I have a bunch of free duct that is a foot square. Could I use the duct on the section that I am building the mass storage? I would like to incorporate it in an outdoor bar. Would it matter if it is larger than the burn chamber?
Anything downstream of the burn chamber will benefit from having a larger diameter exhaust path due to less friction of the exhaust gasses passing along the walls.
This has been the reason why many people have switched over to a bell or stratification chamber design where the gases are allowed to separate out on their own thereby almost entirely eliminating all friction and often lower exhaust temperatures too.
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