How tall should chimney be?

[RichL35]

How tall should the 8" Metalbestos chimney be for my VC Encore? My VC dealer who is handling the chimney install has a total from the top of the stove to the tip of the chimney about 14 feet. This meets and excedes the code requirements for chimney/roof clearences but i'm concerned if this is enough for proper draft.

Thanks,
Rich

 

[Shari]

Does your owner's manual make a statement about this?

Shari

 

[Dave_1]

How tall should the 8" Metalbestos chimney be for my VC Encore? My VC dealer who is handling the chimney install has a total from the top of the stove to the tip of the chimney about 14 feet. This meets and excedes the code requirements for chimney/roof clearences but i'm concerned if this is enough for proper draft. Thanks,

fwiw

Mine is also an 8" metalbestos but 11 1/2' measured from the top of stove to the top of the rain cap.

With 29 years of burning there is no indication of smoke on the white ceiling.

As long as you follow the 2-3-10 rule you should be good to go.

3. Give yourself enough height

A tall chimney performs better than a short one. The taller the column of warm gases the greater the difference between its pressure and that of the outdoor air. We recommend a minimum chimney height of fourteen feet for our stoves. Additionally, all chimneys must conform to the “3 foot, 2 foot, 10 foot rule”. This means it must be a minimum of three feet above the roof on the uphill side of the chimney, and at least two feet higher than any part of the roof within 10 feet (measured horizontally). Where possible, the chimney should be located as close as possible to the highest point in the house. In some cases, a chimney can be too tall, possibly resulting in over drafting which, in turn, can cause a fire to burn too hot. Over drafting can usually be controlled with the stove damper or a pipe damper, or a combination of the two.

(broken link removed to http://www.woodstove.com/pages/good_chimney.html)

Good luck with it.

 

[RichL35]

The manual states that the chimney should be 16 feet. When I spoke to the installer he was concerned about the free height of the exposed chimney above the roof and recommended staying at the quoted length. He did also state that he has beed installing wood stoves and chimneys (including Class A) for over 25 years and that this should work out fine for me.

As far as the 2-3-10 rule. I certainly have the clearence with the chimney. I will have 6 feet of chimney through the roof with a 2/12 pitch.

I was looking for some input from people, like yourselves, that have the experiance of useing wood stoves not install them.

Thanks,
Rich

 

[begreen]

Rich, is the flue straight up interior? If so, I'd try it out. If you are getting signs of lazy draft, go for 16 ft.

 

[BrotherBart]

With your elevation of just 90 ft. above sea level you may be just fine with 14'.

 

[TPC101]

with 6' above the roof line already - and adhering to minimum 3' / 2' above anything within 10' i see no reason why you would encounter draft problems - even if you chose to burn with the doors open.

 

[CrappieKeith]

Make sur eyou have make up air for the burn.
There are a few draft inducer style hoods/wind directional caps you can put on to help create more draft too.

 

[RichL35]

Thanks alot for all the posts. I'll give it a shot and see how it goes. What will some of the signs be if I have a weak draft? Yes, I am a wood burning beginner.

Rich

 

[begreen]

Assuming the wood is dry, (that's important as it can also cause some similar symptoms), signs of weak draft will be smoke spillage from the stove when the door or top are opened. Dirty glass and wimpy fire can also be signs.

 

[RichL35]

My neighbors woodstove chimney (8" Metalbestos, all double walled, about 20ft tall) drafts enough to blow a lighter out when holding it in the middle of the stove (top flue, pre epa) when completely cold and the door is open. Would this be considered excessive draft? He complains about it all the time when he tries to light the stove on real cold winter days.

Rich

 

[CrappieKeith]

That sounds like a normal draft Rich,again I'll refer to a manometer.
There should be a reccomended draft speed that should be set.A barometric draft regulator is the device you'll mount into the flue to control the drafts.The BDR gets adjusted or set with a manometer.