My Immersion chiller makes me sad

I have a 45ish' 3/8" immersion chiller (the copper was free) and I've gone ahead and plumbed a pump with a recirculation port in my keggle to recreate Jamil's IC setup. Still, with a 12.5 gallon post boil, it takes upwards of a half hour to chill to pitching temps. Ground water is usually ~70.

Generally I flow the cooling water through it at max until it start getting cold, then dial it back till it gets warm to the touch.

I'm trying to think of ways to make it cool faster, and the only thing I can think of was to maybe intertwine some copper wire in between the coils of the chiller, as it looks like they lay on top of each other and prevent flow of wort via recirculation, but I can't imagine that would help much.

I tried the sump pump in ice bath method as well, but the pump I had generated it's own heat and was counter productive, lol.

Any other thoughts before I rip it apart and turn it into a CFC? And, if I do, is 45' of CFC enough to cool the wort before entering the fermenter via pump or will I have to recirculate it back?

Thanks

I have heard to keep the flow slow so there is a longer time for heat transfer. For my 5 gallon batch I have 2 twenty foot coils, one goes in the wort the second in a bucket of water and ice. It takes about 1/2 hour. I do find it goes faster if I move the coils to disturb the water and wort around the coils.

I am going to take a small electric motor or drill and attach a paint mixer to, very gently, circulate the wort over the coils.

I recently hooked up Jamil's whirlpool on my setup. I still did my ice water recirculation through a pond pump once I got down around 100 degrees. It seemed to speed up the boiling down to a 100 drop a fair amount. Once I started recirculating the ice water it didn't seem to help quite as much. I would say it maybe reduced my overall chill time by about five minutes. However, because I didn't have to keep coming back and stirring the wort to get it moving, it did free me up to do other tasks during the chill.

Half hour for 12+ gallons with an immersion chiller and you're complaining?

BrewThruYou said:

Half hour for 12+ gallons with an immersion chiller and you're complaining?

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Sure am!

BrewThruYou said:

Half hour for 12+ gallons with an immersion chiller and you're complaining?

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phoenixs4r said:

Sure am!

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More ice, more pump, and more stirring of the hot wort then!

Depending on your water temps, I'm not sure a CFC will do much better than a half hour.

kh54s10 said:

I have heard to keep the flow slow so there is a longer time for heat transfer.[...]

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You have to use a filter on things you hear. Because that makes zero sense...

Cheers!

Some brewers don't chill at all they just cover and let it sit overnight. I have done it and it turned out ok

phoenixs4r said:

Generally I flow the cooling water through it at max until it start getting cold, then dial it back till it gets warm to the touch.

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For me, this was my problem. I read about this slow water = better heat transfer crap and it sounds good in theory but not in practice. Blast that water! When I dialed it back so the exiting water was warm it took me 45 minutes to do cool 5 gallons to 80 degrees. When I had it on blast it took me 25 minutes. All other variables were similar. I'd say try this first.

Good Luck!
Nick
P.S. Happy IPA Day!

certaut said:

Some brewers don't chill at all they just cover and let it sit overnight. I have done it and it turned out ok

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yep I do. works fine.

Slower water flow rate will be more efficient in terms of water usage. I don't pay for water (rent) so i go full blast (earth smerth). But the slower you go the longer the worthas a chance to lose it's heat to the water so less water used but longer time to chill (less driving force). Few more gallons of water is well worth the time saved imo

vp1 said:

Slower water flow rate will be more efficient in terms of water usage. I don't pay for water (rent) so i go full blast (earth smerth). But the slower you go the longer the worthas a chance to lose it's heat to the water so less water used but longer time to chill (less driving force). Few more gallons of water is well worth the time saved imo

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I don't pay for water either but my eco girlfriend goes nuts about the water usage. I think I'll snag some empty water jugs from work and just fill them so she can water the plants with it.

I run the first 10-15 gallons slow, thus getting the exit water nice and hot. Then dump the lot into my washer and run a load of whites

Also, I have 10 ft of 1/2" copper coil (a flat coil) in an ice bath. No pump / no recirculation. water moves from faucet --> ice bath coil --> immersion coil --> washing machine.

So yesterday I ran a test with my sump pump, in 10 minutes it increased 10 degrees. I had hoped that I could just run cold water with some ice cubes in it to help even out the temps between the two vessels, but it is apparent in order for the sump pump to be effective I'd need to get a lot of ice. Meh. I'll pitch warm and let the ferementation chamber chill it down the rest of the way like I have. Still considering turning it into a 45' CFC, but I think thats the bored side of me thinking.

phoenixs4r said:

So yesterday I ran a test with my sump pump, in 10 minutes it increased 10 degrees. I had hoped that I could just run cold water with some ice cubes in it to help even out the temps between the two vessels, but it is apparent in order for the sump pump to be effective I'd need to get a lot of ice. Meh. I'll pitch warm and let the ferementation chamber chill it down the rest of the way like I have. Still considering turning it into a 45' CFC, but I think thats the bored side of me thinking.

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Changing up your system will only help if you're experiencing a low efficiency of heat transfer for some reason or another. From the sounds of it, though, you're just running into the hard, physical limits of thermodynamics.

You need to extract about 190 kJ per degree celsius drop. If you're trying to pitch at 75 degrees, by the end you're needing to run almost three gallons of water per degree in the best case scenario. 30 minutes is pretty good, and I'm surprised it's even that quick with groundwater so warm. As you've concluded, your options are either ice or refrigeration. I've always had good luck sticking the carboy in my fermentation chamber and pitching the next morning.

day_trippr said:

You have to use a filter on things you hear. Because that makes zero sense...

Cheers!

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going slower won't speed it up, but won't necessarily slow it down.

I start at nearly full-blast, then back it down until the copper on the outlet end feels just barely warmer than the copper on the inlet end.

I too have a home made immersion chiller. I think it was about 25' of 3/8 tubing. I put my boil kettle in an ice water bath (12 gallon keg tub) and run the chiller at the same time. I've been thinking about building a pre-chiller using a long length of 1/2" black drip irrigation tubing coiled in an ice bath. My thought is that running colder water into the wort chiller will cool the wort quicker. As it is, it's taking me about 30 minutes to cool my wort, so maybe that's the best I can hope for.

kh54s10 said:

I have heard to keep the flow slow so there is a longer time for heat transfer. For my 5 gallon batch I have 2 twenty foot coils, one goes in the wort the second in a bucket of water and ice. It takes about 1/2 hour. I do find it goes faster if I move the coils to disturb the water and wort around the coils.

I am going to take a small electric motor or drill and attach a paint mixer to, very gently, circulate the wort over the coils.

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This is a myth.... the capacity for heat transfer through the copper is a constant... it has to do with the surface area and the material which both don't change.

Slowing down the flow rate of water will only hurt you. Someday I'll try to explain thermodynamics but its just too hard to type out.

Aside from a pre-chiller, the best way to improve the heat exchange performance of your immersion chiller would be to add a whirlpool stirrer to move the wort through (between) the coils, I've read that it greatly increases efficiency (I'm happy with my 20~30 minutes, so I haven't tried it yet). I think there's a Stainless Steel Paint Mixer called a Jiffy PS-1 that's popular for this.

Keyth

JonnyJumpUp said:

This is a myth.... the capacity for heat transfer through the copper is a constant... it has to do with the surface area and the material which both don't change.

Slowing down the flow rate of water will only hurt you. Someday I'll try to explain thermodynamics but its just too hard to type out.

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I'm not sure what exactly you're saying is a myth here, but certainly slowing down the flow rate can make you more efficient with regards to water usage.

Water usage absolutely. Speed to chill nope, that's the myth. I think you knew that though.

For those who don't: the water will match the temperature of the wort on the other side of the copper in short order thanks to the copper's conductance. The limiting factor in cooling rate is the heat capacity of the wort relative to that of plain ol water. Something we just have to deal with.

The technical options for optimizing are really two: agitate the water/wort such that the water/wort on the inside of the flow gets exchanged with the water/wort on the copper wall of the tube (hence convoluted CFC's and whirlpool arms) or, increase your surface area (bigger chillers). Both are still limited by the heat capacity of the water (once you match the temps, nothing's gonna change from that distance on down the chiller) and each has their design trade offs.

The goal of either design is to make sure that all the water (across flow's cross section) at the exit of the chiller is the same temperature as the wort (either in the kettle in the case of immersion or at the outlet in the case of CFC's and plates) Technically, that's as good as it gets. You can of course chill the water but that's not a chiller design issue, that's execution.

"In this house we obey the laws of thermodynamics!"

I would recommend bending up a whirlpool arm if you have a wort pump, it works very nice. I used to run it for the last 15 minutes of the boil to sanitize the lines then turn on the hose at flame out. Presently I am using a convoluted CFC and have a tangential inlet on my kettle to whirlpool cold wort back in and chill the whole volume as fast as possible.

MalFet said:

I'm not sure what exactly you're saying is a myth here, but certainly slowing down the flow rate can make you more efficient with regards to water usage.

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Indeed.

Phrased slightly differently, there are two potential limiting factors to a heat exchanger system.

The first is the efficiency of heat transfer. In a idealized system, the water leaving the chiller would be the same temperature as the wort. This is relatively easy to measure, and if you're getting a gap of more than a few degrees there are things you can do to improve your system.

However, if you're already outputting water relatively close in temperature to the temperature of your wort, changing your system design won't change anything. The only thing to do in that instance is to either up your rate of water flow or drop your water temperature somehow.

In the OP's case, I suspect he might just be hitting some hard limits imposed by the temperature of his ground water and the rate of water flow he's got. If that's the case, increasing the size of his coil or switching over to a CFC won't actually improve anything. The best thing to do would be to measure the output water to see how much of a difference he's got.

Technical question: anybody able to produce a formula that would describe the volume of water needed in a theoretically perfect system to cool wort from 212 to a given temperature? I tried to figure it out, but my multivariable integration isn't quite what it ought to be.

You know, I was just wishing I still had access to ANSYS Fluent so I could model heat exchange through a chiller. Also, I was wishing I still remembered how to use it.

MalFet said:

your options are either ice or refrigeration. I've always had good luck sticking the carboy in my fermentation chamber and pitching the next morning.

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This is what I do. Especially with lagers. Get it in the 70 F range with the chiller, then place both carboy and starter in the fermentation chamber and pitch the next day. Pitching warm and the cooling down could make the yeast drop out. This way the wort and starter are simpatico. I know the arguments for pitching ASAP, but 12 to 24 hours is soon enough for a healthy starter. I hear that the "NO Chill" guys sometimes wait weeks before pitching and make great beer.

chessking said:

This is what I do. Especially with lagers. Get it in the 70 F range with the chiller, then place both carboy and starter in the fermentation chamber and pitch the next day. Pitching warm and the cooling down could make the yeast drop out.

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Well warm is a relative term. I stray away from lagers. I don't have any issues with pitching at 75 and letting it cool to whatever I ferment at. Typically 65-70 for safale 05 which is what I usually use.

OT: firs time using whole hops in today's brew. Didn't filter, clogged pump city.

Also off topic. Make one of these. 4" to 3" PVC reducer, Gallon paint strainer, SS jubilee clamp, and the belt clip from a 25' Stanley tape measure. Total cost 7 bucks.

I hate hop spiders, but thanks. I'll probably throw a false bottom in the kettle.

MalFet said:

I'm not sure what exactly you're saying is a myth here, but certainly slowing down the flow rate can make you more efficient with regards to water usage.

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I'm saying that the below statement or any variation is a myth:

That to a point slower flow = faster cooling due to increased contact time or whatever.

Doc, had more patience to explain it than me but suffice it to say the above statement goes against the laws of thermodynamics.

PS a student version of chemcad shouldn't be too hard to get your hands on.

MalFet said:

Technical question: anybody able to produce a formula that would describe the volume of water needed in a theoretically perfect system to cool wort from 212 to a given temperature? I tried to figure it out, but my multivariable integration isn't quite what it ought to be.

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Just determine the specific heat of your wort and you should be good to go.

TheZer said:

Just determine the specific heat of your wort and you should be good to go.

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How do you figure? Knowing the specific heat isn't enough to model the system. Assume it's the same as water. What's the equation?

Wouldn't this work? (edit: no it wouldn't. Not pulling heat out of system)

E out = E in
(Sp Ht wort)(mass wort)(dT wort) = (Sp Ht water)(mass water)(dT water)

Solve for mass water.

• I first did Ice Bathes
• Then Ice Bathes with Ice in the wort (boiled and then frozen in ziplock bags)
• Then Wort Chiller
• Now Wort Chiller with a pump to circulate the wort (and create the whirlpool) ALL_GRAIN

Each move I saw improvement and some of the changes were because I went to 5 gallon to 11 gallon batches.

Question: Who is Jamil?

DPBISME said:

Question: Who is Jamil?

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Former home brewer gone pro (heretic brewing) who was either the first or one of the firsts folks who pioneered proper yeast count among home brewers. According to Morebeer, was also the first to recirculate wort while chilling with an IC and publish its benefits.

So I ultimately am thinking I can squeeze a few minutes off my cooling time be seperating the coils slightly. While all of the wort moves a bit, its noticeable while staring at the wort where my chiller is by the flow of wort. What would be the best way to go about this? I would also like to permanently affix said chiller IN the brew kettle, so it'll have to be pretty well cleanable with a recirculation of pbw.

TheZer said:

Wouldn't this work? (edit: no it wouldn't. Not pulling heat out of system)

E out = E in
(Sp Ht wort)(mass wort)(dT wort) = (Sp Ht water)(mass water)(dT water)

Solve for mass water.

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I never took heat transfer. That's the thermodynamic principle equation but dT is what gets you.

dT is going to be an integral across the cross section of the pipe and is going to factor in flow rate and a heat transfer coefficient.

phoenixs4r said:

So I ultimately am thinking I can squeeze a few minutes off my cooling time be seperating the coils slightly. While all of the wort moves a bit, its noticeable while staring at the wort where my chiller is by the flow of wort. What would be the best way to go about this? I would also like to permanently affix said chiller IN the brew kettle, so it'll have to be pretty well cleanable with a recirculation of pbw.

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I would recommend against totally fixing it into the kettle. Maybe a clamp or something off the rim that holds it a bit off the bottom of the kettle for more flow...

As for separating the coils I have seen it done as follows: Use copper wire to entrap each coil in an X of wire where the tubing sits above and below it. You kind of cris-cross your way up the chiller. Also, soldering/wiring each loop to the stem of the chiller on the other side.

I agree with the copper wire to separate the coils, and stirring your wort by whatever means works best for you, it really does help.
As far as water speed....If I can cool 5 gal in 15 mins pushing 2 gallons a min. or the same 5 gal in 30 mins pushing 1 gallon a min, I'll take the quicker cooling time, water usage is the same.

Hmmm. I think I have some stainless wire i can weave. Or if I used copper could a solder all if the wire to the coil so there's no gaps for **** to hide? Probably over kill since its in the boil, but I like my stuff really clean, I just don't like spending time to clean it LOL

a

Docgineer said:

a

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I heartily concur with this sentiment!!!