Home-Built Glycol Chiller

[JAReeves]

Greetings!

So I am using my home-built glycol chiller for cooling wort to pitch temperature, temperature control during fermentation, and now for the first time, cold-crashing before transfer to the keg.

It is a 5,000BTU window A/C unit with a cooler that is holding 7.5G of solution, 5G distilled H2O and 2.5G Food-Grade Glycol.

Normally, the A/C runs seldomly, as I keep it at 50F in order to keep an ale at 65F for pitch and fermentation.

Yesterday, I set it up for the cold crash at 40F. The A/C ran off and on all night, the pump for cooling ran all night, and the temp on the beer was only down to 45F.

For those of you more technically astute than I, is 40F a pipe dream? Is it not feasible given the equipment that I am using? Is there something else I should be doing to drop the temperature more between the glycol temp setup and the fermenter itself? The garage itself dropped to about 50F overnight.

I am hoping to run 3 fermenters in the 60F's regularly, maybe one lager at 50F on occasion, but was still hoping to cold-crash/lager at 40F or below.

Any advice or help is appreciated.

Here is the fermenter with the CO2-filled balloon as the beer cold crashes. I had to refill it at 50F, and it still has some pressure in it still. The second picture is the glycol system.

 

[JAReeves]

I did some research and Probrewer website had a chart that was very useful,

Everything you wanted to know about glycol

I am going to try setting it at 25F and see what it does, then maybe 20F, if I am not happy.

 

[Bobby_M]

The ambitious part is really the coil that Anvil uses. I just don't think it has the surface area for an under 40F crash (though ambient temps have a big part in it). It looks like you have a 48qt cooler there and if you only fill it to 7.5 gallons, about 25% of that coil may be exposed and freeze up in the air space. You can definitely get a smaller cooler (taller and skinnier). When you say "cool wort down to pitching temps", do you mean all the way from boiling? Don't do that. You'll kill that compressor.

The last topic we should discuss is where is the probe for controlling the temperature of the glycol bath itself. There needs to be another controller that is just handling the AC unit on/off based on the glycol temp. The probe for that should be in the bath but not directly touching the coil. You'll also get less cycling if you have low flow pump that is constantly stirring.

 

[JAReeves]

Ok, I was looking at a more vertical cooler, but this was the one that was free in the garage when I was doing the build. If I remember correctly, 25-33% of the vanes on the chilling side are exposed to air, not immersed in fluid.

The A/C unit has a separate temp controller in the cooler, and the glycol returns are all pointed at the cooling coils.

I didn’t think about the anvil cools not having enough surface area, but that might be the major limitation.

I don’t use it to cool the boil, I have a plate chiller that brings it down to below 80F, then the cooling system does the rest.

I may just have to be happy with 45F being as cold as it gets in my fermenters, until the next tech upgrade. Homebrewing is a blast of a journey to be on!

Thank you for your advice!

Reevesie