Thermodynamics & HVAC
Psychrometrics Chart Analyzer
Analyze and visualize moist air properties (enthalpy, humidity ratio, specific volume, wet bulb, dew point) dynamically over temperature sweeps and custom climatic presets.
Atm. Pressure
101.325 kPa
Standard Sea Level
Model
ASHRAE / Stull
Moist Air Relations
Output
CSV
Export ready
Parameters
Climatic Presets
Dry-bulb temperature sweep
Psychrometrics Formulations
Saturation Pressure
P_s = 0.61078 * exp(17.27 * T_db / (T_db + 237.3)) kPa
Partial Vapor Pressure
P_v = (RH / 100) * P_s kPa
Humidity Ratio (W)
W = 0.62198 * P_v / (P_atm - P_v) kg/kg
Specific Enthalpy (h)
h = 1.006 * T_db + W * (2501 + 1.84 * T_db) kJ/kg
Specific Volume (v)
v = 0.287042 * (T_db + 273.15) / (P_atm - P_v) m³/kg
At Dry Bulb Temp of 25.0°C and Relative Humidity of 50%, saturation vapor pressure is 3.168 kPa.
Dew Point occurs at 13.9°C (where moisture begins to condense).
Wet Bulb temperature is estimated to be 18.0°C.
Interactive Psychrometric Chart
Humidity Ratio (W)
9.88g/kg
Wet Bulb Temperature
18.0°C
Dew Point Temperature
13.9°C
Specific Volume
0.858m³/kg
Mixture Enthalpy (h)
50.3kJ/kg
Vapor Pressure
1.584kPa
Saturation and Relative Humidity Curves
Thermodynamic Curve Data
| Dry Bulb Temp (°C) | Saturation W (g/kg) | 50% RH W (g/kg) | Current RH W (g/kg) |
|---|---|---|---|
| 0.0 | 3.77 | 1.88 | 1.88 |
| 2.0 | 4.36 | 2.17 | 2.17 |
| 4.0 | 5.03 | 2.51 | 2.51 |
| 6.0 | 5.79 | 2.88 | 2.88 |
| 8.0 | 6.66 | 3.31 | 3.31 |
| 10.0 | 7.63 | 3.79 | 3.79 |
| 12.0 | 8.73 | 4.33 | 4.33 |
| 14.0 | 9.97 | 4.95 | 4.95 |
| 16.0 | 11.37 | 5.63 | 5.63 |
| 18.0 | 12.93 | 6.40 | 6.40 |
| 20.0 | 14.69 | 7.26 | 7.26 |
| 22.0 | 16.66 | 8.22 | 8.22 |
| 24.0 | 18.87 | 9.29 | 9.29 |
| 26.0 | 21.34 | 10.49 | 10.49 |
| 28.0 | 24.10 | 11.82 | 11.82 |
| 30.0 | 27.18 | 13.30 | 13.30 |
| 32.0 | 30.62 | 14.94 | 14.94 |
| 34.0 | 34.46 | 16.77 | 16.77 |
| 36.0 | 38.74 | 18.78 | 18.78 |
| 38.0 | 43.51 | 21.02 | 21.02 |
| 40.0 | 48.83 | 23.49 | 23.49 |
| 42.0 | 54.76 | 26.23 | 26.23 |
| 44.0 | 61.37 | 29.24 | 29.24 |
| 46.0 | 68.76 | 32.58 | 32.58 |
| 48.0 | 77.00 | 36.26 | 36.26 |
| 50.0 | 86.22 | 40.32 | 40.32 |