Mini WSM PID Help

[TMannion]

I've been using my mini WSM for years now with great results, but have recently started looking into some automatic temp control options. I have an old PID temperature controller I used to use for beer brewing, and I was wondering if I could repurpose it for my mini wsm? Basically instead of plugging in a heating element to control beer mash temperature, I would simply plug in a fan that is connected to my wsm vent. Is there any reason this wouldn't work? What is the best sized fan for a mini wsm? What about attachment to the vent? Attached is a photo of the wiring diagram used. Here is a link to the original build on a beer brewing forum:

https://www.homebrewtalk.com/forum/threads/step-by-step-build-a-110v-portable-pid-controller.379938/

Any help or ideas would be greatly appreciated. Thanks!

 

[Brad VA]

I'm no electrical engineer, but I can't see why plugging in a fan wouldn't work. I think the only issue you might run into is most smoker blower fans aren't plugged for wall outlets but rather the PID controller. Though that seems to be a very minor problem to solve.

As far as size, I have an Auber ATC with the 10CFM for my 22.5" WSM and it works great. I'd say anything up to 10CFM ought to work but the smaller the model the more precise temp control. (Based on an assumption the ATC you built has a 100% on/off function rather than variable speed).

 

[MartinB]

Fans are 12v
And they need to run on low 98% of time
Running full speed will be way too much air.

Operating range is 5-12v.

On off can work, but will need to pinch airflow or use inline resistance, and it wont control good . What works at one temperature also wont do well at another. The characteristics needed to control well are different.

If you have a variable output signal you could use a proportional control DC SSR.

I have a heater meter with damper. . And it does a really good job controlling. But, it also lets you see just how sensitive good control is to tuning parameters as the amount of coals that are burning changes during a cook. Honestly, I don't think I would actually use anything less because it wouldn't work to my satisfaction. I can understand why some people say they have a ATC but don't use it anymore. Mine, makes it a pleasure. total control from anywhere. I can honestly say I used my WSM more because of it then I would without it.

I say this because, when you start something like this thinking its cheap and ez, it frequently turns out to be neither. And doesnt work well. Leading to wasting $$ that might as well have put towards a better solution. More importantly, it consumes your limited time to mess with it and solve problems. . Ive done that many times.....at 52, im starting to learn.....