The problem of indoor air quality (IAQ) is at the centre of international attention and a current topic of discussion due to the implicit repercussions on the socio-sanitary situation in each country. Numerous studies and research carried out all over the world have in fact highlighted that all common environments contain a multitude of pollutants that are harmful to the health of the occupants.
These airborne pollutants are produced by the increasingly widespread use of new products for construction and furniture. In addition, in large cities, traffic, home combustion appliances, the use of chemical products for cleaning, the type of room and the characteristics of the site, inadequate ventilation, tobacco smoke and other causes represent important factors in the decline of indoor air quality.
In response to these facts, special attention has been paid to this important topic in recent years all over the world. This increased sensitivity has, through control of emissions and establishing maximum admissible concentrations, led to a significant reduction of some contaminants in the atmosphere, above all those of industrial origin, and a perceptible reversal in the trends of some related illnesses.
In addition, together with the relative reduction of outdoor pollution, recent years have seen the international medical-scientific community engaged in the public health sector take a stand on the problem of contamination of the air in indoor spaces. In general, indoor pollution is defined as the "presence of physical, chemical and biological contaminants in the air that would not naturally be found in air in high quality outdoor ecological systems" (Italian Environment Ministry, 1991).
The main source of exposure for some airborne pollutants and the only source for others is therefore represented by the level of indoor contamination.
Naturally, the composition of the atmosphere (nitrogen, oxygen, etc.) is the same outdoors and indoors, however the quality and the quantity of contaminants found indoors may differ significantly. The problem becomes even more important if we consider that some groups of people are much more sensitive to atmospheric pollution (the elderly, children, asthmatics, people suffering from bronchitis, emphysema, and illnesses in general, etc.) who, as well as spending most of their time indoors, have weakened natural defences to combat the harmful actions of some pollutants found in the air they breathe.
Since 1995, most Sabiana fan coils have been available with an innovative active electronic filter, called Crystall, which reduces the levels of many pollutants in the air, such as tobacco smoke, dust and fibres, and microbiological substances such as bacteria and fungi that are harmful to the health. The subject of numerous scientific publications, the Crystall filter has proven to be especially effective in reducing the spread of microbiological substances through air distribution ducts, and as a result is also currently available in the Crystall Duct System and Crystall Flex System version.