50 foot CFC ~ to a plate chiller?

Hey guys.

I know the chiller debate has been beat to death, so I'll try and keep this simple. I've done research on all the options and given my planned 20 gallon system, I'd really like to go CFC if possible. The main reason I don't want a plate chiller is that I use pellet hops almost exclusively and don't want to deal w/ filtering or any possibility of clogging during re-circ.

Someone please correct my math if it's wrong (it is a lot), but I found a spec sheet showing standard 1/2" OD copper tubing w/ a .436 ID. So that would come out to: .436*pi*600 ~ 822 square inches of surface area for the CFC. Would you go thicker/longer than 50 ft?

Not sure how accurate the source is, but I found a site claiming the Therminator has 6.5 ft^2 of surface area which is 936 square inches. That is a slight difference, but they seem at least relatively comparable. Does this translate to similar real world results? I've never used anything but an IC.

I also have pretty warm source water (during the summer at least) which gets up to 75-80F if I had to guess. I plan on using a pre-chiller...will this be adequate?

Thanks a bunch guys!

FYI, even with a CFC, you can't count on it not to clog. I've clogged mine with pellet hops before. That's why I use a strainer bag and whole leaf hops now.

Another tip for CFCs - when you wind it, wind it good and tight against something like a corny keg, then make sure you rigidly bind it into a solid, uniform cylindrical tube with no gaps as soon as possible. The reason for this is that when you hold the CFC such that its axis is straight up and down, the coil will not fully drain unless the hose is sloping downward at all points along the length of the coil. Mine will hold a couple of ounces of liquid after I drain it because I didn't bother to bind it until it'd been used a few times, and it ended up a bit lopsided.

Most CFCs use 1/4" tubing so I would have to say your math is off. trying to force 50' of 1/2" copper through a garden hose will be very difficult. Also the flow rate through a plate is higher than through a CFC. I have used both, the CFC with a post chiller. See https://www.homebrewtalk.com/f51/hell-earth-wort-chiller-73315/
Since then I have switched to a 30 plate and use paint strainers to keep the hops out. Yesterday I tested the new build with 62* ground water and got single pass chill of 70* in about 15 min. for 10G. Due to the current rig build(too many feet of SS tubing and solenoid valves) flow was not as good as was expected but still exceeded a CFC. Being all metal contruction plates can be cleaned by simply putting them into the oven during a cleaning cycle. You cant do this to a CFC.

I almost pulled the trigger on a plate chiller a month ago. I read a thread on the green board showing the difficulties some folks were having getting them clean and how much stuff actually stayed in there after a pretty thorough cleaning routine. The really thin passages grab solids very easily, not to mention the corrugation gives it that much surface area to grab onto. I figured copper tubing ought to be much easier to clean.

I wouldn't go with the large copper for a CFC, it isn't all about surface area. 3/8" really does seem to be the magic number and a 25 foot cfc can cool the wort as fast as you can pump it through (provided you are pumping cooling water equally as fast as possible too).

To make a 25 footer you usually have to buy enough material that you can make 2. A fifty footer would be way too long and cripple your flow rates.
With 25' I get about 1.15 GPM. If you want a higher flow rate you can run two 25 footers in parallel. You ought to zip through a 5 or ten gallon batch in no time flat with that configuration.

To help with the complete draining, I made a long spigot that brought it out and down to the size of my fermenters. So it just siphons what ever is left in there now.

To keep hops out of my CFC I've actually started using a small false bottom in my keggle with a bottom drain underneath. That coupled with whole leaf hops means I hardly get anything in the CFC after I've recirculated for a little while. Then I generally recirculate through the CFC to sanitize it during the last 10 minutes of the boil.

conpwerter, maybe you know cause I don't understand. What is the big aversion to filtering hops? I toss mine in a hop sock and clip it to the top of the keggle. It is so nice not to have to dig all that crap out by hand.

You ought to zip through a 5 or ten gallon batch in no time flat with that configuration.

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I wouldn't go with the large copper for a CFC, it isn't all about surface area

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I'll be doing 20g batches mostly, and I didn't even consider the different flow rates FWIW. Are plate chillers really that much better at it? And wouldn't the larger diameter tubing help quite a bit if I did go CFC?

trying to force 50' of 1/2" copper through a garden hose will be very difficult.

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Well I didn't even think of that! Is 3/8" what most ppl are using?

What is the big aversion to filtering hops?

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I've used strainers before and you're right it isn't a big deal. It's just one more thing I'd rather not clean I guess...but I am lazy.

I'm not sure if this will help you but I've compiled data on a bunch of different CFC configurations based on 25' lengths and various tubing diameters...

Counter-flow or Tube in Tube Configurations Data (area in inches square)


CFC Configuration #1 3/8" OD Copper in 5/8" Hose
Wort Flow Cross Sectional Area 0.078
Coolant Flow Cross Sectional Area 0.196
Coolant to Wort Ratio 2.5


CFC Configuration #2 1/2" OD Copper in 5/8" Hose
Wort Flow Cross Sectional Area 0.149
Coolant Flow Cross Sectional Area 0.110
Coolant to Wort Ratio 0.7

CFC Configuration #3 1/2" OD Copper in 3/4" Hose
Wort Flow Cross Sectional Area 0.149
Coolant Flow Cross Sectional Area 0.245
Coolant to Wort Ratio 1.6

CFC Configuration #4 1/2" TypeM Copper in 3/4" TypeM
Wort Flow Cross Sectional Area 0.254
Coolant Flow Cross Sectional Area 0.210
Coolant to Wort Ratio 0.8

CFC Configuration #5 3/8" TypeM Copper in 3/4" TypeM
Wort Flow Cross Sectional Area 0.159
Coolant Flow Cross Sectional Area 0.320
Coolant to Wort Ratio 2.0

Like many around here, I have experience with config #1 and with both liquids run at full speed, the wort comes out at 5F warmer than the incoming coolant. With full coolant flow and about half wort flow (March pump output valve at half) you'll get the two temps about equal give or take. I plan to experiment with config #5 in the future using straight rigid tubing.

I don't know what kind of flow rates you get with a plate, but with the dual CFC I would expect you could do 20 gallons in 8-10 minutes.

If you went with 1/2" tubing you would need to find a larger jacket. The local hardware store has all kinds of tubing that may fit the bill. You could go 1/2" but it would have to be longer. Not sure how long it would have to be to get the same temperature delta as a 25' 3/8" line though.

Just did some quick number crunching and the cross sectional surface area of 2x 3/8 tubes is the same as one 1/2". So I don't know if you need twice the distance to get 1/2" to get the same performance or what. It would require a bit more crunching.

See this thread for number crunching of coiled tube CFCs.

https://www.homebrewtalk.com/f11/ultimate-cfc-calculator-124294/

I've used the hop sack in the past, but once I went electric I've been worried that a hop sack will just wrap itself around the element. The element is at just over the 3 gallon mark, so I can't shorten the bag enough to make sure I still get plenty of extraction.

conpewter said:

I've used the hop sack in the past, but once I went electric I've been worried that a hop sack will just wrap itself around the element. The element is at just over the 3 gallon mark, so I can't shorten the bag enough to make sure I still get plenty of extraction.

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Yeah, I have mine clipped to the side of the keg so it rests at the 4 gallon mark. Hasn't touched the element yet. The hops are loosely floating and don't pack. May try one of those stainless infusers one day.