Comparative performance analysis of commercial unipolar standalone ionisation devices for particulate matter capture

Indoor air quality is a major concern in the modern environment. Amongst different indoor pollutants, submicron particulate matter (PM) is a significant health concern. Although several PM control technologies are available, they have different drawbacks. In this regard, ionisation has multiple advantages for its application in indoors. Therefore, the current study has integrated a charging module with an Electrostatic Precipitator (ESP) plate, forming a hybrid module. The performance of six ionisation devices, including four commercially available carbon brushes, a customised spiked static bar and a stainless steel discharge electrode, was evaluated with respect to the efficiency of PM capture from major indoor sources. Ionisers were ranked as best performing, low performing and poorly performing based on PM capture efficiency. Results from the study showed a V-shaped curve, with total efficiency ranging from 10.47% to 98.02% for sizes of 10 to 1000 nm. A trade-off between ion generation rate and orientation was found to affect PM capture in the tested ionisers. Due to the generation of ultrafine PM, total efficiency of ESP was reduced with PM sources like mosquito coils (75.68%) as well as mixed aerosols (86.46%). Additionally, the study compared ozone generation from the tested ionisation devices, thereby enabling their safer use in indoor environments.