ABSTRACT
Filtration is the most common and most economical means, in many applications, of air cleaning and air sampling. Fibrous or other particle-capturing materials can be easily made in different shapes with high efficiency of particle collection. Air filters are part of our daily life. They are in home furnaces, clothes driers, vacuum cleaners, cars, and facial masks or respirators. Almost all mechanically ventilated buildings are equipped with some kind of filter. In some special cases, such as a medical surgery room or an electronic fabrication shop, high-efficiency particle attenuation (HEPA) filters are necessary.
