Humid Air and the Ideal Gas Law
Calculator for humid air properties using the Ideal Gas Law. Compute partial pressures of dry air and water vapor, total pressure, and individual gas constants based on temperature and density.
Humid Air and the Ideal Gas Law
The Ideal Gas Law expresses the relationship between pressure, volume, temperature, and quantity of gas:
p V = m R T (equation 4)
Where:
- p = absolute pressure (N/m²)
- V = volume (m³)
- m = mass of gas (kg)
- R = individual gas constant (J/kg K)
- T = absolute temperature (K)
For humid air, the total pressure is the sum of partial pressures:
pt = pa + pw (equation 6)
Where:
- pt = total pressure (kPa)
- pa = partial pressure dry air (kPa)
- pw = partial pressure water vapor (kPa)
Individual Gas Constants:
- Air: R = 286.9 J/kg K
- Water vapor: R = 461.4 J/kg K