Glycol vs Water for line cooling

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

BSBrewer

Well-Known Member
Joined
Jan 12, 2010
Messages
344
Reaction score
3
Location
Bergen County, NJ
Ok - so I am not one to cheap out or half ass anything but I don't really have the $$ in the budget right now to get a glycol pump for my system. I want to do a pond pump with a glycol pool but it appears as if a number of inexpensive pond pumps cant handle the glycol.

Other than having a lower freezing point what is the advantage of using glycol instead of just having water going through my trunk line to cool the beer. Does anyone just use water instead of glycol or can recommend a pond pump that can hold up in the glycol bath?
 
I've been reading about glycol coolers too and have wondered about using a salt aolution instead. I pulled this from a wikipedia article:

At a concentration of 23.3%, the freezing point of NaCl brine is lowered to −21°C (252.15 K, −6°F)[

Seems like you'd get a pretty good safety zone, if you want to use this for lagering temps without having to worry about your lines freezing (compared to pure water). Seems like if aquarium equipment can withstand salt water, then it should be able to pull this off too. Of course, if you're using something like AC coils to cool the solution, it may not like the salt.

This is my completely unscientific opinion, though.
 
Well, if you're planning to put the cooling liquid reservoir in the same cabinet as your beer, you're obviously not going to worry about lowering the freezing point of the coolant. Water is fine.
 
Yes - doing a Keezer build (actually inspired by your youtube vid) and figured I'd put my pump and reserve in there.

Any chance you would know how to size a pump for my system? I am running approx 25' of trunk line with 5/16" poly for the coolant -

Opt 1 : will rise 23" - run horizontal 36" - drop 44" - run 16 ft - rise 48" - 5 x 90 deg bends

Opt 2 : rise 23" - run horizontal 16' - rise 16" - 3 x 90 deg bends

Don't have any clue as to what size pump I need - do I need like pond pump that does 210gph (7' lift max) or 325gph (12' lift max) - or is that going to have the stuff shooting out everywhere. Will an aquarium pump be enough?

Any guidance would be INCREDIBLY helpful!

On a side note I met two of the guys you may know from the Whales club - they were up at the Northern NJ brew club on Tuesday night - Gary and ??? (names aren't my forte) - they brought the group brew you guys aged in the apple jack barrel - kudos if you had any part of it.
 
I had a similar question earlier this year. The point somebody brought up that hit home with me was that having at least "some" alcohol in the system will keep mold and other unwanteds out. I don't want to have to clean it as often as the tap lines (even a closed system can get infected).
 
While you could call glycol an alcohol (it's actually two attached to each other), I'm not sure about it's anti-microbial, biotic, whatever properties. You could just as easily use a Tbs or so of bleach in water to the same effect.

The only advantage of glycol cooling is that you can drop the glycol down below 32F without any worries. I'm not sure what the most popular glycol is for brewing, but a 50/50 mix of ethylene glycol and water has a freezing point of -45F or so. That's lower than any freezer goes. A 50/50 mix actually has a lower heat capacity than water (0.8 BTU/(lb*F) vs. 1.0 BTU/(lb*F) for water), which means that you'll need both more glycol as well as a high flowrate of glycol than water to give the same rate of cooling for your wort.

I've seen brine solutions mentioned here in the past, my problem with using a brine solution would be solids formation. You have to be pretty careful that you keep the concentrations correct. Too little salt and your water will freeze, too much salt and you run the risk of solids precipitating out of solution. With glycol, the margin is much greater (a 20% ethylene glycol solution freezes at around 10F, an 80% glycol solution freezes at around -45F)

The moral of the story is; if you don't intend to cool your "cold liquid" below freezing, there's not much point in using anything but water IMHO.
 
What about RV antifreeze? The kind they use in the sink drains and toilets. It's cheap and supposed to be non-toxic.
 
did a test run with a 425gph pond pump from lowes yesterday - comes through my 3/8" cooling line with no issues - test was with water but the final build I am going with the RV coolant
 
Opt 1 : will rise 23" - run horizontal 36" - drop 44" - run 16 ft - rise 48" - 5 x 90 deg bends

Opt 2 : rise 23" - run horizontal 16' - rise 16" - 3 x 90 deg bends
.

Just a note here, but if the output of the lines is submerged, you have a closed loop system, and the height of rise is pretty much irrelevant (other than the initial filling of the system). Only the total length of tubing, diameter, and restrictive fittings matter.
 
Just a note here, but if the output of the lines is submerged, you have a closed loop system, and the height of rise is pretty much irrelevant (other than the initial filling of the system). Only the total length of tubing, diameter, and restrictive fittings matter.

Where were you when I was trying to figure this all out? Thanks for the note - I just strung my test run of tubing up as high as the highest point and let her rip though I think just to decrease the length of the line I am going to run at the collar height vs all the drops/rises.

Thanks again for the input though! :mug:
 
FYI- Check and change the rv anti-freeze, other glycol based liquids every so often-- they gum up over time and the film is hard to clean from lines once deposited....
 
FYI- Check and change the rv anti-freeze, other glycol based liquids every so often-- they gum up over time and the film is hard to clean from lines once deposited....

I had seen somewhere they recommended yearly for glycol - should I go more frequently than this or is once a year sufficient?
 
rv anti-freeze is glycol... so imagine every year is probably fine. It's cheap so i get around to it every six months or so now... i had to change the cooling lines and it gummed up my plate chiller i had in a freezer. PITA.

I used some lengths of copper too 'cause it transfers cold so well but I don't recommend that-- use all plastic and/or stainless instead-- the glycol eats up copper enough to turn glycol bath green! Just insulate the whole thing well it will keep the lines cold.
 
What did you wind up using for a pump?
I bought a Maxi-Jet 1200 for mine. It's tiny, it was $20, and is the only one I found that actually said it doesn't have to be submerged. Plus it's 300GPH, which in practice gives me a 15 second re-circ time.

Can you toss up some pics? I'd like to see how you are building the system!
Here's mine...
 
Any aquarium pump will work-- but maxi jets are great because they last. dr foster and smith .com is good source for that stuff.
 
I was going to buy a Rio. They look more solid, and not much more $$, and threaded input and output! But the instructions say they must be submerged. Bummer.
I'm happy with the Maxi-Jet. It'll do just fine.
 
Maxi jet is ten times better then any Rio! Owned a dozen maxi's and few rio's. By far none the most reliable small water pump.

another hobby of mine--- www.reefcentral.com
 
I went with the 425gph tetra pump from lowes - it was like $45-50 and pumps through my 60' test run of 3/8" poly no prob
 
the biggest maxis are only like 225 gph i think-- they're little guys-- but nice... so if you 60 feet of coolant lines the tetra was a better choice for sure...
 
The RV antifreeze (the red stuff) is Propylene Glycol, while car antifreeze (the green stuff) is Ethylene Glycol. They are color coded so they do not get confused with one another. What you really want is food grade PG, as it is

Propylene Glycol is actually a better at heat transfer then Ethylene Glycol but can not be cooled down as much. It is also thicker, which will increase head pressure on the pump. Additionally Ethylene Glycol is highly toxic and even a tiny bit leaking can kill you. I would HIGHLY suggest you stay away from Ethylene Glycol is a coolant.

You can also make the glycol thinner by adding water. A mixture of 2/3 water to 1/3 PG will be liquid at just above +1F. Of course the less water you mix in the lower the temp can go. But since we are talking about beer I can not really see needing to make it any colder then 32F let alone 1F.
 
Back
Top