Which chiller liquid?

I bought a 150l chest freezer to contain liquid, which I'll use through my Chiller.
I will pre-chill with tap water, but then switch to the chest freezer, using a pond pump to move the liquid through the chiller.
The night before a brew, I will turn on the freezer on and cool the liquid to around 0C - I reckon the pond pump could probably cope with that.
The aim is to get quickly and easily to lager pitching temps.

Question: What should the liquid be, assuming I have a reliable seperation of the wort and coolant paths? Water, glycol, oil

(I am thinking that thermal mass, given finite volume, would give me the maximum cooling potential.)

??

What about antifreeze? Then you can crank that freezer down as far as it will go. Of course make sure all connections are FAR away from your beer so there is no chance of any getting in there.

What about antifreeze? Then you can crank that freezer down as far as it will go. Of course make sure all connections are FAR away from your beer so there is no chance of any getting in there.

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I agree. This is probably the most efficient. Also, there is stuff on the market that is not lethal. Finally, we use to have to add glycol to some closed systems where I use to work. There was a cheapo dye that we put in it and if it ever leaked, it was easy to spot. I'm sure someone on here knows what it is. You could use brine, it would stand a little lower temp and if it leaked into your beer, somehow, you could just add more lime and say it is Miller Chill! Luck - Dwain

I think you'd be better off using it to make a large volume of ice. Fashion yourself a large ice tray to make like 50 pounds of ice at a time, add water and pump that. It's a way to ensure no chemicals near your brew. You can use propylene glycol to lower the freezing point, but it's not cheap. It's less toxic than ethylene glycol though.

They do make a less toxic automotive antifreeze. You can pick it up at any auto parts store. As far as the dye goes, they also make UV dye for the antifreeze. Of course you would have to hit the wort with UV light to see if the dye leaked. No clue if that would work or not, might take some testing. As long as the connections are away from the wort I don't see any reason not to use antifreeze.

SIERRA Antifreeze Home Page These guys make the antifreeze I referred to.

How about RV antifreeze? It's non-toxic. We use it every year to winterize our camper.

https://www.homebrewtalk.com/f51/temperature-controlled-fermentation-81596/

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If you use an antifreeze, you'd be better off dropping the temp well below 0C. If you're just going down to 0, it would be better to make ice because it will have more cooling power (highly technical term) than a liquid at 0C. Is the fear about overchilling the pump impeller? I wonder how cold you can go before it's a problem.

why not just a salt water solution. would be safe to drink if you came up with a leak.

Saltwater has a much lower freezing point (the freezing point is the temperature where something freezes) than freshwater does. And the more salt there is in it, the lower the freezing point gets. So in order to know the exact temperature that it’s going to freeze, you have to know just how salty it is. For saltwater that’s as saturated as it can possibly get (i.e. there’s no way to dissolve any more salt in it no matter how hard you tried), the freezing point is -21.1 degrees Celsius. This is when the saltwater is 23.3% salt (by weight).

saltwater is highly corrosive

So is propylene glycol though. Which one is worse?

i would have a large fear of pump something poisonous and sweet through something thats sweet. i dunno just me.

chris1979 said:

i would have a large fear of pump something poisinous and sweet thorugh something thats sweet. i dunno just me.

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If it's contained and non-toxic the what is the problem? Sure, there is a possibility it could leak into the wort, but only if the system is not leak tested properly. I think using the RV non-toxic antifreeze and cranking the temp down all the way in the freezer would work great.

I dunno. I am kinda curious if the freezer walls could even stand the pressures of that volume of liquid trying to find a way out. I'd expect the insulation to compress, the seams to open up (even if they were silicone seald) and a big mess to explain.

A recent BYO (or was it Zymurgy) did an DIY for a glycol chiller using a picnic cooler for the glycol, then they set the coil isnide the solution. I think they basically gutted a dorm fridge (maybe a window unit) for the main parts and modded it from there. IIRC, from there they just used a submersible pod pump to move the chilled glycol.

i agree it would work great i was just looking murphies' law and that would be a high price to pay for a failure. i personally would feel better using something that wouldnt hurt in any concentration or just pump ice water through it from a cooler (thats what i do and it works great)

Yes, my main concern about going below 0C is that the pump wouldn't handle it well. Its a nominal value, since as long as it was asked to pump liquid, who knows at what temp exactly it would suffer.
Given that 0C is the restriction, are we saying that water has the highest thermal mass?

That said, pouring water over premaid ice and then pumping that water around is probably the best way of cramming as much cooling capacity as possible into the unit - as Bobby M suggest.
Takes care of the toxicity issue.
I guess the issue of mechanical strength is one I will have to find out the hard way - since the ice will all probably be water by the time the chilling is done.

(PS. I have silicon sealed the seems on the inside.)

Brewpastor is doing it with problem for fermentation control so it looks like the chest freezer can handle it. I might want to smear some silicone on the seems though.

If you're going to try it, go ahead and run it at -10C and see if the pump can do it. What's the worst that can happen? I'd also want to run the output of the chiller into a temporary holding vessel so that you don't dilute the cold glycol/water with heat.

I wonder what the freezing point of cheap vodka is? That way if you had a leak it wouldn't kill you! And, if it's a small leak, wouldn't totally ruin the beer.

Hi,

May I suggest another solution?

You could instedad bury a large(er) watertank outside, and use that water for cooling. The temperature, depending on where you live and how often you brew, should be around 5 degrees Celsius. The easliy achieved larger volume, would compensate for the higher temperature.

This is something I am considering myself,...
walther

The problem with -10 is that when you begin re-circ of the cooling liquid, you run the risk of freezing the wort in the chiller exit, though running it non-counter-flow might solve that. May be worth a try, the pump wasn't that expensive.

Might have to straight jacket teh freezer with gaffer tape to keep it from exploding.

Too warm here in Melbourne for burying a tank, and anyway, sounds a little too hardcore to get a wort cooled for me.

How cheap is cheap vodka in the States? Wouldn't be so cheap here given taxes ( $15-20 US a bottle!).

I guess we never discussed what kind of chiller. I had assumed IC.

coming from some with an automotive a/c background why couldnt one just find and old window unit and turn an a chiller in the evaporator. you drop a thermostat in the wort and chill to desire temp. ought to at least save on the water bill and the very least have a super cool factor. the high side pressure on an r-134a vehicle maxes around 300 so some stainless braid brake hose should handle that for a flexible connection. just dont know what the high side would do with the chiller in 200+ degree wort. i think i smell a project for myself.

chris1979 said:

coming from some with an automotive a/c background why couldnt one just find and old window unit and turn an a chiller in the evaporator. you drop a thermostat in the wort and chill to desire temp. ought to at least save on the water bill and the very least have a super cool factor. the high side pressure on an r-134a vehicle maxes around 300 so some stainless braid brake hose should handle that for a flexible connection. just dont know what the high side would do with the chiller in 200+ degree wort. i think i smell a project for myself.

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Pretty sure this is what they did in the BYO/Zymurgy article I referenced above.

It has cool factor for sure but the amount of money saved from your water bill would be obliterated by the cost of electricity to run the compressor. Neither amount is life changing, but 50 gallons of chilling water is like 27 cents.

i saw that article i talking about something differant doing away with the picnic cooler and building a chiller out of a/c tubing and putting it straight into the wort. not a passive cooling system so to speak it would be direct ought to be more efficient anyways. but like i said would to experiment would probaly spike the high to dangerous levels.

Now that would be very cool, but I wonder what the cooling rate would be?
Can you roughly calculate that to see if it is theoretically anywhere near 30 or so minutes.
(The thermal mass of the liquid reservoir - banked overnight, and drawn on during the day - is my way of cooling quickly - the freezer wouldn't keep up 'live', so I'm not sure an AC would do much better would it??

would need someone to figure out the btu's contained in 210 wort and figure from but i suck at math.

Is anyone aware of the expense of running an a/c powered glycol chiller?

Assuming there is about 31 gallons of glycol to be cooled to sub zero with a 15000 BTU air conditioner.

Anyone consider placing water containers with copper heat exchange loops inside the freezer, it would cut down the glycol volume to what was needed in the circulating loop but require a cloosed loop circulating pump. With ice banking the freezer could be fired a day ahead or be left on to maintain ice bank, and ice mass would act as a thermal flywheel during chilling. One caution would be to make the copper coils vertical and make the return bends above the water surface to allow for ice expansion without destroying tubing.

Kladue, I can't really picture this. Can you scan in a quick sketch of the rought concept and attach?

I am guessing at the interior dimensions of the freezer, but came up with a possible method using 4" PVC pipe capped on bottom. The approach was to fabricate 4" pipes and install 4 -5/8" od equally spaced copper loops inside pipe and fill with water to within 1" of return elbows on top. If the guessed at dimensions are correct then you could fit about 14 -32" pvc pipes and 4 22" pipes in chamber and connect copper to flow through all of the pipes in series.
some assumptions on loads and capcaities.

10 gallon batch size, 84.5 Lbs liquid
212 degree boil to 60 degrees, 152 degree delta
cooling needed 84.5 Lbs X 152 delta = 12,844 btu's
Btu's to melt 1 Lb ice = 144
4" Dia X 30" icecube with copper coil = Net 13.46 Lb ice, 1938 Btu's
4"Dia X 20" icecube with copper coil = Net 8.92 Lb ice, 1285 Btu's
Possible loading of freezer might be 14 -32" containers + 4 22" containers 32,272 Btu's possible.
The unknown is the efficiency of the ice melt and water temperature rise in pipes, but running the liquid coolant through the pipes in series might work. It would be prudent to build one pipe and test it to observe performence or lack of before building a larger system. The freezing water should grow verticaly in the tubes and not burst the sides, if one is concerned about that a strip of the 1/8" closed cell packing material taped to the inside of pipe should compress enough to prevent bursting.

That's a very good idea. As you say, would need some testing - particularly as ice expands about 9% upon freezing. I'm wondering what other material would serve instead of the PVC, and would allow for some expansion.(?)

With your BTU calculations:
I imagine that ice at -10C has greater cooling capacity than ice at around 0C. Were your calcs based on 0C?
From your calcs, it seems getting down to lager pitching temp would be quite possible.

Once more, my main concern is that the pump would be able to handle coolant much below zero.
But perhaps I've missed your point, is it ice at about 0C that you are suggesting and making your calcs upon?

I was trying to be conservative as only the heat absorbed during melting of the ice was used, the temperature below 0C, and the temperature rise of the water liberated during melting was not included. The container is not that important but thought that the easiest to build and place inside the freezer would be 4"(100MM) pipe used for drainage. If the ice is allowed to grow verticaly the pipe should survive the experience. One thing that was not calculated was the pressure drop through the inner tubing when circulating coolant, might need to make paralell loops to limit pressure drop instead of one long series loop.

I believe I will try this.
I'll let you know how it goes.

As for the pressure drop - I wonder if this is actually an issue, as it would probably mean a bit of suction leading back to the pump and giving it a little help for a moment.
Cheers.

Have you been monitoring the diy peristaltic pump build? Your suggestions would be very helpful.

My experience with peristaltic pumps is limited to the small displacement types used to move reagents in instrumentation, this large displacement pump system looks interesting. There are few options for self priming pumps for brewing and this method looks interesting if the tubing can hold up under the rollers without splitting or remaining flat under suction. Currently assisting Beerthirty with his build and have incorporated some automatic air vents in the pump piping to see if he can overcome the priming problems and be able to operate his system automaticaly with the brewtroller. When the wet testing is finished he can let folks know how the experiment with his new system has worked out, hopefully it will deal with the march pump priming issues.

Sugar water has similar properties as salt water when it comes to the freezing and boiling points. And if it gets in your wort, you just get a slightly dryer beer.

Instead of using air vents, for my brewtroller build, I am dedicating a valve on the outlet side of the pump as an inlet for mains water. I will be back-flushing the pickup tubes of the tuns to expel air bubbles and allow the pump to prime. This will be part of the session setup, but also between batch sparges.
But that's another thread, I think i'll post on that forum.

Got a chance to prove the concept:
Allow about 10% of the length of the pipe for expansion.
The pipe will not burst.
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