Running Into Problems

[bsimm78]

I used a 1500 watt 120v burner and am using a PID set up from Auber. I insulated the fridge pretty well. Going through autotune, it passed my target temp of 225 and stopped output but the temp kept climbing. All the way up to just under 350 degrees even with intake and exhaust wide open. The outside still felt coot to the touch though, which is a plus. My next step was to set At to 0 and set Hy to 2. Left door open untill unit cooled then shut the door and started her back up. Same problem. My next step will be to use a 650watt 120v element instead and hope that the temp fluxuation will be better with a much smaller element considering I onviously insulated it well enough. Any thoughts? I dont want to install a fan because it would need to be at element level and that may ignite the woodchips. Any thoughts or suggestions or am I on the right track going with a smaller element that SHOULD cool down faster. The 1st element I mentioned is a coil burner incased in cast iron so i definitely know the cast iron is one of the problems with the temp climb.

 

[daveomak]

The element probably reached 1000-1200 degrees before the smoker got to temp... Carryover raised your smoker temp....  You could do something like turning the element on/off for 50% heat or 25% heat or even have the element come on 5 seconds out of every minute to "effectively" reduce the wattage....   Or install a dimmer between the SSR and element to manually reduce the wattage... Price wise, a smaller wattage element and dimmer would be cheaper...  or just the element if you can get close to a balance....  a circulating fan would solve a lot of problems with temp over run...  Grainger has many motors, shaft lengths, blades and motor speed controllers to help you find the correct one....

Dave

http://www.grainger.com/Grainger/ww...le=true&toolbar=false&CatPage=57&Catalog=main

 

[bsimm78]

Well, i already have 650 watt element that i originally used just as a test elememt to quadruple chech everything before i hooked up the intended one. I only set the 650 watt element to run up to an SV of 150 degrees and it did it with no problem. This morning I am going to hook up the 650watt and set SV for 225 and see what happens. If that doesn't work, I thought if something else too. My exhaust is currently 2 inches. I may need to go bigger but feel I shouldn't have to just because of the insulation. Black, 4 inch stove exhaust with built-damper. Long story short, hook up small 650watt element, hook up PID, add pan of water for heating medium and start AUTOTUNE. It's early and I have all day. The PID should learn how to operate the heating element to keep the temp where i want and the variances tight...that's what AUTOTUNE IS FOR, right?!?!

 

[bsimm78]

I ended up just going witht the 650 watt element. With all the insulation it gets to cooking temp in no time and there is absoluty no heat transfer through the insulation to outer walls. It feels cool to the touch, even when I ran it up to 400 degrees. Very pleased!

 

[daveomak]

Cool.... That's good to know....  Now we need some smokey goodness  pictures posted when you make some.... 

 

[quentin sligh]

bsimm78,

I've been toying with this idea for some time, but I must say I have "cold feet!" I've looked at dozens of pics and read multiple articles on how to do it, but all start out with a ventage fridge. I've was wondering if anyone out there has use a modern fridge to build a smoker? I've found one freezer with an alluinmum interior vice plastic and was wondering if this would work or will I need to strip it out and replace this with SS? Can anyone out there give me some help? What was your interior constructed out of?

r,

QSligh

 

[dward51]

It will perform differently with food in there.  Especially a load of cold pork shoulders (say 4 or more).  You may wish you had the 1,500 watt element with that cold mass of meat in there.

Are you certain the SSR trigger was turning off and the SSR "opening" when it reached the set point (make sure the process LED on the PID goes off as does the SSR LED).   Sounds like there was some serious lag there and autotune should have held it a lot tighter than that.  You may want to retry the autotune process.