Adiabatic air mixing enthalpy calculator
Adiabatic air mixing enthalpy
Adiabatic mixing conserves dry-air mass and enthalpy; use flow-weighted rather than unweighted averages.
Units
hmix=m1+m2m1×h1+m2×h2
hmix=m1+m2m1×h1+m2×h2
Calculator
Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.
Worked example
Given
- m1 = 9,000 lb/h
- h1 = 28 Btu/lb
- m2 = 3,000 lb/h
- h2 = 40 Btu/lb
hmix=9000+30009000×28+3000×40=31
Given
- m1 = 3 kg/s
- h1 = 40 kJ/kg
- m2 = 1 kg/s
- h2 = 64 kJ/kg
hmix=3+13×40+1×64=46
Symbols and units
| Symbol | Meaning | Unit |
|---|
| hmix | mixed-air enthalpy | Btu/lb |
| m1 | first dry-air mass flow | lb/h |
| h1 | first air enthalpy | Btu/lb |
| m2 | second dry-air mass flow | lb/h |
| h2 | second air enthalpy | Btu/lb |
| Symbol | Meaning | Unit |
|---|
| hmix | mixed-air enthalpy | kJ/kg |
| m1 | first dry-air mass flow | kg/s |
| h1 | first air enthalpy | kJ/kg |
| m2 | second dry-air mass flow | kg/s |
| h2 | second air enthalpy | kJ/kg |
Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.
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