PBC Upper Vent Modifications - Version X

[mtford72]

Hey Jerod, It works, but it has a very slow response time. This could be down to the length of the pipes (18") or their positioning. I'm going to trim them, because they are just too long. I suspect that a higher mounting (e.g. level with the existing holes) would promote a far quicker response.

The temps seem stable and higher. Which is ultimately the goal I suppose. Testing it without meat: 360 both pipes fully open, 310 half open. So I have the ability to increase and maintain a higher level of airflow, which was the goal.

I will just add that the pipes look pretty too. Matt

[mtford72]

The theory - a lower vent will hopefully mean a stable hot air cell surrounding the meat, (keeping the moisture, etc), while enabling the temp to be modified.

[_John_]

Not sure if it would work, but get like a paper towel or something and hold it over your various vents. If it works you might be able to tell how much that pipe is actually pulling out compared to the existing. I would think with more airflow your existing ones would blow a bit harder.
May not be strong enough to tell though.

[mtford72]

So far, so good. They are definitely smoking - so the air is going the right way. Fully open (with no meat) the temp is holding 360. Half open, 305. Although it's not very responsive. Responsiveness is nice, stability is the goal.

The fact it can get to 360 and hold it is the positive - it means the airflow through the fire is there. With lots of meat in, that temp will come down. It can always be dampered to hold the consistent target of say 295.

I'll post pics and graphs soon enough.

[Jerod Broussard]

It takes A LOT more brain function to do what you did.......compared to what I did.

[David Parrish]

Man that's an awesome result. We want the graphs!

[fzxdoc]

Ditto that. I'm soooo curious to see how the mod works out, Matt.

Kathryn

[mtford72]

Hey Kathryn - here is the final version with the first test graphs.

http://pitmaster.amazingribs.com/forum/grills-and-smokers/charcoal/pit-barrel-cooker/40189-upper-vent-modifications-to-a-pbc-steampunked-gracias-hc