What is the purpose of extending the exhast?

[stickyfingers]

I've noticed in several picures that some extend the exhaust pipe to grate level, why is this perferred?

Thanks!

 

[smokinsquid]

It is to help maintain the heat and smoke in the chamber. If the exhaust is left at the top of the chamber the heat and smoke will move in a diagonal line from the firebox to the stack. With the extension in place they are forced to fill the chamber up to the point where the exhaust has been extended to.

 

[ddave]

It helps even out the heat and smoke across the smoke chamber by drawing the smoke and heat along the grate level rather than to the top of the lid before exiting the chamber.

Dave

 

[smokebuzz]

Nothing in a heavey gage offset, and i seen no change in the SnP's I had or the ones my freinds have. You will benifit more from a heat baffle/deflector

 

[jamesb]

Yep, what he said. Even way back when I was cooking on my SNP (10 years or more ago), extending the stack into the cook chamber helped with heat retention.

 

[pignit]

I found that lowering the exhaust stack into the smoking chamber not only holds the smoke and the heat.... it backs the heat up so that there is less heat difference from one end to the other. After putting in my exhaust mod I only varied a few degrees from one end to the other without a baffle. I was impressed. This is on a heavy gauge offset.

 

[coyote-1]

It does exactly the same thing on cheapo offsets. I'm finding that no other mods are needed if your objective is only to even out temps.
The baffle mod is only necessary to prevent drying out the part of the meat most directly exposed to the incoming heat. It can help regulate temps too, particularly if it's also a water/drip pan, but is not really needed for temp regulation.