DIY Glycol Chiller?

[Luckbad]

Have any of you had success building a DIY glycol chiller? I'd like to put something together with a fairly large reservoir (at least 5 gallons, preferably more like 10) that can work for now as well as in the future when I step up to a 15 gallon Brewers Hardware jacketed conical.

[Maltose Parrot]

A couple of guys in our club have successfully built something along the lines of this:

https://backdeckbrewing.wordpress.com/2 ... ler-build/

[JonW]

Here's a couple pics of my chiller. Same basic idea as the link Tony posted.

IMG_2801.JPG (556.11 KiB) Viewed 7139 times

IMG_2802.JPG (509.58 KiB) Viewed 7139 times

[Luckbad]

Awesome!

Any chance I can see it in person at some point?

[jward]

I'm using a chest freezer as the glycol tank. It works great.

[Luckbad]

Did you plug to the drain in the freezer and add it directly or is it in something?

[JonW]

Awesome!

Any chance I can see it in person at some point?

Yeah Ryan, I don't have a problem with you coming by to check it out. I'm working from home, so I'm around most of the time. Let me know what works for you.

[jward]

Did you plug to the drain in the freezer and add it directly or is it in something?

Yes, I used the drain plug with a little plumber putty. It works fine as a tank.

[bwarbiany]

OK... Educate me...

I see these glycol systems built with AC units, and I see that John is using a chest freezer for a glycol tank. I don't really want to build something out of a glycol chiller.

Problem is I currently have 4 fridges and I'm running out of freezer space because my kegerator doesn't have a freezer and I can't freeze anything in the fermentation chamber when fermenting. I'd love to buy a chest freezer because of the amount of meat/etc that I buy in bulk, but I'm out of room.

So I'd like to perhaps build a glycol chiller, ditch my fermentation fridge, and replace it with a chest freezer.

My understanding of glycol chilling is that you need a cold reservoir full of glycol/water, and a pump. It seems that a refrigerator or a freezer gives you the ability keep a reservoir cold. Put the reservoir into the fridge [or freezer], hook up some sort of a pump, drill some shanks through the door to connect the tubing, and you're good to go, right?

I see all these builds for AC units or buying very expensive glycol chilling units, and that just seems like overkill if I've got a perfectly good refrigerator/freezer available to me, right?

[ScottK]

I'm interested in the reply to Brad...for the same reasons.

[CurtisG]

Put the reservoir into the fridge [or freezer], hook up some sort of a pump, drill some shanks through the door to connect the tubing, and you're good to go, right?

Unfortunately, as far as I know, this wouldn't work as the fridge/chest freezer won't have enough BTUs of chilling power to keep your bath cold enough. You would recirculate through your conical, warm up your bath and the fridge wouldn't be able to keep up.

[JonW]

Exactly what Curtis said. A glycol reservoir in a chest freezer doesn't have any physical contact with the chiller, so chilling the glycol is done by cold air convection. That is incredibly inefficient. Using the window AC units puts the condensor coil directly in the glycol which cools it VERY efficiently. Your glycol bath can recover much quicker and keep up with the chilling needs.

[ScottK]

Thanks for the explanations!

[jward]

There are lots of variables in play. While it is true that the AC coils in direct contact are very efficient the refrigerant can also freeze your coolant essentially requiring a glycol mix as plain water will freeze on the coils insulating them from cooling your reservoir or even freezing up the recirculating system. I run plain RO water without any glycol at this point. If you use some kind of reservoir in a fridge you can compensate for some of the inefficiency by using a larger reservoir. A fan in the fridge will greatly increase the heat exchange over plain convection. Another factor will be how much cooling do you want to do? Are your batches 5 or 10 gallons? Do you plan to ferment at lager temps or ale temps? Do you plan to cold crash to ~32F? I don't cold crash that low. Fridge BTUs can very. A commercial merchandise that is built to be loaded with room temp beverages for quick cooling will likely have plenty of BTUs and a fan while a dorm fridge not so much. My freezer can chill a 5 gallon batch in the jacketed conical and 10 gallon batch in a sanke with the issue being when one is a lager and the other is an ale. The glycol cool enough for the lager seems too cold for ale and has more much temperature swing then I like even if the beer fermented OK. There is more then one way to skin a cat, depending on the cat....

[bwarbiany]

There are lots of variables in play. While it is true that the AC coils in direct contact are very efficient the refrigerant can also freeze your coolant essentially requiring a glycol mix as plain water will freeze on the coils insulating them from cooling your reservoir or even freezing up the recirculating system. I run plain RO water without any glycol at this point. If you use some kind of reservoir in a fridge you can compensate for some of the inefficiency by using a larger reservoir. A fan in the fridge will greatly increase the heat exchange over plain convection. Another factor will be how much cooling do you want to do? Are your batches 5 or 10 gallons? Do you plan to ferment at lager temps or ale temps? Do you plan to cold crash to ~32F? I don't cold crash that low. Fridge BTUs can very. A commercial merchandise that is built to be loaded with room temp beverages for quick cooling will likely have plenty of BTUs and a fan while a dorm fridge not so much. My freezer can chill a 5 gallon batch in the jacketed conical and 10 gallon batch in a sanke with the issue being when one is a lager and the other is an ale. The glycol cool enough for the lager seems too cold for ale and has more much temperature swing then I like even if the beer fermented OK. There is more then one way to skin a cat, depending on the cat....

Interesting... I wonder if plain [RO] water in a fridge in a 6G bucket with a fan circulating in the fridge would be enough thermal mass to chill a 10 gal keg outside the fridge in SoCal summer temps... At least to ale ferment temperatures around 65 degrees? I suppose I could then even use softer bendable copper tubing like folks used to do with homemade immersion chillers...

I could even use a simple submersible pump... I'm not sure whether that works very well with glycol solutions.

John, you say you use a full chest freezer as your tank? I assume you have some sort of a temp controller on it so that it doesn't actually freeze all that RO water solid, right?