Moist Air - Specific vs. Relative Humidity
Humidity is the quantity of water vapor present in air. It can be expressed as an absolute, specific or a relative value.
If we know the relative humidity of the moist air and the water vapor density and the density of the air, the specific humidity can be expressed as:
x = 0.622 φ ρws / (ρ - ρws) 100% (1)
where
x = specific humidity (humidity ratio) of air vapor mixture (kgh2o/kgdry_air)
φ = relative humidity (%)
ρws = density of water vapor (kg/m3)
ρ = density of the moist or humid air (kg/m3)
Related Topics
• Air Psychrometrics
Moist and humid air calculations. Psychrometric charts and Mollier diagrams. Air-condition systems temperatures, absolute and relative humidities and moisture content in air.
Related Documents
Air - Absolute Humidity
Absolute humidity is the actual mass of water vapor present in the air water vapor mixture.
Air - Humidity Ratio
The mass of water vapor present in moist air - to the mass of dry air.
Humid Air and the Ideal Gas Law
Pressure, temperature and volume in a perfect ideal gas like moist air (air with water vapor).
Mixing of Humid Air
The change in state wwhen mixing moist air - enthalpy, heat, temperature and specific humidity.
Moist Air - Density vs. Water Content and Temperature
Density of the mix of dry air and water vapor - moist humid air.
Moist Air - Enthalpy
Sensible and latent heat of moist air.
Moist Air - Properties
Psychrometric table with humid air properties like saturation pressure, specific volume, enthalpy and entropy.
Moist Air - Relative Humidity
Relative humidity in moist air is the ratio of partial vapor pressure to air pressure.
Moist Air - Specific Volume
Specific volume of moist air is defined as the total volume of humid air per mass unit of dry air
Recommended Relative Humidity
Recommended relative humidity level.