Circulation Fan - 3” fan @ 60 CFM too much air movement?

[drano]

Sorry for another fan thread, but I need to join the fan club, and will stop by the local Grainger store Friday (will be better than the mall crowds ;D). 

I've seen posts of people using 2" 35 CFM and 2.5" 45 CFM fans. 
Anyone tried a 3" 60 CFM fan?  Is this too much air movement? 

My smokes are generally a 3-4 lb pork butt, a rack of spare ribs, or 2-3 sticks of summer sausage, so I don't fill the smoker by volume on the racks.  I'll be ordering an Auber PID as a Christmas present to myself, so I might get into more snack sticks once I can control the temp better. 
I have never used the bottom rack, so the fan diameter won't be an issue.  Or I can put wood strips between the shelf rails and the bottom shelf to raise the shelf up a little if I ever decide to use it for a load of snack sticks or something small. 

The Grainger web site says the 3" fan needs 1/4" of shaft to attach vs 3/16" for the 2" fan, and 5/16" for the 2.5" fan, so the 3" fan motor should still work. 

For the fan experts, please let me know if the 3" 60 CFM fan would be a good idea, or will it create problems with too much air movement.  I saw a few posts where people said they wished the 2" moved more air. 

Thanks in advance.
drano

[Smokin Soon]

I would suggest one thing at a time. Get your Auber, get it tuned if need be, do a few smokes and see where, if any the shortcomings are. Have some fun! Enjoy the smoke, and  don't rush the supercharging.
Sausages and beefsticks in my opion should not be mixed with other cooking due to ramp temps and cook times. But that's just me. The elders will be along shortly.

[drano]

Smokin Soon,

Thanks for the reply.  I wasn't clear on my post--I do smoke a few different meats but only one at a time (butt, or summer sausage, or ribs).  I agree, mixing meats in the smoker at the same time adds variables that can work, but requires more thought.  I like simplicity--do one meat at a time. 

I've had a Love TS controller for a while and think a PID would work better for sausage/snack sticks.  The TS lets the temps swing +/- 5 deg or more.  Keeping summer sausage fat from liquifying, but still getting the meat up to temp (155 deg is what I see published most) is a challange.  I think a PID and fan will make sausage/snack sticks much easier, which is why I plan to add both at the same time.  (and I need an excuse to run meat thru my new Cabelas commercial grinder! ;D)

Thanks again, and keep the inputs flowing.
drano

[Smokin Soon]

You go Drano! Make sure you get some pics of your fan mod for us.

[beefmann]

Drano,

a PID and fan work wonders.. here is my fan set up take a look at it

http://forum.bradleysmoker.com/index.php?topic=7203.0

it is a 900 watt finned heater

[Mr Walleye]

Drano

I originally installed my fan to draw air towards the back wall but after using it this way I decided it would be more effective blowing away from the back wall. I used a 2" fan and if you plan to use your bottom rack I'm not sure you will fit in anything larger. Having said that, I think the 2" fan would be easy enough to "tweak" the angle of the blades to slightly increase the CFM because they are just made out of light aluminium. The only other thing I think you have to think about is, if you increase the CFM substantially, is the air current you are creating going to blow through the V-pan vents and create quicker combustion of the pucks on the smoke generator burner plate.

Here is a link that shows how I installed my fan. My smoke generator is permanently installed in a cold smoke set up so I didn't have to worry about increasing the combustion of the pucks on the smoke generator burner plate.
http://susanminor.org/forums/showpost.php?p=848&postcount=22

In my opinion the PID will help lots regarding sausage.

Mike

[drano]

Made it to Grainger Friday.  Got my own account there now, so let the spending begin!!

I picked up the 2, 2.5 and 3 inch fans since each one cost less than the gas to drive there. 
I put them on the shaft, and pluged in the motor.  Wow, the 3" really moves a lot of air--most likely way too much for the Bradley.  I'll try the 2.5" and see how that works.  I'll use the 2" or 3" for cooling the motor--don't know if the shaft will be long enough for the 3" to fit on though. 

Mike, I'll mount mine like you did, and put a shroud over the top.  What size hole did you drill thru the wall for the motor shaft? I'm guessing 1/32" larger than the shaft. 

I'll order my programable Auber PID soon, give it a test run with pork butt, then try the tricked out Bradley on summer sausage and hopefully snack sticks during Christmas holidays. 

I'm glad to see many happy Auber customers here, and that it holds temps +/- 1 degree.

get smokin . . .
drano

[Mr Walleye]

Morning Drano

I can't remember the exact size of the hole I drilled for the shaft but what I would do is measure it with a set of callipers and slightly oversize the hole. I also slightly over sized/slotted the mounting holes for the bracket I made. This gave me the ability to centre the shaft in the hole so that it doesn't rub. It really is a simple project and does help lots making your temps more even in the tower.

Mike

[Smoking Duck]

Dang, Mike!  When are you making the trip to Indiana to help out a mechanically disabled smoker out?  I'd love to do this with my OBS!

SD

[Mr Walleye]

I'd love too SD.  ;)

It really isn't that bad of a mod to do. Pretty straight forward....

You can do it Duckman!

Mike

[Smoking Duck]

Dude, I have a hard time tying my shoes most days....may have to give it a try though.  I just love making things bigger and badder!

SD