Ventilation (air exchange) refers to the change of polluted air in enclosed spaces by outside atmospheric air.
For the first time, scientifically substantiated requirements for air exchange in residential premises were proposed at the end of the last century by M. Pettenkoffer and K. Flygge. Both of them came from fi ziologicheskih apportionment values Niya human carbon dioxide in those chenie hours on the grounds that there is a well defined lenny parallelism between the accumulation of carbon dioxide and other volatile metabolites in the indoor air, with the speed and intensity s this accumulation closely connected us with the volume (cubic capacity of the room), the number of people in it, the nature of the activity and the time of their stay. Since that time, the content of carbon dioxide in indoor air has been regarded as an indirect integral indicator of its sanitary condition.