A lovely day for drying the washing

Just in case you didn't know, tumble dryers are not the only way to dry the washing. There was a lot of free energy out there for the taking today. It was very windy but with a lot of warm sunshine at times. Things dry when the water in them evaporates. The infra-red thermal radiation from the sun is absorbed. This gives the water molecules more energy - energy enough to beat the surface tension forces holding the liquid together. The wind moves escaped water molecules away quickly meaning that the air around the washing is always dry. Air can only hold a certain amount of water vapour at any given temperature. Above that amount and the air becomes saturated, some of the vapour condensing back into liquid water - the opposite of what we want to happen. If the escaped water vapour molecules are moved away quickly by the wind, this does not happen. The warm day with the higher air temperature also helps in this regard too - at higher temperatures air can hold more water vapour before becoming saturated. Now I need to go away and remember what saturated vapour pressure is about.