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
- 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
- Multiply the total bbl’s (total barrels) by 15 bricks.
ex: 36 bbl’s x 15 = 540 bricks - Multiply by 280 BTU
ex: 540 bricks x 280 BTU = 151,200 BTU - 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.
