Author Topic: For anyone having trouble in cold temps  (Read 933 times)

SuperDave

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For anyone having trouble in cold temps
« on: January 07, 2017, 01:37:49 PM »
I've read where a few of us have had trouble getting to set temps this Winter with the Auber.  For me, it was anywhere from 15 to 20 degrees short of set temp.  Last week I ran a cold weather auto tune and saw a range of 100 to 200 point differences in I and D values.  Today, it was 2 degrees outside ambient and the Auber locked in to set temp and has stayed locked in all morning.  The Auber has seemed to function quite differently for many of us with some, like myself, having struggled with it for the 2 years that I've owned it and those whom have never had a single problem.  In any event, if you are frustrated with the temp control in the Winter conditions, try an auto tune and see if you get the same swing in values.  In the short, it seems to have made a big difference for me in getting the desired temp setting. 

Model 4, Harrisville, Utah

noclue

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Re: For anyone having trouble in cold temps
« Reply #1 on: January 07, 2017, 02:13:54 PM »
I just recently purchased a 3D and on my first smoke it was overshooting temps by 20+ degrees, I just did a auto tune and my numbers are

P  76
I  212
D 303
I don't know if that's good, not sure what the numbers mean any insight would be appreciated.

LarryD

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Re: For anyone having trouble in cold temps
« Reply #2 on: January 07, 2017, 03:20:32 PM »
I just recently purchased a 3D and on my first smoke it was overshooting temps by 20+ degrees, I just did a auto tune and my numbers are

P  76
I  212
D 303
I don't know if that's good, not sure what the numbers mean any insight would be appreciated.

|Symbol|Description|Setting Range|Initial|Note
|P|Proportional Constant|0.1~99.9(%)|5.0|6
|I|Integral Time|2-1999(Sec)|100|7
|d|Derivative Time|0-399(Sec)|20|8

Note 6 Proportional Constant (P): P is also called the proportional band. Its unit is the percentage of the temperature range. e.g. For a K type thermocouple, the control range is 1500 C. P=5 means the proportional band is 75 C (1500x5%). Assuming the set temperature (SV) = 200. When integral, I, and derivative, d, actions are removed - the controller output power will change from 100% to 0% when temperature increases from 125 to 200 C. The smaller the P value is, the stronger action will be for the same temperature difference between SV and PV.

Note 7 Integral time (I): Brings the system up to the set value by adding to the output that is proportional to how far the process value (PV) is from the set value (SV) and how long it has been there. When I decreases, the response speed is faster but the system is less stable. When I increases, the respond speed is slower, but the system is more stable.

Note 8 Derivative time (d): Responds to the rate of PV change, so that the controller can compensate in advance before |SV-PV| gets too big. A larger number increases its action. Setting d-value too small or too large would decrease system stability, cause oscillation or even non-convergence.

Auto-Tuning
The Auto-tuning function (also called self tuning) can automatically optimize the PID parameters for the system. The auto-tuning function will use the On/ off mode to heat up the system until it passes the set point. Then let it cool down. It will repeat this about three times. Based on the response time of the system, the built-in artificial intelligence program will calculate and set the PID parameters for the controller. If your system has a very slow response, the auto-tuning could take a long time.

PV = Process Value = Measured Temperature
SV = Set Value = Set (Target) Temperature

Note:  I'm done modifying this post now.  :)  All of this information was taken from a document provided by Auber for their PIDs and is not my interpretation or personal knowledge.
« Last Edit: January 07, 2017, 03:40:40 PM by LarryD »
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LarryD

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Re: For anyone having trouble in cold temps
« Reply #3 on: January 07, 2017, 03:39:27 PM »
I wonder if pre-heating your digitial smokers with the PID turned off before beginning a smoke would make this a lot more reliable for you.  The job of the PID is to make small adjustments on a regular basis to achieve and maintain a target temperature.  Performing the auto-tune in the cold weather probably resets its 'P', 'I', and 'D' values so that it can overcome the super cold initial state, but I wouldn't be surprised if it means that it gives you a much more coarse/rough vs gradual/smooth temperature profile.

Please note... I'm just speculating here based on some reading and research just performed to make my prior post.  I'm a total novice with this and could just be wasting energy.  :)  (The info for the prior post was copied from Auber documents, so that should be pretty reliable.)
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SuperDave

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Re: For anyone having trouble in cold temps
« Reply #4 on: January 07, 2017, 03:41:16 PM »
noclue, others will undoubtedly have different opinions but I believe that the values are somewhat specific to your smoking conditions.  My results would say that someone auto tuning in Florida would get considerably different values than someone in Minnesota if both were done in the Winter time.  Some of the others here say that the values set in their controllers work all year.  The best thing you can do is throw a chicken in the smoker and do a test to see if you have improved your situation. 

Model 4, Harrisville, Utah

NDKoze

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Re: For anyone having trouble in cold temps
« Reply #5 on: January 07, 2017, 10:28:43 PM »
Nice job on your testing Dave! It sounds like you definitely may be on to something.

This may be even more important for those of us who live in areas that have such a huge range of ambient temps that we smoke in.
Gregg - Fargo, ND
Smokin-It #3 that has now replaced the Masterbuilt XL and 10+ Year-Old Big Chief. I also have a Weber Genesis Gas Grill, Weber Little Smokey at home and a Chargriller Deluxe (stick burner) and Camp Chef Three Burner Stove with Grill/Griddle out at the lake place.

noclue

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Re: For anyone having trouble in cold temps
« Reply #6 on: January 09, 2017, 05:51:44 PM »
noclue, others will undoubtedly have different opinions but I believe that the values are somewhat specific to your smoking conditions.  My results would say that someone auto tuning in Florida would get considerably different values than someone in Minnesota if both were done in the Winter time.  Some of the others here say that the values set in their controllers work all year.  The best thing you can do is throw a chicken in the smoker and do a test to see if you have improved your situation.
Thanks for the response, tried mine out Saturday and worked much better than the first time. I am thoroughly enjoying the knowledge on this forum, and the lack of annoyance from everybody when I ask a question that I know was asked before but I'm having trouble locating using the search. 

PigPen68

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Re: For anyone having trouble in cold temps
« Reply #7 on: November 12, 2017, 02:42:16 PM »
I just started a Prime Rib Roast in my new 3D this afternoon.  I noticed that the smoke was out within 2 hrs which was very abnormal.  I smoked some ribs last week and I got smoke the entire 5 hrs with the same wood.  I am using cherry and hickory which I got with my smoker a few weeks ago.  The only change I can think of was the outside temperature was much lower today than it was last week. My process was the same which was put the wood in the smoke box, place the meat inside, setup my thermometers, then turn on the smoker

I am guessing since the temperature range was so drastic the contoler used more watts to achieve the set point as quickly as it did in the warmer weather.   Since this is a Rib Roast I didn't open the smoker and put more wood in, but I am going to do a brisket next week and I don't want to open the box every few hrs. 

My plan is to warm the smoker up to about ~70 deg then put the wood box back in.  Hopefully this will eliminate the ignition of the wood.

Any other suggestions?


 
Dana from DC
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old sarge

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Re: For anyone having trouble in cold temps
« Reply #8 on: November 12, 2017, 08:20:24 PM »
First off, welcome to the forum PigPen68!  I will admit that the technospeak regarding PID values leaves me pretty much confused most of the time.  But I think you are correct in your conclusion that the colder weather caused the controller to run the element for a longer period of time in order to reach the set temp, and that caused your wood to be consumed quicker. In hot weather, the box may reach the set temp in a shorter period of time and the controller is then able to cycle the element off sooner. What the time duration is between on and off is purely a mystery to me.  Maybe preheating the smoker empty as you plan to do will help you sort this all out.  Wen you get the time, and you are feeling comfortable, head on over to the Introduction section and tell us a little about yourself.  Most of us do that with a signature block.  And again, welcome.
David from Arizona
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SconnieQ

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Re: For anyone having trouble in cold temps
« Reply #9 on: November 14, 2017, 09:17:07 PM »
I just started a Prime Rib Roast in my new 3D this afternoon.  I noticed that the smoke was out within 2 hrs which was very abnormal.  I smoked some ribs last week and I got smoke the entire 5 hrs with the same wood.  I am using cherry and hickory which I got with my smoker a few weeks ago.  The only change I can think of was the outside temperature was much lower today than it was last week. My process was the same which was put the wood in the smoke box, place the meat inside, setup my thermometers, then turn on the smoker

I am guessing since the temperature range was so drastic the contoler used more watts to achieve the set point as quickly as it did in the warmer weather.   Since this is a Rib Roast I didn't open the smoker and put more wood in, but I am going to do a brisket next week and I don't want to open the box every few hrs. 

My plan is to warm the smoker up to about ~70 deg then put the wood box back in.  Hopefully this will eliminate the ignition of the wood.

Any other suggestions?

Don't overthink it PigPen. Why turn somersaults over the "appearance" of smoke...and for how long it smoked, or when it started smoking? How did your food taste? Smoke might come later in cooler outdoor temperatures, but your box might heat up more slowly in cooler temperatures, so it all evens out. I've smoked in below zero temps here in Wisconsin. It's not a problem. Give your process an extra 1/2 hour or so. Don't try to create all sorts of fussiness for yourself based on eyeball observations of smoke production. Your taste buds will tell you if adjustments need to be made. These smokers are ungodly simple. Preheating and sliding the smoke box in and out is not how they were designed. It really is not necessary. Don't create extra work for yourself, or you will never want to smoke anything ever again. These are as simple as using your kitchen oven. If you are experiencing combustion in cool temps, then it is better to foil boat your wood, or... if you have already not done so, get some high quality smoking wood with the correct moisture level, like from smokinlicious.com, so combustion is less of an issue.

Meat absorbs more smoke at lower temperatures. If your wood expired more quickly than usual, your meat still probably absorbed plenty of that smoke. That wood produced the same amount of smoke, just faster. Don't be tempted to add more wood. Just let it ride.
« Last Edit: November 14, 2017, 09:20:51 PM by SconnieQ »
Kari from Madison WI "77 Square Miles Surrounded by Reality"
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PigPen68

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Re: For anyone having trouble in cold temps
« Reply #10 on: November 18, 2017, 07:24:28 AM »
Kari

Thanks for the advice! You were right about overthinking what had happened. When I opened the fire box after the smoke one chunk was ashes and the other was just fine.  I am in the process of making a larger post about my first month with the 3D,  but as a preview the Prime Rib turned out amazing.
Dana from DC
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Mechanical Engineer
USMC 00-04

JustChillin

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Re: For anyone having trouble in cold temps
« Reply #11 on: November 18, 2017, 07:54:54 AM »
Looks amazing! All you need is a bowl of fresh ground horseradish and a glass of red wine.
My tools currently include the SI #2 with an Auber, Grill Dome, Solaire 27", Holland Grill (Companion) & Weber (Smokey Joe). The Companion & SJ are primarily used for tailgating. David from Roswell,GA -Happy smoking!