Airborne particulate matter investigation in buildings with passive house technology in Hungary

In this case study, the building infiltration rate and indoor aerosol concentration levels in two buildings equipped with passive house technology and a “conventional” house were investigated in Ocsa, Hungary. Blower-door tests were applied to estimate the average infiltration rate and particle induced X-ray emission (PIXE) analysis was used to characterize the elemental compositions of particle samples. We compared the change in mass concentration, mass size distribution and elemental composition of coarse and fine aerosol fraction in the selected buildings and outdoor sampling site. On the basis of the Blower-door test and our calculations the infiltration rate of the conventional building is approximately 8-19 times higher and the total air change rate is 2-3 times higher than those of the passive buildings. Nevertheless, the concentrations of particulate matter and the average of the indoor/outdoor ratios for coarse fraction aerosols (particles with aerodynamic diameter bigger than 2.5 m) were higher in houses with passive house technology, indicating remarkable accumulation mechanism. On the basis of the mass size distribution, we found the filtration of the coarse size fraction is solved at the passive house. Furthermore, the fine size fraction containing combustion related elements (S, K, Pb, Zn) could be transported with outdoor air through the ventilation system. In these cases the effectiveness of removing contamination through infiltration and window opening are comparable to the effectiveness through mechanical ventilation. Without realizing the effective filtration possibilities of the ventilation system, the indoor air quality cannot be improved even in passive houses.