Humidity ratio

Humidity Ratio (Ordinate). The humidity ratio is the weight of water vapor in the air per unit weight of dry air. 

Humidity ratio The ratio of the mass of water vapor present in air to the mass of dry air. 

Humidity ratio, saturation The humidity ratio of a gas at saturation. 

Humidity ratio, expired air The mass ratio of water vapor to dry air in expired air. 

The inlet air temperature shown is measured right on top of the Zeolite bed. It has already cooled down to about 90 °C between the district heat exchanger and the Zeolite. The outlet air is almost saturated at about 35 °C for about 9.5 h. The desorption was stopped after the outlet air temperature has reached 60 °C. At the same time the humidity ratio of the outlet air has dropped and the equilibrium is almost reached. A continuation of the desorption is not efficient. 

Figure 264. Air Dehumidification and energy storage capacity in an ideal absorption process as a function of the air to solution mass ratio (cooling temperature 24°C, inlet humidity ratio 14.5 g/kg, LICL-H20 solution)...

Relative Humidity ratio of the vapor pressure of water in air compared to the saturated vapor pressure of pure water at the same temperature, measure of the amount of water vapor in an air mass expressed as percent of how much water vapor that air mass can hold Relative Mass mass measured with respect to a standard, atomic masses based on C-12 standard... 

An air sample has a dry-bulb temperature of 95°F (35°C) and a wet-bulb temperature of 80°F (26.7°C). Determine the relative humidity, the dew-point temperature, the humidity ratio and the vapor pressure. 

Eqs. (33)-(35) allow interconversion from one expression for solvent content to another. For example, knowledge of temperature, total pressure, and relative humidity allows the humidity ratio to be determined using... 

Comfort is influenced by temperature, humidity, air velocity, radiant heat, clothing, and work intensity. Psychological factors may mso influence comfort, but their discussion is beyond the scope of this handbook. The reader is referred to Chap. 42 of the HVAC Applications volume of the A.S.H.R.A.E. Handbooks for a full discussion of the control of noise, which must also be considered in air-conditioning design. Figure 5 in Chap. 8 of the HVAC Fundamentals volume of the A.S.H.R.A.E. Handbooks relates the variables of ambient temperature, dew point temperature (or humidity ratio) to comfort under clothing and activity conditions typical for office space occupancy. It also shows boundary values for ET, the effective temperature index. This index combines temperature and moisture conditions into a... 

Curves showing the relative humidity (ratio of the mass of the water vapor in the air to the maximum mass of water vapor the air can hold at that temperature, i.e., if the air were saturated) of humid air appear on the psychrometric chart. (See Figure 2.) The curve for 100% relative humidity is also referred to as the saturation curve. The abscissa of the humidity chart is air temperature, also known as the dry-bulb temperature (T b). The wet-bulb temperature (7 yb) is another measure of humidity it is the temperature at which a thermometer with a wet wick wrapped around the bulb stabilizes. As water evaporates from the wick to the ambient air, the bulb is cooled the rate of cooling depends on how humid the air is. No evaporation occurs if the air is saturated with water hence WB and Fob are the same. The lower the humidity, the greater the difference between these two temperatures. On a psychrometric chart, constant wet-bulb temperature lines are straight with negative slopes. The value of 7 vb corresponds to the value of the abscissa at the point of intersection of this line with the saturation curve. 

The relationships among the psychrometric states, loads, and sensible heat ratio are shown graphically in Fig. 3. For a given pair of entering and leaving air states, sensible, latent, and total loads are proportional to the differences in temperature, humidity ratio, and enthalpy, respectively, as shown in the figure. The SHR is defined by the slope of the line connecting the two points. 

In Table 4.1 saturation pressure of water vapor and related maximum humidity ratio are reported as function of temperature in the range of interest for PEMFC utilization and atmospheric pressure. The humidity parameter is defined as ratio between the mass of water vapor present in samrated air to the mass of the dry air. 

Temperature (°C) Saturated pressure of water vapor (kPa) Maximum humidity ratio (gH2O Sdry air)... 

The different humidification approaches could be classified as internal or external methods. Internal humidification means that humidification procedure concerns exclusively the inner spaces of fuel cell stack, while external humidification involves modifications in feeding stream humidity ratio outside of the stack [1. 29]. 

RELATIVE HUMIDITY. Ratio of the amount of water vapor present in the air to that which the air would hold at saturation at the same temperature. It is usually considered on the basis of the weight of the vapor but, for accuracy, should be considered on the basis of vapor pressures. 

W - rate of work done by the body (W/m2 of naked body area), or humidity ratio (kg of water vapor/kg of dry air)... 

Specific humidity - ratio of mass of water vapor to mass of total air, g H20 (kg air)-1... 

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