Controlling a glycol chiller

[danb35]

Earlier this year, I bought a BrewBuilt IceMaster Max 4 glycol chiller. I've really appreciated the ability to set a temperature on it and have it maintain it, pretty much regardless of ambient. But now I'm looking at brewing a Belgian Quad, and its fermentation schedule calls for increasing the temp by 1 deg F per day over the course of almost two weeks. Of course, I can just bump up the controller one degree every day--but where's the fun in that?

Temp control on this is just a matter of cycling the pump on and off to maintain the desired temp. So it seems to me that it shouldn't be too hard (I know, famous last words) to replace one of its built-in temp controllers with one that's a bit more sophisticated, which specifically means (at the moment) "can operate on a schedule." I suppose some kind of web interface would be good too, and probably monitoring of setpoint vs. actual over time.

I'm assuming there are DIY projects out there that do this, presumably with something like an Arduino, a ESP32, and/or a Raspberry Pi (and I can work with any of these), but I'm not sure what they would be. Any suggestions?

Edit: Some looking around has found a few projects that look like they would, or could be made to, do this. What I've run across so far are BrewPiLess (and thus by extension, presumably, BrewPi) and BierBot. The latter appears to rely on cloud control, which is a negative in my book, though not necessarily a deal-breaker. I'll keep looking, but feedback on these or others would be appreciated. I don't know how interested I am in "automate all the things" right now, but I don't know that I'm necessarily opposed to something that could do that.

I currently have a Raspberry Pi Zero 2W available, along with a few ESP32 boards and an Arduino Mega or two. I don't think I have an ESP8266 handy, though they're cheap enough I wouldn't mind buying one (or a few) if needed. I'm assuming I'd need to buy relays and the like.

 

[Ale-75-IT]

I think an ESP32 will suffice, plus a dallas 18b20 chip and a relay board.

You'll have to design the connections, buy the connectors, and solder everything to make it work (and it always takes a bit of troubleshooting).

At this point you will enter a programming nightmare of trial and error.

I would consider the effort of getting up every morning and pressing a button with your finger!

..but if you want to go further I think I can help a bit with hardware and software.

Bye,
Ale

 

[danb35]

At this point you will enter a programming nightmare of trial and error.

I wasn't really looking to program something myself; my thought/hope was that there's already an existing project that I could use for this. And it looks like there are at least a few (BrewPiLess, BrewPi Remix, and Bierbot are what I've encountered so far), but I'm not too clear at this point on (1) what's available, or (2) how they differ for my purposes. It looks like all of those are really intended for a bigger job than just fermentation temp control, but it also looks like they can all do it.

 

[mashdar]

IDK if modern compressors have this issue, but historically self lubricating compressors needed to start "cold". Most good controllers (used to?) have a 3-10 minute delay upon initial power up and after turning compressor off to let it cool. This should be easy to achieve 9n software.

 

[danb35]

I don't know if this is a normal feature or not (as I've only worked with the one chiller I have), but on my chiller the compressor is on its own controller, set to a constant temperature of -2°C. All I'd be controlling here is a pump--turn it on (pumping the chilled glycol through, in my case, a Temp Twister) when the beer temp is too high, and off when it isn't. If I wanted to get fancy, I might also control a heater when the temp gets too low, but that's out of scope for the moment.

 

[mashdar]

Oooh, I thought you wanted to control the chiller set temp. Poor reading comprehension on my part.

 

[mashdar]

A few options:
https://www.morebeer.com/products/mkii-temperature-controller-wired.htmlhttp://www.homebrewing.com/equipment/fermostat/https://www.morebeer.com/products/r...ontroller-wifi-enabled-portal-compatible.html
I was expecting an inkbird but didn't see one on first look.

edit: I know you talked DIY, but tbh I'd expect it to be a slog to configure. I'm just picturing the various foss media/server backends I've set up. Always takes about 6x the time I expect.

edit 2: slightly sketchy project if you're a python person
https://www.opensourcedistilling.com/controlling-fermentation-temperatures-1/edit: sigh, nm. The github is empty.

 

[danb35]

Those are some interesting links, particularly the first you linked.

I know you talked DIY, but tbh I'd expect it to be a slog to configure.

Maybe, but... Bierbot now recommends this Sonoff device for a DIY "brick":
https://www.amazon.com/SONOFF-THR316D-Temperature-Monitoring-Compatible/dp/B0B5RBVHHF/
It's quite a bit cheaper from Aliexpress, though of course shipping time is longer--and for $20, you have a ESP32 microcontroller, a relay, and a DS18B20 sensor, which are all that should be needed for this task, and a convenient and safe housing to enclose all the power stuff. It appears that it's just a matter of flashing their firmware to the device (something I'm reasonably comfortable with thanks to Home Assistant/ESPHome), and then linking the device to your account on bierbot.com. Then set it up as a "fermenter" and control it from there.

If I want something completely self-hosted, or otherwise don't like bierbot.com or find it not suitable, I'd expect the same device should also run BrewPiLess, which appears to also offer control of a chiller.

Regardless of which way I go (including the devices you posted), I still need to dig into the wiring of my chiller to find/intercept the power wire to the relevant pump. I don't expect that to be hard, but still something that needs to be done.

 

[mashdar]

Looking at the photo of the back of the controls:
1. the pump wiring looks very accessible.
2. You might be able to solder to the back of the up/down buttons instead of adding a new controller. That may be a lazy/quick/cheap way?

 

[danb35]

the pump wiring looks very accessible.

I'd expected so. I've seen some videos about adding heating outlets to the Max 2 model, and it appears that's the case there; I didn't think it would be otherwise on the Max 4 but just haven't dug into it yet.

You might be able to solder to the back of the up/down buttons instead of adding a new controller.

That's an interesting concept, and one I'll probably have to think about a bit more.

I've ordered one of the Sonoff relays, as it looks like that ought to give me some flexibility in application--I know it will work with bierbot, and it seems it ought to work with BrewPiLess. I'd still be interested if anyone knows of other relevant projects.

 

[mashdar]

That's an interesting concept, and one I'll probably have to think about a bit more.

Yeah, I assume everything is surface mount these days, but I'm pretty sure I see 4 thru-hole pins on each button in the photo.

 

[rkhanso]

BrewPiLess, CraftbeerPi3, Fermentrack or many other controllers are out there that do a fermentation profile.
Not that it'll help you out immediately, but I have some BrewPiLess controllers available. They'd need a little more work for your setup, but would work fine and have scheduled temp control.

Once you automate some things, you'll probably want to find more to automate.

 

[danb35]

Once you automate some things, you'll probably want to find more to automate.

Oh, I'm quite familiar with the concept of feature creep. I'm not sure how amenable my BIAB system is to automation of this sort, but I certainly wouldn't rule it out at some point in the future. And I'm thinking about one of your boards, even though I'm not certain I'd want to use BPL in the long term--options are always good.

 

[Thorrak]

I think BrewPiLess has built in support for "fridge" (single point) temperature profiles which is pretty neat.

BrewPi-Remix/BrewPi-ESP both work with glycol (BrewPi-ESP has "low delay" mode for use when controlling pumps) but don't yet have single point temperature profile support. At some point I'll build support for them into BrewPi-ESP, at which point they'll also work in Fermentrack.

BrewPi-ESP works with Kasa Smart Plugs for switching pumps/devices on/off and can use Tilt Hydrometers for temperature readings if you're looking to try to reduce the wiring that is needed.

 

[danb35]

BrewPi-ESP works with Kasa Smart Plugs for switching pumps/devices on/off

That's handy, as I already have a couple of those.

It seems there are a lot of BrewPi offshoots, and I'm having a little trouble making sense of the differences among them.

 

[Thorrak]

That's handy, as I already have a couple of those.

It seems there are a lot of BrewPi offshoots, and I'm having a little trouble making sense of the differences among them.

Very true. There was a comparison of the various projects awhile back, but it's out of date, so I went ahead and wrote an update here. I'm (obviously) partial to a solution with BrewPi-ESP and Fermentrack, but BrewPi-Remix is fantastic software, as is BrewPiLess.

 

[danb35]

I've pretty well settled on Fermentrack/BrewPi-ESP for this--the ease of installing Fermentrack on Proxmox, the ability to handle more than one fermenter in a single interface, and the handy circuit Thorrak designed to control the chiller pumps with no modification at all to the chiller all favor that solution. Testing it (on water, not on beer) shows that it's able to maintain a stable temperature in my glycol-cooled Fermzilla within less than 1°F from the setpoint, which is good enough for me.

But I've received a couple of the Sonoff relays I mentioned, and played around with Bierbot a little bit, and for chillers that don't have integrated pumps it seems like it could be a pretty decent solution. I did have trouble flashing the firmware, and ultimately needed to use esptool.py from the command line on my Mac (couldn't flash it at all under Windows, but that might be due to driver issues--I haven't been able to make BrewFlasher work on my Windows machine either). But once that was done, the relay popped up on my Bierbot dashboard right away, and it can be assigned to control whatever device you might want to use with it. Features I thought were good:

• A nice, clean, responsive web interface
• Broad hardware support--original and 32-bit Bricks (i.e., Sonoff smart relays with their custom firmware), rPi, Tilt, iSpindel, and HYDROM (which I hadn't heard of before, but seems to be another iSpindel-like device).
• Brick firmware is open-source, so can be ported to other hardware, like custom ESP-based devices
• Flexibility in hardware use--you can, for example, use the relay on one brick to control cooling for a fermenter, the relay on a second brick to control heating, and the temp sensor on a third to, well, sense the temperature of that fermenter. All drag-and-drop in their web interface.

Drawbacks, at least for me:

• Depends on "the cloud." Not only does this mean that your internet must be up in order to use the service, it also means they can (and do) limit what you can do unless you pay them. And, of course, if they shut down, your device is pretty much worthless.
  • No doubt this is a positive for some--you don't need to install/configure/maintain your own software, nor have a computer running constantly to run it.
• Related to the above, the limits on the "free" tier are a little restrictive--only three "bricks" (including any Tilt/iSpindel), only one fermentation at a time, and no more than ten days' fermentation profile.
• The particular Sonoff relay they recommend just doesn't work that well in my application. It needs AC power in, and switches the output on command. This works fine in line with an extension cord--cut the cord in two, connect the wires to the appropriate terminals, and plug in whatever device you want to control to the end of the cord. If my pumps had individual power cords, this would be trivial. But since they don't, I'd need to run neutral and hot from the chiller to the relay, and then back to the chiller. Not the end of the world, but more intrusive than a single dry-contact relay in line with the hot wire to the pump.

So, an interesting option, but didn't quite meet my needs.

 

[Dland]

I run my dyi glycol chiller off two inkbird 308 temp controllers. One runs the chiller compressor, , the other the pump. It does not have to get more complicated than that, though no doubt there are other ways to do it.

 

[danb35]

It does not have to get more complicated than that

...except that fails at the very reason I started this thread, which I stated in the OP: I want to be able to change the setpoint over time, automatically. The Inkbirds can't do that. They do what the devices built in to my chiller already do, which is to maintain a set temp.

 

[Dland]

My apologies, perhaps the model 310T would help. I bought one of these when 308s were out of stock a while back, it can control for time as well.

Link from HBT, though coupon is probably expired.

https://www.homebrewtalk.com/thread...ature-controller-itc-310t-b-good-news.631891/