Immersion cooling coil for open fermentor - converted AC?

[Gadjobrinus]

I have a coolbot that can run a large AC down to really low temps. I've decided to ferment inside, in my former cheese cave (this is what I did when making alpine cheeses, used the coolbot).

Problem is, the air coming through the AC is anything but sterile and I fear just getting nasty open ferments, so I'm thinking of an ice-water or glycol system as I've seen, but with an internal attemperator of some sort immersed in the open fermentor. I currently use an Inkbird to heat the room to 65 with a small ceramic heater, and it works great. Just need something to cool in the coming months.

I don't have a clue how to do any of this. Can anyone suggest a starting point, or perhaps even a "so and so did exactly that" that they might know?

Many thanks.

 

[mirthfuldragon]

Two different thoughts:

(a) What level of "open" fermentation are you thinking (sanitized foil for zero pressure fermentation, or a coolship, or somewhere in between?), where an immersion chiller would be fine but a cold room would not be? I am having trouble visualizing the setup.

(b) What temperature range are you looking for, v. what room temperature range are you expecting? I use a water bath and an aquarium heater to warm my Belgians and saisons, and in a rubbermaid tub during the winter, the undisturbed water holds a steady 58-60° in my finished basement, which is ~10° below ambient air temperature. YMMV, but you may not need anything to actually chill and hold temperatures.

 

[mongoose33]

Do you have a pic that can show what you're trying to do?

I'm confused about something. My understanding of open fermentation was that whatever is floating around can drop into the wort, and then do its thing, whatever it is. If that's not correct, I'm open to learning more!

But if that is true, then why would you be concerned about nonsterile air? Help me understand better what you're trying to do.

 

[Gadjobrinus]

Hi guys - sorry for the late reply. I haven't got a pic of just the room, but it's in the basement, and it's very basic. It was my cheese aging cave, actually, so envision a huge window AC in the corner of one wall, hooked up to a coolbot, and...that's it. A room with decently washable surfaces. The inkbird right now controls the small ceramic heater and it works great - brings it up to 65 from 55 with no problem.

I'll be using my MLT, actually, which is about ideal in that it's a 1:1 aspect ratio, close to it. Completely open. The fermentation profile would be: pitch at 60F, free rise to 67, maintain till 1.5-2P above terminal, begin dropping to 50F over 3 days. Rack to a sanke for dry hop x 4 days at 50F, rack to conditioning vessel and hold for several days. Cask, bottle condition, or force carb and keg/CPF bottling.

The issue I'm going to have is if I want to step temps down to 50, in the open fermentor. I'm hoping the room is relatively draft free and it should be, and so I'm not too concerned about open fermentation there, anymore than I would be in a low-traffic area of the house. However, once the AC kicks on, I'm concerned that all the little crap and bugs entrapped in the grills will now be blown all over the place (with violence!), which is why I'm thinking on a controlled attemperator solution. If I had a way to cool the room without an AC, I'd leap to that. I'm even thinking of ice blocks, with the heater fighting their cooling effect to maintain desired temps.

Guys, have I answered your questions/am I making sense? Please let me know if not, and I'll grab a pic or two and try to answer better what I'm talking about it.