Absolute humidity

Generally, if it is only called “Humidity”, “Relative Humidity =RH” will be pointed out, but it is convenient to use the absolute humidity from which a value does not change in a design or control of a drier even if temperature changes.

Quantity the water of which exists in the air with absolute humidity

Quantity the water of which has actually melted with relative humidity to the amount of quantity = saturation water vapor of the water which can melt into the air

Since the amount of saturation water vapor will increase if the sealed air in equipment is heated, relative humidity falls, but absolute humidity does not change.

Absolute humidity includes Volume absolute humidity and Weight absolute humidity (mixture ratio).
Since weight absolute humidity is made into “absolute humidity” in the field related to air-conditioning in Japan, cautions are required.

Volume absolute humidity VH

Capacity absolute humidity shows the quantity of the vapor which what g vapor has come loose in air 1?, or is contained in atmospheric unit capacity by weight.
(Unit: g/m3) It is also called the amount of saturation water vapor.

VH Volume absolute humidity
mw mass of water vapor in the air(g/m3)
Va Volume of total air

Weight absolute humidity (Specific humidity) SH

Weight absolute humidity ( Specific humidity)is a ratio of the weight of the vapor which what kg vapor has melted into 1 kg of air, or is contained in moist air to the weight of dry air.

SH  Weight absolute humidity (Specific humidity)
mw  mass of water vapor in the air(g/m3)
mDA mass of dry air