Conical Fermenter Temperature Control

[snowveil]

Conical owners.....

What's the most effective way you've found to control fermentation temps?

I recently purchased a Stout 14 gallon conical fermenter with a thermowell. I pieced together a cheap "jacket" out of some plastic drain hose, a submersible pump, and a 2 gallon cooler that basically recirculates ice water around the fermenter. The problem with this is that the heat being pulled off of the fermenter quickly warms the ice water supply so that while it's effective initially, it's not really a long term solution.

I currently own a fermwrap and STC-1000 temp controller box capable of switching heating/cooling elements.

I've seen crude plans out there for Peltier cooling involving 1-2 aluminum plates with 2-4 peltiers on them that will mount directly to the conical. This would be preferable *if it works well* for a 10-12 gallon batch size. I'd hate to make the investment to find out I can't drop down to the mid-fifties from room temp if I wanted to do a lager. Although, honestly at this point if I could even just get down to a stable 62-65 during active fermentation I'd be happy.

The other option is of course an upright deep freezer. I'd rather not go this route if I can avoid it due to space limitations where I'd like to keep the fermenter. I can if I have to, though...

Any other suggestions out there I'm missing? I could fashion a copper tube "jacketing" the conical and recirculate something through it, but again it would require cooling the source liquid and KEEPING it cool during active fermentation.

Any thoughts/help would be greatly appreciated...as I came home to my kettle sour ramped up to 77 degrees today . Hopefully Sacc Trois won't get too crazy at that temp.

 

[ajdelange]

First be sure your 'jacket' is removing heat from the beer, not the ambient i.e. be sure to surround the hose winding with insulation. Second, try to tighten the coupling between the beer and the water by using a more conductive tubing e.g. copper. Third, replace the ice water and pump with a chiller (an air conditioner whose evaporator absorbs heat from recirculating glycol rather than air). Peltier devices can be used but they have rather low COPs.

Cornelius and others make suitable chillers as part of soft drink dispensing systems. Home brewers have successfully used these to regulate fermenter temperature.

 

[snowveil]

aj,

Thanks for the quick reply.

I do have a spare air conditioner around the house. The plans I'm seeing online involve dismantling the AC unit, submerging the radiator in water or glycol, then recirculating the liquid around the fermenter. is this what you're suggesting?

It sounds like it'd be effective, however the nosie level is really my only concern. I'm not sure if I could get a quieter pump, by my current pond pump is pretty loud.

 

[sandyeggoxj]

I have a diy chiller made with a window mount AC unit. The evaporator coils are submerged in glycol and I have a stc keeping the glycol at 25°f. It works great. It can be done for cheap and it's effective and pretty quiet.

 

[ajdelange]

I do have a spare air conditioner around the house. The plans I'm seeing online involve dismantling the AC unit, submerging the radiator in water or glycol, then recirculating the liquid around the fermenter. is this what you're suggesting?

Not really. If you were to modify a window air conditioner to do what I had in mind you would remove the evaporator (after recovering the refrigerant per EPA regs) and replace it with something like this: https://www.morebeer.com/products/wort-chiller-counterflow-12-fpt-fittings.html
which is AFAIK a repurposed liquid to liquid refrigeration heat exchanger. Refrigerant would flow through the inner tube and glycol through the outer. You'd add a TXV or other metering device to get the evaporation temperature down below freezing and a reservoir to stored the chilled glycol. But this is all a thought experiment. What I really had in mind was picking up an old Cornelius soda fountain kit which is built the way I just described.

Dunking the evaporator from an existing air conditioner in a glycol bath should work if not quite as efficiently as a coaxial heat exchanger if you can get it out of the unit and into the bath without having to open the system. Of course if you have the equipment you can open the system and add extension lines to place the evaporator wherever you want it.