Go Back   Forno Bravo Forum: The Wood-Fired Oven Community > Pizza Oven Design and Installation > Pompeii Oven Construction

Like Tree3Likes

Reply
 
LinkBack Thread Tools Display Modes
  #21  
Old 02-26-2013, 09:28 AM
K79's Avatar
K79 K79 is offline
Journeyman
 
Join Date: Nov 2012
Location: Maine
Posts: 389
Default Re: 36" or 42"

Quote:
Originally Posted by SCChris View Post
K79,
I have a 42 and most of the time a 36 would be fine. I can say that when the oven is really full is when I have a roast and side dishes going. I don't think I would have been hampered with a 36 but when I made my choice I decided that since I had the room and a suckling pig was one of those things I wanted to roast, I went with a 42. A point not often discussed is the height of the oven entry. If my memory serves me, 60% of the interior height of the oven is what is felt to be the ideal entry height. So for a 42 the entry should be about 12.6 inches and for a 36 about 10.8. These 2 inches may be more important than floor space. Insulation is in my opinion critical and given you're in Maine I think you'd be doing yourself a disservice by cutting corners here. Also I think you want to think about some oven house and covered work area but these really depend on how you want to use the oven and how often.

Chris

I'm a little confused here. Not with the math just that it contradicts the FB plans. A 36" oven with a high ceiling height of 18" would give me a 10.8" entry according to your math. When I look at the FB plans they show a 12" entry? Can anyone clarify?
Reply With Quote
  #22  
Old 02-26-2013, 09:39 AM
Il Pizzaiolo
 
Join Date: Jun 2009
Location: So. Orange County, CA. USA
Posts: 1,157
Default Re: 36" or 42"

The plan ration is 66.7% of the oven height, I went by memory rather than referencing the plan. Go with the plans ratio. So corrected the 42 would have a 14" oven entry verses the 36 at 12".

Sorry for the confusion.

Sincerely

Chris
Reply With Quote
  #23  
Old 02-26-2013, 10:05 AM
K79's Avatar
K79 K79 is offline
Journeyman
 
Join Date: Nov 2012
Location: Maine
Posts: 389
Default Re: 36" or 42"

Quote:
Originally Posted by SCChris View Post
The plan ration is 66.7% of the oven height, I went by memory rather than referencing the plan. Go with the plans ratio. So corrected the 42 would have a 14" oven entry verses the 36 at 12".

Sorry for the confusion.

Sincerely

Chris
Ok, so lets just say I decide on building a 40" diameter oven. How do I figure the interior height so I can come up with the correct opening height?
Reply With Quote
  #24  
Old 02-26-2013, 10:10 AM
Il Pizzaiolo
 
Join Date: Jun 2009
Location: So. Orange County, CA. USA
Posts: 1,157
Default Re: 36" or 42"

The math would be, the radius of the oven times .667.
So a 40 inch diameter oven will have a 20" radius, the height of the interior, this number times .667, or 13.34 inches.

Chris
Reply With Quote
  #25  
Old 02-26-2013, 10:35 AM
K79's Avatar
K79 K79 is offline
Journeyman
 
Join Date: Nov 2012
Location: Maine
Posts: 389
Default Re: 36" or 42"

Ok, I was wondering how to find out the inside ceiling height of a 40" dia. oven. That formula is to find the opening height isn't it?
Reply With Quote
  #26  
Old 02-26-2013, 10:42 AM
Il Pizzaiolo
 
Join Date: Jun 2009
Location: So. Orange County, CA. USA
Posts: 1,157
Default Re: 36" or 42"

The Pompeii is a hemisphere, so if you use a "Hendo" tool, also known as an indispensable tool" to place the dome bricks, the oven interior height will be half of the diameter, a 20" interior height and 40" oven.

Chris

http://www.fornobravo.com/forum/f28/...idea-2573.html (Hendo's dome gauge -- nice idea)

These tools can be very simple and easily made.. Highly recommended!

Last edited by SCChris; 02-26-2013 at 10:46 AM.
Reply With Quote
  #27  
Old 02-26-2013, 10:43 AM
deejayoh's Avatar
Il Pizzaiolo
 
Join Date: Jul 2010
Location: Seattle
Posts: 1,347
Default Re: 36" or 42"

Quote:
Originally Posted by K79 View Post
Ok, so lets just say I decide on building a 40" diameter oven. How do I figure the interior height so I can come up with the correct opening height?
Your interior can be whatever height you choose, it doesn't have to be the same as the radius of your oven. For instance, if you use an IT to build your oven, the height will usually be at least an inch higher than the radius of your oven because of the distance between the oven floor and IT pivot. I used a plywood form on my oven in order to have an 18" dome height on a 19.5" radius. So for my oven size, - the height could have ranged from 20.5" had I used an IT to 18" the way I built it. That's +/- 2.5" based on preference.

Also, the door height ratio you're talking about (60-65%, IIRC) is simply a rule of thumb - I think based on observations about the dimensions of old ovens in Europe. It is not some sort of hard and fast law based on physics. Applying the 60-65% rule to a 20" high oven - that's a range of +/- an inch in the door height based on builder preference.

So my $0.02 is that door and oven height are not tied to oven size by any sort of inviolable math formula. Choose the oven size you want, then optimize oven height and door height based on how you want to use the oven. Low oven domes are better for pizza-specific ovens, higher domes give better access for baking and big dishes.
__________________

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.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #28  
Old 02-26-2013, 10:53 AM
Il Pizzaiolo
 
Join Date: Jun 2009
Location: So. Orange County, CA. USA
Posts: 1,157
Default Re: 36" or 42"

I concur with Deejayoh. The safe course is to follow the plans, however these ovens are very forgiving with regard to dimensions and even shapes. Remember however that it's easier to learn from others than forging something altogether new.

There is a wealth of knowledge about materials and mortar formulas. These are well known and proven and you will be delighted with the results.

Chris
Reply With Quote
  #29  
Old 02-26-2013, 10:59 AM
deejayoh's Avatar
Il Pizzaiolo
 
Join Date: Jul 2010
Location: Seattle
Posts: 1,347
Default Re: 36" or 42"

Quote:
Originally Posted by SCChris View Post
The Pompeii is a hemisphere, so if you use a "Hendo" tool, also known as an indispensable tool" to place the dome bricks, the oven interior height will be half of the diameter, a 20" interior height and 40" oven.

Chris

http://www.fornobravo.com/forum/f28/...idea-2573.html (Hendo's dome gauge -- nice idea)

These tools can be very simple and easily made.. Highly recommended!
I think it is more accurate to say the height of the dome will be "close" to the radius. Plenty of builders have planned that way and then been surprised when their oven is higher than they expect.

Using a design like what is shown in Hendo's post, the dome is going to be about inch higher than the radius due to the distance between the IT pivot and the floor. Protection layer over the floor bricks + IT pivot that is even higher than that. Result is that the arc of your IT starts that distance above your floor and raises the height of the dome. Couple of ways around this are to sink the pivot of the IT to the floor height (remove the center bricks) or use some sort of adjust on the fly IT. Couple of builders have used a turnbuckle in their designs to accomplish the latter.

I get a bit anal-retentive about this because I was flummoxed by it for a while when I was working out the math in my spreadsheet. Once it hit me it was obvious, but it took a while.

It now strikes me that I should modify said spreadsheet to give builders the range of suggested door heights!
__________________

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.


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

Last edited by deejayoh; 02-26-2013 at 11:02 AM.
Reply With Quote
  #30  
Old 02-26-2013, 11:18 AM
K79's Avatar
K79 K79 is offline
Journeyman
 
Join Date: Nov 2012
Location: Maine
Posts: 389
Default Re: 36" or 42"

Quote:
Originally Posted by deejayoh View Post
I think it is more accurate to say the height of the dome will be "close" to the radius. Plenty of builders have planned that way and then been surprised when their oven is higher than they expect.

Using a design like what is shown in Hendo's post, the dome is going to be about inch higher than the radius due to the distance between the IT pivot and the floor. Protection layer over the floor bricks + IT pivot that is even higher than that. Result is that the arc of your IT starts that distance above your floor and raises the height of the dome. Couple of ways around this are to sink the pivot of the IT to the floor height (remove the center bricks) or use some sort of adjust on the fly IT. Couple of builders have used a turnbuckle in their designs to accomplish the latter.

I get a bit anal-retentive about this because I was flummoxed by it for a while when I was working out the math in my spreadsheet. Once it hit me it was obvious, but it took a while.

It now strikes me that I should modify said spreadsheet to give builders the range of suggested door heights!
Any way to get a look at that spreadsheet
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Perth 42" Pompeii - dome to flat entry integration jab49 Pompeii Oven Construction 20 07-07-2012 12:03 AM
36" vs. 42" COLORADO PIZZA GUY Modular Refractory Oven Installation 12 11-21-2011 10:10 AM
Damian's 42" Pompeii Damian Pompeii Oven Construction 3 09-26-2009 12:00 AM
36" vs 42" blacknoir Pompeii Oven Construction 20 08-05-2009 04:13 AM
vent size for a 36" internal tuscan? waynebergman Pompeii Oven Construction 4 12-07-2007 12:29 PM


All times are GMT -7. The time now is 09:35 PM.

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