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THE FEUTEX TOOLKIT

Counterflow Exchanger Effectiveness

Calculate counterflow effectiveness, duty and outlet temperatures from heat-capacity rates.

Thermal workspace● Runs in your browser
01 Your input
02 Your result
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Formulaε=(1−e^(−NTU(1−Cr)))/(1−Cr e^(−NTU(1−Cr))); equal-rate limit ε=NTU/(1+NTU).
Sources and model references

Worked example

Inputs

Overall conductance
2000 W/K
Hot capacity rate
2000 W/K
Cold capacity rate
1000 W/K
Hot inlet temperature
100 °C
Cold inlet temperature
20 °C

Expected results

Counterflow effectiveness
0.7746003264
Number of transfer units
2
Heat duty
61968.02612 W
Hot outlet temperature
69.01598694 °C
Cold outlet temperature
81.96802612 °C

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter every input in the labeled units; use measured or independently specified properties.
  2. Check the stated model assumptions before calculating.
  3. Interpret the output as a model estimate and verify it independently for the intended application.

Try this example

{
  "ua": 2000,
  "hot": 2000,
  "cold": 1000,
  "thi": 100,
  "tci": 20
}

Accuracy and scope

Ideal counterflow with constant heat-capacity rates, no external heat loss or phase change. Outputs effectiveness and NTU; duty is εCmin(Thi−Tci). Educational engineering estimate only; not structural or safety certification, equipment selection, or operating recommendations.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.