Alen Air makes 5 different air purifiers and each one has it's place. I just finished a short article on the different units, filtration type, coverage and best places to use according to our customers. In fact we have had very good feedback from our customers about Alen Air since we took on their line of air purifiers. Anyway follow this link to the article on the Alen Air purifiers.  

Wishing you the best of health
Mike Krause
AllergyStore.com - Serving Customers Since 1989
800 771-ACHOO