01
Temperature properties answer different questions
Dry bulb is ordinary air temperature. Dew point is the saturation temperature corresponding to the existing vapor pressure and helps assess cold-surface condensation. Thermodynamic wet bulb is an ideal evaporation endpoint influenced by temperature, moisture and pressure.
At 25 °C and 50% RH at 101.325 kPa, those values are 25 °C dry bulb, 13.864 °C dew point and 17.889 °C wet bulb. They are connected, but not interchangeable sensor labels.
02
Moisture has three common representations
Relative humidity compares actual and saturation vapor pressure at the current temperature. Vapor pressure is water vapor's partial pressure. Humidity ratio is water-vapor mass per dry-air mass and is the practical coordinate for moisture balances.
Heating at constant humidity ratio lowers RH but leaves vapor pressure and dew point approximately unchanged. That is why an RH trend needs temperature context.
03
Energy, volume and density need a basis
Moist-air enthalpy combines dry-air sensible and vapor contributions on a declared reference and per kg dry air. Specific volume is commonly per kg dry air. Moist-air density includes both constituents per mixture volume.
At 25 °C/50% RH/101.325 kPa, the engine reports 50.326 kJ/kg dry air, 0.858 m³/kg dry air and 1.1770 kg/m³ moist-air density. Keep those labels attached.
04
Independent pairs versus duplicate information
At fixed pressure, dry bulb plus RH, wet bulb or dew point can define a state. Dry bulb plus humidity ratio or enthalpy can also work. Dew point plus humidity ratio is dependent because both encode the same vapor amount and cannot establish dry bulb.
The solver lists only supported pairs and rejects an under-specified or impossible state. More displayed properties do not mean more independent measurements.
05
Select by decision, then verify
Use dew point for a surface threshold, humidity ratio for water balance, enthalpy for an energy difference and density for flow conversion. Use the complete state to cross-check the interpretation rather than presenting one property without pressure or basis.
Next action: enter the verified example, switch SI and IP once, and confirm that the physical state is unchanged. Review the methods page before using results outside preliminary analysis.