Chiller GPM Calculator
Water Side
GPM CALCULATOR
Estimate chiller water flow from design pressure drop and current pressure readings.
Evaporator Flow
Evaporator
Calculated flow
Condenser Flow
Condenser
Calculated flow
Flow is an estimate, not a direct flow measurement.
Want to understand the method? Read the Chiller GPM Pressure Drop guide →Advanced
METHOD
Pressure Drop Method
FORMULA
GPM₂ = GPM₁ × √(ΔP₂ / ΔP₁)
EXPLANATION
This formula estimates water flow from the current pressure drop and the chiller’s design flow and design pressure drop.
Assumptions and limitations: Design flow and design pressure drop are required. Measured pressure difference is entering pressure minus leaving pressure. Unit conversion occurs before the pressure-drop ratio is calculated. This is an estimate, not a direct flow measurement. Results depend on correct design data and valid pressure readings.
Want to compare this result to last month, document changes, or hand this to a customer? That requires a structured log.