Would it ever make sense to use a barometric damper on a smoker chimeny stack?

[Chef Jacob Burton]

I was researching dampers yesterday in anticipation of possibly building my own pit, and came across this video explaining a barometric damper which are commonly used on boilers: https://www.youtube.com/watch?v=wd_HTnZJ88E

It got me thinking, would it make sense to ever have this on your BBQ chimney stack, while still utilizing a traditional damper at the top of the stack? I think it would alleviate any back-draft that comes from not properly burping before you open the lid, but that would only be a by product. My real reason for adding it would be more control over the actual temperature of the BBQ.

My initial thought is no, it doesn't make sense, or else you would see them on lots of different BBQs, which I couldn't find any examples of, but I also want to understand the science behind why. Thanks!

[Ahumadora]

The lid on your stack is to keep out rain, bugs, birds. Leave the stack wide open when using your pit and control your temp by the amount of wood and air intake.

[Chef Jacob Burton]

Interesting. I'm new to the smoking game, and I always assumed that to control the heat, it was a mixture of your intake air and how open you damper was on the stack. So really it's just a matter of leaving the stack open and controlling your air intake? Thanks for the info.

[Huskee]

For the most part I'd say yeah leave your exhaust open...but not necessarily for every cooker and not necessarily in all situations. I can control the airflow, and therefore the heat at the far end of my smoker, using my exhaust damper. I NEVER close my intake, it is always open since I want a hot fire. I control the heat by controlling the size of & amount of the splits I feed the fire, and the airflow with the exhaust damper. But just like your spouse or your child, not all of them will behave and respond to the same treatment. As far as barometric damper, I'd worry more about heat and quality of (color of) the smoke myself than anything automated, but alas I have no experience with those.

[Chef Jacob Burton]

@Huskee

Thanks for the info. I'm still exploring this site and I know there's already been a ton of info posted. Your comment about judging the quality of smoke by its color intrigues me. Can you offer me a link so I can research further?

Also, what kind of smoker do you use, and how do you set your intake and chimney to achieve a consistent temperature (again, I'm sure it's already been covered on this site, so if its easier to post a link that allows me to further research I'd greatly appreciate it).

Thanks for taking the time to post!

[EdF]

Check this one out: http://www.genuineideas.com/Assets/i...%20Blonder.pdf

[Chef Jacob Burton]

EdF,

Wow, this PDF is awesome! Thanks so much for the link!

[EdF]

Yeah, it's a good one!

[Histrix]

Some smokers do also use a top vent in order to control airflow (and thus temperature) thru the cooker. Kamados for instance use a top vent in addition to a bottom vent to help hold temps in the "low and slow" range.

There are pit controllers - devices that will do the work of adjusting the amount of air able to flow thru the cooker in lieu of the top vent. The Tip Top Temp and Smobot are two examples.

The Tip Top Temp uses a simple coil spring just like those used in smoker thermometers to move a vane/damper to hold a specified temp. The unique thing about the Tip Top is that it is a free standing gizmo that does not need a fan, batteries, temperature probe, etc. You just set it over the top vent and adjust it to the temp you want.

The Smobot is a servo controlled device that has a damper that adjusts its opening to control the amount of air able to flow from the exhaust/vent. It is computer controlled.

If you are looking to build a stick burner type of pit then they are generally controlled solely by the vent of the firebox. That said there isn't really a te3chnical reason you couldn't possibly work in one of the boiler type of atmospheric dampers to add some automation to controlling the amount of air entering the firebox but I can't really think of any advantage to doing that over the more traditional designs. A stick burner requires a lot of attention to adding wood and there is more art than science involved in working the fire.

[Huskee]

Happy to help! I shoot for a light blue smoke, but I don't stress much if I get some thicker smoke here & there. A HOT (but small) fire is the best way to go to get a flavorful smoke that's less harsh and less sooty. You want a fire that's hot enough burning to give you a cleaner, clearer, blueish to clearish smoke (ideally)...but you also want that fire small enough to stay in the temp range you want. For my smoker I liek to use quarter split logs, on the smaller side, maybe 10-12" long. As far as universal fire size, log size, etc, that can't be stated with certainty really unless you were to have the same smoker as me or someone else. You have to learn yours just like your kid or your spouse. Weather matters, air temp, especially rain, etc.

A few background articles that will help you understand smoke and its different types and such:

https://amazingribs.com/more-technique-and-science/grill-and-smoker-setup-and-firing/what-you-need-know-about-wood-smoke-and

https://amazingribs.com/more-technique-and-science/grill-and-smoker-setup-and-firing/stickburning-smoking-wood

And a great video interview with Dr Blonder on smoke: https://pitmaster.amazingribs.com/fo...g-runs-1-38-47

[Jerod Broussard]

I had one rule when running wood- All the oxygen it could get.

[Frozen Smoke]

Good advice already given here. Huskee's #4 post pretty much nails it. My approach has always been keep it simple, don't over think things and for me personally keep the gadgets and gizmo's to a bare minimum. It's fire and meat it's been going on for thousands of years.

[Troutman]

I agree with the overthinking comments. In our small chamber cookers we concentrate on good air flow since inherently they tend to be poor thermodynamic engines. In bigger cookers, which I'm thinking is what the poster is leaning toward, it's establishing good draw. Think of it as you would a fire place in your home. A tall stack that draws lots of air entering the front of the fireplace and the thermo induction that draws the heat up and out of your house is exactly what you are trying to achieve in a large stick burner. Take Kreuz's Market (really any old traditional bbq house) over in Lockhart. They essentially build a fire, completely open for maximum oxygen draw, and a very tall stack that induces and draws the heat and air out of the pits. The rush of that smoke filled air over the meat is the method of cooking. Simple and to the point. To me those are the principles that need to be adhered to when building a proper smoker. Note the small size of the fire, the open fire box and the huge smoking chambers.

[Spinaker]

I wanted to snuggle up into one of those sawdust piles and take a nap when I was in there!

[Chef Jacob Burton]

On this particular style of smoker, are they controlling the heat based on the size of the fire they build and maintain?

[Troutman]

Yea absolutely chef. The fire you see above looks to me like a starter fire to establish a coal bed. When I was there a couple of weeks ago they had maybe three splits on top of a good size bed of coals. Again you want clean, thin blue smoke. It's about knowing your BTU levels, the thin smoke is flavor.

[Chef Jacob Burton]

WOW, tons of great info! Thank you everyone for your input and especially the links. Looks like I have some homework to do!