Please see below for an overview on glycol chiller sizing with Spike fermenters.

How to use the charts:

  1. Get the total "Cold Crash" BTU/hr needed for all vessels you want to cold crash at the same time.
  2.  Add the "Maintain Cold Temps" BTU/hr for each vessel that you want to hold at cold temps after the batch is cold crashed.
  3.  Add the "Fermentation" BTU/hr for each additional vessel not counted in steps 1 or 2
  4.  With all of the numbers added together, you now know the minimum amount of BTU/hr needed for your setup.  A good rule of thumb is to always allow an additional 20% when picking a chiller.


  • 4 CF15 fermenters
  • Cold crash 2 at a time = 1400 BTU/hr
  • Maintain cold in 1 = 200 BTU/hr
  • Ferment in 1 remaining= 100 BTU/hr

Subtotal = 1700 BTU/hr, +20% Buffer of 340 BTU/hr

Total = 2040 BTU/hr needed. 1/3HP Glycol Chiller would be a great fit!


Important Note - The charts assume you are using insulated tanks in mild ambient conditions (<80F) and cold crashing is over an 24hr window.  While this would apply to most users there are some who need to make adjustments because their situation is a bit different.  Use the numbers for the next size up fermenter if any of the following apply:

•Your fermenting ambient temperature is above 80F

•You would like to fully cold crash in less than 24 hours