Temperature Control - Do you have any?

[mdboulier]

I've never brewed a lager before. I've always been limited on equipment. Recently a few fellow students (ME students from Georgia Tech) and myself decided to develop a home brew temperature regulation system (without a refrigerator) for those who want the ability to precisely control fermentation temperatures and may not have the space or money to buy a full sized refrigerator and control unit.**

We've successfully developed a prototype that cooled beer from 104F to 42F overnight. We're working on a control system to allow brewers to maintain any temp (user selected) below ambient. If you're tired of brewing ales because you can't lager, or maybe you have trouble brewing in the summer when your home is too hot, we'd love to know what you dislike about temperature control and/or what you've done to solve fermentation temperature issues (or what you haven't done and wish you could do).

We have a survey to obtain a better understanding of our market. Just a 2 minute questionnaire if you have time, we'd appreciate your input.

https://spreadsheets.google.com/viewform?formkey=dE91LXlET1RtOURxMnlIcEZTbmZ1d3c6MQ

In addition, please post any questions or concerns that you think we should address. Also, feel free to email me, [email protected]

Thanks,

Mark

 

[MalFet]

What kind of cooling system is it?

 

[Catt22]

What kind of cooling system is it?

Peltier would be my guess. Power consumption would be the deal killer for me.

 

[mdboulier]

It didn't take us long to rule Peltiers out. Awesome devices, but like Catt22 says, they require too much power. Also, we want to allow brewers to use their current fermentation vessels. Trying to cool a glass carboy or plastic bucket with a Peltier is unpractical. Right now we' having success with a simple heat exchanger that is constantly pumped with cold water (~0 deg C). It fits inside a carboy after modifying the stopper to move the airlock, placing it in direct contact with the beer (much faster heat removal). Where ice baths are uncontrollable, this device will regulate the heat removal from the vessel through the heat exchanger. This allows us to maintain ANY temp between ambient and near freezing.

 

[Kahler]

So, a plate chiller that fits into your carboy??

 

[MalFet]

It didn't take us long to rule Peltiers out. Awesome devices, but like Catt22 says, they require too much power. Also, we want to allow brewers to use their current fermentation vessels. Trying to cool a glass carboy or plastic bucket with a Peltier is unpractical. Right now we' having success with a simple heat exchanger that is constantly pumped with cold water (~0 deg C). It fits inside a carboy after modifying the stopper to move the airlock, placing it in direct contact with the beer (much faster heat removal). Where ice baths are uncontrollable, this device will regulate the heat removal from the vessel through the heat exchanger. This allows us to maintain ANY temp between ambient and near freezing.

So is it ice powered? Glycol? Where does the cold water live? What is the advantage of having the heat exchanger actually submerged into the carboy versus something like this? Certainly it would be more responsive than all the various bucket-in-a-bucket submersion methods, but I've always found the water chiller linked above to be "good enough". If you figure in a pump, a temperature controller, and storage for the ice water, does this end up being smaller or cheaper than a fridge and temp controller? Sorry for all the questions...I'm curious to see alternatives to what's out there now.

I've had good luck with peltiers, but they are a bit futzy. They aren't energy efficient, but nor are they terrible. In the grand scheme of my household energy consumption, they are a very small part.

 

[IrregularPulse]

So you would be running water through the system for the 1-2 week long fermentation? is there a collection system for the water to be re-cooled/recycled? For me, it is one more thing to harbor infection sitting in my wort, vs just plugging in a fridge and setting the temp.
Filled out the survey. Interested to see your project.

 

[Cpt_Kirks]

Wasn't there a company recently trying to push a thermo-electric "blanket" that covers a carboy? They were catching a bit of flack, because every time you refreshed their page, the price changed. They were trying to find a price sweet point.

This "inside the carboy" idea is interesting, but I see a couple of issues:

- It takes up space. Unless it is a s thin as a thermowell, that is space beer could be in. Plus, there is the blow off problem to consider.

- It contacts the fermenting beer. Real or imagined, this could be an infection issue. Some brewers are borderline psychotic when it comes to potential infections.



Good luck with your idea, and keep us posted.

 

[sjlammer]

Interesting. I have something like this cooking up myself.

 

[ClaudiusB]

For me, it is one more thing to harbor infection sitting in my wort, vs just plugging in a fridge and setting the temp.

Real or imagined, this could be an infection issue.

My conicals all have internal cooling coils, get cleaned and sanitized the same way as the fermenters and never see daylight after cleaning.
Why do you think it could be an issue and how do you feel about plastic fermentation buckets?

Cheers,
ClaudiusB

 

[kmk1012]

Why keep us in suspense? I'm pretty curious about this.

 

[mdboulier]

So is it ice powered? Glycol? Where does the cold water live? What is the advantage of having the heat exchanger actually submerged into the carboy versus something like this? Certainly it would be more responsive than all the various bucket-in-a-bucket submersion methods, but I've always found the water chiller linked above to be "good enough". If you figure in a pump, a temperature controller, and storage for the ice water, does this end up being smaller or cheaper than a fridge and temp controller? Sorry for all the questions...I'm curious to see alternatives to what's out there now.

I've had good luck with peltiers, but they are a bit futzy. They aren't energy efficient, but nor are they terrible. In the grand scheme of my household energy consumption, they are a very small part.

Thanks for the link, I hadn't seen that yet. The concept is very similar to ours other than where the heat is removed from. The submerged bucket method removes heat from around the vessel, our current model removes heat from inside the vessel. I can't say that ours would have a huge advantage over what you've shown other than price. We hope to develop a very precise control to help maintain very consistent temps.

Based on what we've spent on this, its looking like we can do it for around...

$10 - copper
$3 .25 x .175 PE tubing
$3 .600 black tubing
$1 new carboy stopper
$0? Cooler for ice reservoir $10 for some foam
$18 modified digital thermostat for HVAC
$5 Thermocouple wire
$12 submersible pump (amazon.com)

We abandoned peltiers for considering the cooling of our fermentation. It doesn't seem practical without designing a customized bucket or something. They are pretty cool though and may be useful to help maintain a cold reservoir, at least partially. I hope we have time to look back into them for that purpose. Using 1 peltier isn't bad. My main problem is, since they require a of current, getting a 12V power supply to pump out 6A each can easily be more expensive than all the other components of our system.

Sanitation. I know it is a big deal and concern for lots of folks. I can't imagine much of an issue thought. Pop it in the carboy while you're sanitizing, right?

 

[kladue]

I opted for the external stationary cooling band for carboys, here is the old thread https://www.homebrewtalk.com/f51/carboy-cooling-system-83916/.