Kegerator Thermostat Control

(Cory S) #1

I have a home kegerator system, and one of the biggest pains about it is even though it is relatively high-end, the thermostat sucks. CO2 dispensed beer is very temperature sensitive and even a variation of a few degrees off target can cause you to get a pour of 90% foam.

I wasted nearly an entire 200 dollar keg making little adjustments to the crap analog dial thermostat only to have it make unpredictable vast swings in one direction or another. There are of course bulky upgrade systems you can retro fit, but they require drilling into your 1,200 dollar + kegerator, and are overly complicated.

I wonder if a combination of the temperature sensor, and the smart outlet could be a solution to this problem. The outlet could cut and restore power based off the readings of the temperature sensor. It could also send alerts if the temperature gets off target and it is unable to bring it back.

This would require the temperature sensor to be accurate though, within a degree or two, and it may need some kind of “learning” logic on when it should turn the system back on to maintain the temperature it’s currently at.

(Andrew Urman) #2

An absolutely great use case. Our out of the box temperature sensor is pretty darn accurate, but it seems you’re looking for a more fine tuned option. Since we have our Arduino ThingShield and ThingModule, you could build something with a higher degree of accuracy. I’m not sure how the current temperature sensor fits in your setup, but you could find a multitude of sensors and connect them to an Arduino/ThingShield.

You could program the Arduino to report as often as you would like, then create a smart app to turn on/off an outlet when a certain threshold is met. If it seems like a lot of work don’t fret, its not :D. Plus when the time comes you could post it here and people could help you through it.

P.S. What kind of beer do you brew?

(Cory S) #3

Hey Andrew,

I don’t brew a lot anymore, I had an over-boil episode once which cracked a new 3,000 dollar cooktop and now the wife wont let me :frowning: Soooo I import most my beer from Europe along with a couple from local Houston breweries. My main go to is a double IPA called endeavor from Saint Arnolds brewery.

How accurate is the Smartthings multi sensor for temperature? If it is around a degree or two it should be just fine. As far as building my own…I would definitely be interested in  something like that, but wouldn’t even know how to begin…is there any beginners information out there on that kind of thing?


(Andrew Urman) #4

The sensor on the SmartSense Multi is rated at +/- 2 degrees. There is some loss of information when running through the ZigBee chip as well, but not large. I’d say you could give it a try? If not, a simple Arduino setup could get very accurate temperature. You could even add other sensors for less than a dollar. I’ve never brewed myself, but I have a lot of friends who do it. I’m going to run some questions by them. You’re not the first to bring up SmartThings for beer related projects, which is awesome.

An entire brew process controlled by SmartThings accessible from your phone. Now that would be smart.

But back to a kegorator. I’ve been recently looking over plans for them as well. I thought an awesome idea would be to not only have SmartThings manage the environment (CO2, temp, humidity, etc) but could also pour the beer for you! Over the next couple of weeks I’m going to be looking to start this project. Maybe I will start a thread with the whole build process.

(Cory S) #5

If it could manage CO2 then that would be incredible. The main reason for that is that there is a lot of chemistry in pouring a draft beer. Everything from the diameter & length of your beer line, down to the temperature as in relation to the Co2 level effects the pour. Biggest issue I have is matching the Co2 to the temperature.

I don’t know how such a device would be built though, I imagine it have to be some kind of servo controlled regulator installed before the tap.


I also would like to build something to control temperature of my barbecue smoker for those 20 hour briskets I like to do.

(Andrew Urman) #6

I’ve seen some controllable valve’s, but they’re quite expensive. You could definitely rig up you’re own valve using an Arduino and ThingShield using a solenoid or something. I have a kegerator that I plan on hacking to pour a beer via SmartThings mobile app. Using hands is soooo 2012.

(Cory S) #7

How do you plan on getting a proper pour using an automated dispenser? There is some technique involved in getting the appropriate amount of head ontop.

(Andrew Urman) #8

No clue. There are a few home brewers in the office. I’ll have to learn a lot from them first!

(Mike L) #9

I’m glad this conversation is happening!  I’ve been thinking about SmartThings integration with my kegerator as well- I completely agree with you… the traditional kegerator thermostats are horrible.  I’d like to come up with a unit that would have:

Analog In: Temperature
Analog In: Load Sensor for keg weight
Analog In: Pressure Sensor for CO2
Analog In: Current Sensor - monitor compressor/log energy usage
Digital In: Liquid Flow Meter - Measure beer volume dispensed
Digital In: Door switch
Digital Out (Relay): Refrigerant Compressor
Digital Out: Indicator Light (visual notification on kegerator for high temp/low beer level)
Digital Out: Dispense Solenoid

Did I miss anything?

I have an arduino board, but unfortunately have no idea how to program it yet.  I’m in industrial design/programming, so this is going to take some getting used to.  If I ever figure it out I’ll come back for a followup!

(Cory S) #10

I love the idea for a keg weight sensor…that could be really helpful

(Andrew Urman) #11

The Arduino Uno could handle that fairly easily. The interesting part is how to get all of that info displayed in the iPhone app and still look pretty.

Before our multi-sensors we’re developed, we used a temperature/humidity sensor by a company called Wulian. I’m pretty sure its this unit. I can double check when I have on in hand. The datasheet says the relative humidity accuracy is +/-4.5 Not sure how accurate that is.

(Ash ( / Ashutosh Jaiswal) #12

Do you know if Wulian products are compatible with SmartThings Hub? They follow Zigbee…and their product line is quite impressive.

(Andrew Urman) #13

Some Wulian products should be. Especially if they are ZigBee Home Automation.

(Terry) #14

I wanted to delete this post but there is no way I can