Effects of Ionization on the Filtration of Fine and Ultrafine Particles in Indoor Air

As we spend approximately 80% of our time indoors, improving indoor air quality is necessary to lessen the spread and impacts of respiratory diseases and other health issues caused by particle pollution. Currently, in many countries, the primary method of cleaning indoor air is by using better, higher-grade filters in a recirculating air system or increasing ventilation with outdoor air. One way to supplement these time-tested approaches is by implementing ionization. We used a bipolar ionizer to test the removal efficiency of filters on different particle sizes with and without ionization. Calibrated cigarettes were used to generate smoke into a 28-cubic-meter chamber with a recirculating air handling system. It was found that ionization had a 275% increase in the removal efficiency of the most penetrating particle sizes (100-500 nm). We conclude that ionization drastically improves the filter removal efficiency of fine and ultrafine particles in indoor environments.