A Review of Portable Air Cleaner Devices: Purification Processes, Performance Standards, and Effectiveness in Controlling Indoor Air Pollutants

Background and Objective: Indoor air pollutants are among the five most important environmental health risks. In recent years, concerns regarding indoor air quality in buildings have increased. This review has investigated studies conducted on portable air cleaners. Materials and Methods: After determining the keywords, conducting comprehensive searches in the internet databases, and taking into account the inclusion and exclusion criteria, a complete review was conducted to obtain the latest findings and the general trend of the studies. Results: Portable air cleaner devices are very diverse and are divided based on the type of technology used. Many standards have been developed to evaluate the performance of these devices in different countries, but none of them cover all aspects of performance. The effectiveness of these devices in removing VOCs is between 20% and 80%, depending on the type of technology and other influencing factors, and their effectiveness in removing suspended particles is between 70% and 95% on average. Furthermore, their efficiency in controlling COVID-19 is reported to be above 80% in cases where HEPA filters with grades 13 and above are used. Conclusion: Devices equipped with the HEPA filtration process have been found to be very effective in controlling indoor suspended particles. The use of devices equipped with UVGI, plasma, and ozone technologies should be accompanied by caution due to dangerous by-products.