This study evaluated the interrelations between indoor and outdoor bioaerosols in a bedroom under a living condition. Two wideband integrated bioaerosol sensors were utilized to measure indoor and outdoor particulate matter (PM) and fluorescent biological airborne particles (FBAPs), which were within a size range of 0.5‐20 μm. Throughout this one‐month case study, the median proportion of FBAPs in PM by number was 19% (5%; the interquartile range, hereafter) and 17% (3%) for indoors and outdoors, respectively, and those by mass were 78% (12%) and 55% (9%). According to the size‐resolved data, FBAPs dominated above 2 and 3.5 μm indoors and outdoors, respectively. Comparing indoor upon outdoor ratios among occupancy and window conditions, the indoor FBAPs larger than 3.16 μm were dominated by indoor sources, while non‐FBAPs were mainly from outdoors. The occupant dominated the indoor source of both FBAPs and non‐FBAPs. Under awake and asleep, count‐ and mass‐based mean emission rates were 45.9 and 18.7 × 106 #/h and 5.02 and 2.83 mg/h, respectively. Based on indoor activities and local outdoor air quality in Singapore, this study recommended opening the window when awake and closing it during sleep to lower indoor bioaerosol exposure.

In the simulation of acoustic agglomeration, the conventional temporal model assumes spatial homogeneity in aerosol properties and sound field, which is often not the case in real applications. In this article, we investigated the effects of spatial nonhomogeneity of sound field on the acoustic agglomeration process through a one-dimensional spatial sectional model. The spatial sectional model is validated against existing experimental data and results indicate lower requirements on the number of sections and better accuracy. Two typical cases of spatial nonhomogeneous acoustic agglomeration are studied by the established model. The first case involves acoustic agglomeration in a standing wave field with spatial alternation of acoustic kernels from nodes to antinodes. The good agreement between the simulation and experiments demonstrates the predictive capability of the present spatial sectional model for the standing-conditioned agglomeration. The second case incorporates sound attenuation in the particulate medium into acoustic agglomeration. Results indicate that sound attenuation can influence acoustic agglomeration significantly, particularly at high frequencies, and neglecting the effects of sound attenuation can cause overprediction of agglomeration rates. The present investigation demonstrates that the spatial sectional method is capable of simulating the spatially nonhomogeneous acoustic agglomeration with high computation efficiency and numerical robustness and the coupling with flow dynamics will be the goal of future work.

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