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

[harleygirl64]

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 !!

 

[Backwoods Savage]

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.

 

[dougand3]

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.

 

[DAKSY]

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.

 

[harleygirl64]

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 )

 

[Shari]

(thats the way the stove was manufactured )

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

Shari

 

[wellbuilt home]

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

 

[LLigetfa]

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.

 

[grommal]

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.

 

[Wet1]

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.

 

[LLigetfa]

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.

 

[Wet1]

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.

 

[LLigetfa]

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.

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.

 

[Wet1]

Gotcha, sorry.

 

[Backwoods Savage]

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.

 

[Highbeam]

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.

 

[semipro]

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.

 

[harleygirl64]

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

 

[PapaDave]

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

 

[harleygirl64]

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

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..