Optimum Glycol Ratio %

[*hop*cone*]

I have inherited a chest freezer for Nada,

What is the correct Glycol Water percentage to run in the freezer?

What temperature is the optimum to have the glycol at?

I am planning to either seal the freezer up with sealant and run the glycol in the cab of the freezer. Or is it more benifitial to run a container in the freezer and a small swampy pump (evap cooler pump) Cost $45 30 LPM magnetic drive and can be restricted no probs. I plan to slow it down to faccilitate efficient cooling.

I have searched this site for a ratio but to no avail. Lots of good info was found on the hard ware, but all I know is that squire tried 5 Litres of glycol in 70 L of water and it formed an Ice bank. I want to avoid this at all costs. I think the swampy pump would crap itself.

Loads of Questions I know, Maybe we can Airlock the thread for future reference.

Thanks,

HC

 

[wessmith]

HC, you need 30% propylene glycol. You may get away with 20% but I would suggest a "suck it and see" approach. Most commercial systems run at -1 to -3C using 30% glycol.

Wes

 

[Wortgames]

HopCone, what is it you plan to actually do with the chilled glycol?

I used to run pre-mixed car antifreeze from a bucket in the freezer compartment of an upright, through to my bar and through a flooded font. The antifreeze never froze, but the freezer compartment became clogged up frequently with (presumably) water vapour that left the mixture for the drier air around it.

If this is what you plan to do, I would say that the best way to do it would be a sealed system - for example, a spare corny keg dedicated to the glycol. This would give you a good 'reserve' volume of properly chilled glycol to circulate.

Apologies if I've got the wrong end of the stick here.

 

[*hop*cone*]

HopCone, what is it you plan to actually do with the chilled glycol?

I Plan to chill a 4 way flooded font.

The antifreeze never froze, but the freezer compartment became clogged up frequently with (presumably) water vapour that left the mixture for the drier air around it.

I had a feeling it may separate as this has explained.

If this is what you plan to do, I would say that the best way to do it would be a sealed system - for example, a spare corny keg dedicated to the glycol. This would give you a good 'reserve' volume of properly chilled glycol to circulate.

So I take it that a large quantity is not really needed. But is 18 litres enough at 30% to chill four taps and Ice up the font?

HC, you need 30% propylene glycol. You may get away with 20% but I would suggest a "suck it and see" approach. Most commercial systems run at -1 to -3C using 30% glycol.

Wes

I was thinking around minus 10 in the freezer, oops. So is the temperature effected by the distance tavelled? I was planning to locate the freezer well away from the bar and insulate the pipes with lagging. I think a brizzy brew fridge mate would keep the temp correct in the vessel of glycol. Would that be ok?

Thanks,

HC

 

[Wortgames]

Hi HC,

As a reference point, I used a submerged fountain pump, rated at 450L per hour, in about 10L of antifreeze in the top freezer compartment of an upright fridge-freezer. I had probably about 2m of line each way to and from the base of the font, with no real head other than the height of the font itself. It was a standard 4-tap font, and the bundle of lines was half-assedly lagged with normal pipe lagging.

I never got ice, but had condensation 24/7, and it certainly helped me pour a decent beer.

18 litres of antifreeze in a 'better' freezer, at the right temp (trial and error) would stand a pretty good chance of frosting up nicely I would reckon.

 

[Darren]

Hey Hops, anyone?

I must have asked this question before, but does propylene glycol corrode copper?

If it does, I would recommend ensuring that the "coil" in your chiller is made of stainless.


cheers

Darren

 

[Sammus]

I would assume that if commercial systems (in a pub, for example) run glycol to chill their fonts, andale and lancer pacific and whoever else makes flooded fonts that all the pubs use wouldnt make it from something the glycol would corrode... just a thought. I think its brass anyway, and im still interested to know, is glycol corrosive to copper? If it is in hinders a certain project I've been thinking about that involves redirecting glycol flow from my font temporarily to chill wort and other liquids...

And can you confirm its propylene glycol? For some reason I assumed it was ethylene glycol (I think thats what they use in cars...)

 

[*hop*cone*]

Hi HC,

As a reference point, I used a submerged fountain pump, rated at 450L per hour, in about 10L of antifreeze ...... I never got ice, but had condensation 24/7, and it certainly helped me pour a decent beer.

18 litres of antifreeze in a 'better' freezer, at the right temp (trial and error) would stand a pretty good chance of frosting up nicely I would reckon.

I think that your system is fine, maybe slow it down a tad.

I have been thinking about this today and have come to the conclusion that if you slow down the rate of replacement of the glycol it will enable the glycol to keep a more constant temperature. I spoke to a fridgie a long time ago and he was of the opinion that the slower the better. He quoted 6 liters a minute replacement. So I was thinking about using 40 liters of glycol/ water mix at around 30% as suggested and experiment with the replacement rate of the glycol in the tank. I may experiment with the return tube also, I would like to aggitate the glycol some how to get a more unform temperature within the glycol mix.

I am only formulating ideas off the cuff so to speak. Can anyone add some experiences?

HC

 

[Darren]

Hey,
I realise it doesn't corrode quickly but does it corrode over time (say 5-10 years)? If it does you would want to be aware of it, otherwise one night you might be drinking propylene glycol mixer.


cheers

Darren

(PS, my radiator fluid never really looks that clean. Is it the iron in the system rather than the copper?)

 

[Sammus]

wiki http://en.wikipedia.org/wiki/Anti-freeze implies that either glycol isn't corrosive, since its used as an anti corrosive. If you mix differently engineered antifreeze solutions (like newer OAT antifreezes) with older styles they form an acid that will corrode various metals, so beware of that I guess. Apart from that it seems safe anywho...

 

[*hop*cone*]

I think it is worth buying the food grade glycol to avoid me growing a third head if anything should go wrong

 

[Darren]

wiki http://en.wikipedia.org/wiki/Anti-freeze implies that either glycol isn't corrosive, since its used as an anti corrosive. If you mix differently engineered antifreeze solutions (like newer OAT antifreezes) with older styles they form an acid that will corrode various metals, so beware of that I guess. Apart from that it seems safe anywho...

Sammus,

Thanks. I guess mixing with good clean water would also be appropriate especially if one opted for the cheap radiator versions.

All the metal/salts in tap water probably do not help the anti-corrosive properties of propylene glycol.

I always imagine that its a bit like rust. Once it starts it is almost impossible to stop.

Then again slow release, copper infused beer, might be good for you.

Also, how do you clean the copper bugger? What if you passed some infected (Lactobacillus etc) beer through the lines?

Is copper chill common in pubs? All the "pub coils" I have seen were stainless!

cheers

Darren