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Design Point
Operating Point
CDU Heat Exchanger Calculator
Design-point UA and off-design performance for a counterflow heat exchanger.
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Design Point
1. Input manufacturer's design data to calculate UA
Calculated UA
BTU/hr·°F
Operating Point
2. Select inlet or outlet and input operating temperatures for both loops
TW DP
psi
Secondary Loop (TW)
Primary Loop (CHW / FW)
% of Design
CHW DP
psi
3. Adjust inputs above to achieve desired capacity
Capacity:
kW
of Design
4. Enter the desired return temperature to calculate mixing valve bypass flow
°F Return:
GPM
Detailed calculation steps are shown below.
Heat Exchanger UA Calculations
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NTU Effectiveness Calculations
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Pressure Drop Calculations
Pressure drop scales with the square of flow relative to the design point, assuming the same fluid and unchanged flow resistance. Cv uses the selected fluid's fixed specific gravity; viscosity and temperature corrections are not included.
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