outside pipe draft issues ?

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Bruce P

New Member
Aug 10, 2015
93
Whiting NJ
Looking at installing a wood stove Chimney would be 25' The easiest and cheapest way would be to go through the wall and up ouyside along the side of the house. Would I have a backdraft issue with that much cold air ? Could also run up through the ceiling ,a bedroom and attic about two k more for labor. Would having the pipe inside make for an easier cleaner burn ?
 
For 2k more I wouldn't do it. Run it outside. I have a very similar height chimney here at the place I rent and was burning sub par wood (low and mid 20s moisture content) starting end of October. Swept once New Years day and once at end of April (end of season). Had roughly 4 cups of light brown creo each time with a little black stuff at the top 3 ft section. The 2 grand you save will hire a sweep multiple times if your not keen on climbing on roofs. Make sure you have dry wood and run the flue temps up good and warm on reloads. I like to run it up to 350-450 surface temps 16" above stove. I'm sure others will chime in as well.

As for draft on cold starts you may have some issues. Open a nearby window for 10 mins or so while getting the fire going. Research top down fire starting method and get yourself a propane torch for lighting and point it up the flue for a few minutes and then light your fire. With a few attempts you'll get the hang of turning a draft back around. If burning 24/7 you should keep enough heat going to keep the draft.
 
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Often the parts are cheaper for a straight up, interior installation. There are no elbows or tees involved and a bit less chimney pipe. 2K more for labor sounds exorbitant. For sure having the pipe indoors makes for a warmer chimney which helps starting be easier and burning cleaner.
 
Looking at installing a wood stove Chimney would be 25' The easiest and cheapest way would be to go through the wall and up ouyside along the side of the house. Would I have a backdraft issue with that much cold air ? Could also run up through the ceiling ,a bedroom and attic about two k more for labor. Would having the pipe inside make for an easier cleaner burn ?

I went with an outside chimney due to the way my house was built. I had read that sometimes this can result in drafting issues, more creosote and the loss of heat . . . and this all may be true . . . but in my case I have found that the only time I have any drafting issues (along with nearly everyone else regardless of how their chimney is built) is in the early fall and late spring when the inside and outside temps are very close to each other . . . oftentimes placing a candle in my firebox for a few minutes or opening a nearby window is enough to get the draft flowing in the right direction.

Creosote: No issues. I get some of the dusty soot, but never any of the crunchy creosote . . . then again I also burn well seasoned wood, inspect and sweep monthly (over kill on my part admittedly) and burn at the right temps (not too hot, not too cold.)

Heat loss: I suspect I may lose some heat by going out and up vs. going straight up and out . . . but I have always said that modern woodstoves really seem to be built more to heat the woodstove and have the heat transfer from the stove to the house vs. heating with the chimney and its residual heat.
 
My experience with class A is that a thru wall install is usually a little more cost in parts. Those tees are expensive.

And 2K more in labor? That's just a plain ole ripoff. How much labor is quoted for the thru wall install?

Jason
 
My bad it was about 1100 more to run inside including rocking around the pipe ready to paint. Today I got a phone estimate from another place and the internal run was actually a little cheaper but I dont think that includes sheet rock and framing Go figure.
 
Yeah that seems reasonable factoring in the finish work
 
But to answer your original question. Yes straight up and out is better as far as draft goes but out the wall and up will work fine as well. The biggest difference comes from the elbows not the fact that it is outside. An outside chimney will take a little bit more to get draft started but most of the time that is not much of an issue.
 
if the pipe was left unframed in would it radiate any heat into the bedroom it would run through ? Just wondering might be able to run it through a closet
 
But to answer your original question. Yes straight up and out is better as far as draft goes but out the wall and up will work fine as well. The biggest difference comes from the elbows not the fact that it is outside. An outside chimney will take a little bit more to get draft started but most of the time that is not much of an issue.
Each 90 deg. turn slows down the smoke. Estimates are that each 90 turn is equivalent to reducing the flue height by around 3 ft.. Add a cold outside pipe and draft can suffer significantly with a chimney that just makes minimum spec, especially in milder weather.
 
Something else to consider with a straight up flue, the sweeping is done from inside the house with a soot eater, or messing with taking the stove apart to get the sweepings from above to fall into the firebox.

An exterior chimney will allow a clean out T at the bottom after going through the wall to outside and the mess stays outside. Remove the small interior section and carry it outside to clean it. LESS MESS inside is key in my eyes anyway.
 
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I clean my stove with a soot eater after pulling the baffle. I take my time and have the plastic curtain taped over the front of the stove. I wipe each rod with a damp cloth as it is being pulled out of the stove. Although I expected a mess there is almost none in the house.
 
Each 90 deg. turn slows down the smoke. Estimates are that each 90 turn is equivalent to reducing the flue height by around 3 ft.. Add a cold outside pipe and draft can suffer significantly with a chimney that just makes minimum spec, especially in milder weather.
does that include the 90 degree turn inside the house before it gos through the wall ? I have 9' cielings can it be angled at less than 90 degrees inside ?
 
does that include the 90 degree turn inside the house before it gos through the wall ? I have 9' cielings can it be angled at less than 90 degrees inside ?
Yes, it does. Softening the 90 deg turn with a pair of 45 and a short connecting offset piece can help.

two 45s for flue connect.jpg Yurt stove.jpg
 
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what about radiant heat off the pipe if it runs internally through the house ?
Yes, the house gains a bit of heat from the pipe and the warmer house temps keep the flue gases hotter in the pipe.
 
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Add a cold outside pipe and draft can suffer significantly with a chimney that just makes minimum spec
yes but the op has 25' i doubt there will be an issue
 
if the pipe was left unframed in would it radiate any heat into the bedroom it would run through ? Just wondering might be able to run it through a closet
Most, if not all, of the time the pipe needs to be enclosed to satisfy code. Vents could be installed in the enclosure, both near the floor and the ceiling, in order to facilitate air flow and heat escape to the room.
 
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