How to Size a Brewery Chiller

How to Size a Brewery Chiller

Calculating the size of chiller for your brewery is not rocket science.  However, given that you want to protect your recipe and ensure that temperatures are maintained, it is critical to the success of your brewery.  If you follow the formula below, you will be able to determine the size of the chiller you require.  U.S. breweries work off imperial measurements, however, most of the equipment is made elsewhere which can add to confusion when determining barrel, hectoliters and bbl.  If you are still concerned, don’t worry, our staff is ready to assist you at any point in time.  Just call 209-522-3701 if you need assistance. 

Sizing a Brewery Chiller.

In order to calculate the size of the Brewery Chiller you require, a few other calculations must be determined first.  Let’s start with the bbl, which is the number of barrels your brewery is able to produce.  If you are able to produce 20 barrels at one time, you have a 20 barrel system (bbl).  If you are able to produce 10 barrels in one shot, you have a 10 bbl.  Seems simple enough.

Next you need to determine the pull down aka crashing.  Pull down occurs when the temperature of your vessel drops (other than wort cold crash).  This is normally the largest influence in determining the size of the required chiller.  In addition to bbl and pull down, there are a few factors you must know before you begin:

  • The size of your tanks
  • Temperature Differential
  • Length of time to achieve desired temperature

Calculate the Pull Down Loads

  1. Calculate the volume in gallons of your tanks
    (1 bbl = 31 gallons) 
    ex: 9 bbl tank = 279 gallons

Use the assumption we have four, 9 bbl tanks
279 x 4 = 1,116 gallons

 

  • Multiply the total gallons by 8.33 to get the total pounds
    ex: 1,116 x 8.33 = 9,296.28 pounds
  • Multiply the total pounds by your temperature difference
    This is often 75°F – 34°F = 41°F
    ex: 9,296.28 x 41 = 381,147.48 Total BTU
  • Divide by the hours of your pull down 
    ex: 381,147.48 /18 = 21,174.86 (BTU/HR)
    (381,147.48/24 = 15,881.145 (BTU/HR if your pull down is 24 hours)

This is the BTU/HR required for your pull down process.  It is not uncommon for brewers to add 10 – 15% to this number to accommodate for extra heat being added by the pumps, unexplained heat loss or other inefficiencies.  

Calculate the Heat Load for Active Fermentation

  1. Multiply the total bbl’s (total barrels) by 15 bricks.
    ex: 36 bbl’s x 15 = 540 bricks
  2. Multiply by 280 BTU
    ex: 540 bricks x 280 BTU = 151,200 BTU
  3. Divide by 70 Hours
    70 hours is typically the amount of time that the majority of heat gain from yeast occurs, even if/when the fermentation period is longer than 75 hours.  
    ex: 151,200/70 = 2,160 BTU/HR

This is the TOTAL BTU/HR’s Needed for Active Fermentation

Add the pull down load and the active fermentation load together for the total BTU/HR load

ex:  21,174.86 (BTU/HR) + 2,160 BTU/HR = 23,334.86 BTU/HR

 

For this example, a chiller capable of providing a minimum of 23,335 BTU/HR @28°F Leaving Glycol Temperature would be required.  

It is critical that the chiller you are purchasing is sized correctly.  Chillers in the United States are sized by horsepower or tonnage. Regardless, it is imperative that the chiller also factors in the glycol percentage. Normally gylcol percentages are 30% o 40% glycol to water depending upon the lowest outdoor temperature or 28°F (whichever is lowest).  Propylene glycol requires more surface area in the heat exchanger than water.  

It is that simple.  If you have any questions, or would like a quote customized to meet your specific needs, just click on the button below.