I live in a city with bad air pollution and no central HVAC system. I have two air purifiers and an air quality monitor. Both air purifiers are effective in reducing the particulate matter count. But unless they are run at full speed 24 hours a day the indoor air quality doesn't stay within a safe range. If they are run at less than full speed then a safe particle count is only reached after many hours. When a window or exterior door is opened the particle count shoots up quickly.
I want to be able to freely open doors and have a bearable amount of noise. It's possible that other air purifiers run quieter but it seems noise level and effectiveness are directly correlated. Are there any other measures to increase the effectiveness of an air filtration system? Should I seal doors and windows with weather strips? Our home has fans in both the kitchen and bathroom. When running these fans the air quality gets worse. If the bathroom/kitchen doors are kept well-sealed and closed would it help?