the air after having been created by boiling water Isothermal humidification

# The air after having been created by boiling water

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the air after having been created by boiling water. Isothermal humidification requires an external source of energy to change the state of the water. Adiabatic Humidification finely atomized water is introduced into the air. The adiabatic process does not involve the contribution of thermal energy from an external source. There is no heat Humidification

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Humidity ( H ) a measure of the amount of water vapour (moisture) in the air. It is generally reported as relative humidity or absolute humidity. measured in terms of mass of water vapour per unit mass of dry air Humidity chart ( Psychrometric ) study the relationships between air and its associated water Saturated air Air that contains maximum amount of water vapour (moisture) at given conditions of pressure (P) and temperature (T). Relative humidity is 100%. Humidity - T erminologies
Humidity

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Relative Humidity – 6 June 2019 (5.00 pm, Malaysian time) KUALA LUMPUR 88% RH @ 27 o C BEIJING 73% RH @ 23 o C LONDON 50% RH @ 17 o C NEW YORK 95% RH @ 21 o C
Humidity Formulas

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The air in a room is at 26.7 o C and a pressure of 101.325 kPa and contains water vapour with a partial pressure, p A = 2.76 kPa. Calculate: a) Humidity b) Saturation Humidity c) Percentage Humidity d) Relative Humidity Question
a)Given: p A = 2.76 kPa, P = 101.325 kPa Hence, H = 0.01742 kg H 2 O/kg air b)Refer steam table, at 26.7 o C, 101.325 kPa, p AS (partial pressure of water vapour in saturated air) = 3.5 kPa (steam table) H S = 0.02225 kg H 2 O/kg air c) H P = 78.3% d) H R = 78.9% Solution

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Saturation Temperature-Pressure Table
a convenient chart of the properties of air- water vapour mixtures at 1 atm abs pressure humidity, H, is plotted versus the actual temperature of air- water vapour mixture (dry bulb temperature) Humidity - Psychrometric Chart

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Dry Bulb Temperature : refers basically to the ambient air temperature. It is called "Dry Bulb" because the air temperature is indicated by a thermometer and not affected by the moisture of the air. Wet Bulb Temperature : it is the Saturation Temperature . Wet Bulb temperature can be measured by using a thermometer with the bulb wrapped in wet muslin. Humidity Ratio : is the mass of the water contained in the air per unit of dry air. This is often expressed as kg of moisture per kg of dry air ( or g of moisture per kg of dry air ). T erms - Psychrometric Chart
Dew Point : Temperature where water vapour starts to condense out of the air (the temperature at which air becomes completely saturated with water vapour). Above this temperature, the moisture stays in the air (vapour). Enthalpy : the heat energy content of moist air. It is expressed in kJ/kg of dry air and represents the heat energy due to temperature and moisture in the air.

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