Moisture is the water vapour content of air, soil and other materials or environments. In the context of air, it describes the amount of water present in the atmosphere. It is most often expressed as relative (the ratio of the current amount of water vapour to the maximum amount the air can hold at a given temperature, given as a percentage) or absolute (the mass of water vapour contained per unit volume of air, expressed in g/m³).
It has a significant impact on thermal comfort, human health, technological processes and the condition of buildings and materials. Too high humidity promotes the growth of mould and corrosion. Conversely, too low a temperature can lead to the drying out of materials and health problems such as irritation of mucous membranes or dry skin.
