Multistack industrial air purifier features Multistack: Nojan Multistack air purifier and purification system, with high variety and great flexibility in the variety and composition of filters inside. This system has been designed and marketed following the study of various cases of work spaces with polluted air in Iran and the various needs and expectations of the personnel working in them. The Multistack industrial air purifier, in addition to using particle fiber filters, can also hold up to 20 kg of chemical adsorbents.