My Kegerator/Temp chamber project

[frodus17]

Earlier this year, I came across some Conviron Temperature chambers for sale on craigslist. I wanted to regulate fermentation better and had been looking around for several months for something reasonable. What I found was essentially lab-grade temperature/humidity and light controlled chambers used for plant cell growth. A local lab used them for seedling starts in a study they did, but upgraded and were selling them (Still one left at $300 if anyone wants it, located in Portland, OR area).

Anyway, the Chambers, while a little old, were touchscreen controlled and can run programs for varying the temp/humidity/light. Outdated for sure, as they had an old PC104 SBC computer and Floppy disk drives. The chambers themselves are HUGE, and can fit 8-9 corny kegs in the bottom level.

I went to take a look, and 2 of the 3 worked. I made an offer for $400 for one working and one not-working as gamble. I got them home, plugged them in, and one worked just fine. The other, after digging some, had a completely fried motherboard due to an actual Bug. No replacement could be found, so I figured I'd gut the controls and put my own in.

I decided that I would not touch the working one for now, and use as a fermentation chamber, and maybe even dabble in Mycology again (I used to grow Oyster and Shiitake). The other one, would be modified to be used as a big kegerator/beer fridge.

Just like I did on my brew controller (still finishing it up), I decided to use a Raspberry pi and some Modbus PID temperature controllers. The compressor, fans, and even heater inside were saved, as well as some alarming features for low/high temp, and the rest was gutted.

This last weekend, I started working on it more aggressively because I have a beer I need to serve in a couple weeks when it's finished. I added 4 Intertap SS Faucets/Shanks and an ACU Precision Sheet Metal Drip tray and mounted it into the door.

Working on the controls now. I can turn the Fans on and plug in the compressor, just need to install a new temperature sensor and my controls along with a solid state relay. The Pi will run some control software as well as Rasbperry Pints or Taplist.io or something similar on a 7" Touchscreen.

 

[Rob2010SS]

Nice Setup!!! I'm a little jealous of what you got going on in that garage haha.

 

[frodus17]

Nice Setup!!! I'm a little jealous of what you got going on in that garage haha.

Haha, thanks. My little 10 Gallon electric brewery. Need to throw up something against those walls, maybe some vents, but it's coming along well. Just moved in last year, and Brewing took back seat to house projects. Finally getting to play

 

[jschein]

Nice setup, I like how you pushed the BL all the way to the back

 

[frodus17]

Nice setup, I like how you pushed the BL all the way to the back

Yeah, gotta have cheap beer sometimes, right? I don't like Beerpong with good beer!

It's nice that there's so much storage. Plenty of room for bottles, and cans, as well as kegs. I'm waiting for the conical to finish fermenting this weekend, and cold crash to see how cold she can get and sustain that temperature.

Right now, the chamber is set for 21 degrees C, and it's sat there, dead nuts on.

 

[frodus17]

A little update on my Blog:
It’s been a pretty busy summer, so some of my projects were put on hold a while. A few weeks ago, I got new taps and drip-tray and installed into the temperature chambers. I spent a little while since then removing any unnecessary electrical components on the chamber that were left over from the broken controls. I also worked a bunch on the new control system using the Raspberry Pi.

New chamber fits roughly 9 corny kegs in the bottom, and has room up top for cheap beer, bottles and beer glasses. The chamber has a hole in the top that will house a 7″ touchscreen LCD that will eventually show a tap-list running on the Raspberry Pi. Also running on the RPi, is an HMI that I created (using the same software for my brew control system) that will allow me to set the temperature and view alarms. I can even set it to email or sms message me if an alarm threshold is reached.

Next up is wiring the SSR into the existing components and getting just the cooling working. I’m hoping to have this finished in the next couple weeks. I’m running out of space in our fridge for beer, and need somewhere cool to store everything.

 

[Rob2010SS]

Nicely done! I like your tap list feature on there. That's pretty sweet.

 

[frodus17]

Thanks Rob!

The tap list is a work in progress. There's Taplist.io and RaspberryPints I've looked at so far. Still trying to figure out which direction to go. I'll probably have one of them embedded into the HMI screen so I can sort of toggle between pages (Temp control, settings, taplist).

Also, Heating is on there for future use in the Temp Chamber where I ferment and want to heat and cool. The Kegerator will be cooling only.

 

[TheLostBeer]

What is all the tech in the first pic in your last post? Some looks familiar but some
Does not

 

[frodus17]

On the DIN rail is a Power supply, the Raspberry PI (It's housed in a Raspibox enclosure that has a 24V to 5V converter on it, and some terminals), and a Eurotherm RFS PID Temperature controller (Modbus) + PT100 temp sensor. The background has another PID controller, a little data logger I'm not using, and an SSR/Heatsink.

Raspibox:
https://www.modmypi.com/raspberry-p...n-plus-prototyping-din-rail-raspberry-pi-case

RFS PID controllers:
http://www.eurotherm.com/products/ero-electronic-products/compact-basic-control/rfs

Instead of having to cut out holes for PID controllers, and mount switches for auto/manual, indicator lights, etc and having to wire it all up, I'm using the RPi and touchscreens to control everything over Modbus RTU. I'm using the same exact setup for my brew controller, so many of the parts and pieces and software all port straight over.

 

[Gadjobrinus]

Jaw-dropped impressed and inspired. I've been trying to find a way to roll an open fermentor from the brewery, on the driveway, to a completely cleanable/sanitizable ferm chamber, and one that can be well temp-controlled with an outside ambient range of 0-110F.

 

[frodus17]

Thanks Gadjobrinus! It's definitely a bit of overkill, but for the price, I couldn't pass it up. I was only going to get the 1 for fermentation, but the second one had a broken computer part inside, so was "dead". $100 for the "broken" one. Sure, it wouldn't work as is, but I think even just a simple temp controller could have brought this beast back to life, as all of the mechanical worked just fine. Having 2 of these in the garage proves I have a very awesome wife!

Going to work tonight and some this weekend on getting it running and then doing some auto-tune to see how well everything functions. It's not just a compressor. There's a heating AND a cooling solenoid (It's a heat pump, and can run in both directions), a fan inside, a defrost heating element that I've got to figure out. For now, I'll just wire in the Cooling solenoid and inside fan to come on when compressor comes on. Trying to avoid using a PLC if I can manage.

 

[frodus17]

Finally back to this. Spent a lot of last year working on our house, so this took back seat.

When I was first planning the build, I looked into some other software that does controls for homebrewers. There’s Craftbeerpi, Brewpi and a few others. I stumbled upon another software that runs on the Raspberry pi, that was geared more towards plant and mushroom growth, called MyCodo, by Kyle Gabriel. I was hesitant at first because I don’t have experience with the DS18B20 temperature sensors.

So after months of tinkering, I decided to give it a shot and I’m really glad I did. Not only did it eliminate my problems, but it has some features that I really wanted to have. It turns the kegerator into a full temperature controlled chamber, with a receptacle inside I can control on and off if needed. I can control the heating and cooling solenoids on the heat pump, the compressor and fan, and display humidity, temperature etc. depending on sensors used.

One really awesome thing it can do, is use methods to change the PID setpoint over time, i.e. ramp/soak profiles for lagering and cold crashing.

I wired it to drive some SSR’s directly to control the compressor/fan at the same time, and heating/cooling solenoids independently as needed. I know the kegerator won’t need heating, but it’s just another cheap SSR, so I’ll wire it in and if I need it, it’s there. Once I prove it out, I’ll gut the controls on my other Conviron chamber, and overhaul it. Chamber 2 already has Temp, humidity and light control which I want to keep. The thought is, I can use it for fermenting as well as growing mushrooms, growing plants, etc.

So last week I got some SSR's and DIN rail mounted heatsinks. Working on the display mounting currently, and will wire it in for basic temp control in the coming weeks.

 

[Jtk78]

Really jealous! 50% from the sweet deal you found, and 75% from the knowledge you have on the technical side of controls and what not. I'm a fairly tall guy, but that stuff seems WAYYY over my head. I would love to do a taplist, espically with flow meters to track keg levels. Maybe one day.

 

[frodus17]

It was a screamin' deal for sure! The knowledge didn't come easy, almost 20 years of working in the automation and controls industry and a Bachelors! Here if you have any questions though.

Taplist wasn't that hard, it was pretty easy to follow instructions and get working. The tracking sensors might be harder though, haven't tried that.

 

[frodus17]

So it looks like I can't get it to regulate down low, so I need to get the refrigerant recharged. Unfortunately it's Freon. I plan to have a local company I called, come in sometime in the next week or so to check for leaks and refill.

 

[frodus17]

It's working!

I got a local company to come fill the refrigerant. The unit is about 17 years old, so being low wasn't a surprise, especially since this one in particular had broken control electronics and was sitting. We looked for obvious leaks and couldn't see anything. They came and recovered the R22, and filled up with N22. It was a night and day difference.

Still have some finishing up to do, but it's working and I can now store beer and kegs. I set it for 50F for now, just to keep an eye on it and see how it does. So far it's regulating pretty well without any issues.

To do:
- Replace the RPi 7" touchscreen with the 10" permanent Touchscreen I got from Ebay
- Buy and install CO2 manifold
- Build/Install a Tank holder on the back, to keep the bottle out of the inside
- Add an SSR to control the internal fans and keep them on (or at least more often)
- Add another temp sensor to monitor liquid temperature