This is a pivotal, 12-month, randomized, sham controlled, parallel group, multicenter, double blind study with an allocation ratio of 1:1. The study population is children between the ages 6 to 17 years, with mild to moderate persistent asthma. The purpose of the study is to determine whether the CREON2000A, an environmental control device, will decrease asthma severity, as measured by the Composite Asthma Severity Index (CASI), in children with mild to moderate persistent allergic asthma over a twelve month period.