# Wort Chiller Just Ain't Chillin



## Ollieb (10/6/14)

Hey fellas - looking for some feedback and or tips from anyone who has experience using SS wort chillers.

With high hopes of being able to abandon no chill brewing and cubing I purchased my first wort chiller the other week. The ones that are like spirals looping around from the bottom and leading to the top of the kettle so to speak.... Bit like a good ole slinky.... damn they were fun....

All the material I have read indicated to me that once plumbed up and dropped in your kettle at the end of the brew it should bring down your wort temp to approx 20-25 degrees within about 15-20 minutes of running normal tap water through it.

I got no where near that sort of efficiency out of it. After half an hour I managed to only bring it down to about 50 degrees. In the end I turned it off because I felt so bad wasting all that water!

Has anyone else experienced this and or have a few tips on how to use these things properly.

For the finer details the ambient temp on the day was about 22-24 degrees. The tap water running through the chiller was about 20 degrees (I measured out of interest) and the pressure of the tap water was reduced to a slow rate of flow.

I am lead to believe that the water coming out the other end is meant to be pretty damn hot hence transferring the heat from your wort, mine at best was lukewarm.

Feed back of any description would be super great!

Cheers,
Ollie


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## peter.b (10/6/14)

Is it a counterflow or straight immersion?? Its all about flow rate. Too fast and the cooling water wont be in contact with the hot stuff for long enough to absorb the heat. Stainless is great for cleanliness but not the worlds greatest heat conductor. Copper is better for heat transfer. Slow your flow and give that a crack. 

Beers,


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## Judanero (10/6/14)

You can always make a pre chiller coil.

Get some copper pipe, make a "birds nest".

http://aussiehomebrewer.com/topic/71974-ghetto-immersion-chiller/page-3

Put said birds nest in an esky filled with ice slurry or ice blocks in water (ice cream containers make nice sized ice block), and have this before the 'in' of your SS immersion chiller. That will bring the temp down even further as the water through your chiller will be colder.

It also helps to agitate the immersion chiller inside your kettle thereby exposing more of the wort to the chiller, is there space in between the coils of your chiller? That will also help expose more wort to the chiller.

I used to run my 'out' water to a sprinkler that watered the garden, or back into the rainwater tank to reduce the waste factor that comes with an immersion chiller.


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## Ollieb (10/6/14)

peter.b said:


> Is it a counterflow or straight immersion?? Its all about flow rate. Too fast and the cooling water wont be in contact with the hot stuff for long enough to absorb the heat. Stainless is great for cleanliness but not the worlds greatest heat conductor. Copper is better for heat transfer. Slow your flow and give that a crack.
> 
> Beer


 Peter - it is a straight up immersion chiller, perhaps I need to slow the flow rate right down... I'll give it a crack as you suggest.


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## Ollieb (10/6/14)

Judanero said:


> You can always make a pre chiller coil.
> 
> Get some copper pipe, make a "birds nest".
> 
> ...


Judanero - that birds nest ghetto chiller is intense... I like the idea of having a chiller to run the "in" pipe of water through the esky before it hits the immersion chiller.

Also mine is pretty tightly packed/spiraled together so I might try stretching it apart a little as well. Great tip about recirculating the water for the garden, I will definitely give that a go.

Thanks for tips mate.


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## Ducatiboy stu (10/6/14)

The spiral immersion chillers are THE WORST type. They look nice, but really do a bad job of chilling hot wort quickly

The best design is a random birds nest of tube or the " flying spaghetti monster"chiller.

The reason that coils dont work that well is because the coil only takes heat away from the wort that is surrounding the coil. If you place a thermometer near the coil, then in the dead center of the coil you will notice a big variation in wort temp. Water is a poor conductor of heat so it takes ages for the volume to cool. 

If you have a coil then the best thing to do is agitate or stir the wort. Unfortunatly this stops the trub from settling on the kettle floor.


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## JaseH (10/6/14)

Or ditch it and get a plate chiller.


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## Black n Tan (10/6/14)

They work fine as long you keep the wort moving.


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## Batz (10/6/14)

Black n Tan said:


> They work fine as long you keep the wort moving.


True, nothing wrong with them at all.


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## The Judge (10/6/14)

Like the others said - keep it moving.

With respect to copper vs stainless:

Copper rate of heat transfer 400 W/m/C
SS316 rate of heat transfer 17 W/m/C

Copper transfers heat at a rate of around 380 Watts per unit thickness per degree in temp more than stainless steel. i.e. waaaay better.


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## dago001 (10/6/14)

I had no problems with mine when using it a few years ago. Moved to a plate chiller now as I used the IC coil for my herms. The biggest issues is trying to put too much water through it. The water needs plenty of contact time in the wort to chill effectively, so as you said, it should be hot water coming out when you start chilling. So the only way for it to not chill effectively is to have too much water flow. 1/4 of a hose water flow max.
When you first turn the water on, just turn it on so it just starts to flow out of the hose. Thats it.
Cheers and hope that helps
LB


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## dicko (10/6/14)

The ability of any chiller relies on the temperature of the coolant being cooler than the desired wort temperature.
I have made pre chillers similar to what is described above and they require the coolant that they sit in to be constantly on the move or you will have locallised heating and the chiller wont work.
Even with the coolant moving that method is very inneficient unless you possibly had a giant pre chiller vessel.

I have an immersion chiller and our water supply can be as high as 30 deg c in the summer from the tap.
I have a 60 litre container (old Fermenter) that I sit a submersible pump in and with 40 litres of ice slurry I can get my wort to 9 deg c in the middle of summer by pumping the slurry water through the chiller with it sitting in my kettle.

I use the tap water to get the wort to around 40 deg and then switch the hoses to the submersible pump and return the water to the tank (fermenter).
I will have my tap water on for 10 minutes to get down around 40 deg and I save the hot water for cleaning and then switch to the submersible and then when I am about 6 to 7 deg from what I want to achieve in my kettle I drop the return line into two 20 litre cubes and use the same water next time.

The advantage of an immersion chiller is that you have the option not to carry any trub from your kettle to your fermenter....exactly the same as when the big boys use settling tanks.

The OP needs to consider many variable before he takes the advice of some and discards his IC.


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## The Judge (10/6/14)

LagerBomb said:


> The biggest issues is trying to put too much water through it. The water needs plenty of contact time in the wort to chill effectively, so as you said, it should be hot water coming out when you start chilling. So the only way for it to not chill effectively is to have too much water flow. 1/4 of a hose water flow max.


This doesn't make sense to me. If you increase the flow rate of water, (the water isn't so hot as it exits the exchanger), meaning that it is cooler inside the exchanger. A bigger temperature differential between your wort and cooling medium means a bigger rate of heat transfer. Unless you're trying to save water I don't see how that is efficient for cooling.


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## Ollieb (10/6/14)

LagerBomb said:


> I had no problems with mine when using it a few years ago. Moved to a plate chiller now as I used the IC coil for my herms. The biggest issues is trying to put too much water through it. The water needs plenty of contact time in the wort to chill effectively, so as you said, it should be hot water coming out when you start chilling. So the only way for it to not chill effectively is to have too much water flow. 1/4 of a hose water flow max.
> When you first turn the water on, just turn it on so it just starts to flow out of the hose. Thats it.
> Cheers and hope that helps
> LB


Cheers LB - I think reading everyone's comments it appears my pressure was to high for the water to make contact. I will also do my best to keep it moving a little.
Appreciate the feedback.


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## Ducatiboy stu (10/6/14)

Black n Tan said:


> They work fine as long you keep the wort moving.


That is one of their downfalls. You need to keep the wort moving. But in saying that they are good for whirlpooling.

Personally, I like to keep as much trub as possible in the kettle, and with something like the FSM style you can chill without the need to agitate the wort. 

Using a coil without moving/agitating will take a long time. But, if you are prepared to do that then they work well, with advantages over a plate chiller like not having to filter/screen the input of a plate,sanitation of the plate chiller internals. But plate chillers have other advantages.

Whatever method you use, you need to be aware of there downfalls and benifits and take that into account. All chillers acheive the same result at the end of the brew day ( including throwing hot cubes in next doors pool ). 

Over time you will work out what is best for you.


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## SnakeDoctor (10/6/14)

I use a stainless chiller, works great but you DO need to keep wort moving, I spend 10 minutes moving the chiller around in the urn after the initial cooling has been done, about 20 minutes to chill down to ale pitching temp.


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## Beertard (10/6/14)

I'll have to try keeping the wort moving for a bit next time, but I do like to see it settle and go clear in the kettle.


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## Ducatiboy stu (10/6/14)

Beertard said:


> I do like to see it settle and go clear in the kettle.


Thats where the majic happens.


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## LorriSanga (10/6/14)

I do the roll of copper pipe in iced water pre chiller as well.
Water full boar plenty of cubes to collect water - cleaning/plants etc.
After 10 mins - stir. After 8 more mins - 24oC. Yahtzee!


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## Black n Tan (10/6/14)

dicko said:


> The ability of any chiller relies on the temperature of the coolant being cooler than the desired wort temperature.
> I have made pre chillers similar to what is described above and they require the coolant that they sit in to be constantly on the move or you will have locallised heating and the chiller wont work.
> Even with the coolant moving that method is very inneficient unless you possibly had a giant pre chiller vessel.
> 
> ...


I use the same method as Dicko and it works well. I have a water tank so it is pretty guilt free and I typically only need the ice when making a lager. I also have a plate chiller, but prefer the immersion chiller for the reasons Dicko has highlighted. The plate chiller however works well in tandem with a hop rocket.


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## Ducatiboy stu (10/6/14)

I used to love my big ( 30,000lt ) tank. Half buried.

I used to pump the chiller water back into it. And it was allways around 15-18*c .

Being in town sucks balls.


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## Black n Tan (10/6/14)

Ollieb said:


> Cheers LB - I think reading everyone's comments it appears my pressure was to high for the water to make contact. I will also do my best to keep it moving a little.
> Appreciate the feedback.


Slowing down the flow through the chiller will not make it chill faster. That said slowing down the flow may be more efficient in terms of the amount of water needed to chill your wort. If you touch the inlet and outlet of the immersion chiller, you could adjust the flow such that the outlet feels significantly warmer than the inlet, and play around with it to see what works for you. It is a balancing act between the ying of cooling the wort quickly and the yang of unnecessarily wasting water.


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## Judanero (10/6/14)

The post from Dicko is almost exactly the method I was using with my immersion chiller (it was copper) even down to the pre chiller in 60L fermenter of ice slurry.

As said previously, just a couple things to consider and try for next time.

Cheers :beer:


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## donald_trub (10/6/14)

I have a SS immersion chiller and the coil on it doesn't look very long at all. I stir it around constantly but it would take me at least an hour to get down to pitching temp. Now I get it down to mid twenties and then chuck it in the fermenter/fermenting fridge and pitch the yeast the following day.

Once I get more space for brewing (I brew in an apartment) I'll build my own immersion chiller and make one of those whirlpool ICs on MrMalty.


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## lael (10/6/14)

I had another go on the weekend with a 90L batch. Two immersion chillers and whirlpooling with pump = 100 to 60C in 4mins... and I accidentally had both elements on. Realised a few mins later when it was stalled at 52C... and pulled the plug on the brauduino controller, instead of turning the element off via switch... plugged it back on, turned the pump back on and forgot about the other element. Dropped to around 32 pretty quick, stalled, realised the other element was on. Down to 26C was quick (around 20mins total even with faffing about) and then down another 3 degrees was sloooow - another ten mins or so?

Be interested to do it properly next time...


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## dago001 (10/6/14)

Putrino said:


> This doesn't make sense to me. If you increase the flow rate of water, (the water isn't so hot as it exits the exchanger), meaning that it is cooler inside the exchanger. A bigger temperature differential between your wort and cooling medium means a bigger rate of heat transfer. Unless you're trying to save water I don't see how that is efficient for cooling.


 The water has to spend enough time in the coil to transfer the heat from the wort. You are removing heat from the wort, not adding cold to the wort. Too fast and the water does not have enough time to remove heat. Slightly different with a plate chiller because of the larger surface areas involved. Nothing to do with saving water.


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## Online Brewing Supplies (10/6/14)

Ducatiboy stu said:


> I used to love my big ( 30,000lt ) tank. Half buried.
> 
> I used to pump the chiller water back into it. And it was allways around 15-18*c .
> 
> Being in town sucks balls.


Bet my town bore water is colder than your out of town tank 
26 M of earthy coldness, chills like a trooper and makes the garden grown fantastically.
Nev


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## Burt de Ernie (10/6/14)

> The biggest issues is trying to put too much water through it. The water needs plenty of contact time in the wort to chill effectively, so as you said, it should be hot water coming out when you start chilling. So the only way for it to not chill effectively is to have too much water flow. 1/4 of a hose water flow max.
> 
> LB


This is Irish engineering at its best.....I agree that more contact time is better but you achieve this by having more contact surface area e.g. more pipe work


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## Ducatiboy stu (10/6/14)

Online Brewing Supplies said:


> Bet my town bore water is colder than your out of town tank
> 26 M of earthy coldness, chills like a trooper and makes the garden grown fantastically.
> Nev


So....your the one sucking the Artesian Basin dry from WA and heating it up with your chiller water..


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## Online Brewing Supplies (10/6/14)

Burt de Ernie said:


> This is Irish engineering at its best.....I agree that more contact time is better but you achieve this by having more contact surface area e.g. more pipe work


Not if he has only what he has, slow flow will make a big difference with out having to re spend.
Nev


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## Online Brewing Supplies (10/6/14)

Ducatiboy stu said:


> So....your the one sucking the Artesian Basin dry from WA and heating it up with your chiller water..


No just recycling and making beer.
Nev


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## Parks (10/6/14)

LagerBomb said:


> The water has to spend enough time in the coil to transfer the heat from the wort. You are removing heat from the wort, not adding cold to the wort. Too fast and the water does not have enough time to remove heat. Slightly different with a plate chiller because of the larger surface areas involved. Nothing to do with saving water.


I don't buy it either. Heat is going to be transferred regardless of the speed, it'll just be a much, much smaller amount per litre of water.


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## Ducatiboy stu (10/6/14)

Burt de Ernie said:


> This is Irish engineering at its best.....I agree that more contact time is better but you achieve this by having more contact surface area e.g. more pipe work


Well...I know where you both are coming from..

I found that running cold tank water flat out through my chiller didnt chill it any faster that if I slowed the flow down. But there was a balance of flow v heat transfer. Unfortunatly several longnecks,kids,swmbo,washing,etc stopped me from taking note of the exact position of the tap.


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## danestead (10/6/14)

Parks said:


> I don't buy it either. Heat is going to be transferred regardless of the speed, it'll just be a much, much smaller amount per litre of water.


Im with you. Of course fast flowing water is going to cool the wort down. There wont be much of a difference in the temp of water going into the chiller to that which is coming out but that is because its flowing so fast! This seems like a very simple concept to me! No it wont be as efficient in terms of the ratio of water used to wort cooled but itll cool it faster!


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## Burt de Ernie (10/6/14)

> Not if he has only what he has, slow flow will make a big difference with out having to re spend.
> Nev


To be sure, to be sure!

So if I slow my chiller down to 1 litre/hour my wort will chill faster??

This definitely needs some proof testing!


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## Online Brewing Supplies (10/6/14)

Burt de Ernie said:


> To be sure, to be sure!
> 
> So if I slow my chiller down to 1 litre/hour my wort will chill faster??
> 
> This definitely needs some proof testing!


Its all about balancing and laminar flow, you need to read, to be sure.
Nev


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## Ducatiboy stu (10/6/14)

To fast a flow wont capture the hot water on the inner surface of a pipe...

IE the cold water travelling fast in pipe wont drag the hot water sitting against the surface of the tube.

Think of it like jumping in a train. The passengers are the hot water and the train is the cold water. If the train is doing 100kmph then no passangers can jump on the train. Slow the train to 10khp then all the passengers can run and jump on the train. Then the train can carry a lot more hot passengers.


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## pk.sax (10/6/14)

Your analogy is a bit daft but laminar flow does play a part in any fluid flow situation. Won't it be a simple solution to give the coil a sharp pinch every so often to cause the laminar flow to break up into turbulent flow throughout, forcing the fluid flowing through the pipe to mix and draw more heat out.


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## dago001 (10/6/14)

Agree with the above posts. You are not chilling the wort you are removing the heat. Too fast water flow and the heat won't transfer efficiently, exactly the problem that the OP had. I wont comment anymore. I have to go back to work. My boss thinks I'm cleaning our 200 plate heat exchangers at the moment. 
Cheers
LB


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## Kodos (10/6/14)

One question that hasn't been asked, is which direction is the water flowing through the chiller? 

If the cooling water is going into the pipe that goes straight to the bottom of the kettle, and exits via the coil, it will take longer to cool down.

So you want the coldest water coiling around the top of the wort, and by the time cooling water has picked up as much heat as it can get, it's exiting the pot as quickly as possible, otherwise the (now hot) water in the chiller sort of works against the cold water going in.

If that makes any sense.


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## danestead (10/6/14)

Googling came across this.


http://homebrew.stackexchange.com/a/6613

Theres a post there that references a brewing magazine and some tests they did.

Whilst I can understand the laminar flow theory, Im not sure I believe the water can be so smooth flowing (not turbulent) that laminar flow issues with heat transfer could be a factor.


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## lael (10/6/14)

Won't it also depend on the temp of the water in the coil? So as the wort cools down, I imagine longer exposure (slower flow) would be better.


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## Parks (10/6/14)

I still can't see how it could possibly ever be quicker running it slower. You maintain a larger surface area of the coil at a lower temperature the faster it runs meaning a greater temp differential on average to the wort.


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## pk.sax (10/6/14)

Let's just say that turbulence means energy spent.

Usually, any system is keen to lose energy to surroundings of lower energy and settle into a more entropic state.

However, for losing energy there has to differential. I.e., for flow to turn turbulent it will need a source of pressure to cause it to store energy that can be spent by turning turbulent. If the flow induced is smooth with little head pressure then there is little to lose and flow should remain laminar, besides, the regular shape of the pipe aids such flow.
If you were to introduce a kink in such a pipe, then sudden constriction causes reduction of area, I.e., rise of pressure that then suddenly drops past the constriction, in other words loss of energy can happen with a slow down of flow.

Narrow tubes are better for transporting highly pressurised fluid simply because the fluid acts more viscous under pressure and boundary layers shrink.
Wider tubes are better to be used at lower pressure with turbulent flow in them to keep breaking up the boundary layers sticking to the walls.

^ off the cuff reminiscence of high school science, might have errors in thinking.


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## The Judge (10/6/14)

Copper beats stainless steel, and higher water rates cool more quickly than lower rates. Thermodynamics wins.


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## Black n Tan (10/6/14)

practicalfool said:


> Let's just say that turbulence means energy spent.
> 
> Usually, any system is keen to lose energy to surroundings of lower energy and settle into a more entropic state.
> 
> ...


No idea what you just said, but surely the higher the flow rate the more turbulence, which means more efficient heat exchange. The link Danestead made, although not directly to the Zymurgy article, notes "His result was that the chiller worked best with the highest water pressure, and that swirling the chiller in the wort chilled the wort even faster." Surely that should be enough to put this to bed, although if someone has a copy of the Jan/Feb 2012 Zymurgy article that would be great.


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## lael (10/6/14)

Any one know just how much difference stainless vs copper makes?


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## Burt de Ernie (10/6/14)

> No idea what you just said, but surely the higher the flow rate the more turbulence, which means more efficient heat exchange. The link Danestead made, although not directly to the Zymurgy article, notes "His result was that the chiller worked best with the highest water pressure, and that swirling the chiller in the wort chilled the wort even faster." Surely that should be enough to put this to bed, although if someone has a copy of the Jan/Feb 2012 Zymurgy article that would be great.


This is the summary from Zymurgy 2012 jan/feb






Nuff said!


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## Burt de Ernie (10/6/14)

In the interest of all here I have uploaded the whole article for reference below.


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## danestead (10/6/14)

Whats the summary of the article? Its too poor quality to read im afraid.


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## Burt de Ernie (10/6/14)

> Whats the summary of the article? Its too poor quality to read im afraid.


Laminar flows mean jack shit.

Run the water as cold and as fast as you can and increase surface area (AKA pipe length)


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## Black n Tan (10/6/14)

Look at figure 1. In all cases increasing the flow rate improved the cooling performance.


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## Ducatiboy stu (10/6/14)

practicalfool said:


> Your analogy is a bit daft


Sorry for my simplistic view.


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## Burt de Ernie (10/6/14)

> Sorry for my simplistic view.


Don't worry mate....I loved it....


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## Ducatiboy stu (10/6/14)

Putrino said:


> Copper beats stainless steel, and higher water rates cool more quickly than lower rates. Thermodynamics wins.


Yep. I did have a stainless coil. 

Copper does win.


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## Ducatiboy stu (10/6/14)

Burt de Ernie said:


> Don't worry mate....I loved it....


Please..dont...you will upset the uber brewers


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## Ducatiboy stu (10/6/14)

Burt de Ernie said:


> Laminar flows mean jack shit.
> 
> Run the water as cold and as fast as you can and increase surface area (AKA pipe length)


Cold is good....fast wont give better results.


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## pk.sax (10/6/14)

Ok, a few observations:

1. It does not address optimisation wrt total mass of water put through chiller - assumption is infinite source of cold water.

2. Look at the graphs, the effect of increasing flow rate yields diminishing reduction in chilling time.

3. Wider pipes chill better.

4. Flow rates used in the study aren't too extreme, all of them would lead to a low pressure situation. I.e., pressure effects aren't much in play. If you start turning the flow rate up higher you have to start taking into account flow layers and separation effects. Especially for narrower tubes.

Look up the term Reynolds coefficient. Every experiment needs to be standardised to mean something.

In practice, unless you got a dam full of cold water at your back or don't give a **** about how much you pour onto the lawn you are going to look at your comfort point on the curve where you accept the cooling rate vs flow rate.

Small tweaks that play with pressure can help, if you put some thought into it.


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## Ducatiboy stu (10/6/14)

One thing I do want to try is the crimped/ribbed copper tube. 

Its the ribbed tube which, after talking to an aircon mech gives a better surface area which should give a better heat transfer, both internall & external. But not cheap


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## Burt de Ernie (10/6/14)

> One thing I do want to try is the crimped/ribbed copper tube.
> 
> Its the ribbed tube which, after talking to an aircon mech gives a better surface area which should give a better heat transfer, both internall & external. But not cheap


This is what Rinnai use in their heat exchange systems for the same reason. Although they would probably be a lot harder to clean.


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## The Judge (10/6/14)

Aaaaaaaaalternatively, get a massive bundled ball of copper wire, leave it in the freezer for a few days before brewing, and then chuck it into the hot wort for a super dooper crash chill :super:

Also watch out for freezer burn.

Sorry OP for being way off topic!!


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## The Judge (10/6/14)

I was joking.... but i might actually try that.


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## Ducatiboy stu (10/6/14)

He is an aircon mech. He lost me after the use of ribbed tube...

I just thought ribbed tube tube might be benificial to brewing . Bit like walking into a kitchen shop h


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## SnakeDoctor (11/6/14)

Kodos said:


> One question that hasn't been asked, is which direction is the water flowing through the chiller?
> 
> If the cooling water is going into the pipe that goes straight to the bottom of the kettle, and exits via the coil, it will take longer to cool down.
> 
> ...


It makes sense, but my testing (and the instructions) indicate that the opposite is the fastest way to chill the wort, you want the cold water going down to the bottom so that heat transfer can take place with the greatest temperature differential.


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## dago001 (11/6/14)

Well I got home from work and read the Zymurgy article as it was hard to read on my phone. You had to read the whole article to get the full story. Its ok to look at the graph and say that this proves the theory. And the graph does prove his theory, BUT, his garden hose turned on flat out puts out 2.5 US gallons per minute. I dont know what your water flow/pressure is like, but mine is approx 3 times that (I'm not checking, I'm going to bed). So by going with the Zymurgy experiment, turning you hose on to between 2 and 2.5 gpm is the most efficient flow rate to cool using an immersion chiller. Somewhere between *7.5* to *9* litres per minute. There in lies the answer. Turn your hose on flat out into a 20 litre bucket for a minute and see how many litres you get. If its only 7.5 to 9 litres per minute, then I would be complaining to the local water authority. As Nev said, ya gotta do the reading.
Cheers
LB


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## The Judge (11/6/14)

You should clarify that rate is for a specific surface area and concerning efficiency. If you're looking to minimise duration of the cooling process, despite the diminishing returns on flow rate, you would want to have the water flowing at full bore.


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## Kodos (11/6/14)

SnakeDoctor said:


> It makes sense, but my testing (and the instructions) indicate that the opposite is the fastest way to chill the wort, you want the cold water going down to the bottom so that heat transfer can take place with the greatest temperature differential.


Wouldn't the hottest wort rise to the top, meaning the greatest temperature differential is at the top?

If you were not agitating the wort as you chilled (and it seems to be agreed that you should, I whirlpool with a pump while chilling to achieve this), you would create a layer of cooled wort at the bottom, and the wort at the top would stay warm, reducing convection. Cooling at the top, warmer, layer, would encourage convection currents.

But, I'm not sure I've done proper testing, it's been more anecdotal experience of my own and other brewers. And my copper coil didn't come with instructions 

I'll have to go back to reading the article posted above and others.


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## wereprawn (11/6/14)

Kodos said:


> Wouldn't the hottest wort rise to the top, meaning the greatest temperature differential is at the top?
> 
> If you were not agitating the wort as you chilled (and it seems to be agreed that you should, I whirlpool with a pump while chilling to achieve this), you would create a layer of cooled wort at the bottom, and the wort at the top would stay warm, reducing convection. Cooling at the top, warmer, layer, would encourage convection currents.
> 
> ...


 Don't use an immersion chiller but when chilling in sink immediately after the boil the top layers are so hot its bordering on painful and an inch or so at the bottom is cool when changing the water.


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## Ducatiboy stu (11/6/14)

I remember the first time I used an imersion chiller.....

Needles to say it was the first and only time I stood near the outlet...... They spit hot water everywhere.


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## Parks (11/6/14)

Ducatiboy stu said:


> I remember the first time I used an imersion chiller.....
> 
> Needles to say it was the first and only time I stood near the outlet...... They spit hot water everywhere.


You have to be very careful if you sanitise your plate chiller via recirc of hot wort for 10min too - any water left in the chill sections gets turned to steam and spits out.


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## Ollieb (11/6/14)

Rightio then.... just spent the last 45 minutes reading everyone's very helpful responses and conflicting opinions along with the attached material. EPIC work team... Thank you all!

I have several different tests and options available to me that is going to make for some fun testing on the weekend for my next brew. I will be sure to update the post with what I find from the experiments to hopefully settle a few differing opinions. 

I had no idea that this would generate so much interest/ discussion but it made for some great reading... Thanks to everyone who offered their advice and wisdom. To those who just threw in off the cuff smart ass comments... Good job! I love that shit it always breaks up the seriousness of the discussion.

Cheers to all. :beerbang:

Ollie


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## dago001 (11/6/14)

Plenty to try Ollieb - please report back so we know how you went.



Putrino said:


> You should clarify that rate is for a specific surface area and concerning efficiency. If you're looking to minimise duration of the cooling process, despite the diminishing returns on flow rate, you would want to have the water flowing at full bore.


^^^ Foundation member of the Flat Earth Society.


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## Black n Tan (11/6/14)

LagerBomb said:


> Well I got home from work and read the Zymurgy article as it was hard to read on my phone. You had to read the whole article to get the full story. Its ok to look at the graph and say that this proves the theory. And the graph does prove his theory, BUT, his garden hose turned on flat out puts out 2.5 US gallons per minute. I dont know what your water flow/pressure is like, but mine is approx 3 times that (I'm not checking, I'm going to bed). So by going with the Zymurgy experiment, turning you hose on to between 2 and 2.5 gpm is the most efficient flow rate to cool using an immersion chiller. Somewhere between *7.5* to *9* litres per minute. There in lies the answer. Turn your hose on flat out into a 20 litre bucket for a minute and see how many litres you get. If its only 7.5 to 9 litres per minute, then I would be complaining to the local water authority. As Nev said, ya gotta do the reading.
> Cheers
> LB


LB. The point of debate was whether increasing flow rate would increase or decrease the cooling rate. The Zymurgy article clearly demonstrates that the time to chill wort decreases with increasing flow rate ie. higher flow rates cool wort more quickly. The highest flow rate tested was 3G/min (11.4L/min) not 2.5G/min, but what you can see from slope of the lines in graph 1 is that time to chill is continuing to improve even at 3G/min and there is no suggestion that the line has yet begun to plateau. With a lack of a plausible theory to the contrary, I think it is reasonable to assume that in real world situations (above 3G/min) the chill time will continue to decrease as flow rate increases (it may start to plateau, but it won't go in the other direction). So I don't think there is any need to restrict the coolant flow rate to 2.0-2.5G/min as you have suggested. I will continue to turn my tap full on because I have a water tank and know that this will cool my wort the quickest. If you are using mains water, you may wish to use a lower flow rate: it will take longer but you will save water. For example with 1/4" tubing it will take 31 minutes to cool at a flow rate of 1G/min (3.8L/min or 118L total), but it is only 6 minutes quicker to chill at three times the flow rate (11.4L/min or 285L ). 



LagerBomb said:


> Plenty to try Ollieb - please report back so we know how you went.
> 
> ^^^ Foundation member of the Flat Earth Society.


Not sure I understand your criticism of Putrino's statement?? Seems pretty reasonable to me.


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## Burt de Ernie (11/6/14)

LagerBomb said:


> Well I got home from work and read the Zymurgy article as it was hard to read on my phone. You had to read the whole article to get the full story. Its ok to look at the graph and say that this proves the theory. And the graph does prove his theory, BUT, his garden hose turned on flat out puts out 2.5 US gallons per minute. I dont know what your water flow/pressure is like, but mine is approx 3 times that (I'm not checking, I'm going to bed). So by going with the Zymurgy experiment, turning you hose on to between 2 and 2.5 gpm is the most efficient flow rate to cool using an immersion chiller. Somewhere between *7.5* to *9* litres per minute. There in lies the answer. Turn your hose on flat out into a 20 litre bucket for a minute and see how many litres you get. If its only 7.5 to 9 litres per minute, then I would be complaining to the local water authority. As Nev said, ya gotta do the reading.
> Cheers
> LB


I don't get this statement......it sounds like you are saying that you understand the article better than others here and that you refute the findings.

Obviously the "lower flow is more efficient" argument was born on not fully understanding the science behind what had been written.


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## pk.sax (11/6/14)

What he is saying is that too little information is dangerous.

That's what I 'think' he means.


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## Feldon (11/6/14)

Its not that hard. Theory and science are all very well. But you have know how to apply it.

When cooling your wort with an immersion coil you want the exit cooling water to be as hot as possible. This means that the water is extracting the heat in the wort to the maximum potential of your cooling system (ie. whatever type of coil you use; whatever mains water pressure you have; whether or you jiggle the coil or not, etc, etc, etc).

So put a thermometer in the outflow water (good idea to plumb a short-stick dial thermometer with a T-piece at the exit end of your coil). Increase the input water flow until the temp just starts to drop. This is the point at which the water flow is so high that the cooling water does not have enough time in the coil to heat up by absorbing as much heat as it can from the wort. Back off the water flow a tad.

But the situation does not remain the same.

Heat transfer from wort to water is not a constant. The greater the temp difference between the wort and the cooling water the greater is the rate of heat transfer between the two. So the maximum potential heat transfer occurs at the start of cooling process when the wort is just off the boil.

As the wort cools the temp difference between the wort and the water is reduced, so the rate of heat transfer diminishes. This means you have to give the water more time in the coil to account for the poorer rate of heat transfer. So you have to progressively back off the water flow as the wort cools to give the water more time to absord the wort's heat. If you don't you are needlessly wasting water.

Towards the end, when you're getting down towards pitching temp, the rate of heat transfer is appalling compared to the beginning. It will take the most time, but the least water, to knock off the last few degrees. If you have another coil to put in an ice bath (ie. a pre-chiller) this is the time to use it. You will increase the temperature difference between the water (which is now icy cold) and the now not-so-hot wort and thus increase the rate of heat transfer between the two. (Note that at the start of the cooling process its pretty pointless using a pre-chiller because the temperature differential is large anyway - you will get max use out of the ice in your pre-chiller bucket by using it towards the end of the wort cooling process).

Hope this dispels the idea that you can just pick one water flow rate for the whole process to run at best efficiency. Nature disagrees.

Re. the copper is better than stainless myth - in a practical sense, in a homebrew immersion coil situation, there is not really any difference between using either of the two metals. Both are more than adequate conductors of heat - the weak point in the chain of events is the relatively poor abilty of both wort and water to transfer heat to and from the metal. You can't do anything about this. You could make a coil out of gold (better conductor than copper)and it would not make much difference to the cooling of the wort.


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## dago001 (11/6/14)

I'll make some justification. I do this stuff everyday as part of my job. I work in an industry that relies heavily on heat exchangers for cooling water, oil and blast furnaces. I speak not only from practical experience but also from the knowledge gained from research into flow rates to achieve efficient cooling. Even cooling a 700 degree shaft in a furnace has a limit to how much water flow is required. Too much water flow will result in less cooling (heat exchange) resulting in downtime and thousands of dollars in expenses. We monitor our flows to maintain the correct flow for efficient heat transfer. I've been doing this stuff for 25 years. A geeky 30 minute test in a beer magazine proves only half of the theory behind the what is really happening. But anyway, open your taps fully, I couldn't give a **** anymore. 
Cheers
LB


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## Parks (11/6/14)

LB - are you literally saying it will take longer if the flow rate is too fast or are you talking about heat transfer efficiency?

I believe people in this thread are confusing the two separate issues and would like to know exactly what you mean.


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## Goose (11/6/14)

> Too much water flow will result in less cooling (heat exchange) resulting in downtime and thousands of dollars in expenses.


Sorry mate I do not agree with the first part of this statement. More water flow will result in more heat exchange, but the result is just less temperature difference in the water in vs out. I do not disagree however, with the expense part. Of course you will use more water in the process which costs more.

Any other Chemical Engineers out there ?


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## dago001 (11/6/14)

It will take longer if the flow rate is too fast. What I said in my first post. They are both relative. Heat transfer efficiency is effected by flow rate. Feldons post sums it up nicely.


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## dago001 (11/6/14)

Oh ****. I give up. Argue amongst yourselves, telling each other how smart you are. The flat earth society is gaining new members by the minute.


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## The Judge (11/6/14)

Goose said:


> Any other Chemical Engineers out there ?


I'm a Process Engineer, specialising in thermohydraulics!


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## pk.sax (11/6/14)

Goose said:


> Sorry mate I do not agree with the first part of this statement. More water flow will result in more heat exchange, but the result is just less temperature difference in the water in vs out. I do not disagree however, with the expense part. Of course you will use more water in the process which costs more.
> 
> Any other Chemical Engineers out there ?


Chem engineers are girls


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## Goose (11/6/14)

LagerBomb said:


> It will take longer if the flow rate is too fast. What I said in my first post. They are both relative. Heat transfer efficiency is effected by flow rate. Feldons post sums it up nicely.


With all due respect, this is incorrect. Do not be confused by heat (change in temp x specific heat x weight of medium) vs temperature change alone.

I believe the theory is that the faster the flowrate the higher the turbulence in the pipe and the faster it will conduct heat away from the surface it contacts.

Anybody got a copy of the classic text "Process Heat Transfer" by Kern ?


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## Not For Horses (11/6/14)

I'm just theorising here but could it have something to do with boundary layers? 

Pipes have a relative roughness (k value from memory) causing a turbulent boundary layer between the pipe and the liquid flowing through it. A slow flow rate would have much less or even no boundary layer.
A boundary layer would mean that the cool water was no longer in contact with the hot copper but rather with the hot water in the boundary layer.
Water to water is a much slower conducter of heat than water to copper resulting in less heat transfer at higher flow rates.

I say again, only theorising.


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## Burt de Ernie (11/6/14)

> Its not that hard. Theory and science are all very well. But you have know how to apply it.
> 
> When cooling your wort with an immersion coil you want the exit cooling water to be as hot as possible. This means that the water is extracting the heat in the wort to the maximum potential of your cooling system (ie. whatever type of coil you use; whatever mains water pressure you have; whether or you jiggle the coil or not, etc, etc, etc).


This is incorrect. Slowing the flow will bring efficiency to water consumption at the loss of time to chill wort.

I get that you will have hotter discharge water however I would rather exchange 100 watts of heat using ten litres of water in one minute than 100 watts using five litres of water in two minutes.


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## Burt de Ernie (11/6/14)

> Any other Chemical Engineers out there ?


Im hydraulic!


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## Goose (11/6/14)

Many examples out there:


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## Burt de Ernie (11/6/14)

> Oh ****. I give up. Argue amongst yourselves, telling each other how smart you are. The flat earth society is gaining new members by the minute.


I don't know you personally...im sure you are a nice guy but this is an arrogant statement and surely not needed.

I believe it was you who qualified yourself first as a heat exchange expert all because you have been cleaning them for the last 25 years.


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## Feldon (11/6/14)

> This is incorrect. Slowing the flow will bring efficiency to water consumption at the loss of time to chill wort.
> 
> I get that you will have hotter discharge water however I would rather exchange 100 watts of heat using ten litres of water in one minute than 100 watts using five litres of water in two minutes.


You need to re-read my post and try (really hard) to understand it.


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## Burt de Ernie (11/6/14)

> You need to re-read my post and try (really hard) to understand it.


I do understand it.....you are arguing that faster flow doesn't chill faster which is contrary to all evidence presented in this thread.


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## Feldon (11/6/14)

> I do understand it.....you are arguing that faster flow doesn't chill faster which is contrary to all evidence presented in this thread.


I'm not saying that at all. I'm saying that the cooling system has an upper limit after which increasing water flow will not have any further effect.

You are saying that the system has infinite cooling potential. By your reckoning if you could squirt a billion litres of water through the coil in a few seconds it would cool the wort almost instantly. It won't.

I understand you've gone out on a limb here, but time to climb down from your tree.


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## Burt de Ernie (11/6/14)

> You are saying that the system has infinite cooling potential. By your reckoning if you could squirt a billion litres of water through the coil in a few seconds it would cool the wort almost instantly. It won't.


Ummm....I never said anything like this I think you are putting words in my mouth.

I have said that you will lower chill time by increasing chiller surface area and also that I disagreed that by slowing flow chill time will decrease .

That's it


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## Parks (11/6/14)

This is exactly the misunderstanding that is turning this thread sour.

Feldon is saying that increased flow won't necessarily make it cool faster.
LagerBomb is saying that at a point increased flow actually cools slower.
Others are talking about heat exchange efficiency and wasted water.


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## Not For Horses (11/6/14)

And I'm now scratching my head thinking about turbulent and laminar flow...


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## danestead (11/6/14)

Mods...... this thread has turned pathetic


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## pk.sax (11/6/14)

Crybaby


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## Goose (12/6/14)

Not For Horses said:


> And I'm now scratching my head thinking about turbulent and laminar flow...



Reynolds number


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## Ducatiboy stu (12/6/14)

One thing I have noticed, in a pure practicall suck it and see method is that the temp drop from say 100*-70* is quicker than from 40*-20*. As for the the theory as to how & why, I couldnt care less.

As for flow rate v time v temp drop....I have no idea. But know someone who used to lecture thermo dynamics at Melb Uni so they prop would.


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## wide eyed and legless (12/6/14)

Just purely from a logical point of view, what we are doing is exchanging the heat from the wort through the copper (copper is a far better conductor of heat than s/s ) to the water running through the copper tube, there would I imagine, be a set flow rate for the efficient transfer of heat from the copper tube the the cold water, so just thinking logically for the cold water to pick up the heat from the copper I wouldn't imagine it travelling to fast.


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## Dave70 (12/6/14)

So, in conclusion..


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## TheWiggman (12/6/14)

There are two pretty conflicting viewpoints here. Here's the science/engineering for those interested. What we're concerned about the the convection coefficient of the liquid inside the tube (water), of the tube itself, and outside the tube (wort)

For _laminar_ flow, the formula for the heat transfer convection coefficient, W/(m2•K), of the fluid inside a circular pipe is -

hbar = mdot * cp x (Tout - Tin)
pi * D * L T diff

mdot is the mass flow rate. Therefore if the flow is increased, the convection coefficient becomes higher and more heat energy is able to be transferred.
HIGHER FLOW = better

For _turbulent_, the general approach can be applied -

q = h * A * (T diff)

For h, the Nusselt number is needed. One approximation is the Dittus-Boelter equation for Re > 10000 (more info below)

Nu = 0.023 * Re ^4/5 * Pr^n

Higher flow will increase the Reynold's number, which increases the Nusselt number, which increases h. This in turn results in a higher energy transfer in J/s (q).
HIGHER FLOW = better

For 10l/min through a 1/2" stainles tube the Reylond's number is ~36000, which is well turbulent (>4000 is considered turbulent). The only reason I included the first equation is that even if you did get your water flow down to laminar, the result is still the same - more flow is better.

*If you want to cool the wort down faster, increase the flow of your water.*

*Just as important *is flow in your wort. If you don't have a recirc pump on it, move the coil around in your kettle to get a nice whirlpool going. Otherwise yes it will take a long time.

PS: if you slow the water flow down the temp of the water coming out will be higher. This isn't relevent for what we're trying to do - we don't want hot water coming out, we want as much energy transferred as possible.


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## Ducatiboy stu (12/6/14)

A chiller is quicker than no-chill.


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## JaseH (12/6/14)

I haven't bothered reading all the shit fight about cooling physics, but if your goal is to chill quickly with minimal water wastage - piss the coil chiller off and get a plate chiller.

27L of 100C wort into the fermenter in under 5min at ~2C above tap water temp. If cooling speed/efficiency isn't the goal then the all this discussion seams a pointless?


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## TheWiggman (12/6/14)

OP owns the chiller and isn't getting performance out of it. He wants aid getting better performance out of it (or clarification it's no good)

Maintain high water flow
Keep the wort and/or chiller moving

I'm guessing he wasn't doing the latter.


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## Ollieb (12/6/14)

Whoa fellas what about how out of control this thread became overnight....!

All I wanted to do was start a chat about chilling some beer... I think some of us could take 5, go chill and have a beer.. (even if it is only 11:45 am).

I appreciate everyone's help and opinions but let's keep it pleasant between each other. This is not a measuring contest huh...

With so much info here and lots of good stuff for me to test and trial with my chiller I think we can leave this one for now.

I will be sure to let everyone know what worked once I brew on Sunday. Slower rate of flow or faster rate of flow.

Thanks again for everyone's contributions.

Ollie


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## Ducatiboy stu (12/6/14)

Whatever you do.....dont start a yeast if you think this thread is getting epic.....


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## Dave70 (12/6/14)

TheWiggman said:


> *If you want to cool the wort down faster, increase the flow of your water.*


This seem to run counter to the bush mechanic practice of knocking a couple of teeth of a cars water pump in order to prevent overheating. Bush mechanics being a highly specialized field. 


I'd agree the must be an optimum 'range' of flow, but the law of diminishing returns must kick in at some point. 

That sad, I'm pretty fuked at maffs.


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## TheWiggman (12/6/14)

You're absolutely right, there is a point of diminishing returns. Efficiency will reduce, but efficiency and performance are different. Industrial heat exchangers come with an efficiency curve for this reason.

Eg. in a car if you want to go faster, open the throttle more. There will be a point at which your l/100km will increase and lots of extra fuel gives minimal gain, but the more you put your foot down the faster the car will go.
That's an example of efficiency, not necessarily analogous to this problem.


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## Goose (12/6/14)

Yep all good stuff, however it seems to me that the eloquent prose from some here may have confused the thinking between the property of temperature and definition of heat.





> Its not that hard. Theory and science are all very well. But you have know how to apply it.
> 
> When cooling your wort with an immersion coil you want the exit cooling water to be as hot as possible.


This is where the confusion begins, because it is not necessarily correct. Your objective is to have the wort as cool as possible in as short a period of time as possible. There are many variables involved, the main ones being total surface area, conductivity of the metal, entry temperature of coolant and what seems to be contentious here because it is well within our control which is the water flow rate.



> This means that the water is extracting the heat in the wort to the maximum potential of your cooling system (ie. whatever type of coil you use; whatever mains water pressure you have; whether or you jiggle the coil or not, etc, etc, etc).


Maximum temperature of cooling water outlet does not necessarily mean maximum heat rate of removal.



> So put a thermometer in the outflow water (good idea to plumb a short-stick dial thermometer with a T-piece at the exit end of your coil). Increase the input water flow until the temp just starts to drop. This is the point at which the water flow is so high that the cooling water does not have enough time in the coil to heat up by absorbing as much heat as it can from the wort. Back off the water flow a tad.


This saves water, granted. But it does not mean more heat is removed.



> But the situation does not remain the same.
> 
> Heat transfer from wort to water is not a constant. The greater the temp difference between the wort and the cooling water the greater is the rate of heat transfer between the two. So the maximum potential heat transfer occurs at the start of cooling process when the wort is just off the boil.
> 
> ...


You use less water but also lower your heat removal rate.



> Towards the end, when you're getting down towards pitching temp, the rate of heat transfer is appalling compared to the beginning. It will take the most time, but the least water, to knock off the last few degrees. If you have another coil to put in an ice bath (ie. a pre-chiller) this is the time to use it. You will increase the temperature difference between the water (which is now icy cold) and the now not-so-hot wort and thus increase the rate of heat transfer between the two. (Note that at the start of the cooling process its pretty pointless using a pre-chiller because the temperature differential is large anyway - you will get max use out of the ice in your pre-chiller bucket by using it towards the end of the wort cooling process).
> 
> Hope this dispels the idea that you can just pick one water flow rate for the whole process to run at best efficiency. Nature disagrees.


Nature disagrees and so do I. Efficiency can be defined in many ways. Time ? Economy ? Rate of heat transfer ? Our variables as homebrewers are mostly flowrate and cooling water starting temperature. If you are not worried about water usage and you want maximum heat transfer, that is to cool your wort as quickly as possible, then you need maximum possible flowrate and minimum possible coolant entry temperature.

Thankyou, and goodnight.


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## Online Brewing Supplies (12/6/14)

I find it strange when out camping if I run past a campfire it doesnt warm me,
but if I walk past slowly I get hot.
Nev


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## Goose (12/6/14)

> I find it strange when out camping if I run past a campfire it doesnt warm me,
> but if I walk past slowly I get hot.
> Nev


LOL

yes nev mate, you do.

but if a thousand cold people ran past that campfire in the same time you stood there they'd all get a little bit warmer and the sum of the heat transferred to them in the same time would be more than the total transferred to you.

Thats because we all agree (at least) that the greater the temperature difference, the greater the rate of heat transfer. So each new bod that runs past the fire is the same cold temperature to start with.. whereas you standing there as you say you get hotter and hotter so you absorb less and less with each increment in time..

Make sense ?


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## Ducatiboy stu (12/6/14)

So...does a given volume of water transfer a given amount of heat. 

So more volume passed thru transfers more heat. 

So the faster flow passes more volume which transfers more heat.


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## The Judge (12/6/14)

Online Brewing Supplies said:


> I find it strange when out camping if I run past a campfire it doesnt warm me,
> but if I walk past slowly I get hot.
> Nev


Trolling statement of the thread!


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## Online Brewing Supplies (12/6/14)

Well someone had to lighten up this thread. :lol:
Nev
ed sp


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## Dave70 (12/6/14)

OK, in the same vein, a question I don't think I've ever heard answered with any clarity. 
What time frame actually constitutes chilling, and why does it even matter?

Just for the sake of the argument, say its pertinent for the reason of hop aroma / chill haze / hot break or whatever to have the wort temp reduced from 90 deg to 30 in X amount of time. 
If truths exist about chilling at all, there must be a window in which optimum results are obtained, anything outside X must see desirable results taper off sharply. 

It seems a given that we strive for the quickest chill possible, but is there really any justification in time / effort / expenditure of $$$ to shave 10 minutes off the time it took to drop down to pitching temp? 

Would, given identical everything else, an ale that took 30 minutes to chill from 90 to 20 deg turn out demonstrably better than the same wort that took an hour to cool? 

I'm interested because we obviously calculate bitterness and hop additions around chill / no chill, but what about slow chill? At what point does it cross the line? 

??
???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????


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## Ducatiboy stu (12/6/14)

Dont be starting an argument Dave.......them engineers will get involved. And that will involve complex stuff like working out if your hose fitting is corect or if the time it takes is based on daylight savings time.


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## TheWiggman (12/6/14)

"[SIZE=10pt]Arguing with an Engineer is a lot like wrestling in the mud with a pig: After a few hours, you realise the pig likes it.[/SIZE]"


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## Not For Horses (12/6/14)

For Dave

http://aussiehomebrewer.com/topic/80799-time-frame-for-chilling-a-musing/


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## Ducatiboy stu (12/6/14)

TheWiggman said:


> "Arguing with an Engineer is a lot like wrestling in the mud with a pig: After a few hours, you realise the pig likes it."


You can put lipstick on an engineer......


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## pk.sax (12/6/14)

Dave70 said:


> OK, in the same vein, a question I don't think I've ever heard answered with any clarity.
> What time frame actually constitutes chilling, and why does it even matter?
> 
> Just for the sake of the argument, say its pertinent for the reason of hop aroma / chill haze / hot break or whatever to have the wort temp reduced from 90 deg to 30 in X amount of time.
> ...


I take if as knock it below isomerization temp and then knock it down quick enough to prevent infection. Then pitch quick enough to avoid spores activating and taking hold. In that sequence.

I fact, I find dunking in a large body of water to be the most efficient - if possible.


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## Ducatiboy stu (12/6/14)

This was the reply I got back. Written by someone who has a Phd

" Heat transfer is proportional to the mass flow rates of the two liquids concerned, so if you increase the flow rte of the cold liquid, you will increase the heat transfer. You can also increase it by reducing the temp of the cooling water. The formula is Q=mc(T2-T1) where Q is the quantity of heat being transferred, m is the mass flow rate, c is the heat capacity of the fluid ( a unique constant for any fluid) and T2 and T1 are the initial and final temperatures. So the important variable is the mass flow rate. So, make he coil with fatter tubing and up the flow rate to maximise the cooling. Where you will reach a limit is in the max flow rate you can get through the tube: fluids basically choke and reach a max flow rate.


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## pk.sax (12/6/14)

That choke is called getting to compressibility and the ability of the source to supply the energy for the fluid to compress.

Like I said before, there are actually ways to trick the system to use good flow while getting optimal water usage. Flow rate isn't the only variable, fluids and heat transfer behave in ways.

Take that analogy of thousands of people running by a fire, well, the material of fire (pipe) will play a small part. I have a hunch steel is more radiative than copper. Copper is more conductive. Convection works a bit as well. Why some of the measured equipment will use slower flow is also because slower speed flow cases can be analysed to achieve best bang for the buck. High speed and compressible flows are more expensive to compute for their peculiarities.

Like, for example, if I am getting buffeting due to flow separation behind something in the wind I might try to put spoilers in the flow behind the object splitting the flow. It will cause the slower laminar flow to separate from the surface and mix with the faster vortex, effectively absorbing energy and reducing the buffeting effect of the separated flow.

In a pipe, a lower speed flow could be manipulated, creating local compression and decompression with minimal energy input required from the water source. Such tricks will ensure the water getting out is not laminar and has absorbed as much energy as possible in the time it took for it to make it from point a to b.
Really fast flow though is too energetic, there are less ways to create mixing as the pipe itself will channel the flow and cause it to get laminar. This is the source of inefficiency.


----------



## Ducatiboy stu (12/6/14)

So can i buy a manipulator at Bunnings or the plumbers shop ?


----------



## pk.sax (12/6/14)

If you so desire.


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## Ducatiboy stu (12/6/14)

You got a description of said part so when I go in I can describe it to the bloke behind the desk


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## pk.sax (12/6/14)

Vice grips


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## Ducatiboy stu (12/6/14)

So your talking crimped tubing


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## dago001 (12/6/14)

Ducatiboy stu said:


> You got a description of said part so when I go in I can describe it to the bloke behind the desk


Its right next to the variable flatuator. Aisle 6 I think. Ask for it, he will know what your talking about.


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## Ducatiboy stu (13/6/14)

practicalfool said:


> I love a pure engineers respons
> 
> Yes. Heat transfer is more efficient if the flow is turbulent.


----------



## Ducatiboy stu (13/6/14)

.


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## Ollieb (15/6/14)

Hi guys

So today was brew day and plumbed up the chiller all good and proper with new fittings from Bunnings.

Tested both theories that have been discussed with much enthusiasm on this thread.

Theory One: Increased/fast water flow will cool faster. 

Theory Two: Decreased/slow water flow will cool faster.

Any one want to quickly wage a bet???

Drum roll please.... the winner is Theory Two; slower water flow cooled it faster.

Someone somewhere back on page who knows what suggested agitating the wort chiller every few minutes to assist in speeding up the process. This can also be confirmed and made a HUGE difference. 

So there it is guys, thanks everyone for your input and I guess regardless of your theory or argument the results speak for themselves.

Thanks everyone for your input -until the next argument (ahem debate) chat soon and thanks for your time.

Ollie


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## Black n Tan (15/6/14)

Hi Oilie glad to hear things went better. How did you compare the methods?


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## Burt de Ernie (15/6/14)

> Hi guys
> 
> So today was brew day and plumbed up the chiller all good and proper with new fittings from Bunnings.
> 
> ...


I assume that you did two brews today and tested them side by side and agitated equally.

What flow rate did you run each chiller at?


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## Ollieb (15/6/14)

Burt de Ernie said:


> I assume that you did two brews today and tested them side by side and agitated equally.
> 
> What flow rate did you run each chiller at?


 Hey Burt - so I was not that technical and didn't do a side by side brew but i def agitated the same way and with the same energy. Basically a circular motion in the kettle which almost created a gentle whirlpool....

For the flow rate I tested a quarter turn of the tap and a half turn to figure out the flow rate.

I was very clear that the slower water flow worked better. As soon as you turned up the tap to the half turn mark it started flowing luke warm then after about 5 seconds to almost cold water.
Slow it down and within about 10-15 seconds the temp of the outflow increased heaps. Then agitate the chiller in the kettle and it dropped again.

Took me 30 mins to get it from boiling to 25 degrees. I was really happy with the results.


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## Bribie G (15/6/14)

How about attaching a vibrator (massage type vibrator) to the copper pipe to break up laminar flow?


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## Burt de Ernie (15/6/14)

Cool, now I understand....but I think you missed the point.

Nobody disputed that lower flow equals higher temperature discharge however, the temperature of the discharge water is not an indicator on how fast the wort is cooling.

The whole point to your thread is that you wanted to drop the wort temperature faster, not increase the temperature of the discharged cooling water.

The positive is that your experiment findings are useful if your intention is to use hot cooling water for cleaning your brewing gear.


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## Burt de Ernie (15/6/14)

> How about attaching a vibrator (massage type vibrator) to the copper pipe to break up laminar flow?


I don't think his mum will let him use it for that!


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## TheWiggman (15/6/14)

Just as important as the flow inside the tube is the flow outside, as you found out. The more you move it around the better it'll work, otherwise you just chill the liquid in contact with the pipe. You want it to chill everything. 30 mins isn't all that long really. Though in Orange it maxed at 6°C today and I reckon it would have done the same just sitting there. 
I'll bet a bag of snakes cranking the water up would have dropped your time, but it wouldn't have been much. Conserve water and carry on I say.


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## TheWiggman (15/6/14)

Actually while you're experimenting, move the chiller around a bit with moderate flow until the water's coming out almost scalding hot. Then, drop it there and don't move it. Give it a min or 2 until it starts coming out cooler and then agitate the chiller again. It's crazy how much hotter it will come out just by doing that.


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## Burt de Ernie (15/6/14)

> Actually while you're experimenting, move the chiller around a bit with moderate flow until the water's coming out almost scalding hot. Then, drop it there and don't move it. Give it a min or 2 until it starts coming out cooler and then agitate the chiller again. It's crazy how much hotter it will come out just by doing that.


With this experiment the discharge temp does matter!


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## Bribie G (16/6/14)

I could collect it in my black camping shower bag and have a shower. Howdy neighbours.


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## Goose (16/6/14)

Ollieb said:


> Hi guys
> 
> So today was brew day and plumbed up the chiller all good and proper with new fittings from Bunnings.
> 
> ...



Howdy Ollie. Thanks for posting this.

As said, there are many variables involved. As homebrewers, the ones in our control are the temperature of the cooling water inlet, its flowrate, and also the one you have identified which is the flowrate of the wort across the surface where we are trying transfer the heat. In the case of an immersion chiller, that would mean how fast the wort is circulated around the immersion chiller coils, and in the case of a plate chiller how fast it allowed to pass through the exchanger.

It would be a challenge to make an accurate conclusion as to the effect of cooling water flowrate on rate of heat removal from the wort unless you can keep all the other variables constant. That would probably best be tested by two consecutive cooling runs where you measure the temperature of the _wort _as a function of time for a fixed cooling water flowrate. I am assuming your cooling water starts at ambient and there will not be much variation in that, and that however you agitate the wort is the same for each run you do. Every other variable should be the same as well, including where you measure the temperature of the wort.

It is meaningless to make a judgement on the rate of heat removal based on the cooling water exit temperature if you are also changing the wort flowrate by random agitation, and changing the cooling water flowrate during the run.

Would be great if you could re-run the experiment as described above and let us know the result. You don't need to do it on wort either, just use water in place of wort for the purposes of the experiment.


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## Ollieb (17/6/14)

Goose said:


> Howdy Ollie. Thanks for posting this.
> 
> ....
> 
> Would be great if you could re-run the experiment as described above and let us know the result. You don't need to do it on wort either, just use water in place of wort for the purposes of the experiment.


Hey Goose
Next time the burner is firing up will def not be for only water! ... I will be sure to give it another test and let you guys know any more details I get but it will not be for a few weeks as I am heading away.
Cheers


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## Ducatiboy stu (17/6/14)

Did you constantly agitate or move the wort.

Its really going to be meaningless if you didnt.

What you need is a way of agitating it at a constant rate...some sort of mixer paddle in the middle of the coil with a fixed speed. That way you know the wort is agitating at the same constant speed for both tests.


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## Parks (17/6/14)

It was already meaningless as he judged based on the temperature of the outlet water.


Sent from my iPhone using Tapatalk


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## Ducatiboy stu (17/6/14)

True


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## Bribie G (17/6/14)

Just jumping on here to ask something I posted a few days ago but no response, and I don't think it's worth raising a thread:

Do pond pumps of the sort sold by Bunnings or Masters use normal garden hose or do you have to get a special hose for I/O ?


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## wide eyed and legless (17/6/14)

The temperature of the outlet water can be monitored as long as the temperature of the wort is being monitored at the same time and the outlet temperature has to be lower than that of the wort otherwise the heat from the outlet will be heating the temperature of the wort.
Bribie I have a pond pump and it does take a garden hose.


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## Bribie G (17/6/14)

Cheers, I'll hit up Masters tomorrow.


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## danestead (17/6/14)

wide eyed and legless said:


> The temperature of the outlet water can be monitored as long as the temperature of the wort is being monitored at the same time and the outlet temperature has to be lower than that of the wort otherwise the heat from the outlet will be heating the temperature of the wort.
> Bribie I have a pond pump and it does take a garden hose.


In reference to this, if it was a counterflow copper coil chiller or counterflow plate chiller, I'm thinking it would be possible to have hotter water coming out of the outlet of the chilling water, than the outlet of your wort going into the fermenter. I haven't tested this, however Im thinking it's possible.

Thoughts?


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## Goose (17/6/14)

> What you need is a way of agitating it at a constant rate...some sort of mixer paddle in the middle of the coil with a fixed speed. That way you know the wort is agitating at the same constant speed for both tests.


The best way that I have seen is in the Cheeky Peak 3V setup. Check out the lower pump and the inlet/outlet to the boiler. That's a whirlpool system which is operated as you cool, to keep the wort circulating in the HLT which also serves the purpose of coning the trub in the centre prior to rundown to the fermenter. Great idea IMHO.


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## Bribie G (17/6/14)

danestead said:


> In reference to this, if it was a counterflow copper coil chiller or counterflow plate chiller, I'm thinking it would be possible to have hotter water coming out of the outlet of the chilling water, than the outlet of your wort going into the fermenter. I haven't tested this, however Im thinking it's possible.
> 
> Thoughts?


That makes my brain hurt.


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## Parks (17/6/14)

danestead said:


> In reference to this, if it was a counterflow copper coil chiller or counterflow plate chiller, I'm thinking it would be possible to have hotter water coming out of the outlet of the chilling water, than the outlet of your wort going into the fermenter. I haven't tested this, however Im thinking it's possible.
> 
> Thoughts?


No.

Yeah, I re-read it and decoded the cypher and I agree with below it should be OK but not sure what the point is.


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## Goose (17/6/14)

danestead said:


> In reference to this, if it was a counterflow copper coil chiller or counterflow plate chiller, I'm thinking it would be possible to have hotter water coming out of the outlet of the chilling water, than the outlet of your wort going into the fermenter. I haven't tested this, however Im thinking it's possible.
> 
> Thoughts?


of course. but what is _not_ possible is to have the wort _exit_ temperature be lower than the cooling water _inlet_ temperature.

(That is if I read your hypothesis correctly, and I am referring to a plate chiller)


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## Ducatiboy stu (17/6/14)

Or the wort inlet temp lower than your chiller out temp.


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## danestead (17/6/14)

Ive even confused myself here. I cant even figure out how to put what i was meant to be getting at into words haha


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## danestead (17/6/14)

Ok, I think i have sussed out what was going on in my brain a few minutes ago. I was mistakenly thinking he was saying that your cooling water outlet must be cooler than the 'outlet of the wort' ie into the fermenter. On rereading he was actually saying it must be cooler that the wort still in your kettle, which makes sense now.

Anyway, back to my counterflow chiller theory, if you had 100 degree wort and 20 degree tap water and you ran them at the same flow rate, you would expect the temperature to equal out in the middle ie 60 degrees, however because I was talking about a counterflow chiller, you will do better than halfway ie 50 degrees or whatever.

If you flow your tap water faster than the wort though, you'd expect the wort to chill down to much lower than 50 degrees though.

Ok. Ill just shut up now and go back to my box

Edited: added some stuff and rephrased


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## Ducatiboy stu (17/6/14)

Um....er...no...would depend on your volumes, surface areas, length etc

You would get a different result if you used different sized tube. 

The longer/bigger you counter flow chiller the more heat you can transferr


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## Parks (17/6/14)

Your wort should be 20 degrees coming out of the chiller in this case. You need to have the wort flow slow enough and the water flow fast enough to achieve it.


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## danestead (17/6/14)

Ducatiboy stu said:


> Um....er...no...would depend on your volumes, surface areas, length etc
> 
> You would get a different result if you used different sized tube.
> 
> The longer/bigger you counter flow chiller the more heat you can transferr


Yep you are right, I'm just retarded and should just keep quiet. I know how it all works, I am just hopeless at explaining and am missing bits here and there


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## Burt de Ernie (17/6/14)

wide eyed and legless said:


> The temperature of the outlet water can be monitored as long as the temperature of the wort is being monitored at the same time and the outlet temperature has to be lower than that of the wort otherwise the heat from the outlet will be heating the temperature of the wort.


So, by this statement it sounds like you are saying you can heat the wort using a chiller and cold water??

I must be reading this wrong.....what is it? Cold fusion?


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## Burt de Ernie (17/6/14)

danestead said:


> In reference to this, if it was a counterflow copper coil chiller or counterflow plate chiller, I'm thinking it would be possible to have hotter water coming out of the outlet of the chilling water, than the outlet of your wort going into the fermenter. I haven't tested this, however Im thinking it's possible.
> 
> Thoughts?


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## Back Yard Brewer (18/6/14)

peter.b said:


> Is it a counterflow or straight immersion?? Its all about flow rate. Too fast and the cooling water wont be in contact with the hot stuff for long enough to absorb the heat. Stainless is great for cleanliness but not the worlds greatest heat conductor. Copper is better for heat transfer. Slow your flow and give that a crack.
> 
> Beers,


My chiller of choice. Expensive but I swear by it. http://wortwizard.com/cart/ChillZilla-Chiller


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## wide eyed and legless (18/6/14)

Burt de Ernie said:


> So, by this statement it sounds like you are saying you can heat the wort using a chiller and cold water??
> 
> I must be reading this wrong.....what is it? Cold fusion?


I am referring to a copper immersion chiller, cold water goes in and as the heat exchange takes place the water coming out is hot, when travelling through to slow the cooling will heat up to the same temp as the wort, therefore keeping the wort at a high temp speeding up the water just enough to have the water coming out a few degrees less than the temp of the wort would be ideal.


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## TheWiggman (18/6/14)

Not necessarily wideeyed. Many in this thread are focussed on the temp of cooling water coming out. Think of it the other way around - the temp of the coil in the wort.
Because really, what are we looking at here? Trying to heat the water (eg. HERMS) or trying to cool the wort?

Assume tap water is 20°C.
If I dipped a big coil in the wort that maintained a constant temp of, say, 20°C across the entire coil then the wort will be exposed to a big thing which is a lot cooler than the wort. Ignoring the "doesn't have time to transfer heat" argument (which is false) just think what's going to happen if you have a big coil in the wort that stays at 20°C. The liquid contacting it will be 20°C, and thus the more it's moved around the quicker it will chill the whole thing because it's not relying on conduction.

If the liquid is running absolutely flat out i.e. at theoretical limits the IN temp of the water will be 20°C and the OUT temp will be 19.99°C. The majority of the coil will be very cold. More exposure to cold = quicker chilling.
If the cooling liquid is slowed so that you have OUT at 80°C immediately after flameout then there will be a big temperature gradient from 20 - 80°C across the length of the coil, because the wort is heating the cooling water. Thus less exposure to cold = slower chilling.

Again, ignore the cooling water and just think about what the liquid in the kettle is seeing - if it's exposed to a large, cold surface then it will chill. The colder and greater the surface area, the faster it will reach that temp.


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## wide eyed and legless (18/6/14)

*heat exchanger**,* any of several devices that transfer heat from a hot to a cold fluid. In many engineering applications it is desirable to increase the temperature of one fluid while coolinganother.


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## Goose (18/6/14)

wide eyed and legless said:


> _Speeding up the water just enough to have the water coming out a few degrees less than the temp of the wort would be ideal. _


Ideal for the hottest exit cooling water you can achieve. Ideal to save water too, and great if you need hot water for a shower or washing up. But not necessarily good for cooling your wort as quickly as possible


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## TheWiggman (18/6/14)

Exposing something cold to something hot will result in an exchange of heat (or more to the point, energy). It is not desirable to increase the temp of the cooling fluid, it's desirable to decrease the temp of the wort.
If water's running through the coil an exhange of energy will take place no matter what - didn't think I needed to say that. As I and others have said earlier, the more turbulent the water is, the more effective the heat transfer.

Stop thinking about what's happening to the cooling water, think about what the wort is being exposed to first. That should tell you why you don't want hot water coming out of the coil (assuming you have good flow outside the coil).


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## wide eyed and legless (18/6/14)

They are called heat exchangers for a reason, heat is exchanged from one fluid to another, in this case the wort to the cooling fluid, the outlet of the cooling water temperature is significant, if it is hot then an exchange of heat is taking place,and rapidly taking heat away from the wort.

http://www.engineersedge.com/heat_transfer/parallel_counter_flow_designs.htm


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## Ducatiboy stu (18/6/14)

But if it is hot comming out, then it cant transferr as much heat from the hot wort. If the the chiller water is heating up in the first section of the coil, at the chiller input/ wort output, and remains hot all the way to the other then it cant transferr as much heat as the chill water is hot for the remaining section. If the water coming out of the chiller at the wort input end is cold then it will start to chill the wort right at the start instead at the other end. If the wort hits cold water at the input of the chiller then its going to be able to transferr more heat along its path to the output because its in contact with cold water for longer.


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## Online Brewing Supplies (18/6/14)

All my experience with chilling has been with plate chillers both commercial and at home.
My point from the beginning is there is a sweet spot (balance point) when chilling where you are getting maximum efficiency from your cooling process given a set apparatus..
IE you turn up cold flow it does nothing to increase heat removed from the wort in the chiller, (as shown on an outlet thermo), this is a practical example not theories on paper and after all aren't we looking for the most efficient way to achieve the result ? I know I am.
Nev


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## TheWiggman (18/6/14)

You're right Nev, there will be a point at which there will be little to no gain. You're saying you're judging this on the wort temperature - THAT'S what matters. With an immersion chiller it's nigh-on impossible to know this point. Textbook examples will give you the same results.



wide eyed and legless said:


> "if it is hot then an exchange of heat is taking place,and rapidly taking heat away from the wort."
> 
> http://www.engineersedge.com/heat_transfer/parallel_counter_flow_designs.htm


This statement is incorrect. If the temperature _has changed_ it means an exchange of heat is taking place. It doesn't need to be hot for the many reasons explained before. The link you sent me is for a counterflow which is a different system, but still proves that point. High temp difference = better. If the Tcout on the graph on the right was lower, you'll maintain a high temperature difference which will give you a Thout that is lower.

I think I've reiterated the same point enough - I'm abandoning this thread!

ED: Please disregard any theory and continue to sell the HERMS coils Nev because they work a treat.


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## Ducatiboy stu (18/6/14)

wide eyed and legless said:


> if it is hot then an exchange of heat is taking place


It has taken place. Once its hot it can no longer transferr anymore heat. Once its hot you need to move it so that more water can exchange heat.

If your not moving the chilling water away from the hot wort it will just heat up and stay hot.


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## wide eyed and legless (18/6/14)

Ducatiboy stu said:


> It has taken place. Once its hot it can no longer transferr anymore heat. Once its hot you need to move it so that more water can exchange heat.
> 
> If your not moving the chilling water away from the hot wort it will just heat up and stay hot.


Of course, but the cooling water is not static it is moving through the heat exchanger constantly, picking up the convected heat, I have a copper coil made from 19 mm tube and do as you used to do, my cooling water recirculates from the bottom of 5000 litre water tank and cools the wort down in no time, if as has been said in previous posts the wort is kept moving.
Which method would be the quickest, to keep the coil at a lower temperature by speeding up the water and stirring the wort as Wiggman suggests I don't know, but I was more than happy with the way I was doing it when I was cooling my wort instead of no chilling. Also it would depend on each individual with whatever they are using to cool the wort and if they have a supply of water like a tank or having to use town water.


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## Goose (18/6/14)

Howdy WEAL,

I am a Goose, so am struggling to see your point. Are you able to state it succinctly please ?

Cheers


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## wide eyed and legless (18/6/14)

Hi Goose,
Its pretty straight forward,I have, as said above a 19 mm copper coil immersed in the wort, cold water went in and hot water came out, my water is drawn from the bottom of a water tank and the heated water goes back in to the top of the tank, I never measured the temp of the water coming out but it was an efficient way for me to cool the wort effectively.
If the flow of the water is to slow the heat from the wort will not dissipate effectively so the balance has to be found for the equipment the brewer is using as Nev stated.


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## Burt de Ernie (18/6/14)

> I am referring to a copper immersion chiller, cold water goes in and as the heat exchange takes place the water coming out is hot, when travelling through to slow the cooling will heat up to the same temp as the wort, therefore keeping the wort at a high temp speeding up the water just enough to have the water coming out a few degrees less than the temp of the wort would be ideal.


Ok ...I misunderstood however if you want to chill wort fast, the colder the discharge water the quicker the chill.


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## Burt de Ernie (18/6/14)

> They are called heat exchangers for a reason, heat is exchanged from one fluid to another, in this case the wort to the cooling fluid, the outlet of the cooling water temperature is significant, if it is hot then an exchange of heat is taking place,and rapidly taking heat away from the wort.
> 
> http://www.engineersedge.com/heat_transfer/parallel_counter_flow_designs.htm


This is poor theory....simple fact is... the cooler the discharge water...the quicker the wort temp will drop.

As previously proved in this thread, the way to get cooler discharge is to increase flow. The result of this is that the wort cooling time will be reduced


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## wide eyed and legless (19/6/14)

I am on the right tram now, found some very informative articles on some of the American brewing sites, going through Chemo at the moment so the little grey cells aren't working quite so good,apologies to Wiggman, he was right and I was wrong.


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## Burt de Ernie (19/6/14)

> going through Chemo at the moment so the little grey cells aren't working quite so good


Oh man....sorry to hear this and I hope get and feel well soon!


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## dago001 (19/6/14)

Maybe some of the google experts should go and buy an immersion chiller and give it a try instead of howling down those that own one and give their honest opinions to what is actually occurring for them.
A bloke asked for help - a few offered help - a lot argued about it - some did their research - op did his test and reported back his results - a few still argue the semantics of the result.
Give it a rest fellows - buy a chiller and turn the tap on - do your own tests and stop arguing theory.
Cheers
LB


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## Black n Tan (19/6/14)

Are you serious LB? I have found this a good and robust discussion. Do you recall calling people that had a different view to you "Foundation member of the Flat Earth Society"? No-one here has treated you with the same disrespect. A lot of strong theory and practical data has been presented and I don't think it can be any clearer: increasing flow rate increases performance (time to cool wort), but is less efficient (amount of water required to cool wort). The engineers and scientists agree (I am a scientist BTW and own and use an immersion chiller). OllieB said his findings were to the contrary, but upon further clarification it became apparent that he was measuring the coolant temperature (efficiency) and therefore once again his observation was consistent with the theory. If you can produce some data that contradicts the aforementioned theory and practical data, I and the scientific community would love to see as it would turn a number of theories on their head. In the meantime I will continue to turn my tank water on full.


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## dago001 (20/6/14)

Nope - The OP stated early on that he tried to cool his boiling wort with his immersion chiller, at full flow from the tap and it took 30 minutes to get to 50 degrees. His subsequent test showed that a reduced flow rate gave him a result of cooling his wort to 25 degrees in 30 minutes. I never argued that the science isnt correct, because it is. But flow rate is important. And many people confuse flow rate with pressure. The test that was originally posted from the Zymurgy article was stating 2.5 - 3 US gpm (approx 11lpm ) flow rate. Im not too sure what your flow rate from your tank water is, but my flow rate is over 30 lpm from my mains. The whole exercise is to reduce the temperature of the wort as quickly as possible, and all the texts that I have read all state that the flow rate for an immersion type chiller has to be managed to get the best result. Counter flow chillers are a different beast. I use a plate chiller and get the best results from a higher flow rate, in fact a flow rate similar to what I used for my immersion chiller gives a very poor result.
The important issue that needs to be remembered is that while google is everybodies friend, we are all correct, have the relevant qualifications to discuss this (I'm a plumber by the way, drive a holden, prefer Fender guitars and tube amps) the OP wanted to cool his wort quicker.
Im not too sure how to measure "turn my tank water on full". But it doesnt seem very scientific to me. I thought scientists pushed the boundaries, experimented to determine results, questioned theories to find better ways, researched, but no they "turn their tank water on full" because google said so. How many lpm is that??? - but at around 10-11 lpm as per the zymurgy article, thats where my immersion chiller worked best. How did I work this out. I experimented with multiple brews to get the optimum results.
Turn your tap on until you get a full pipe of water coming out of the immersion chiller. That (IMHO) is the best flow rate for an immersion chiller.
Cheers
LB
OH, and sarcasm is lost on the internet.


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## booargy (20/6/14)

Black n Tan said:


> (I am a scientist BTW and own and use an immersion chiller).


Being a scientist means **** all and what do you study immersion chillers. Bit like someone who studies medicine telling someone who studies climate that sea levels arent rising. Or because I am doing an electrical trade I know all about baking.


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## StalkingWilbur (20/6/14)

Hahaha. This thread is hilarious.


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## Burt de Ernie (20/6/14)

I feel like we are traveling in circles.


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## Burt de Ernie (20/6/14)

LagerBomb said:


> LB
> OH, and sarcasm is lost on the internet.


but you are right with this point....I am having a lot trouble pulling you're sarcasm out of you're trolling.


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## Burt de Ernie (20/6/14)

Black n Tan said:


> Are you serious LB? I have found this a good and robust discussion. Do you recall calling people that had a different view to you "Foundation member of the Flat Earth Society"? No-one here has treated you with the same disrespect. A lot of strong theory and practical data has been presented and I don't think it can be any clearer: increasing flow rate increases performance (time to cool wort), but is less efficient (amount of water required to cool wort). The engineers and scientists agree (I am a scientist BTW and own and use an immersion chiller). OllieB said his findings were to the contrary, but upon further clarification it became apparent that he was measuring the coolant temperature (efficiency) and therefore once again his observation was consistent with the theory. If you can produce some data that contradicts the aforementioned theory and practical data, I and the scientific community would love to see as it would turn a number of theories on their head. In the meantime I will continue to turn my tank water on full.


relax...LB is just trolling you.


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## wide eyed and legless (20/6/14)

Thanks for your consideration Burt de Ernie (21 days in another 147 days to go of feeling shit) 
What I was wondering was the immersion chiller with the greatest surface area in the i.e. tightly wound coils would it be possible that this would work quite differently to one with loosely wound coils and less surface area, obviously the first would rapidly cool the wort
with a fast flow but would it also be right that the cooling liquid would come out a lot warmer than one with the less surface area due to the length of time travelling through the hot coil.


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## Ducatiboy stu (20/6/14)

Burt de Ernie said:


> I feel like we are traveling in circles.


No...its more of a spiral. We have completed the first loop in an immersion coil. And its going to spiral right to the bottom...


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## Ducatiboy stu (20/6/14)

wide eyed and legless said:


> Thanks for your consideration Burt de Ernie (21 days in another 147 days to go of feeling shit)
> What I was wondering was the immersion chiller with the greatest surface area in the i.e. tightly wound coils would it be possible that this would work quite differently to one with loosely wound coils and less surface area, obviously the first would rapidly cool the wort
> with a fast flow but would it also be right that the cooling liquid would come out a lot warmer than one with the less surface area due to the length of time travelling through the hot coil.


In theory, a larger surface area will chill quicker. Be it more coils or a bigger diameter tube.


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## Black n Tan (20/6/14)

booargy said:


> Being a scientist means **** all and what do you study immersion chillers. Bit like someone who studies medicine telling someone who studies climate that sea levels arent rising. Or because I am doing an electrical trade I know all about baking.


Agreed, my comment came off as arrogant and self-serving -_-, which wasn't my intention. It was meant to read in the context of LB accusing those that disagreed with him as being "google experts" who didn't even own an immersion chiller. I felt I was neither of those things. You don't need a PhD in immersion chilling to get involved and I am in no doubt that electricians and bakers can equally contribute to the debate. h34r:


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## Ducatiboy stu (20/6/14)

Indeed we can.

Here is my scientific conclusion.

You put immersion chiller into hot wort. You run cold water thru coil. Eventually the wort cools. Sometimes it takes 3 beers, sometimes 4. 

Once wort is cool you put into fermenter.


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## barneyhanway (20/6/14)

Lagers cool more quickly than ales though right? Surely we can all agree on that :blink:


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## Dave70 (20/6/14)

barneyhanway said:


> Lagers cool more quickly than ales though right? Surely we can all agree on that :blink:


Only if you paint your cube black - in accordance with Kirchhoff law of thermal radiation. 


Doin a doppelbock this weekend. 
Gonna no chill. 

Just say'n..


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## Ducatiboy stu (20/6/14)

That means stout chills quicker than pale.

Makes sense.


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## pk.sax (20/6/14)

Ducatiboy stu said:


> That means stout chills quicker than pale.
> 
> Makes sense.


Just to round it off, I take racial offence to that.


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## Burt de Ernie (20/6/14)

Ducatiboy stu said:


> Indeed we can.
> 
> Here is my scientific conclusion.
> 
> ...


I only ever get 2 beers in. This must be because of the higher flow through my chiller!


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## Ducatiboy stu (20/6/14)

Burt de Ernie said:


> I only ever get 2 beers in. This must be because of the higher flow through my chiller!


Some of us drink quicker than others.....


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## Online Brewing Supplies (20/6/14)

I get 4 down because I go for efficiency and I like beer


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## Ducatiboy stu (20/6/14)

practicalfool said:


> Just to round it off, I take racial offence to that.


Chill bro


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## Burt de Ernie (20/6/14)

Ducatiboy stu said:


> Some of us drink quicker than others.....


Obviously your scientific testing system is well worked!


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## pk.sax (20/6/14)

Ducatiboy stu said:


> Chill bro


Ah, OK then.


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## danestead (20/6/14)

Ducatiboy stu said:


> Some of us drink quicker than others.....


My immersion chiller drinks quicker....


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## Steve (20/6/14)

so is it better to have the water go straight down to the bottom and work its way up the coils or the other way around?


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## Ducatiboy stu (20/6/14)

Steve said:


> so is it better to have the water go straight down to the bottom and work its way up the coils or the other way around?


Good question.

Prob depends on how many beers you have left over..


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## Dave70 (20/6/14)

Steve said:


> so is it better to have the water go straight down to the bottom and work its way up the coils or the other way around?


I'd say it makes no difference. I'd put money on it.


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## Ducatiboy stu (20/6/14)

$1.50. Each way

or

$1.10 on the nose.


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## Steve (20/6/14)

Legit question. Haven't used a chiller in 7-8 years and after a 3 year break from AG brewing decided to get back on it and built myself a new one and have forgotten which way the plumbing went.


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## Ducatiboy stu (20/6/14)

Steve said:


> Legit question. Haven't used a chiller in 7-8 years and after a 3 year break from AG brewing decided to get back on it and built myself a new one and have forgotten which way the plumbing went.


In theory put the input at the then go and grab a beer....

I can see engineers fighting over this one...heat rises to the top..but pumping hot chiller fluid down to the ( theoretical) cold bottom could heat the wort at the bottom.

After4 beers...if it isnt getting cold....then I would swap taps in the laundry sink...


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## Mattrox (20/6/14)

Steve said:


> so is it better to have the water go straight down to the bottom and work its way up the coils or the other way around?


Conventional practical procedure has water flow against gravity as much as possible. This allows maximum contact of water to heat exchanging surface. Since most heat exchange occurs in the coil, I'd say water traveling up the coil. 

Move the wort around to prevent cold wort gathering at the bottom.


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## dago001 (20/6/14)

I'm going no chill. Botulism over Internet arguements any day.


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## Steve (21/6/14)

Mattrox said:


> Conventional practical procedure has water flow against gravity as much as possible. This allows maximum contact of water to heat exchanging surface. Since most heat exchange occurs in the coil, I'd say water traveling up the coil.
> 
> Move the wort around to prevent cold wort gathering at the bottom.


 Thanks...will do. I used to stir the wort and it worked well and whirlpooled the trub at the same time.
Cheers
Steve


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## Steve (21/6/14)

LagerBomb said:


> I'm going no chill. Botulism over Internet arguements any day.


Know what you mean. This thread gave me a headache half way through. I went no chill for years but after a spate of infections (that eventually led to me packing it in) im going back to what worked for me.
Cheers
Steve


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## lael (21/6/14)

I found a solution:

http://www.marshallscientific.com/Thermo-EK45-Immersion-Chiller-p/th-ek45.htm


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## dago001 (21/6/14)

lael said:


> I found a solution:
> 
> http://www.marshallscientific.com/Thermo-EK45-Immersion-Chiller-p/th-ek45.htm


+ - youll earn 25 points towards a future purchase - bargain.


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## pk.sax (21/6/14)

Did some actual flight testing this week.

Amazing what flow separation can do. The flow reverses direction in some areas and literally goes in circles in others. All it takes is a little breaking up of the laminar flow. Different speeds make sod all difference, 120 knots to 220 knots. Doesn't matter, separation is key to turbulent flow. My guess is it would yield far greater dividends than in leaving flow rate.

We could see the zones on the belly where there was no separation, at higher and higher speeds the flow still remained stubbornly laminar.

And yes, the earth is not flat. I cannot quote more or I will have to send the asio over to abduct you and transport you to woomera.


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## itmechanic (21/6/14)

Really cant believe I just read through this thread.
Knockout of 540L of wort to 23 degrees takes about 15 minutes on my 7m3 plate chiller, I end up with about 600L of 65 degree hot water in the HLT.
I can knock out heaps faster by increasing both coolant and product flow, to a point, the further its pushed the less cooling effect. Yes faster coolant flow will cool faster, and yes faster coolant flow will cool slower, depending on all the other variables involved.
An immersion chiller is a whole different scenario, the closer the product temperature to the coolant temperature the less efficient the heat exchange will be.
Crashing a tank from 20 to 10 degrees takes only an hour, whereas taking a tank from 5 to 2 degrees takes hours, the closer you get to the coolant temperature the longer it will take. In my case glycol temperature is -2 degrees.


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## Burt de Ernie (22/6/14)

I just so happened to be watching the BREWHA instructional video and they say it all @ 25.43.

https://www.youtube.com/watch?v=6ojtYKokOD8#t=437


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## Bribie G (24/6/14)

I had one of those moments as I woke up this morning and said "Ha".

When I get my immersion chiller in couple of weeks I intend, as suggested by an earlier poster, to use a $25 submersible pond pump dropped into around 70 L of water at 2 degrees in my 60L fermenter (will fit)

Then recirculate that through the coil immersed in 23L of wort at 100 degrees.

So when the heat exchange has been finally done, it's the equivalent of mixing 70 and 23 litres at different temperatures.

I used the handy tool Online Conversion of Liquids and it shows me that the final temperature would be a somewhat disappointing 26 degrees.
However subbing six kilos of ice for some of the coolant water (2 ice cream 3L containers) would bring me down to around 18 degrees that would be good... finish off to lager temps in the FV before pitching.

Then the 70 L of coolant can be run straight out to the veg garden that's just outside the door. This I expect would lead to a fairly rapid cooling initially, then diminishing returns as the system trends towards equilibrium. However minimal water usage and the plants get a drink, which I'd be doing anyway as it's the dry season here, supposedly.

I'll post results.


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## Online Brewing Supplies (24/6/14)

Burt de Ernie said:


> I just so happened to be watching the BREWHA instructional video and they say it all @ 25.43.
> 
> https://www.youtube.com/watch?v=6ojtYKokOD8#t=437


Yes your right its a classic example of a very inefficient way to chill, just let the wort sit there with no motion and expect to chill it by throwing 5000L of chill water at it. :huh:
That expensive equipment just got a whole lot more expensive to use.
Nev


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## Bribie G (24/6/14)

That's five _tonnes _of water :blink:


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## Online Brewing Supplies (24/6/14)

Maybe a SLIGHT exaggeration on my behalf to make a point.


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## pk.sax (24/6/14)

Bribie G said:


> I had one of those moments as I woke up this morning and said "Ha".
> 
> When I get my immersion chiller in couple of weeks I intend, as suggested by an earlier poster, to use a $25 submersible pond pump dropped into around 70 L of water at 2 degrees in my 60L fermenter (will fit)
> 
> ...


I know you are usually right, but, ice will also suck energy due to the act of melting and also, how below 0C it is when you chuck it in. Might get you to lager temps yet


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## Burt de Ernie (24/6/14)

> Yes your right its a classic example of a very inefficient way to chill, just let the wort sit there with no motion and expect to chill it by throwing 5000L of chill water at it. :huh:
> That expensive equipment just got a whole lot more expensive to use.
> Nev


5m3 of water?? WTF! Please...


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## Goose (24/6/14)

> So when the heat exchange has been finally done, it's the equivalent of mixing 70 and 23 litres at different temperatures.
> 
> I used the handy tool Online Conversion of Liquids and it shows me that the final temperature would be a somewhat disappointing 26 degrees.




Did somebody mention ice ?



Have posted this before but for good order;


1) it takes 4.18 KJ for every Kg of water, to raise or lower the temperature by 1 degree C

2) it takes 334 KJ for every Kg of water to phase change to ice at 0 deg C and visa versa

so you can see that a little bit of ice goes a long way in terms of cooling potential versus a water bath .... ie just 16 litres of melted ice warmed to 26 deg C has the same heat removal capability of 70 litres of your 2 degree C water moving up to 26 deg C...

a little bit of ice goes a long way... fwiw LOL


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## itmechanic (24/6/14)

Its a bit hard to pump ice though.


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## lael (24/6/14)

Is it cheaper to use 70L of cold water or pay for the electricity to freeze 20L?


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## Goose (24/6/14)

itmechanic said:


> Its a bit hard to pump ice though.



let me think about how you solve this one B)


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## zarniwoop (25/6/14)

Goose said:


> Did somebody mention ice ?
> 
> 
> 
> ...


I knew number 1 but didn't know 2, thanks.


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## Not For Horses (25/6/14)

Online Brewing Supplies said:


> Yes your right its a classic example of a very inefficient way to chill, just let the wort sit there with no motion and expect to chill it by throwing 5000L of chill water at it. :huh:
> That expensive equipment just got a whole lot more expensive to use.
> Nev


5000L?! That's about $4 here in Tas. Can't get rid of the stuff fast enough


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## Goose (25/6/14)

itmechanic said:


> Its a bit hard to pump ice though.


Ok I'll remove the sarcasm.

The point I was trying to make is that a huge amount of heat is removed by process of the phase change from ice to water. So if Bribie still wants to use his 70 litre cold water reservoir AND achieve a lower equilibration temperature than 26, he can easily calculate how much ice he needs to throw in for his target temperature.

Thankyou, and goodnight.


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## dago001 (25/6/14)

Not For Horses said:


> 5000L?! That's about $4 here in Tas. Can't get rid of the stuff fast enough


Might be at the moment, but the way the water authorities are being run you might have to add a few zeros to that in a couple of years.


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## Parks (25/6/14)

Hrmz, you didn't mention what temperature the ice was...


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## Goose (25/6/14)

Parks said:


> Hrmz, you didn't mention what temperature the ice was...



I assumed zero degrees for sake of example. 

Unless you are referring to the heat capacity of ice .. .


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## Parks (25/6/14)

Well the ice coming from my freezer is -28deg C which would make a massive difference to the cooling capacity compare to 0.


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## Goose (25/6/14)

Wouldn't say massive. A bit, and almost insignificant when compared to the phase change heat needed to melt ice. It is also worth noting that the heat capacity of ice is about half that of water (see below), though every bit helps.

Specific heat capacity, ice: 2.108 kJ/kg-K
Specific heat capacity, water: 4.187 kJ/kg-K
Latent heat of melting, ice to water: 334 kJ/kg-K


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## Parks (25/6/14)

Wow, that's really interesting. So that means it takes roughly twice as much energy to increase water temp as ice temp?


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## Goose (25/6/14)

> Wow, that's really interesting. So that means it takes roughly twice as much energy to increase water temp as ice temp?


for the same weight, correct


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## Mattrox (26/6/14)

To add to what Goose has said......

Have enough water to be pumped through the system. Dump enough block ice in the water. Add a good dose of salt. 

That will reduce the temperature of the water..... while there is ice still in it.... to below 0° if you do it right.


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## Goose (26/6/14)

> Add a good dose of salt.
> 
> That will reduce the temperature of the water..... while there is ice still in it.... to below 0° if you do it right.


Interesting one. Yes it would reduce the temperature of the water.... but not so sure I want salt on the water side of my plate chiller somehow... :unsure:


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## Parks (26/6/14)

Not to mention the fact I don't like putting salt on my garden.


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## Bribie G (26/6/14)

I'd forgotten about the latent heat of melting / freezing. Will recalculate.


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## Mattrox (26/6/14)

Goose said:


> Interesting one. Yes it would reduce the temperature of the water.... but not so sure I want salt on the water side of my plate chiller somehow... :unsure:


Not sure how a plate chiller works, but in a copper coil it should be fine.


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## Mattrox (26/6/14)

Parks said:


> Not to mention the fact I don't like putting salt on my garden.


Think of it as bath salts.... warm bath after a brew session?


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## The Judge (27/6/14)

Be mindful that long exposure to salt water can foster corrosion. Glycol is harder to get your hands on, but won't corrode your fancy steel and alloys.


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## pk.sax (28/6/14)

I can attest to the corrosion issue. However a soft water rinse goes a long way in negating that, don't leave any salt on the steel when it goes dry.


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## Ducatiboy stu (28/6/14)

Putrino said:


> Be mindful that long exposure to salt water can foster corrosion. Glycol is harder to get your hands on, but won't corrode your fancy steel and alloys.


Its in every car parts shop. Even BigW & Kmart.

Its the green stuff you put in your radiator


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## The Judge (28/6/14)

Totally never thought of that Stu


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## itmechanic (28/6/14)

I wouldn't use automotive glycol under any circumstances (ethylene glycol), you should use a food grade polypropylene glycol in case of accidental leaks and ingestion. Not really that hard to come by.


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## booargy (28/6/14)

Cheaper to buy metho in 20L drum about from bunnings if it contaminates your brew you will know but it won't kill you. If you have noticed 40% vodka won't freeze solid. So 20l will give ya 50l of coolant.


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## danestead (28/6/14)

booargy said:


> Cheaper to buy metho in 20L drum about from bunnings if it contaminates your brew you will know but it won't kill you. If you have noticed 40% vodka won't freeze solid. So 20l will give ya 50l of coolant.


Wont kill you..... maybe not in a small amount but I personally know of a guy who decided it was a great id to drink some metho (not sure how much). Result, coma for about a week then they switched off life support.....


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## Ducatiboy stu (28/6/14)

itmechanic said:


> I wouldn't use automotive glycol under any circumstances (ethylene glycol), you should use a food grade polypropylene glycol in case of accidental leaks and ingestion. Not really that hard to come by.


Good point.

Forget that they are 2 different glycol.

You could always saline water if your not putting it on your garden.


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## Goose (28/6/14)

how would you lads in tend on cooling the glycol please ?


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## Steve (30/6/14)

Chilled with my home made immersion chiller today. Worked great. Went from boiling to 20 degrees in 19 mins. Dropped 50 degrees in 10 mins! Slow flow rate with continuous stirring. Used approx. 40 litres of water which has been saved for the HLT for the next batch. Happy with that.


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## The Judge (30/6/14)

Goose said:


> how would you lads in tend on cooling the glycol please ?


I don't use glycol, but... I'd have it stored in the freezer in an insulated cube, and when it's ready to use, recirculate it through a counter-current coil exchanger using a dedicated pump (i.e. one that is never used for pumping anything that comes in contact with wort).


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## Dave70 (1/7/14)

itmechanic said:


> I wouldn't use automotive glycol under any circumstances (ethylene glycol), you should use a food grade polypropylene glycol in case of accidental leaks and ingestion. Not really that hard to come by.


Bit of glycol wont hurt ya..
Just the ticket for that 'sweet stout'. 


http://en.wikipedia.org/wiki/1985_diethylene_glycol_wine_scandal


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