#1  
Old 07-19-2011, 04:26 PM
Peasant
 
Join Date: Jun 2011
Location: bethlehem, Pa
Posts: 40
Default elbows in flue/chimney

I would like to have roof hang over oven entrance - cantilevered - it would require the flue/chimney be pushed back to a central position over oven - to allow longer ridge beam. Does using 30 degree elbows significantly hamper draft? Is stainless steel duravent only way to go or alternatives???
Reply With Quote
  #2  
Old 07-19-2011, 05:56 PM
horrocks007's Avatar
Laborer
 
Join Date: Oct 2009
Location: Roosevelt, NJ
Posts: 96
Default Re: elbows in flue/chimney

I am sure you can use other venting pipe brands like Metal-fab, Metalbestos, etc. as long as they're Class-A Chimney Vents. Simpson-Dura vent is one of the most expensive.

You can also use galvanized venting pipe. (still Class-A) It has a stainless steel core, but galvanized exterior- cuts the price down.

30 degree angles are fine.

Or- I've seen pictures of people doing the whole thing out of brick.
Reply With Quote
  #3  
Old 07-20-2011, 04:32 AM
dmun's Avatar
Moderator
 
Join Date: Jul 2005
Location: New Jersey USA
Posts: 4,216
Default Re: elbows in flue/chimney

Duravent systems seem expensive until you consider the labor of a flue-tile-lined masonry chimney. They are also lighter, and easier to support for offset chimneys.

To your original question: straight line flues do draw better. Consider going through the roof and flashing around the chimney.
__________________
My geodesic oven project:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #4  
Old 08-01-2011, 09:42 AM
Serf
 
Join Date: Aug 2011
Location: Costa Rica
Posts: 6
Default Re: elbows in flue/chimney

Hello there. Could you tell me how tall can a chimney be?
Reply With Quote
  #5  
Old 08-01-2011, 01:51 PM
brickie in oz's Avatar
Il Pizzaiolo
 
Join Date: Mar 2009
Location: Whittlesea
Posts: 3,455
Default Re: elbows in flue/chimney

Quote:
Originally Posted by eavila View Post
Hello there. Could you tell me how tall can a chimney be?
As tall as you want it.
You need to get it at least 300mm above any roofs etc or 300mm above a point that is within 3.5M.

__________________
The English language was invented by people who couldnt spell.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #6  
Old 08-01-2011, 01:54 PM
GianniFocaccia's Avatar
Il Pizzaiolo
 
Join Date: Jun 2009
Location: Disneyland, CA
Posts: 1,444
Default Re: elbows in flue/chimney

Pretty tall if you think about flues/chimneys that are attached to 3-story houses.

Below is a calculator for Natural Draft Air Flow and Velocity that takes into account external and internal temperature differences. I used to have the URL of a site that calculates flue pressure based on it's diameter and length dimensions, but can't find it.

Air Flow and Velocities due to Natural Draft
Reply With Quote
  #7  
Old 08-01-2011, 02:47 PM
Serf
 
Join Date: Aug 2011
Location: Costa Rica
Posts: 6
Default Re: elbows in flue/chimney

Thank you, that is very clear.

While I'm at it, I will build a 42" oven. I downloaded the instructions from Forno Bravo, and I'm trying to understand all the aspects of the building process. I will build the oven on the outside of the house while the opening will be inside the kitchen. The wall is 5" thick.

How long should the vent wall need to be in order to house the chimney on the outside, without making it unconfortable to work the oven from the cooks position on the inside.

¿Can an oven have a second opening, for wood feeding, on the outside?, ¿Can the chimney be attached to this second opening?

Thank you again,
Reply With Quote
  #8  
Old 08-01-2011, 06:54 PM
GianniFocaccia's Avatar
Il Pizzaiolo
 
Join Date: Jun 2009
Location: Disneyland, CA
Posts: 1,444
Default Re: elbows in flue/chimney

Study some of the outside builds on this site. Many have entryway depths of 12-14", not including the decorative arch face bricks. You can angle your flue back towards the rear of the dome (30deg max) so that it rises vertically from the center of the dome. I am ignorant of the code regarding enclosing a flue with one side of the enclosure being your house.

Don't consider a second opening at the back of your oven for chimney, wood-feeding or winking at the wife through the oven inside your house. Ovens work utilizing a proven air-in, exhaust out path through the front of the oven only.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 05:46 AM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
© 2006/10 Forno Bravo, LLC