PID controller for reverse flow smoker

[smc51]

Good Morning,
Does anyone have experience with Temperature controllers for a Reverse Flow Smoker (Pid Controller)???
I am wanting to take my Meadow Creek TS120P (reverse flow smoker) to the next level with Temp. control[/color][/size][/b]

[Gizmo]

I couldn't get one (guru) to work on an RF - at least not as well as old-schooling it - please keep us posted if you make any progress ...

[Frank_Cox]

Good Morning,
Does anyone have experience with Temperature controllers for a Reverse Flow Smoker (Pid Controller)???
I am wanting to take my Meadow Creek TS120P (reverse flow smoker) to the next level with Temp. control[/color][/size][/b]

Hey smc51! good to hear from you again! How do you like the new rig?
here is a thread by alleyrat on his smoker guru rig....
More Power!!!

[alleyrat58]

The more I mess with my Guru, the less I like it since I converted my smoker to a reverse flow. The other day I just opened my ash door on the firebox and let it run entirely on natural draft, it ran pretty good, I must say.

If you go with a Guru, they will sell you a splitter to add up to two fans to your setup, you will need that as a minimum. In my post that Frank mentioned above I used +12v DC blowers each of which are 25 CFM. I am currently working with an AC power fan so that I don't have as much circuitry that can break on me. If your interested in how to set something up to give you more power I can gladly show you what I am doing and what parts I am using.

[Gizmo]

alleyrat do you think the guru has a programming/algorithm problem with the delay time of a reverse flow?

or do I need to go wait in the corner and quit asking stupid questions ...

[Frank_Cox]

I would say that is correct Rick. In my honest opinion, reverse flows if properly tuned will operate best without a guru or other stoker. once the dampers are set for the correct drafts and the fire is the correct size keeping the fire consistent and maintained is the ticket.

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[alleyrat58]

I would say that is correct Rick. In my honest opinion, reverse flows if properly tuned will operate best without a guru or other stoker. once the dampers are set for the correct drafts and the fire is the correct size keeping the fire consistent and maintained is the ticket.

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I'll keep beating this horse - I don't like the on/off of the Guru at all - I like a nice constant stream of air which is why I built my rig to allow me to bypass the guru and run the fan directly. I am no physics major, but you are essentially pressurizing one box to feed hot air into another that is pulling that air through the stack. So when the Guru starts blowing the firebox reaches a a certain pressure and pushes that air into the cooking chamber. The cooking chamber is pulling that air up through the stack. Now, when the Guru pauses as the desired temp is reached that pressure drops suddenly, then rises as the Guru starts up again. This creates a situation where you are burning your fuel quickly and creating dirtier smoke in the process. What I do now is run all four of my fans until I am up to temp and then cut one or two of them off so their is just a nice trickle of air, constant pressure, and consistent draft, resulting in a thin blue smoke out of the stacks if any at all. My firebox is undersize and the fans help account for that. My goal is rebuild that dog one of these days and get it up to proper size and hopefully quit relying on electricity to cook altogether.

[SoloQue]

While I do not as of this time have a GURU yet I really think from reading all this that I might try the system but just not completely close the dampers which would be the normal process when using the fans. I'm thinking that I might reduce them a bit from what I think is needed for my target temp and let the fans subsidize the air flow. Everything I read gives the impression that the RF set up might lead to such a gradual temp change that the Guru can't contend with it. Maybe with an ever present air flow although minimized this will keep heat flowing and drastic temp spikes down. I'm a sucker for a good experiment, just a shame this one will cost so much.

[Gizmo]

Just thinking out loud here but could you rig a 12 volt power supply to a cheap computer fan(s) and put a pickle switch on them and run it manually for a little while to get a feel for it?
A LOT cheaper and you might learn something about it's tendencies before you spend the $$$ ... jm2cw ...

[alleyrat58]

If I were you, Solo, which I was about 4 years ago, I would wait and spend more time with your rig, try some different fire management techniques and such. I can guarantee with relative certainty that you will be happier in the long run if you do.

Just thinking out loud here but could you rig a 12 volt power supply to a cheap computer fan(s) and put a pickle switch on them and run it manually for a little while to get a feel for it?
A LOT cheaper and you might learn something about it's tendencies before you spend the $$$ ... jm2cw ...

That said, if you want to try what Rick is suggesting I can certainly help to get you up an running with very little $$$ out of pocket.

[Frank_Cox]

What I do now is run all four of my fans until I am up to temp and then cut one or two of them off so their is just a nice trickle of air, constant pressure, and consistent draft, resulting in a thin blue smoke out of the stacks if any at all. My firebox is undersize and the fans help account for that. My goal is rebuild that dog one of these days and get it up to proper size and hopefully quit relying on electricity to cook altogether.

I think you are on to something there alleyrat.

[erniesshop]

I would say that is correct Rick. In my honest opinion, reverse flows if properly tuned will operate best without a guru or other stoker. once the dampers are set for the correct drafts and the fire is the correct size keeping the fire consistent and maintained is the ticket.

Sent from my iPad using Forum Runner

I'll keep beating this horse - I don't like the on/off of the Guru at all - I like a nice constant stream of air which is why I built my rig to allow me to bypass the guru and run the fan directly. I am no physics major, but you are essentially pressurizing one box to feed hot air into another that is pulling that air through the stack. So when the Guru starts blowing the firebox reaches a a certain pressure and pushes that air into the cooking chamber. The cooking chamber is pulling that air up through the stack. Now, when the Guru pauses as the desired temp is reached that pressure drops suddenly, then rises as the Guru starts up again. This creates a situation where you are burning your fuel quickly and creating dirtier smoke in the process. What I do now is run all four of my fans until I am up to temp and then cut one or two of them off so their is just a nice trickle of air, constant pressure, and consistent draft, resulting in a thin blue smoke out of the stacks if any at all. My firebox is undersize and the fans help account for that. My goal is rebuild that dog one of these days and get it up to proper size and hopefully quit relying on electricity to cook altogether.

I couldn't agree more !!
On my new smoker , I have already bought a 25 amp ssr and a PID..................Though I have not wired them in yet .
On my first cook last week ( 150# of brisket and pork butt's ) I filled my basket with 40# of kingsford...Had a 12v fan hooked to a battery Ran it for 2 hrs straight .......top temp gauge read 265...........Put a Oven gauge in middle rack it read 350........turned fan off and after 1 hr it settled in at 265.

Here is a pic of the cooker , It has 3 racks that are 40" x 48".



Here is a pic of my air supply set up......2" pipe NO other fresh air source....All doors have Gasket's



Today , I put 40# of kingsford in....Ran the fan till the cooker reached 200.....Shut the fan off and 5 hours later ( stayed right between 245 and 265 ) this is what was left in the fire basket...............



On my last cook here is a picture of the bottom rack , about 3" above the RF plate.



I'll save the power source and PID for another day !

[Smokeone]

NIce set up Ernie.
Great looking grub also!

[Frank_Cox]

i forgot....

[onesquin]

There is a guy 40 miles south of me with a variable speed squirrel cage fan he uses to control air flow to the firebox. I want to check out his setup and get pics. I think he just has a knob to dial in the speed. Supposedly he can load up the wood and set the speed and walk away for several hours at a time.

[erniesshop]

There is a guy 40 miles south of me with a variable speed squirrel cage fan he uses to control air flow to the firebox. I want to check out his setup and get pics. I think he just has a knob to dial in the speed. Supposedly he can load up the wood and set the speed and walk away for several hours at a time.

My system is 12 volt.....a rotary dimmer switch that you would buy for your living room will work to control your fan speed.

[The Czar]

i forgot....

X3

[Chadta]

Nothing like reviving a 6 year old thread.

Has anybody got a PID and fan working correctly ?

Im going to give it a try, my set up worked well on my COS, I recently completed building a reverse flow, 20 diameter, 36 long CC.

I have my temp probe in the end plate, right at the end of the baffle plate, measuring air temp as it turns and heads towards the stack, my temp guages are at baffle plate end on the bottom rack, and chimney end on the top rack.

I have 2 fans, blower style 38 cfm, 10V, I have one running off 5v hooked up to the alarm of the PID, which is set for 175, it is on during warm up, and then again gives me a blast if temp starts to drop, Im going to add a buzzer and a toggle switch so I can shut the alarm off. The other fan is currently 5V on a SSR off the pid, which is tuned for my COS, im assuming ill have to pay with that a little. Im going to put a dimmer on that and run it, with the plan of getting it to basically run non stop.

Gonna run it this weekend and see how it goes, Ill report back my findings

[Chadta]

Nothing like reviving a 6 year old thread.

Has anybody got a PID and fan working correctly ?

Im going to give it a try, my set up worked well on my COS, I recently completed building a reverse flow, 20 diameter, 36 long CC.

I have my temp probe in the end plate, right at the end of the baffle plate, measuring air temp as it turns and heads towards the stack, my temp guages are at baffle plate end on the bottom rack, and chimney end on the top rack.

I have 2 fans, blower style 38 cfm, 10V, I have one running off 5v hooked up to the alarm of the PID, which is set for 175, it is on during warm up, and then again gives me a blast if temp starts to drop, Im going to add a buzzer and a toggle switch so I can shut the alarm off. The other fan is currently 5V on a SSR off the pid, which is tuned for my COS, im assuming ill have to pay with that a little. Im going to put a dimmer on that and run it, with the plan of getting it to basically run non stop.

Gonna run it this weekend and see how it goes, Ill report back my findings

Initial trial, temp probe is level with baffle plate in the end wall. Set for 280, holding +-5, gauges are off, should have got good adjusting ones. Oven gauge and ir gun confirm temp is 225 on both ends of lower grate.

Been this way for an hour, started fire with 1 full chimney of lump, and a fist sized split, added another split 15 minutes ago. Smoke is barely visible, didn’t get any thick white when I added the wood. Really happy with it so far.



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[Chadta]

And just after I say that I let the fire get two small. Had to add another split, and have a bit of white smoke. Lester a few minutes seems to be stable again now though.


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[alleyrat58]

I use my guru on my GF and natural draft on my RF. I got tired of the electrical for my RF.