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The wet-bulb temperature is the temperature a parcel of air would have if it were cooled to saturation (100% relative humidity) by the evaporation of water into it, with the latent heat being supplied by the parcel.〔Oxford Reference, A Dictionary of Weather, ISBN 978-0-19-954144-7〕 A wet-bulb thermometer will indicate a temperature close to the true (thermodynamic) wet-bulb temperature. The wet-bulb temperature is the lowest temperature that can be reached under current ambient conditions by the evaporation of water only. Wet-bulb temperature is largely determined by both actual air temperature (dry-bulb temperature) and the amount of moisture in the air (humidity). At 100% relative humidity, the wet-bulb temperature equals the dry-bulb temperature. == General== The thermodynamic wet-bulb temperature is the lowest temperature which may be achieved by evaporative cooling of a water-wetted (or even ice-covered), ventilated surface. By contrast, the dew point is the temperature to which the ambient air must be cooled to reach 100% relative humidity assuming there is no evaporation into the air; it is the point where condensate (dew) and rain would form. For a parcel of air that is less than saturated (i.e., air with less than 100 percent relative humidity), the wet-bulb temperature is lower than the dry-bulb temperature, but higher than the dew point temperature. The lower the relative humidity (the drier the air), the greater the gaps between each pair of these three temperatures. Conversely, when the relative humidity rises to 100%, the three figures coincide. For air at a known pressure and dry-bulb temperature, the thermodynamic wet-bulb temperature corresponds to unique values of the relative humidity and the dew point temperature. It therefore may be used for the practical determination of these values. The relationships between these values are illustrated in a psychrometric chart. Cooling of the human body through perspiration is inhibited as the wet-bulb temperature (and absolute humidity) of the surrounding air increases in summer. Other mechanisms may be at work in winter if there is validity to the notion of a "humid" or "damp cold." Lower wet-bulb temperatures that correspond with drier air in summer can translate to energy savings in air-conditioned buildings due to: #Reduced dehumidification load for ventilation air #Increased efficiency of cooling towers 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Wet-bulb temperature」の詳細全文を読む スポンサード リンク
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