Ultimate CFC Calculator

So after reading a lot of questions such as...

"How big does my CFC need to be?"
"Is 1/4" tubing OK?"
"How much water will I be using?"
"How long will it take to drain my kettle?"

...I decided to do some calculations. And being the engineering nerd that I am, one thing led to another and the spreadsheet became quite thorough!

This spreadsheet will allow you to:

1. Decide what the minimum length you need for a CFC is
2. Decide what the exact differences are between using 1/4 and 3/8 tubing
3. Discover how much water you'll be using with the hose wide open and whether you can throttle this flowrate back and still cool the wort
4. Discover how fast your kettle will drain and how long the overall process should take
5. Discover how much you can feasably cool your wort (to what temperature)
6. Other cool stuff

The only problem is I'm not a Premium member so I can't post an attachment! Anyone willing to PM me an email address and post the attachment for me? I'd really like to share this spreadsheet with others. (and SWMBO says signing up for premium memberships in forums is no longer allowed )

Example calculation:

CFC is 1/4" tube inside 3/4" hose and is 25ft long.
Tap water is at 55psi and at 65F.
Hot wort is at 200F. Kettle is 3ft above bottom of CFC.

Results:
Max water rate is 6 2/3 gallon per minute
Min cool wort temperature is 73F
It will take around 19 minutes to completely drain the kettle (5 gallon batch)
Only 12-13ft of the CFC is required, so it is plenty big enough at 25ft.

Here it is:

looks pretty cool, and I'll run the numbers from my system soon and see how they match.

thx!

View attachment wort_chiller.zip

Thanks AZ_IPA!

How to use the spreadsheet:

Step 1: Go to the Wort Flow worksheet. Fill in the yellow fields. Please note the definition of "h". This spreadsheet will approximate the expected flowrate of the wort -by gravity- through the CFC.

Step 2: Go to the Water Flow worksheet. Fill in the yellow fields. Note the hose length INCLUDES the distance from the spiquet to the CFC and any additional hose coming off the CFC. This spreadsheet will approximate the maximum flowrate of the cooling water.

Step 3: Go to the CFC worksheet. Fill in the yellow fields. Change your "Cool Wort T" until all of the Feasible?'s answer "YES".

That's it! Any feedback is appreciated!

With tube diameter > 0.31, or so, you start attempting SQRTs of negative numbers

The only way for fNre^2 to be negative is if there is a negative driving force. This will happen if "h" becomes a negative number.

Try adjusting your kettle diameter and/or height to more accurately reflect your system. Increasing these numbers will prevent your entire volume from draining during time increment 1.

BTW, if you see the curve suddenly drop to zero at any time increment, this is what has happend. h has become =< 0.