Chiller Tonnage Size Calculation

One of the most frequently asked questions about chiller specifications is how to calculate its sizing/tonnage. Properly sizing a chiller for your application can depend on a large number of variables.

Chiller Capacity Conversion Calculator

What Parameters Do You Need to Get the Right Chiller Tonnage

Fill in the boxes with the following three parameters to get the estimated chiller size you need for your application.

• The flow rate
• The incoming water temperature
• The chilled water temperature you require

Chiller Tonnage Calculation Formula

• Calculate Temperature Differential = Incoming Water Temperature (°c) – Required Chilled Water Temperature
• Calculate the water flow rate that you need per hour(m³/hour)
• Calculate tons of cooling capacity = Water Flow Rate x Temp. Differential ÷ 0.86 ÷ 3.517
• Oversize the chiller by 20% Ideal Size in Tons = Tons x 1.2
• You have the ideal size for your needs

For example, what size of chiller is required to cool 5m³ water from 25°c to 15 °c in 1 hour?

• Temperature Differential = 25°c-15°c=10°c
• Water Flow Rate = 5 m³/hour
• Ton Capacity = 5 x 10 ÷ 0.86 ÷ 3.517 = 16.53 Tons
• Oversize the chiller = 16.53 x 1.2 = 19.84 Tons
• A 19.84 Tons chiller is required