The air is filled with millions and millions of small solid & liquid particulates, which can have tremendous impact on human health. Particulates include living organism, such as the respirable-size particle; bacteria, viruses, and some molds and other indoor particles include dust mites, tobacco smoke, and pet dangers.These particulates are of principal concern from health perspective as the smaller particle can penetrate deeply into respiratory tract while the larger particles provoke allergic reactions to the nose, throat and eyes in many people. Thus, it is crucial to dilute the concentration of pollutants indoor especially in closed-up room where the air is re-circulated without or with very little air change. Of these, the smallest particles are most harmful to health as it will most likely reach and deposit in the alveola of the lungs, and can be embedded for years. Infants, elderly , and people with chronic allergic respiratory problems . Such as asthma, rhinitis, and sinusitis are most vulnerable to the effects of airborne pollutants.