Simple 2 Stage Fermenter Temp Control for Small Studio (Cooler / Peltier / Ice Probe)

I have a small one-room studio. No room for another fridge or chest freezer. Also, I think a water bath is a lot better at controlling temps inside the fermenter anyway. This turned out to be simple but effective:

Better-bottle fermenter sitting in a water bath inside of a 10G Home Depot Cooler. Two stage controller controls an Ice Probe for cooling and an aquarium heater for heating.

The spigot hole was enlarged and an Ice Probe is inserted there (no leaks yet). Inside is an aquarium heater, and little $13 fountain pump to circulate the water bath (turns out it really stratifies if you don't have that). And of course the controller sensor.

Results:
- Heating was no problem in the winter. Not sure what the limit is for a cooling differential, but the second pic is with an active fermentation going on a hot day (82 out/65 in).

- Temp inside the better bottle seems to not be more than 1F off than the water bath temp, even during an active fermentation.

- Small, quiet, great for a small studio apt. Looks ok if you turn it around and try to cover up the ugly home-depot-orange

 

Awesome build.

 

Wow, what a cool project...I went to the site for the chiller but could not find pricing and where to purchase, any chance you could elaborate?

Thanks,
Corey


Sent from my iPad using Home Brew

 

Very nice!

How low can you get the temps?

 

It's called and "Ice Probe" -- I got it on ebay a while back for a bit over $100. Looks like they're available on Amazon for a bit less.

How low? The pic was taken on one of the hotter days so far w/ an active fermentation inside. The cooler was running most but not all of the time.

I'm hoping to do some actual tests at some point.

Note: This was the fast but not the cheap way to do it. I could see a build for less than 1/3 of the money (or less) if you could put the individual parts together yourself. Would love to see someone sell something that you could just bolt on to a Home Depot cooler, cut the hole in the top, plug it in and go...

 

http://www.brewjacket.com/, these guys have what seems to be a real good product....bit pricy though.


Sent from my iPad using Home Brew

 

Do you have any details on the heater and pump? Pics of the interior?

Great build btw


Sent from my iPhone using Home Brew

 

not really -- go to amazon and enter:

50W aquarium heater

Fountain pump

and pick the cheapest one -- both under $15

 

Thanks! I don't see how a fountain pump fits in there though...does it fit between the sides of the carboy and the cooler?


Sent from my iPhone using Home Brew

 

Here's a pic of the inside (I've been away for a while and finally pulled the bottle out). The pvc couplings are just something hollow to keep the bottle elevated inside. The pump just blows water up the side and keeps things circulating.

 

That seems like a really really tight fit, but that last pic obviously shows it works just fine. I just bought the ice probe chiller for my water bath tub last week so i could finally brew during the summer again. You'd think a basement thats fully underground with only one access stairwell wouldn't get to 75F, but it most certainly does! Im finding that during active fermentation the one chiller can't keep up, but im attributing it to the total lack of insulation of my plastic bin.

I really like your solution, but i typically do two batches and need a bath capable of cooling/heating two carboys together. so im searching around for what others have done to figure out the best method of insulating so the one chiller can keep up. If the iceprobe and temp controllers were a lot cheaper id have 2 of what you built though.

 

Chain up a second one w/ the pump pumping from one to the other and then a fairly large piece of tubing siphoning a return.

I actually did this once, but not w/ two active fermentations at the same time.

Not elegant looking but it worked.

 

Since i posted i actually did the nested tub with expanding foam thing to get some better insulation. I have it set at 19.5C and its keeping it within a few tenths of ambient of around 77 so it's managing 8-10F below ambient which is good. Of course im now 3 weeks into fermentation so it only has to fight against room temp rather than primary fermentation.

I was really hoping to get away with only one chiller seeing as they cost over $100, but i think im dealing with too much water volume and headspace in a dual carboy setup for that to be realistic. I can easily fit a second chiller, but i think im going to attempt more insulation and possibly a insulboard foam lid cut out for the airlock before i get a second chiller. Especially since were getting closer to fall and lower temps.

thanks for the suggestions though.