Effectiveness–NTU Heat Exchanger Calculator

Calculate heat duty, overall heat transfer coefficient or area with the effectiveness–NTU method. Compare parallel and counter flow heat exchangers.

1. Choose what to calculate

What do you want to calculate?

Heat transfer rate (Q) Overall heat transfer coefficient (U) Effective heat transfer area (Aꜱ)

Flow configuration

Parallel flow Counter flow

Parallel: fluids move in the same direction. Counter: fluids move in opposite directions.

Heat-capacity rates

Hot fluid heat-capacity rate (C₁)

Heat-capacity rate = mass flow rate (kg/s) × specific heat capacity (J/(kg·K)).

Cold fluid heat-capacity rate (C₂)

Heat-capacity rate = mass flow rate (kg/s) × specific heat capacity (J/(kg·K)).

Temperatures

Input units: °C / K / °F. Each input uses its selected unit; changing units converts values automatically.

Hot fluid inlet temperature (T₁,in)

Cold fluid inlet temperature (T₂,in)

Material and geometry

Overall heat transfer coefficient (U)

Effective heat transfer area (Aꜱ)

Heat transfer

Enter a positive heat-capacity rate for each fluid. The result uses the magnitude of the inlet temperature difference.

Resets fields and units to their defaults. Saved calculations remain.