HEPA filters to improve vehicle cabin air quality – advantages and limitations

Maintaining a good indoor air quality level has received growing attention in the past years. Especially the smaller particles like PM2.5 (particles of aerodynamic diameter less than 2.5 μm) and UFP (ultrafine particles, aerodynamic diameter less than 100 nm) might lead to higher health risks. Vehicle cabin is one challenging environment due to the elevated particle concentrations from the surroundings.