Psychrometrics Workbench
Moist-air states from dry-bulb temperature, absolute pressure and one moisture quantity; adiabatic mixing, sensible heating and cooling with dehumidification. All specific quantities are per kilogram of dry air.
Inlet state 1
Inlet state 2
Overlays are drawn only when their pressure matches the chart pressure. Range limited to −30 to 100 °C.
Moist air is treated with the saturation-pressure and mixture model reported in the provenance block of each result (for example ASHRAE Handbook psychrometric relations or a real-gas moist-air formulation, as stated by the engine). Saturation over liquid water vs ice follows the engine's documented convention below 0 °C.
- RH is limited to 0–100 %; no supersaturation or fog-region states.
- Wet-bulb input is the thermodynamic (adiabatic-saturation) wet-bulb, not a psychrometer reading with ventilation corrections.
- h and v are per kg of dry air; degree of saturation μ = W/Ws is reported. Steam humidification takes steam enthalpy at the air pressure and rejects unsaturated (wet) inlet steam. The coil model mixes the apparatus-dew-point state with bypassed inlet air by the bypass factor. Evaporative humidification adds liquid water at its own enthalpy and refuses outlets that would be supersaturated (fog). The chart joins inlet and outlet states with straight lines.
- Cooling assumes condensate leaves at the outlet temperature unless the engine's steps state otherwise.
Engine: CoolProp 8.0.0 (pinned) — I. H. Bell, J. Wronski, S. Quoilin, V. Lemort, "Pure and Pseudo-pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library CoolProp", Ind. Eng. Chem. Res. 53(6), 2498–2508 (2014), doi:10.1021/ie4033999. Distributed under the MIT licence. Water: IAPWS-95 (HEOS) and IAPWS-IF97 (industrial formulation) as implemented in CoolProp. Humid air: CoolProp HAPropsSI real-gas moist-air model (Herrmann, Kretzschmar and Gatley, ASHRAE RP-1485). Remaining limitations are listed above.