01
Choose the pair that matches the evidence
Dry bulb plus relative humidity is the usual pair for electronic probes. Dry bulb plus wet bulb suits a properly operated psychrometer. Dry bulb plus dew point suits instruments that report condensation temperature. Enthalpy plus humidity ratio can reconstruct a state from an airside balance, while pressure remains a separate required context.
The solver supports 15 documented independent pairs. It rejects two moisture-coordinate values—such as dew point plus humidity ratio—when they cannot determine dry bulb, as well as non-finite, out-of-range and supersaturated inputs.
02
Verified example and complete result
Enter 25 °C dry bulb, 50% relative humidity and 101.325 kPa. The canonical result is 17.889 °C wet bulb, 13.864 °C dew point, 9.883 g/kg humidity ratio, 50.326 kJ/kg enthalpy, 0.858 m³/kg dry-air specific volume and 1.1770 kg/m³ moist-air density.
These are connected properties of one equilibrium state, not separate estimates. Small displayed rounding differences are normal; exported values retain more precision. Switching units converts at the interface and does not recalculate from rounded display text.
03
Interpret the result by the decision
For condensation risk, compare dew point with the coldest surface—not relative humidity alone. For a moisture balance, compare humidity ratio. For heat-flow estimates, compare enthalpy on the same reference basis. For volumetric-to-mass flow conversion, select the stated density basis and use actual pressure.
Always record the input pair, pressure source, unit system, timestamp and instrument uncertainty. Agreement between two calculated properties does not validate the sensors because both may originate from the same measurement error.
04
Mistakes the solver is designed to expose
Relative humidity must remain from 0% to 100%; 150% is not silently accepted. Gauge pressure is not total barometric pressure. Elevation is not pressure unless a standard-atmosphere estimate is acceptable. Fahrenheit and Celsius values must match the selected unit system.
A result near saturation is sensitive to small temperature errors. An equilibrium state does not model droplets, fog, transient adsorption, local stratification or coil bypass. Use measured pressure where the density or flow consequence matters.
05
Model boundary and workflow
The calculation core uses perfect-gas moist-air relations over documented temperature and pressure ranges. Enhancement factors and high-pressure non-ideal effects are outside the current model. Use it for preliminary engineering and teaching, then verify critical decisions independently.
For commissioning, calculate each airside location with the same pressure and compare humidity ratio before enthalpy. For process work, carry the saved start state into the process or mixing calculator and retain the exported record.