The most significant factors of indoor air quality – besides temperature and humidity – are the concentrations of carbon-dioxide (CO2) and radon (222Rn). Radon seepage is caused by and affected by the materials used in walls and floors, the quality of insulation, cracks and even the amount of pipes running through the walls. The amount of CO2 is predominantly affected by the biological processes of the inhabitants, and possibly by potentially faulty HVAC systems. The energy efficiency related upgrades to family homes, which often only extend to window replacements and better insulation have a significant effect and could potentially increase concentrations of both radon and CO2 which has a significant effect on the well-being of the inhabitants. Our tests conducted in Hungary have proven that by using automated heat recovery ventilation (HRV) both energy efficient operation and low concentrations of radon and CO2 are achievable. Our results prove the significance and prevalence of the issue of higher concentrations of these pollutants, and offer a viable solution.

Particulate matter (PM) is the main determinant of air pollution caused by a variety of natural and human-caused sources. Because it can be suspended in the atmosphere for long periods of time and travel long distances, it can cause a major health crisis for humans and damage the environment as well. Studies are still required to understand how the PM moves around obstacles, especially in urban areas. In this study, small scale experiments were carried out to look into the effects of simple obstacles, heights and distance from the source on the PM10 concentration. Results show that when obstacle heights and distance from the source increase, the PM10 average concentration decrease. Also, turbulence created by the obstacles affects the PM10 concentration in both sensors before and after the obstacle, mainly in cases of high wind speed. In addition, the use of incense sticks as a source of PM pollution illustrated that moderate burning of incense sticks in indoor places could skyrocket the PM10 concentration to an unhealthy level.