RAK-RC filtering units have been developed for general ventilation/filtration. They can be used in any places where it is not possible to apply local exhausts, or they are not sufficient in extraction efficiency. Both, the appliances can be used in not large rooms as well in large buildings, under the condition that several filtering units are used, which are suitable to the sort of pollution emission source. Each device features four-step filtration system: pre-filter, filtering pad, compact filter and carbon filter, absorbing the part of gaseous contamination. At the moment the filters reach the limit pollution degree, replace them for new – they cannot be submit to regeneration.