This HEPA air purifier is made for a medium-large space. Claims to provide 5 room air changes per hour in a 175 square foot area. Removes dust, pollen, pet dander and smoke. Also removes certain bacteria and viruses. We have placed it in our bedroom and have noticed a difference in air quality. We have 3 cats and a wood stove. It runs very quiet and takes up very little space. Considering getting a larger capacity model for a larger area. The HPA5100B is the medium sized unit and takes care of the bedroom. Easy to use controls and Honeywell quality gives us confidence that it does the job as described.