Question about chimney

[chorn]

So I don't have a brick oven, but a brick BBQ pit, so I thought this might be an appropriate place to ask this question, though, considering there are a lot of chimney experts here.

I have a cinder block set sideways near the top of the smoker (see picture, there is a course of blocks around the "vent" now). The smoker will have a cast iron lid.

Basically, I'm trying to run some kind of chimney pipe through that hole in the block. Thought maybe a curved pipe or something...

Questions - what to use? what diameter/length to get proper draft? How to seal pipe into block?

As opposed to the need for strong draft for heat purposes, I'm really only looking to draw moisture out of the chamber and keep the smoke moving to keep creosote, stale smoke, etc from building up.

Here's the pic with the chimney vent block in the back right.

[azatty]

Re: Question about chimney

BBQ Pit Building Calculator

Assuming you're building a brick smoker, the above link will give you dimensions of the firebox and chimney relative to the cooking chamber. I can tell you from pit building experience that if the picture you have represents the firebox, you can have a cooking chamber three times that volume. The guys over at Www.thesmokering.com are pit bulding pros who can give you additional input.

For the chimney, select the pipe diameter in the calculator and it will give you the correct length. And try to avoid bends in the flue. It messes up the draw if you put too much of an angle on the flue (it can be done, but I don't recall what the allowable angles are). You would probably be best served to use flue liner (clay or stainless steel) and building around it instead of running it through the block. CMU's aren't intended to take high levels of heat, the rough surface will accumulate soot quickly, and your chimney sweep will curse you.