Designation (also air humidity) for the proportion of water vapor in the gas mixture of the earth's atmosphere or in rooms. Liquid water such as raindrops, fog droplets, ice or snow crystals are not included. Humidity is one of the many factors in the weather or in the long-term weather pattern of the climate, From the free water surfaces (Rivers, lakes, seas), individual water molecules always pass from the water volume into the air volume. Absolute air humidity is the amount of gaseous water vapor contained in one cubic meter of air, which is usually represented in g / m3.
The most common measure, however, is the relative humidity (RH), which is the ratio of the actually contained to the maximum possible amount of water vapor in the air, measured in%. However, the air can only absorb a limited amount of water vapor. The warmer the air, the higher this amount of saturation: 50 g at 40 ° Celsius, 200 g at 65 ° Celsius and 600 g at 100 ° Celsius. If the amount of saturation is exceeded, tiny water droplets in the form of mist form as a result of condensation, as well as dew on surfaces close to the ground. Air humidity is an important parameter for meteorological processes. A relative humidity between 55 to 65% is optimal for humans, animals and most plants.
In viticulture, air humidity is very important for the growth of the vines. Adequate relative humidity prevents the absorption of nutrients and increased growth and decreased water delivery. Plants give in the dry air or too low relative humidity over the leaves very much water to cool the air. Through this as evaporation designated operation it may be too water stress come. Usually affects during the fruit set (Phase of development of the flowers into berries) a high humidity with sufficient sunlight especially in the afternoon through a continuous photosynthesis with optimal formation of sugar and flavorings positively on the wine quality.
Such conditions exist, for example, in Germany, Austria and Switzerland. Regions with low humidity usually have a hot climate. Increased dew formation as well as high air humidity especially in connection with high temperatures can be a number of fungal diseases favor. The critical value for the formation of various molds is around 70% RH. Humidity is also very important for storing and maturing the wine in barrels or bottles. in the wine cellar the ideal value is 70 to 80%. See also under aging. basement mold. bottle aging. Wine Cabinet and wine temperature,