BBQ Chimney design

[Lee Nowell]

Hi all,

Are there any chimney designers out there???

I have an outdoor brick built BBQ which has a brick surround on all 3 sides. There are bushes on all 3 sides so I was looking to construct this type of chimney so it is sealed where the bushes are and the smoke comes out above the cook's head :)

http://www.variety.co.uk/big-k-tarragona-stone-crystal-bbq.html

The open face of the BBQ is approx 1800mm wide and 900mm high. I am keen to get as much draft as possible and was wondering what the best thing to adjust would be. Due to the design, I can change the angles of the 2 "roof" sections (does this make any difference?). I could create a higher rear section by raising the "hole" i.e. adding a wall section from the top of the lower "roof" to the bottom of the hole. I could also adjust the hole size itself of course.

Any advice would be greatly appreciated.

Thanks in advance

Lee.

[JimK]

On Sunday, 24 August 2014 10:06:17 UTC+1, Chris Hogg wrote:
> On Sun, 24 Aug 2014 00:10:02 -0700 (PDT), Lee Nowell

> You've got the wrong model! You should have got the Florida Masonry
>
> one, a lot cheaper too at half the price.
>
> http://www.variety.co.uk/big-k-florida-masonry-bbq.html


You've read the post wrong......

Jim K

[JTM]

In article <giajv95p7kuepjpbo...@4ax.com>,

Chris Hogg <m...@privacy.net> wrote:
> On Sun, 24 Aug 2014 00:10:02 -0700 (PDT), Lee Nowell
> <leen...@yahoo.co.uk> wrote:

> You've got the wrong model! You should have got the
> Florida Masonry one, a lot cheaper too at half the price.
> http://www.variety.co.uk/big-k-florida-masonry-bbq.html

I've had one like this (florida) for about 20 years and
unless you get a good fire to start, it's smokey.

I extended the chimney up another 8 inches, but (just like
any other fire I guess) it really needs heating for a good
draw.

--
John Mulrooney
NOTE Email address IS correct but might not be checked for a while.

No matter how early you arrive, someone else is in line first.

[David]

Assuming the link was just to illustrate the result you hope to achieve,
perhaps you could post a picture of the current setup?

This isn't a binary NG so you have to post elsewhere and supply a link.

Cheers

Dave R

--
Windows 8.1 on PCSpecialist box

[l...@nowell.me]

Yeah exactly. This was what I was trying to achieve. I will take a photo in the morning and send a link. I have knocked up a wooden temporary prototype which I used today with mixed results. I will post a full update with the photo.

Thanks

Lee..

[robgraham]

Many years ago now so details are a bit vague - and probably useless anyway.

We went to friends' friends BBQ - reasonable amount of ground and he was a builder so he had built this brick BBQ. Brick fire sides supporting a grill at working height and a flue going up possibly another 4 ft; there was access to this so you could put Al foil wrapped fish, or the likes, up the top to bake.

I was doing my turn at cooking and had thrown some sausages on to the cooking plate - usual chatter going on and I wasn't really concentrating on the cooking, but a sharp movement on the grill made me turn and look - nothing apparant, but then it happened again and a sausage disappeared into the small gap between the grill plate and the flue; the draw was so great it was sucking the sausages off the grill and into the chimney!!

Rob

[l...@nowell.me]

Lol :). Even a remote draft would be good. Unfortunately weather was bad today for the photo opportunity. I will do it as soon as I can.

[Lee Nowell]

Hi All

Firstly appologies for the delay in getting the photos posted.... but here they are...

http://s44.photobucket.com/user/leenowell/library/Mobile%20Uploads?sort=3&evt=email_share&page=1

A couple of things to note...
1. please ignore the black drum in the photos. I use this to create an oven when cooking joints of meat. Usually, I cook directly on the grills over the coals
2. the wooden structure is the prototpe chimney to see how effective it is
3. as mentioned above, the open face is around 1800mm x 900mm

I used the prototype chimney this weekend with mixed results...
1. When I lit the coals using one of those chimney starters, there was no draw at all and the smoke came out of the front
2. After a minute or so (I guess once the air warmed) the smoke started coming out of the top as expected.
3. There was no noticable breeze but the smoke path varied from
- coming out of the chimney then going up as expected
- coming out of the chimney but then coming straight down onto the cook (i.e. me!)
4. Although in general, the smoke came out of the front of the chimney as expected, there was no noticable draw that you could see from the coals (e.g)

In order to try and reduce the amount of smoke for the neighbours, I had an idea of spraying a light mist of water (I had read that this would capture the smoke particles and reduce the smoke). It did appear to do this but as soon as I started spraying across the chimney opening, the draw completely stopped... So much for that idea :)

Only other relevant thing I can think of is that the trough holding the coals is cast out of concrete with bricks on the base. There are no vent holes in it. The cooking grids then sit on top of this....

Any advice would be very much appreciated

thanks in advance

Lee.

[fred]

In article <52f090bd-839f-427e...@googlegroups.com>, Lee
Nowell <leen...@yahoo.co.uk> writes

>Hi All
>
>Firstly appologies for the delay in getting the photos posted.... but here they are...
>
>http://s44.photobucket.com/user/leenowell/library/Mobile%20Uploads?sort=3&evt=
>email_share&page=1
>
>A couple of things to note...
>1. please ignore the black drum in the photos. I use this to create an oven when
>cooking joints of meat. Usually, I cook directly on the grills over the coals
>2. the wooden structure is the prototpe chimney to see how effective it is
>3. as mentioned above, the open face is around 1800mm x 900mm
>
>I used the prototype chimney this weekend with mixed results...
>1. When I lit the coals using one of those chimney starters, there was no draw at
>all and the smoke came out of the front
>2. After a minute or so (I guess once the air warmed) the smoke started coming
>out of the top as expected.

I can't really help on the chimney design but do you have any
ventilation into the pit for the coals? Speaking to those that barbecue
a lot (Africans) it is essential. Personally I would find some method of
restricting or cutting off the air too in case it ran away with itself.

On the chimney, you do have an awful lot of air to heat up there before
it would actually begin to draw so perhaps it needs some kind of a more
restrictive throat to make a lesser amount of air create a draw, much
like an old fashioned coal fire. There ends my chimney knowledge I'm
afraid.
--
fred
it's a ba-na-na . . . .

[Lee Nowell]

Thanks for the reply.

The trough itself has no holes in it at all. I initially had the same concerns as you but it works fine. I have seen a few Greek bbqs with a similar design.

Anyone have any thoughts about improving the draw? I was wondering whether it is the reduced area of the hole as a result of the first roof bit is the significant one or the ultimate front opening?

Thanks

Lee.