Is the "chimney effect" just a myth?

[willbird]

Originally Posted by Terry Hesticles

I've only cooked twice on my week-old UDS, but I used the KISS method with 8 1/2" holes in a 15" diameter across the top of my flat lid. So far it's worked great and seems to offer plenty of exhaust, neither of my meals were ashy/sooty. In fact, despite calibrating my thermo, I've worried through both cooks that it was stuck because it held at the exact temp I wanted it to for the couple of hours I needed.

I also smoke on my patio with a large overhang so it's safe from precipitation. In furthering the KISS method, when it's time to choke the flame, I shut off my intake(s) and tear off small bits of aluminum foil to plug the holes. I do so in a manner similar to bits of toilet paper on your bleeding shaving nicks. Leaving the bits flat, I use my fingertip to settle them down somewhat into the holes and then I use my palm to flatten the foil around the holes. Simple and secure and within an hour or so my thermo reads ambient temps.

My UDS snuffs out just fine without plugging my 1/2" holes

Bill

[TurboDog]

I use a weber lid on my UDS , and I had noticed that even the slightest breeze would mess up the draft , I set a scrap piece of 4" pipe over the exhaust and it seems to work way better. As posted above I could see a can with both ends removed work as well.

[tikiboy02]

I agree with Willbird. My flat lid has 8 holes and I can cut off the bottom vents and my charcoal will go out (save for another time). This is probably caused by the chiminey effect and heat.

[SkinnyVinny]

Well this is interesting. I have the flat lid, with a 2 inch bung on it and no chimney. Is this bad? I always assumed it was enough for smoke to escape.

For those that added a chimney, what did you use? I do have threads in the hole, just don't know what to look for. Similar piping material to the nipples?

[Mo-Dave]

The chimney effect is real that is why in ye olden day homes had tall chimneys so in the winter it made lighting and maintaining a hot fire much easier and in the summer it drew cool air through the home.

If I had a flate lide I would want at least a nipple taller than the edge of the barrel so water would not collect on the top and fall into the drum but I have a weber dome so its not a problem.
Dave