Charcoal filter plates for air conditioning systems

A gram of high quality activated charcoal has an inner and outer surface of about 1,000 m2 and more. That explains why activated charcoal is able to take up to 40% of its own weight of absorbed gases or odorous substances under favourable conditions. At normal concentrations present in the atmospheric air, service lifes of a year and over are obtained for this kind of filter equipment in practice, due to this enormous storing capacity. It is thus economically conceivable to use such filters as well as dust filters to improve the air. (orig./LH)