DESC: In one hour, the VI-2500 will remove over 98% of the most dangerous respirable particles from the air in a very large(1,000 cu ft room). These are the germs or pollutant particles that can lodge deep in the lungs (respirable fraction ) that the body cannot exhale. The results are ten times better than the competitive widely sold unit. A sealed safety room would continue to be almost particle free as long as the unit runs continuously.