Infra-red shot of wsm


 

Dave Russell

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Maybe someone else has already brought the infra-red shot of the wsm that Chris A. put on the site. It was sent to him of a brand new 22" wsm that "Scott" just purchased and fired up.

I noticed a couple of things. First, doesn't it look like Scott has the lid with the exhaust vent positioned on the door side? I've always set my cooker up opposite of that, thinking it would make for more even temps.

The second, and more obvious thing is the higher temps around the door. Is this the device picking up the heat better because of the leaks around the door?

What say you?
 
Dave - I've not to this point thought about the position of the exhaust vent relative to anything else. I would say though, that given the laws of thermodynamics, it would make sense that there is an "optimal" position to be had. Not an expert, but it makes sense to me. On the other side of the coin, what we do isn't rocket science and we're not making plutonium or something, so for me, it's really how the food turns out and whether or not people like it. Have had nothing but compliments thus far.

2nd item - IMO it very well could be given the material thickness of the door (regardless of leaks). However, using that logic, I would expect to see spikes around the control vents and exhaust vent. It is also a hollow round object (technically) which might account for some of the variation that is seen. Again, IMO, I think the heat signature here is about what you would expect. Seems like pretty even/well dispersed from bottom to top (meaning hotter at the bottom and gradually less as you get near the top).

I'd be interested to see what an Engineer from Weber might say about this. VERY INTERESTING! Great Pic's.
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Keith Pietranczyk:
Dave - I've not to this point thought about the position of the exhaust vent relative to anything else. I would say though, that given the laws of thermodynamics, it would make sense that there is an "optimal" position to be had. Not an expert, but it makes sense to me. On the other side of the coin, what we do isn't rocket science and we're not making plutonium or something, so for me, it's really how the food turns out and whether or not people like it. Have had nothing but compliments thus far.

2nd item - IMO it very well could be given the material thickness of the door (regardless of leaks). However, using that logic, I would expect to see spikes around the control vents and exhaust vent. It is also a hollow round object (technically) which might account for some of the variation that is seen. Again, IMO, I think the heat signature here is about what you would expect. Seems like pretty even/well dispersed from bottom to top (meaning hotter at the bottom and gradually less as you get near the top).

I'd be interested to see what an Engineer from Weber might say about this. VERY INTERESTING! Great Pic's. </div></BLOCKQUOTE>

Regarding the position of the lid vent in relation to the door, I think I first read G. Wiviott's advice in his book, "Low and Slow" to put the top vent at 1 o'clock and the door at 6 o'clock. I guess I thought that might follow logic since because there's more intake around the door, exhaust should be on the opposite side.

I'd like to see infra-red photos with the cooker full of meat, to see what happens then.
 
If that's a new 22", where the heat shield. I think it would be interesting to see pics with and without the heat shield.

As for the unevenness of the heat around the cooker, it might have more to do with the wind than anything else.

At first, I thought you were questioning the temp of the door itself, which is showing as cooler than the rest of the cooker. I'm not much of an expert on thermal videos, but I know for infrared thermometers, you have to have the emissivity of the material into account for the most accurate measurements. I suspect the epsilon figure at the bottom (0.95) is the emissivity set for the system. I'm thinking the emissivity of the door is rather different than the rest of the cooker.
 
I was more interested in what the heat distribution looked like above the heat shield (water pan / clay saucer, sand, whatever). It appears that the temperature distributions in the cooking chamber (except for the area right around the top of the door) are pretty even, which is what would be important. How the heat is distributed in the cooking chamber might say something about how the charcoal burns or is burning, but its that top part of the cooker that is interesting to me.

Pat
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dave Russell:
Regarding the position of the lid vent in relation to the door... </div></BLOCKQUOTE>I don't think it matters one bit. I've cooked with the lid vent both ways and I never noticed a difference.

Why complicate something what doesn't need to be complicated by worrying about whether the lid is in one position or another?

Regards,
Chris
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Chris Allingham:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dave Russell:
Regarding the position of the lid vent in relation to the door... </div></BLOCKQUOTE> Why complicate something what doesn't need to be complicated by worrying about whether the lid is in one position or another?

Regards,
Chris </div></BLOCKQUOTE>

Get Wiviott back and ask him.
icon_wink.gif
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The second, and more obvious thing is the higher temps around the door. </div></BLOCKQUOTE>

Uhh.... If you lok at the scale on the right, the door is actually cooler than the rest of the body. It's mostly blue with a bit of purple near the top.

It would be really interesting to take a couple of shots after it's been running for a couple of hours. Maybe we could FINALLY put the whole temperature differential thing to bed.

Chris, is Scott going to send any more shots? We've got a thermal camera here at work that does the same thing. If he isn't then I can see if the boss will let me take it home for a weekend.
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Russ Sylvester:
Chris, is Scott going to send any more shots? </div></BLOCKQUOTE>Not sure when he will have time to take more shots. Anyone with access to a thermal camera that wants to take shots and send them to me is welcome to do so.

Regards,
Chris
 
Hmmmm ...

~ Is that really a 22"? The door looks right but where's the heat shield? Why are the legs straight like the older 18" model? Compared to the chimney, in size, it looks like an 18".

~ As John already mentioned, wind conditions can affect heating patterns.

~ Since the door is made of different materials and unpainted, you'd expect it's heat 'signature' to be different.

~ Only 10 minutes after startup looks purdy but, as Russ said, a couple of hours in would probably be more informational.
 
Chris - I agree. No need to complicate matters. Many folks like to do things a certain way and definitely have their own opinions which is absolutely fine. IJS for me, it doesn't matter as long as I and the people I cook for enjoy the food.
 
The pics are def of an 18 1/2 smoker. Straight legs and they are narrow in width..

We used the infared camera from time to time, but it's a generality. A lot of testing was done with themocouples through out the smokers and grills and recording the temps over time.

For all the smoking I've done, Chris is right. Don't complicate things. The notions that the vent location, temp grates vs. lid, etc... If you have good results, great and go with it. But it's really voodoo and black magic. It's like when I tweak a tone knob on my guitar from 5 to 5.5, even though the volume is on 11 and the guys in the back playing pool aren't paying attention.

You're cooking for hours and hours and at a very low temp.
 

 

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