Volatile organic compounds (VOCs) are a major gaseous contaminant group affecting indoor air quality. Various technologies have been applied for the removal of VOCs. There are conventional systems based on adsorption process, i.e., activated carbon and/or potassium permanganate alumina pellets in trays or deep beds, particulate filters incorporating very thin beds of activated carbon or alumina pellets, and carbon cloth. The objective of this study is to investigate the effects of air flow rates on the performances of oxidation-based air cleaning technologies including UV with photocatalysts, plasma and ozone generators.