Infiltration of outdoor combustion-generated pollutants to indoors due to various ventilation regimes: A case of a single-family energy efficient building

Abstract

The paper presents the quantitative assessment of the influence of various ventilation regimes on particulate matter and polycyclic aromatic hydrocarbon concentrations in the newly built, low energy unoccupied house. Experimental measurements were conducted over five-week period of February–March, which is affected by combustion particles resulting from residential heating and traffic in outdoor air. Number concentrations of particles (PNC0.3-10), mass concentration of PM2.5, as well as vapor and particle phase polycyclic aromatic hydrocarbons (PAHs) were measured both outdoors and indoors during several ventilation regimes. Ventilation regime with minimum natural and no mechanical ventilation (air change rate (ACR) of 0.16 1/h) caused the lowest infiltration of outdoor pollutants in this particular building as represented by I/O ratio of PM2.5 (0.22), PNC0.3-10 (0.20), and total PAHs (0.23 and 0.33 for particle and vapor phase, respectively). Natural ventilation via leaky windows regime (ACR – 0.42 1/h) caused the highest infiltration of the particles and PPAHs (I/O PM2.5–0.45, PNC0.3-10 – 0.51, and PPAHs - 0.47). At the same time, mechanical ventilation resulted in the highest I/O of VPAHs of 0.58 at ACR of 0.80 1/h, while I/O of PPAHs were moderate (0.38–0.45). Such results indicate that outdoor combustion particles are only partially arrested in a filter commonly installed in air handling units (grade F7, ePM2.5 = 66%). At the same time, conventional residential air filtration systems are less efficient in the removal of gas phase pollutants, which needs to be addressed by specific engineering measures.