The properties of moist air, mapped and interactive.
Click or drag anywhere on the chart to set a state point and instantly read dry-bulb temperature, relative humidity, humidity ratio, dew point, wet-bulb temperature, enthalpy, and specific volume.
BUILDING PHYSICS TOOL
Click or drag anywhere on the chart to set an air state point. The four families of lines — relative humidity, wet-bulb temperature, specific volume, and enthalpy — let you read multiple properties at once from a single point, the same way a printed psychrometric chart works. Calculated at standard sea-level pressure (101.325 kPa).
Dry-bulb temperature (x-axis) vs. humidity ratio (y-axis), 0–50°C.
State Point
Any two independent properties fully define the air state — type values, or click/drag the chart.
All Properties
Wet-bulb temperature uses the Stull (2011) empirical approximation (valid 5–99% RH, −20–50°C, mean absolute error < 0.3°C) rather than an iterative psychrometric solution. All values at standard sea-level pressure (101.325 kPa).
Click or drag on the chart to move the state point. Touch and drag works on mobile.
