# Direct Glycol Cooling Solution



## Goose (3/5/13)

I've long been envious at how fast some of the craftbreweries I have visited can crash cool freshly boiled wort down to pitching temperatures so I thought I'd share some number crunching I did to look at the feasibility of a direct cooling system for crashing wort down to lager temperatures.

My dream was a machine that I could plug into a wall socket, pump in 100 deg c wort and have it come out at 12 dec C. Right now I am using a shedload of ice in a water bath that I recirculate though a plate chiller, it works, but I do need literally a shedload of ice to cool 50 litres of wort down which is a right pain.

So I figured surely a glycol chiller could do the trick. have seen these on the Morebeer site. The question is, could it work asuming I could spend the kind of cash they want for one of these units.

So lets say I have 50 litres of wort I need to cool to 12 deg C. Amount of heat I have to remove is Cv*W*Dt where:

Cv = heat capacity of wort (water is 4.18 Kj/Kg.K , close enough)
W = weight of wort (use 1.0 Kg/Kg, or 50 Kg close enough)
Dt = change in temperature (looking at 100 to 12 ie 88 deg C)

so this equates to 4.18*50*88 =18392 KJ of heat I need to pull out.

say I want to do this in 1/2 hour, or 1800 s, rate of heat removal I need is 18392/1800 = 10.2 Kj/s or 10 KW.

now, my single phase electricity supply is fused at 13A and is 240V, maximum power draw from our trusty P=V*I equation is 3.12 KW. ! OMG, nowhere near enough, even at 100% efficiency could I cool down 50 litres of wort in 1/2 hour.

So, again if I assume 100% efficiencey and 3 KW rate of hear extraction, it would take me 18392/3/3600 or 1.7 hours to cool.... which is madness.

So conclusion is, it cant be done unless I want to spend a bomb on a glycol chiller and wait nearly 2 hours for wort to cool.... :wacko:

What rapid cooling solutions do you guys have ?


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## Phoney (3/5/13)

Have you considered hiring a cylinder of liquid nitrogen and pumping that through your plate chiller?

We have one at work approx 2m in diameter, and 6m high. I've watched folks pour it into smaller cylinders, the shit is freakin cold! It can't be that expensive given plumbers use it to freeze pipes and block water flow while they carry out repairs.


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## GalBrew (3/5/13)

Liquid nitrogen can be reasonably dangerous though, I work with it quite a bit. Not sure how well your plate chiller would survive the rapid freeze-thaw cycles also. I would consider using dry ice before liquid N2 (outside of course). I have heard that using a whirlpool immersion chiller first and then pumping the beer through a plate chiller can work quite well also. I plan to implement this on my new build, but can't comment on its effectiveness ATM.


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## Truman42 (3/5/13)

Im envious of a lot of things that craft breweries have that I dont, stainless conical fermenters, 1000 litre bright beer tanks, hot chicks working their bars..etc...But they are spending money to make money

Whats the hurry anyway? With a craft brewery time is money. With a homebrewer its not.

I run the wort through my chiller and in summer its chilled to around 32-35C. So I put it in my fermentation fridge and pitch the next day. In winter it chills to 25C so i usually pitch after transfer. i certainly wouldnt want to spend shit loads of money on a glycol system just so I can pitch 12 hours earlier.


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## GalBrew (3/5/13)

That being said, you could just cross over to the dark side and no-chill........ :beerbang:


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## donburke (3/5/13)

liquid nitrogen can snap metal and fittings, I don't think its practical for a homebrewer

I use my glycol chiller to cool my wort down

I chill approx. 85 litres of wort using tap water, takes approx. an hour to chill to 25 - 30 degrees

I then divert the tap water through the product lines of the glycol chiller, which prechills the water before it enters my immersion chiller, takes another 15 min or so to get to 18 deg and say another 15 - 30 mins to get to 12'ish deg

my glycol chiller has a 20 litre tank and usually sits at around -2 to -3 deg

when i start to pump tap water through, it starts to rise, and I try to regulate flow to that the glycol bath doesn't exceed 7 or 8 degrees, that way the compressor can keep up

i'm keen to hear of any other methods in rapid chilling as at times the 1.5 hour wait can be tedious


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## Goose (3/5/13)

Truman said:


> Im envious of a lot of things that craft breweries have that I dont, stainless conical fermenters, 1000 litre bright beer tanks, hot chicks working their bars..etc...But they are spending money to make money
> 
> Whats the hurry anyway? With a craft brewery time is money. With a homebrewer its not.
> 
> I run the wort through my chiller and in summer its chilled to around 32-35C. So I put it in my fermentation fridge and pitch the next day. In winter it chills to 25C so i usually pitch after transfer.  i certainly wouldnt want to spend shit loads of money on a glycol system just so I can pitch 12 hours earlier.



Are you not concerned about wort oxidation ? I understand its ok for the no-chillers because they have zero airspace in their cubes while they wait for them to cool ?


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## donburke (3/5/13)

did have a thought for a somewhat inexpensive method, providing you have the room, which I don't otherwise I would have tried it

chest freezer set to 1 degree filled with 300 or 400L of water can be turned on a couple of days before brewing and pumped through the chiller, there is a fair bit of cooling power in that volume,

or better still, 30-40% glycol solution will let you get the temp down to -18 which is what a deep freeze can sit at

might need a few days to get there


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## donburke (3/5/13)

Goose said:


> Are you not concerned about wort oxidation ? I understand its ok for the no-chillers because they have zero airspace in their cubes while they wait for them to cool ?


also the risk of your non inoculated wort sitting at temperatures ideal wild yeast and bacterial growth


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## Goose (3/5/13)

I like the chest freezer idea ... good one...





donburke said:


> did have a thought for a somewhat inexpensive method, providing you have the room, which I don't otherwise I would have tried it
> 
> chest freezer set to 1 degree filled with 300 or 400L of water can be turned on a couple of days before brewing and pumped through the chiller, there is a fair bit of cooling power in that volume,


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## Phoney (3/5/13)

Truman said:


> I run the wort through my chiller and in summer its chilled to around 32-35C. So I put it in my fermentation fridge and pitch the next day. In winter it chills to 25C so i usually pitch after transfer. i certainly wouldnt want to spend shit loads of money on a glycol system just so I can pitch 12 hours earlier.


The first and last time I did that my wort was infected when I went to pitch the next day.

What sort of a chiller do you have? Do you run your water tap on full blast? 

I have a mashmaster chillout mkIII and im able to chill to 25 - 27C in summer and 18 - 21C in winter and I'm 1000km north of you. I discovered sitting the chiller in a mop bucket & putting in half a dozen giant ice blocks and pour in around an inch of water keeps the chiller cold and that helped knock off a few degrees.


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## Nodrog (4/5/13)

Even In nz summer my ic gets it down to 30ish deg c pretty quick. Tap water around 18 c. I have Eski with 4 x ice cream containers frozen water, and filed up with water, done when mashing, so have 40l of iced water by time ready. Running this through ic gets last bit of wort down to sub 20s.

Think your turbo charged glycol chiller maths would get more realistic answer if you used 'conventional' means to get the wort down to 30 or 40, then throw some technology at it??


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## woodwormm (5/5/13)

sorry for not answering your question re glycol - I don't know much about it. but have you considered a larger plate chiller and then using the chest freezer idea mentioned above as a source of super cold water? 
http://www.aliexpress.com/item/FHC052-Brazed-Plate-Heat-Exchanger/533334820.html

these guys make up to 150plate chillers...


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## mikk (5/5/13)

2 wort chillers, inline with each other. The first chiller uses tap water to get the wort down to 25-30, the second chiller uses iced water or glycol to get the temp down to 10-15 deg.


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## treefiddy (5/5/13)

mikk said:


> 2 wort chillers, inline with each other. The first chiller uses tap water to get the wort down to 25-30, the second chiller uses iced water or glycol to get the temp down to 10-15 deg.


I think most people just slapped themselves on the forehead for not thinking of this before.


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## /// (5/5/13)

i hate single stage wort chillers and ones that run off a cold liquor.

Make a stand if you have too, search for something like an alfa laval 2 stage online if you need to see one. The good thing is to divert the hot water back to your hlt for batch #2, comes out in the high 60's on the systems i use.


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## woodwormm (5/5/13)

treefiddy said:


> I think most people just slapped themselves on the forehead for not thinking of this before.


hold on a minute... i'm getting in first... rainwater tank and pump in first chiller to save the precious planet


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## Goose (6/5/13)

mikk said:


> 2 wort chillers, inline with each other. The first chiller uses tap water to get the wort down to 25-30, the second chiller uses iced water or glycol to get the temp down to 10-15 deg.


Although the same could be achieved by recirculating back to the boiler... first using tapwater as the coolant then iced water... thugh not as elegant of course.


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## Goose (6/5/13)

Nodrog said:


> Even In nz summer my ic gets it down to 30ish deg c pretty quick. Tap water around 18 c. I have Eski with 4 x ice cream containers frozen water, and filed up with water, done when mashing, so have 40l of iced water by time ready. Running this through ic gets last bit of wort down to sub 20s.
> 
> Think your turbo charged glycol chiller maths would get more realistic answer if you used 'conventional' means to get the wort down to 30 or 40, then throw some technology at it??




Can I add some more turbo maths to your turbo sarcasm 

I reckon a frozen eski is a good idea, but by allowing the ice to melt first you are wasting most of the heat extraction potential. The latent heat of melting is the amount of heat it takes to melt 1 kg of ice at 0 degrees C. This is 334 KJ for every Kg of ice. By comparison, it takes only 4.18 KJ for every Kg of water, to raise it by each 1 degree from 0 thereafter. Its a huge difference.

I realise you cant pump ice through your exhanger, but add just a bit of chilled water atop the ice level to prime the pump, you may save yourself a bit of electricity next time


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## markymoo (6/5/13)

hi Goose,

their Glycol system works on a refrigeration circuit, so the Coefficient of Performance is above 3:1, therefore your 3kW power in would result in over 9kW of cooling capacity.

at the temperatures we are talking (100degree wort down to 12degC) and on a mild day that efficiency would be much higher, say 6:1 plus.

This is why the refrigeration circuit is such a popular way of heating and cooling


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## Goose (6/5/13)

markymoo said:


> hi Goose,
> 
> their Glycol system works on a refrigeration circuit, so the Coefficient of Performance is above 3:1, therefore your 3kW power in would result in over 9kW of cooling capacity.
> 
> ...


Good stuff thanks, but this assumes that i have a sufficient "reservoir" of low temperature to begin with, and that the "pump" does work to move the heat from one reservoir to the other.

My calculation just works out the total amount of heat that needs to be moved out of the wort....


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## Truman42 (6/5/13)

Goose said:


> Are you not concerned about wort oxidation ? I understand its ok for the no-chillers because they have zero airspace in their cubes while they wait for them to cool ?


The wort won't oxidise sitting in a fermenter inside a fridge dropping down to 21C overnight. Likewise I've never had an infection problem doing this. I must admit it was a concern but after being advised to do this by a few fellow brewers on here I've tried it without any problems. Also im confident with my sanitary practices. 
Often I make up my starter from the wort so it's not ready until the next day anyway. Saves having to pour off the beer from a 2 litre starter made from ldme which may change the taste of a stout I've just brewed. 

My plate chiller is one of those smaller ones (12 plate I think it's called). So in summer even with the water running fast it sometimes only drops to just below 30C. 

It works for me. YMMV


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## Goose (6/5/13)

Truman said:


> The wort won't oxidise sitting in a fermenter inside a fridge dropping down to 21C overnight.


In the literature the generally accepted temperature cutoff where the oxidation is unlikely to occur is below 80F (27 Deg C) which suggests the risk is in the time it takes you to cool from pitching temperature to around 27. Below that and its just infection risk.

If you are just below 30 you are probably ok.

Anyway, like u say, what works for you works for you


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## mikk (8/5/13)

Goose said:


> Although the same could be achieved by recirculating back to the boiler... first using tapwater as the coolant then iced water... thugh not as elegant of course.


I think this would take much longer to cool, as maximum cooling occurs when there's a big difference in temp between the wort & the cooling liquid.

Initial cooling when recirculating back to the boiler would be ok, but the cooling rate would slow markedly as the wort gets closer to the cooling water temp. Cooling water usage would also need to increase considerably if recirculating.


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## Goose (8/5/13)

mikk said:


> I think this would take much longer to cool, as maximum cooling occurs when there's a big difference in temp between the wort & the cooling liquid.
> 
> Initial cooling when recirculating back to the boiler would be ok, but the cooling rate would slow markedly as the wort gets closer to the cooling water temp. Cooling water usage would also need to increase considerably if recirculating.


An excellent point.

Which is why I just ordered me a Blichmann Therminator for a first stage cooling using tapwater. Reckon its going to look like hose city when its all connected up. :blink:

Should save me a stack of ice and hence freezer space and hence energy (I hope).

Thanks for the discussion lads.


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## Goose (19/5/13)

mikk said:


> 2 wort chillers, inline with each other. The first chiller uses tap water to get the wort down to 25-30, the second chiller uses iced water or glycol to get the temp down to 10-15 deg.


Ok got the additional piece and hooked it up for a trial run yesterday..... worked a dream, wort out of first exchanger 30 degrees using tapwater on the other side, then into second heat exchanger and wort out at 10 deg C using chilled water from ice bath.

45 litres of wort 100 deg C down to 10 deg C in 20 mins... cant complain.

Here's a couple of pix, excuse the direction of the wort out thermometer and proximity of power socket


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## Mardoo (19/5/13)

Nice thread guys. Thanks.


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## mikk (19/5/13)

Nice work! Any idea how much tap water & iced water you ended up using during the process?


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## Goose (19/5/13)

mikk said:


> Nice work! Any idea how much tap water & iced water you ended up using during the process?


Yeah thanks for the tip mikk 

I used half the ice I normally use, ie 15 litres odd, as much as I can squeeze into one shelf of a dedicated freezer, (approx. 4x 4 litre food storage containers) but then then it wasn't fully melted so just loaded containers up with ice + cold water from bath for a freeze ready for the next batch.

On the water side hard to say, though the benefit is that the water coming out of the first exchanger is 60 degC +, so this got recycled back into the HLT for later cleaning of my 3V system. The HLT was full before the cooling had finished, the rest I had to put to the drain. My HLT is 50 litres, I'd estimate maybe 75 was used in the cooling.

In the past I had to add water into the HLT and heat it .... this process saving me LPG and electricity at the expense of a bit more water...

Interesting though, I'd transferred a shedload of heat from my boiler back to my HLT in this process.


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## Laura Houra (29/8/18)

Generally if the cooling result is too much difference with the reasonable range, there may be two reasons: a. There may be some mistakes with the internal structure of the heat exchanger b. The city water flow capacity is not big enough. But the probability of an error on heat exchanger is too small.. So let us analyze as below:

1. When the glycol water temperature exceed 20 celsius, how many hours it will need for the chillers reduced it back to -4. If it could reduce 4-5 celsius/Hr, just mean the chillers works normally.
2. How about the flow capacity of your city water? Generally for the 15bbl system, the city water flow cannot less than 3T/hr. If the water flow is enough, the city water temperature should raise to above 50 celsius after it cooled the wort, now a effective heat exchanging occured. And now the wort temperature should at about 40-50 celsius.

more details, please help to check the link: http://microbrewerysystem.com/Blog/Why_our_glycol_system_cannot_make_our_wort_cold_enough__829.html

Laura Houra


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