Study of HEPA Filter and Finding it's Efficiency with Change in Air Pressure

The physical behaviors of indoor air particles were studied in order to test the efficiency of air filter. The filteration characteristic of filter media in terms of its efficiency and effectiveness, were evaluated and analyzed. During testing, the efficiency of filter medium showed maximum efficiency of 93.9% with drop in pressure from 80.73kg/m³ to 75.73 kg/m³. The ability of filter to capture particles depends on the size of particles passing through its fibers as well as the velocity of the flow passing through the filter. The velocity of air depend on energy provided, therefore filter media should be energy efficient. In-situ measurements were taken using a manometer which is placed to measure the pressure drop between the two sections just before and after the filter, thus it displays the pressure drop induced by filter medium. The pressure drop increases with time because the resistance to the air is increased with the particles captured in the filter. As the resistance to the air increases, more energy is required to maintain the same air pressure. The ability of filter to move air through the system is reduced when the pressure drop increases. When this ability is reduced, more energy is required to provide the same air flow. When the efficiency of a filter increases, the pressure drop usually increases too.