This Air Purifier is the one you want. After moving from a regular single dwelling house into an Apartment on the 16th floor, I noticed a cough I never had before. A friend mentioned that it would highly likely be the air quality (or lack thereof) in the Apartment. Researching for the best quality Air Purifier I came across the Alen BreatheSmart Purifier. Although it was the highest priced I decided to go for it. NEVER regretted it, it is an amazing product, worth every penny. Have recommended it to friends and will continue to do so ...