very safety conscious so there is nothing near the piping in the utility room. As long as it works properly and is efficient as we can get it to be, I'll be happy. Liking the heat so far - warm and cozy.

Thanks again for the info.
 

Bradcole1827

New Member
May 31, 2014
19
Graniteville, VT
Thanks to all for the suggestions and great input. I'll definitely do the 3 45s configuration.

1 last question. How do you suggest bracing the end of the run? With the up-and-out run, given it's 3+ feet of elevation as cladmaster said, that will put the last 45 at least 3 feet from the house. That seems like a long span for the braces I have seen to support that much weight. Would driving a pole into the ground under the end and mounting to it be wiser?
 

bags

Minister of Fire
Oct 12, 2014
2,400
Kentucky
What do you mean by 3 ft out from the house?
 

Bradcole1827

New Member
May 31, 2014
19
Graniteville, VT
3 feet out from the house? - As I'm reading the suggestions, the middle 45 would point both 45 upward from level, and it would point 45 degrees outward from vertical. If the final height of the end cap is to be at least 3 ft, then my math shows the distance from the outside of the house would be at least 3 feet away as well as 3 feet above the height where the pipe exits the wall. Correct?
 

bags

Minister of Fire
Oct 12, 2014
2,400
Kentucky
OK, I'm with you now. Brain fart! How much more for 4" pipe to use the 90*'s which would keep it closer to the house? That 45* 3" thing turns that into an eyesore and a wind sail. You are correct in your figures. At a 45* angle for every 12" you would go out 12". Ex: a 12/12 pitched roof is a 45* angle.

Keep this thread going because someone will chime in with a Wha La problem solved possibly. The status quo is the more bends and the longer the length the bigger the pipe. I am new to the pellet game but do understand this stuff. I am no expert on the exhaust venting unlike many others here.
 

Bradcole1827

New Member
May 31, 2014
19
Graniteville, VT
Thanks Bags.. Hey this whole thing started with my brain fart. ☺ sounds like a couple guys on here are pros and know the EVL regs by heart. Yeah, if I were to place the clean out T at the end of the pipe exiting the house, the place the 45 on top of that, run diagonal up, then terminate with a 45 and end cap, that would be far more slightly. But that effectively adds a 90, right?

So that would mean 3 45s and a clean out T. Given a 3 ft diagonal rise, how does that fit the EVL chart? 3 ft or now 4?

Cladmaster seemed to recommend this, I believe. Smokeythebear seemed to want to avoid the clean out T. If making the diagonal up pipe into a 4 is necessary, I'm OK with that. But if the EVL can be met using this, I'd like to stay with 3. Maybe I'll go research how to calculate evls and report back ☺
 

Bradcole1827

New Member
May 31, 2014
19
Graniteville, VT
OK, that wasn't too hard. 45s are worth 3 ft. The clean out T is worth 5. The exit pipe is 1. The 4ft diagonal is 3 or 4. So yeah, the clean out T puts it into the 4" pipe range.

I have all the 3" pipe already from my current basement location (which ain't cutting it in a 110 year old house with granite slab blocks for a foundation). I'd hate to have to scrap all that and go to 4".

Which is probably what smokeythebear knew intuitively when he recommended not using the clean out T.

That then brings me back to, how to mount the terminus if 3 feet away from house? ☺
 

SmokeyTheBear

Minister of Fire
Nov 10, 2008
13,363
Standish, ME
OK, that wasn't too hard. 45s are worth 3 ft. The clean out T is worth 5. The exit pipe is 1. The 4ft diagonal is 3 or 4. So yeah, the clean out T puts it into the 4" pipe range.

I have all the 3" pipe already from my current basement location (which ain't cutting it in a 110 year old house with granite slab blocks for a foundation). I'd hate to have to scrap all that and go to 4".

Which is probably what smokeythebear knew intuitively when he recommended not using the clean out T.

That then brings me back to, how to mount the terminus if 3 feet away from house? ☺

Could you provide a picture of the outside of the house where the vent will exit that shows the porch.

If the stove allows horizontal venting then you could use a 45 and then straight out close to the porch use a jet cap on the end and brace it using the porch railing to mount a brace just before the jet cap. No clean out needed and only 1 45 degree angle. But you have to watch out for the horizontal run limits or figure on doing a lot of vent cleaning.

You can also use a 90 degree clean out inside go up 4 feet inside the house and use a 90 degree elbow and a bit of horizontal to go through the wall terminate using a jet cap. That might put the porch outside of the clearance to the termination requirements (don't know about other things out there). This would be the just about the maximum EVL for 3" vent.
 
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