Dry air is air that has a low relative humidity. When the relative humidity drops below about 40% the air feels dry to skin. If very low relative humidities persist it can make the skin dry, lips chapped and can put more static in the air. In the Winter when air with a low dewpoint from outside is heated and brought inside the air will decrease in relative humidity. To add moisture to the air some people will buy humidifiers. Although this air is referred to as dry air it is not perfectly dry. In some cases air will be referred to as dry even when the outside relative humidity is high but the dewpoint is low. This is because even if the air has a high relative humidity of 90% outside, once that air is brought inside and heated the relative humidity will decrease significantly. In situations in which the dewpoints are low outside (less than around 32 F) that air will often be referred to as dry by weather forecasters especially if the skies are clear
When you consider that individuals for the most part are most agreeable when the relative dampness is around 40 percent, you can perceive how dry indoor air can incur significant damage on your family. Low stickiness causes friction based electricity, dry skin, lips and hair, scratchy throats and noses, and tingling and chapping.Heaters and cool temperatures amid the winter months regularly prompt dry air with low moistness that can cause dry skin, bothersome eyes and aggravated sinuses.
