Better cooling efficiency with counterflow wort chiller

[yourfavo]

I just got a new SS counterflow wort chiller for Christmas. Made my first batch with it on Wednesday day night. Hooked everything up and my tap water was coming out about 45 F. I had tested it out previously and it didn't seem to cool enough with the ball valve wide open so this time i only opened about a 1/3 of the way, just enough to get a good flow. I went straight into my fermenter and it came out @ 90 F. I'm impressed it dropped that much in the 30 mins it took me to drain (112 degrees), but what could i do to get it down to pitching temp? I've heard about putting the chiller in an ice bath or running it through twice.

What is everyone else doing here?

 

[walqua]

How long is your counterflow? Maybe it's just a problem of short length of the counterflow pipes which results in reduced heat exchange surface.
I have a 10 m (32.8 feet) long counterflow with wort pipe having 12 mm (0.47 inches) of inner diameter and I can cool wort from 105/110 C (221/240 F) down to 25 C (77 F) using tap water at ca. 10 C (50 F).
Hope it helps...

 

[LandoLincoln]

I just got a new SS counterflow wort chiller for Christmas. Made my first batch with it on Wednesday day night. Hooked everything up and my tap water was coming out about 45 F. I had tested it out previously and it didn't seem to cool enough with the ball valve wide open so this time i only opened about a 1/3 of the way, just enough to get a good flow. I went straight into my fermenter and it came out @ 90 F. I'm impressed it dropped that much in the 30 mins it took me to drain (112 degrees), but what could i do to get it down to pitching temp? I've heard about putting the chiller in an ice bath or running it through twice.

What is everyone else doing here?

Wait a minute. You have 45° F water and you're only getting your wort down to 90 in a single pass? Something ain't right. You should be getting it down to pitching temps with the wort going full blast while the water is turned way down.

Do you have the water and wort flowing in opposite directions?

 

[yourfavo]

This is my chiller...

http://webcache.googleusercontent.c...-CHILLER-P3452.aspx+&cd=1&hl=en&ct=clnk&gl=us

It says 12' long 1/2" OD. Yes I am running in opposite directions, i set it upright and the wort ran down with gravity and the water pumped up using only the pressure of my kitchen faucet.

 

[poptarts]

How long is your counterflow? Maybe it's just a problem of short length of the counterflow pipes which results in reduced heat exchange surface.
I have a 10 m (32.8 feet) long counterflow with wort pipe having 12 mm (0.47 inches) of inner diameter and I can cool wort from 105/110 C (221/240 F) down to 25 C (77 F) using tap water at ca. 10 C (50 F).
Hope it helps...

water boils at 100c how do you have wort at 110c? You might want to re calibrate your thermometer because that is literally impossible.

 

[yourfavo]

A little off topic poptarts but it is possible if he has a high grain bill and in a higher elevation.

 

[walqua]

As suspected your counterflow length seems quite short...
You could try to chill down your tap water letting it pass into a copper immersion chiller drowned into a bucket with iced water. It should improve heat exchange efficiency.

 

[walqua]

To poptarts: wort boiling temp depends of its OG and normally it's higher than water boling temp. If you boil a triple's wort you can easily reach 110 C. Sugars inside the wort have the effect of raising boiling temp.

 

[LandoLincoln]

This is my chiller...

http://webcache.googleusercontent.c...-CHILLER-P3452.aspx+&cd=1&hl=en&ct=clnk&gl=us

It says 12' long 1/2" OD. Yes I am running in opposite directions, i set it upright and the wort ran down with gravity and the water pumped up using only the pressure of my kitchen faucet.

Holy cow. That's really disappointing. I mean, I know that copper transfers heat better than stainless, but I didn't know that it was THAT big of a difference.

Maybe your faucet's aerator is severely restricting flow?

I know stainless is awesome and everything, but if I were you I'd send that sucker back and get one made out of copper. Or save yourself a ton of dough and make one out of copper, and make it longer than 12 feet. Copper has three things going for it in this particular application that stainless steel lacks:

1) Heat transfer. Apparently copper is way better than stainless in transferring heat.
2) Yeast nutrient. Copper is a very beneficial mineral for yeast. If you don't have any copper in your boil or post-boil setup, then I'd recommend cutting a 2-inch piece of copper pipe and just keeping that in your boil kettle.
3) Anti-bacterial. Copper is naturally anti-bacterial, so you would THINK that stainless CFC's would be more sanitary, but I don't think that this is the case.

 

[day_trippr]

I wonder if the wort was actually fully filling the chiller. You might reverse the flows so the wort enters at the bottom and the water enters at the top. That should fully fill the wort tubing which would give the best thermal transfer, and you'd have better control over wort velocity. Ie: if you just trickled the wort through the chiller from top to bottom you can imagine the thin stream would just ride along the bottom part of the tubing all the way down, but if you did the same thing from bottom to top the tubing would still be 100% filled.

And don't make the common mistake of turning down the water flow because the exhaust water temperature doesn't seem warm. Thermal transfer is highest with highest differential; you want the water to flow at the maximum - unless you have the situation where even with the wort flowing at the highest rate possible it's coming out too cold...

Cheers!

 

[yourfavo]

I think the length might be the culprit here but I would have thought others would have had the same issue since I bought this from a popular online retailer. I did read that SS is a bit less conductive than copper but I don't think that is the case here. I like the idea of flipping the chiller over. I can see how that way the flow might still be slow enough to cool it more.

Is anyone against the ice bath or running it through twice?

 

[LandoLincoln]

I think the length might be the culprit here but I would have thought others would have had the same issue since I bought this from a popular online retailer. I did read that SS is a bit less conductive than copper but I don't think that is the case here. I like the idea of flipping the chiller over. I can see how that way the flow might still be slow enough to cool it more.

Is anyone against the ice bath or running it through twice?

Either option would certainly help. If you had a pump, you could just keep recirculating it back into the boil kettle until all of the wort reached pitching temps. A good excuse to buy more equipment!

 

[yourfavo]

That's a great idea but my equipment budget is blown. We'll see how the next batch goes with the ice bath.

 

[yourfavo]

That's a great idea but my equipment budget is blown. We'll see how the next batch goes with the ice bath.

 

[rossi46]

Yeah, I have a copper one and still have recirc until the kettle temp is below 120 degrees. For that type of chiller you really need a pump.

 

[yourfavo]

Thanks. Glad to know I'm not alone. Thought maybe I was doing something majorly wrong.

 

[govner1]

Thanks. Glad to know I'm not alone. Thought maybe I was doing something majorly wrong.

Actually, I disagree. I used my CFC w/ gravity feed very successfully for almost two years before I added a pump to my system. I live in the Deep South so I had to prechill & eventually added a recirc system. In the summer I definitely need 10-20 lbs of ice.

 

[yourfavo]

Govner1, what is the length of your chiller?

 

[govner1]

govner1, what is the length of your chiller?

25'

 

[10ACbrew]

If you have 45F water coming out of faucet and are only getting down to 90F with wort to fermenter, it's probably the wort needing to run upward through chiller in order to attain full contact with wall of CFC as day_trippr mentioned.
You don't have to wait til next brew session to test out. Heat up some water and run it through to test. A lot cheaper than messing up a batch. It may also allow you to get better idea of flow rates for both wort and incoming water.

 

[yourfavo]

good idea, ill give it a try this weekend.

 

[purplehaze]

This may seem obvious but its a counter flow chiller. Are you sure the hot wort is flowing in one direction while the cooling water flows in the opposite direction?

 

[yourfavo]

This may seem obvious but its a counter flow chiller. Are you sure the hot wort is flowing in one direction while the cooling water flows in the opposite direction?

Yes, I'm sure.

 

[LandoLincoln]

I just looked up the thermal conductive properties of copper and stainless. Looks like copper is around 20 times more thermally conductive than stainless. I'm jus' sayin'.

 

[yourfavo]

I just looked up the thermal conductive properties of copper and stainless. Looks like copper is around 20 times more thermally conductive than stainless. I'm jus' sayin'.

I found this....
https://www.youtube.com/watch?v=yz4CoITHX3M

looks like copper is a LITTLE bit better than stainless when it comes to cooling wort, but i would think that would mean a difference in a few degrees. In my case I was 20 degrees higher than I had to be. I think, if done correctly, i should have been around 75 or so.

 

[TenaciousJ]

i'm glad i found this thread b/c i'm having similar experiences. for reference i use a copper convoluted CFC from morebeer. the CFC is mounted vertically with the wort being pumped upwards via march pump. water flowing downwards at temperatures as low as 45F.

i'm starting to believe these chillers are just not built as single pass chillers. if i modify the wort/water flow rates i can get temps down to 75-80F. i achieved this by putting a valve where the wort exists the CFC. by keeping this valve barely cracked and restricting flow prior to the CFC with another valve on the pump, you can get there but it'll be a trickle and take about an hour to chill a 10 gallon batch.

the more efficient plan is to recirculate until the temp is down to 100/120F at higher flow rates, then restrict as noted above. i think this should take about 1/2 hour for 10 gallons hopefully. i suspect this will create a better cold break too

i would love for someone to come in this thread and tell me i'm wrong since i bought the chiller to re-circulate and single pass, but i don't think these chillers are built for that.

 

[AutoDog]

TJ,

I've had nearly the identical experience (and arrived at the same final methods) with my stainless CFC unit from Williams. I had thought maybe the poor performance was due to the difference in heat transfer between copper and SS. However, given your copper experience is nearly identical to mine with SS, I have to wonder.

Sure would be great to hear any words of wisdom from others that might improve both our situations.

-AD

 

[purplehaze]

My homemade copper CFC is 20' of 3/8" inner pipe. Your CFC is 12' of 1/2" pipe. SS or copper at almost twice the length and smaller ID pipe cools more.

 

[yourfavo]

After a few uses I too am realizing I have to recirculate to cool. I put a valve on my water out and I need another one on my wort out and I should be set. Last time I used it I cooled 6 gals in about 30 mins.


Sent from my iPhone using Home Brew

 

[mjohnson]

After a few uses I too am realizing I have to recirculate to cool. I put a valve on my water out and I need another one on my wort out and I should be set. Last time I used it I cooled 6 gals in about 30 mins.

You want to run your water at full blast and slow your wort. Think of it this way, if you slow your cooling water, it will warm as it travels through the chiller. The warmer it gets as it travels, the less it is cooling the rest of the chiller length. You want the biggest temp differential you can get for as long as you can get.

 

[KegWrangler]

One "problem" with the CFCs is that both the water and the wort flow need to be flowing fast enough to be turbulent (mixing). If you throttle back the wort (say below 0.5gpm for a 1/2" OD pipe or 0.375gpm for a 3/8" OD pipe) the flow switches from turbulent to laminar(non-mixing). The result is that the fluid near the pipe wall gets cold but the middle of the flow stays hot.

The most efficient way to run CFCs is fast, full open, both water and wort. If you don't have a pump you can drain to the fermenter (bucket?) then dump it back into the kettle and run it again (and again, and again) until you reach your desired pitching temp. At least you'll be fully aerated when your done!

Start saving your pennies to buy a pump for when your back gives out from all the additional lifting.

 

[Jdaught]

I have the exact one built on electricbrewery.com from morebeer. My water flows up at 55 degrees and my wort flows down, with gravity, from kettle. I run a hose from wort exit to carboy. I put a small vice grip on the end of the hose to restrict the flow into the carboy to a small stream, little more than a trickle and I have the water flowing full blast. My wort is entering the carboy at 58 degrees in one pass. Takes about 30 min to get it all in the carboy.

 

[AutoDog]

KW - Good points about avoiding laminar flow at low wort flow rates. No doubt I'm running into this myself. That said, I imagine there's a limit whereby running the pump wide-open will be so fast that cooling efficiency will drop off...?

I'm also curious if anyone has creative ideas on how to externally induce turbulence on the wort & chill water going into the CFC? E.g. using creative shapes on the plumbing on the liquid-in side?

-AD

 

[RmikeVT]

KW - Good points about avoiding laminar flow at low wort flow rates. No doubt I'm running into this myself. That said, I imagine there's a limit whereby running the pump wide-open will be so fast that cooling efficiency will drop off...?

I'm also curious if anyone has creative ideas on how to externally induce turbulence on the wort & chill water going into the CFC? E.g. using creative shapes on the plumbing on the liquid-in side?

-AD

I've seen plans where folks wrap some sort of metal wiring in a spiral, similar to a gun barrel rifling, and soldier along the way, so the water running through the CFC gets real mixed up and spirals around the copper.

I have a 20' home-made CFC and have found I need to re-circulate to about 170* before I can start filling up carboys. But I do get the wort coming out at 65* with 60* ish tap water. I probably need 5 minutes of re-circulating full blast on both and then I throttle down and go into the carboys. The whole process probably take 30 minutes. Not bad for 12 gallons of wort.

I found an example on the youtubes:
[ame]https://www.youtube.com/watch?v=DVf-lTFpR2c[/ame]

 

[LandoLincoln]

The wire wrap thing doesn't do anything. There is plenty of turbulence with the water hitting the side walls of the helix.

Now, if you had a straight 25' piece of tubing with no turns, then yeah, the wire wrap would be helpful.

 

[KegWrangler]

The wire wrap thing doesn't do anything. There is plenty of turbulence with the water hitting the side walls of the helix.

Now, if you had a straight 25' piece of tubing with no turns, then yeah, the wire wrap would be helpful.

I'd tend to agree with that. Anything over 1gpm in the outer hose is plenty turbulent.

I also agree with the idea of either running the wort up from the bottom of the CFC to the top or putting a valve on the downstream end of the CFC to make sure the tube is completely filled.

I don't believe there is any loss in efficiency (overall) by running full open. When you run full open the temperature if the wort coming out will be higher than running at a trickle but that actually makes for a greater efficiency of rate of heat transfer because the rate of transfer is proportional to the difference in temperature between the wort and water. The drop in efficiency that will occur is the greater amount of water used to affect the cooling - but you wanted to chill it faster, right?