People spend most of their time indoors, and therefore exposure to aerosols and precursor-gasses in the indoor environment is of extreme concern with respect to people’s health, well-being, working efficiency, and overall life quality. Such sources include both those emitted inside as well as those which may intrude from the outside. To better quantify and understand these sources and their impacts we employ multiple air quality monitors and simple models, both within and outside of various residential environments located in different cities of different development levels in China. To enhance the livability of the indoor environment, we further work to quantify two newly relevant factors: portable indoor aerosol filters and the idea of “increased ventilation”. The combined goal of this work is to understand the combination of factors leading to an improvement in Indoor Air Quality (IAQ), including but not limited to: mass transfer to/from the indoor environment, removal and/or enhancement due to the filters and ventilation, removal from the room itself, emissions, and other possible non-linearities not accounted for on this list. Concentrations of aerosols across different sizes from 0.3um to 10um are measured and analyzed at 2-minute intervals over a minimum of 20 days, allowing for an analysis that encompasses all of the possibilities of natural and anthropogenic variability typically encountered in a real environment. This includes analysis both with and without filters, under extreme outdoor loading conditions, with intense indoor emissions sources, pseudo-equilibrium conditions, and measurements made during different meteorological events, both with and without high rates of indoor to outdoor air exchange. Results show that the impacts are relatively large under both equilibrium and high event conditions, include both the magnitude of the drop as well as the time taken to achieve the reduction. A further conclusion is that increased ventilation may lead to a worsening of IAQ. A final conclusion is that larger particles more likely associated with PM2.5 are removed at a different rate from much smaller particles more associated with PM0.5 or PM1.