# 6 inch or  8 inch pipe which too use..??also  any preference for installation.?



## harleygirl64 (Oct 18, 2009)

HI Ya All..  thanks for taking the time to read my questions and hopefully provide me with some answers ..  I have read for days trying to figure this out and frankly  I'm not finding any answers.  sooooo..  I'm getting ready to install an older  tag says 1985 Harman  Mark 2 wood stove, it  has a 6  inch  flue  (guess thats what its called ) LOL opening in the back  of the stove  ..!!  any ways  my SO other is wanting to use  8 inch  insulated pipe  the problem that I'm  having  is this  at LOwes  you can buy  a Supervent  wall support kit  but the stores only stock  the 6 inch kits  at around  $217  thats for either  kit  straight  up thru the roof or   the  out the back of the stove and thru the wall.   they sell both 6 inch and 8 inch insulated pipe soo thats not the problem the problem  I'm  finding is that I'd have too special order the 8 inch kit at a  total cost of $ 420 bucks plus tax.  that being said  My SO  is   almost is demanding  we purchase  the 8 inch  kit even with the extra cost  his  stance is  we'd get better draw..   the house is surrounded by trees and   we also have  a roof line  within 10 foot of the pipe sooo we would be running 15 foot of pipe.to get the clearence we need. ( thats 15 foot from the elbow toowhere the   chimmeny cap connects .I just  want to be sure before I spend the extra money that the 8 inch pipe is really WHAT WE NEED  I want too be  informed and edumacated  LOL about all this soo I can truley make an informed decision and is there   any  particular reason why  one would  install  either straight up thru the roof or  out thru the wall and  the  majority of the pipe be outside..  HELP..!! Gawd I hate winter ..!! I just wanna ride My Harley..!! LOL.. any who  thanks  for any information  !!


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## Backwoods Savage (Oct 18, 2009)

Do not go from a 6" to an 8" or you will not be a happy camper. Your SO is totally wrong. Stay with 6" all the way.

Good luck.


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## dougand3 (Oct 18, 2009)

Welcome to the forum. harleygirl64. Stay with the same flue size = 6". It should draw BETTER than expanding to 8". Obey the "10-2-3 ft" rule.


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## DAKSY (Oct 18, 2009)

Get the 6-inch Class A unless you plan on going to a monster like the Hearthstone Equinox.
You SO is mistaken on how your chimney will draft.
6-inch - all the way from the Flue collar on the stove to the cap - is BY FAR 
the best way to go to get a good draft.
Not sure what his rationale is, but it's not based on hearth industry guidelines.


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## harleygirl64 (Oct 18, 2009)

DEnnis thanks soo much for your answer BUT I need  too  know why  we should stay with 6 inch .. hes hard headed  as can be soo I need too be able to back my ass up with a  reason as too stayin with 6 inch (which BTW thats what I feel we should doo too as thats the way  the stove was manufactured )


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## Shari (Oct 18, 2009)

harleygirl64 said:
			
		

> (thats the way  the stove was manufactured )



You just answered the question.  The stove was manufactured for 6" so go with 6".

Shari


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## wellbuilt home (Oct 18, 2009)

You should stay with the 6" pipe all the way up . 8" will cut down on the draft .
 The smaller the pipe the hotter  the chimney  gas will stay.  The less creosote build up you will have .    
  I would run the chimney pipe thru the roof .  The flue  will stay warmer inside  and less bends in the pipe will be better to clean and give better draft .
          John


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## LLigetfa (Oct 18, 2009)

Flue gas slows down in an 8 inch and has more time to cool and lose draft.  the 6 inch will maintain the upward momentum and exit quicker.


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## grommal (Oct 19, 2009)

harleygirl64 said:
			
		

> DEnnis thanks soo much for your answer BUT I need  too  know why  we should stay with 6 inch .. hes hard headed  as can be soo I need too be able to back my ass up with a  reason as too stayin with 6 inch (which BTW thats what I feel we should doo too as thats the way  the stove was manufactured )


The reason has to do with the exhaust gas velocity in the pipe.  It will be moving much more slowly through the larger pipe, giving more time for it to cool.  This negatively impacts the draft and increases the creosote deposition.  6" all the way.


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## Wet1 (Oct 19, 2009)

These guys are spot on, go with the 6".  The 8" will have worse draft, build up more creosote, and waste your hard earned money with the initial purchase.  Again, go up through the roof.  Exterior chimneys get cold, and this means worse draft and more creosote.


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## LLigetfa (Oct 19, 2009)

If you have a very tall chimney going up through the interior, there is a possibility of too much draft and a case could be made to use 8 inch.  The slower velocity will allow more of the heat to be extracted to the room and the interior chimney is less likely to build up creosote than an exterior chimney.


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## Wet1 (Oct 19, 2009)

LLigetfa said:
			
		

> If you have a very tall chimney going up through the interior, there is a possibility of too much draft and a case could be made to use 8 inch.  The slower velocity will allow more of the heat to be extracted to the room and the interior chimney is less likely to build up creosote than an exterior chimney.


She said 15' of pipe, she doesn't want to use 8" for this.


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## LLigetfa (Oct 19, 2009)

Wet1 said:
			
		

> LLigetfa said:
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Agreed.  15 feet is not too much pipe, perhaps not even enough.  Just playing Devil's advocate as to why someone might want to use 8 inch on a stove designed for 6 inch.


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## Wet1 (Oct 19, 2009)

Gotcha, sorry.


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## Backwoods Savage (Oct 19, 2009)

harleygirl64 said:
			
		

> DEnnis thanks soo much for your answer BUT I need  too  know why  we should stay with 6 inch .. hes hard headed  as can be soo I need too be able to back my ass up with a  reason as too stayin with 6 inch (which BTW thats what I feel we should doo too as thats the way  the stove was manufactured )



harleygirl, it looks like the other fellas answered your question before I got back and I hope you are able to back your arse up with the right reason. On top of it all, you will save some dollars going with 6" rather than 8".  

Good luck.


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## Highbeam (Oct 19, 2009)

You asked about internal vs. external pipe runs as well. Your draft will be superior if you run the pipe from the stove vertically through the ceiling and through the roof vs. going outside to a tee and then up the outside of the house. The chimney stays warmer so it drafts better. The outside chimney bolted to your exterior wall looks bad and gets cold so it drafts worse.

An eight inch pipe looks hokey when setting on a regular sized woodstove. It's freaking huge. 

Take the savings on that 8" pipe and use it to buy a nice new englander woodstove from Lowes. The modern stoves burn so much better.


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## semipro (Oct 19, 2009)

harleygirl64 said:
			
		

> DEnnis thanks soo much for your answer BUT I need  too  know why  we should stay with 6 inch .. hes hard headed  as can be soo I need too be able to back my ass up with a  reason as too stayin with 6 inch (which BTW thats what I feel we should doo too as thats the way  the stove was manufactured )



Your SO may be thinking about the stovepipe as a pressurized pipe where a larger size would result in less resistance.  (sort of like open pipes on your bike).  However, wood stoves don't really pressurize the pipe, they heat it.  The rising column of heated gases creates a (small) vacuum in the flue that pulls gas from the stove.  The vacuum created would only be decreased by going to a bigger pipe resulting in less draft and worse stove performance. 

Go 6 inch.


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## harleygirl64 (Oct 21, 2009)

JUst wanted  to thank everyone  for all the input !!  I was able too provide  the SO with the facts in black and white  soo NOW  we are doing 6 inch pipe


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## PapaDave (Oct 21, 2009)

harleygirl64 said:
			
		

> JUst wanted  to thank everyone  for all the input !!  I was able too provide  the SO with the facts in black and white  soo NOW  we are doing 6 inch pipe



Bing, Bing, Bing

We've got a winner.
Not so hardheaded after all, eh?

Dave


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## harleygirl64 (Oct 21, 2009)

PapaDave said:
			
		

> harleygirl64 said:
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 LOL     HA HA   ya and a little help from the club i carry around  just for HIM..!!   No really  I  kinda put my foot down on this issue.. plus it was much easier when i   showed him in writing  the facts..


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