Circulation fan help/ TEMP UNEVEN

[mikecorn.1]

I installed a fan kit got from smokeandstuff. The fan is blowing like it should. I put a piece of tissue paper in front of it and it moves it good. While rolling smoke today I can tell that it is pushing air/smoke around.
Problem/question is that ive had a 20' temp difference from the top to bottom. I've interchanged the probes locations they will read what the other one was. So I know the probes are good. I'm monitoring with the  PID and a maverick.
Any suggestions as to why such a temp difference. There is plenty of space between the stix, I have them on the racks. Didn't have time to make a contraption to hang them. Thanks

They look like this on the rack. 7 to a rack in the smoker.


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[NePaSmoKer]

Wish i could help but i dont have the fan yet. Did you get with Mike or Jim?

[mikecorn.1]

Wish i could help but i dont have the fan yet. Did you get with Mike or Jim?

Bad with names. Gimme their forum names :D


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[SamuelG]

Wish i could help but i dont have the fan yet. Did you get with Mike or Jim?

Bad with names. Gimme their forum names :D


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Which way is it blowing?


SamuelG

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[mikecorn.1]

Wish i could help but i dont have the fan yet. Did you get with Mike or Jim?

Bad with names. Gimme their forum names :D


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Which way is it blowing?


SamuelG

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Towards the door.


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[SamuelG]

Wish i could help but i dont have the fan yet. Did you get with Mike or Jim?

Bad with names. Gimme their forum names :D


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Which way is it blowing?


SamuelG

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Towards the door.


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Sent you a PM


SamuelG

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[Mr Walleye]

Mike

Just looking at your picture it looks like you are using frog mats under the sticks. I think between the small holes of the frog mats, the sticks blocking a certain amount, and add to that each level of sausage giving off moisture and influencing the temps in the higher part of the cabinet. I would try hanging them next time and see how you make out. I have always had better luck hanging them, although there certainly are a number on the forum that use the racks.

Just my 2 cents.  ;)

Mike

[mikecorn.1]

Mike

Just looking at your picture it looks like you are using frog mats under the sticks. I think between the small holes of the frog mats, the sticks blocking a certain amount, and add to that each level of sausage giving off moisture and influencing the temps in the higher part of the cabinet. I would try hanging them next time and see how you make out. I have always had better luck hanging them, although there certainly are a number on the forum that use the racks.

Just my 2 cents.  ;)

Mike

Could be possible. I didn't have time to rig something up to hang them  Will try next time without the mats along with some other good info I got from other members. Thanks all. Nice when member send their numbers to call them and discuss possible problems and solutions.


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[viper125]

I too have the fan mod installed and also have varying temps. Personally I don't think the fans are strong enough. I know some have done two or bigger units with good results. But I have yet to get this problem taken care of.

[Sailor]

I too have the fan mod installed and also have varying temps. Personally I don't think the fans are strong enough. I know some have done two or bigger units with good results. But I have yet to get this problem taken care of.

I seem to have great results with my mod.  I get even temps at top and bottom, front to back.  Will send you a PM.

[viper125]

OK thanks Sailor always appreciate the help!

[Sailor]

I have a 10 pound load of SS going right now.  I am getting a 9 degree difference between the top and bottom.  Smoke has been rolling for about 20 mins.  I don't know what the meat temp is but I would guess it would be about 100 as that is where it usually is after an hr or so of drying.  I had to move my cabinet probe to the bottom because the bottom was getting 20 degrees hotter than the top.  Moved the meat probe to the top and temps are evening out.  Still experimenting with probe placement.  Bottom line is that I get more even temps using the fan mod than without it.

[Sailor]

I have a smoke going so I could not measure the inside of the OBS.  Measuring the outside using rough measurements I come up with about 2.6 cubic feet of inside space measuring from the V-tray to the top and width.  I think I read that the fan kit has 34 cfm.  If this is true, then the cabinet should be turning over 13 times every min.  I think my math is right 34/2.6 = 13.  I have my blade set with the set screw close to the door with the flat edge of the fan close to the back wall.  I moved the blade about 1/16 to 1/8 inch away from the back wall.  This is pushing air to the back wall and picking up the heat off the wall moving it to the outside walls.  I don't get a big blast of air.  I guess if the blade were reversed putting the set screw close to the wall and the edge of the blade to the end of the shaft one would get a blast of air blowing toward the door. I have not tried that set up so I can't comment on the effects of balancing the temps.  I do know that the way I have mine set I can move the blade closer and it gives an entirely different air movement.  I can pull it away 1/8 of an inch and it changes the air movement.  When I set the fan up I used a piece of tissue paper to watch where the air was moving.  It was sucking a lot of air into the fan from the front and blowing it against the back wall and moving the tissue toward the door when placing the tissue on the side walls.  My thought was I wanted to get the heat off the back wall and move it to the front.  Blowing to the back wall covers more area on the wall than sucking from the wall blowing out.  That's about covers the way I have mine set up.

Jim

[viper125]

Thanks Sailor I'll give that a try! Thanks for all the help!

[Mr Walleye]

Jim

In order to reverse the "pull or Push" of the air flow coming off the fan you have to reverse the rotation of the motor. If you simply turn the fan around you will still have the same direction of air flow.

I originally had reversed my motor to pull the air towards the back of the cabinet. It helped but in my opinion the air flow continued to push the heat up the back of the cabinet which is the inherent problem on the Bradley with the heating element mounted at the back of the cabinet. I reversed mine back so the air flow is blowing towards the door and I feel I get a better balance front to back and top to bottom this way. Don't get me wrong, I feel having the circulation fan running in either direction provides a measurable improvement in balancing the temps in various parts of the cabinet.

Another thing I have always done is to tweak the vents in the V-pan. The vents in the back half I gently squeeze them closed a bit. The front ones I use a large screwdriver and gently twist, opening them a little more. This, in theory anyway, allows less heat to flow through the back half of the V-pan and more heat through the front half.

Also, depending what your smoking and how large the load is you may still have to rotate racks even with the circulation fan, however you would be rotating much more frequently with out it.

Just my 2 cents from my own personal experience.

Mike