Anyone use 1/2" OD copper tubing in CFC?

I've read the 27 pages of the "how to build a CFC" thread and it's all 3/8" OD tubing. I've already got ~40 feet of 1/2" OD and wonder if you could use it in a CFC with a regular 5/8" ID garden hose. Would 3/4" ID hose be better? Should I just buy the 3/8" copper and get it over with? Thanks in advance for the advice.

I believe the reason that 3/8" is used for the CFCs is because 1/2" doesn't give very much room for the cooling water to flow through.

If you used 3/4" ID garden hose, it should work fine if your coolant temp stays nice and cold.



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

I use 1/2 inch with 3/4 outer hose.
If you use, or intend to use a pump, particularly the March that everyone uses, don't use 3/8. Too much internal resistance, so very Very low flow.
If you intend to keep using gravity then, yes, 3/8 has better surface area to volume BUT:
Assuming you intend to use a single pass through your CFC to your fermenter, and if you are going to brew lagers, especially all-grain, then you will be leaving most of your wort at high termperature for too long and forming DMS.
So:
Use a CFC if you are going to use a pump, and recirculate back to your boil kettle, therfore dropping all of your wort temp at the same time, before then diverting to your fermenter. Therefore use 1/2. Additional benefit of being able to whirlpool, and avoid taking break and hop to your fermenter.
Otherwise, use an IC.

Devil's advocate Yorg, if your coolant water is pretty close to your desired wort output temp, you'd have to throttle the flow of wort with a valve anyway. The only time you can run a 1/2" chiller full bore is if your coolant is 60F or less.

Mine is 1/2" copper with 5/8" hose. The water coming out the CFC hose is cool and I still have to throttle back the pump.

Next week I am going to try to whirlpool through the CFC with the pump and water on full blast. I did this with water a month ago and it looked promising.

BW