Fermentation/lagering chamber - temp control, PID?

[whoaru99]

Started scanning the local papers and such for a small chest freezer to make a fermentation/lagering chamber.

Since I'm severely into gadgets, rather than use something straightforward like the Johnson Controls or Ranco units, was thinking to use Auber 2342 to have heating & cooling cycles.

Big questions at the moment:

1. Do you typically monitor and control -
a. chamber air temp
b. fermentation/lagering container surface temp
c. beer temp with immersion probe

2. Assuming answer "C" above would be best, does the Auber "auto tune" work well enough to learn the proper cycling regarding overshoot/undershoot, or is that asking too much?

Not opposed to tweaking on the settings but trying to get some idea if it would take a couple practice runs or many to get it dialed in?

 

[cscade]

You'll be wanting to monitor "a" for conditioning and storage, and also "c" if you are fermenting.

PID control is not normally recommended for control of long-cycle processes, like a freezer compressor. PID control is suited to processes that can be turned on/off rapidly, which in brewing tends to be resistive loads like heating elements, etc.

I use a BCS-460 for what you're talking about, in hysteresis mode with a setpoint. Recommended!

 

[DakotaPrerunner]

Another BCS-460 user here. I have it set up to power a small heater via PID control in the winter and the freezer compressor via hysteresis in the summer. The BCS has been one of the greatest additions to my brewing and fermenting setups. Checking on, and being able to control, your fermentation while on vacation is priceless.

 

[whoaru99]

PID control is not normally recommended for control of long-cycle processes, like a freezer compressor. PID control is suited to processes that can be turned on/off rapidly, which in brewing tends to be resistive loads like heating elements, etc.

Agreed.

I should have been more clear to say I'd use the on/off control method with setpoint & hysteresis functions of the PID controller.

 

[diS]

I am using ebay aquarium temp controller, actually two of them and they are doing great job.
Suppose you already found this thread, in case if someone didn't:
https://www.homebrewtalk.com/f51/ebay-aquarium-temp-controller-build-163849/

 

[whoaru99]

No, didn't see that one. I looked at several threads but for basic temp control most seemed to be using a single stage unit like the Johnson Controls or Ranco(?) units.

Ordered the Auber 2342 an hour or so ago.

Based on more reading of the instructions I'm thinking the auto tune isn't applicable to on/off control. Dunno for sure through so may have to call Auber unless someone here knows for sure.

That's the type of box I'm looking to build though. One receptacle for heating, one for cooling, and even though the Auber has 10A capacity for one circuit and 3A for the second, I'll probably put in a relay for heating and one for cooling just so the controller doesn't have to do any high current stuff at all. I have a number of 50A SPST mercury-wetted relays from a different project that never materialized but they're probably a little overkill.