Use this engineering calculation for a transparent preliminary estimate or independent arithmetic check when geometry, materials, loads, operating conditions, and units are defined consistently.

Dry Bulb Celsius (°C)

Required number input.

Humidity Ratio Kg Per Kg Dry Air (kg/kg)

Required number input.

Moist-air enthalpy per kg dry air from dry-bulb Celsius temperature and humidity ratio; standard HVAC approximation at ordinary pressure. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Enthalpy Kilojoules Per Kg Dry Air (kJ/kg)

The resulting enthalpy kilojoules per kg dry air returned as a number.

• Thermodynamic results require consistent reference states, property data, phase assumptions, composition, pressure, and sign conventions. Constant heat capacity, ideal gas, reversible process, or moist-air approximations apply only over suitable ranges.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check assumptions against drawings, measurements, current material data, and the applicable design code. Apply required load combinations and safety factors, then obtain qualified review and testing for consequential designs.

• Otto Cycle Efficiency

  Ideal air-standard Otto-cycle thermal efficiency 1−1/r^(γ−1) from compression ratio and constant heat-capacity ratio.

• Cooling Tower Approach

  Cooling-tower approach temperature as cooled-water outlet temperature minus ambient wet-bulb temperature.

• Sound Pressure Level

  Sound pressure level 20log₁₀(prms/pref) in dB, using an explicitly supplied reference pressure such as 20 µPa in air.