Heat Exchanger Calculator

Calculate heat exchanger performance using LMTD or NTU-effectiveness methods.

Hot Side

Cold Side

Heat Transfer Rate
--
BTU/hr
LMTD
--
°F
Effectiveness
--
%
Required Area
--
sq ft
UA Product
--
BTU/hr-°F
NTU
--
Heat Transfer (kW)
--

Heat Exchanger Design Methods

Q = U x A x LMTD

LMTD = (dT1 - dT2) / ln(dT1/dT2)

Effectiveness = Q_actual / Q_max

NTU = UA / C_min

  • LMTD method: Best when all four temperatures are known
  • NTU method: Best when outlet temperatures are unknown
  • Counterflow is always more effective than parallel flow

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