Performance of ventilation filtration technologies on characteristic traffic related aerosol down to nanocluster size

Figures & data

Figure 1. Experimental setup consisting of aerosol particle generators (both nucleation and soot), mixing chamber, ventilation channel, test filters, dilution, and aerosol measurement instruments.

Table 1. Description of the tested filters: F7, HEPA 1, HEPA 2, Electret, ESP. Errors for pressure drop, volumetric flow and face velocities have been determined by the information provided by the device manufacturers.

Dimensions (mm)	610 × 610 × 620	610 × 610 × 580	295 × 295 × 120	610 × 610 × 600	525 × 325 × 205
Pressure drop (Pa)	43 ± 0.5	152 ± 0.5	90 ± 0.5	115 ± 0.5	3 ± 0.5
Volumetric flow (l/s)	500 ± 25	500 ± 25	53 ± 2.6	500 ± 25	170 ± 8.5
Face velocity (m/s)	1.34 ± 0.07	1.34 ± 0.07	0.61 ± 0.03	1.34 ± 0.07	1 ± 0.05

Figure 2. Example of the upstream particle size distribution used in the experiments (solid [blue] line) and the fraction of electrically charged particles (dashed [orange] line). Zoomed size distribution shows the particle concentrations in the PSM detection size range.

Figure 3. Stability of the aerosol generation system measured by the Nano-SMPS (dark gray [blue], D_p< 20 nm) and Long-SMPS (light gray [green], D_p > 20 nm) (top), and by the ELPI (total particle concentration, D_a > 30 nm) (bottom).

Figure 4. Particle filtration efficiencies for the tested filters calculated from upstream and downstream size distributions measured by the PSM (D_p 1.3–2.9 nm), Nano-SMPS (D_p 3–20 nm), and Long-SMPS (D_p > 20 nm).

Figure 5. Uppermost row shows the normalized particle size distributions from the left: NM (this study), SM (this study), test aerosol (this study), Helsinki road side (Virtanen et al. 2006), Peking (Wu et al. 2008), Helsinki accumulation mode (AM) only (Hussein et al. 2004). The rows below indicate what size distribution exists indoor after row corresponding filtration, and the percentages indicate the total number filtration efficiency for the corresponding aerosol.

Virtanen, A., Rönkkö, T., Kannosto, J. et al. (2006). Physical Characteristics of Winter and Summer Time Emissions of Busy Road at Helsinki. Atmos. Chem. Phys. Discuss., 6:549–578.

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Wu, Z., Hu, M., Lin, P., Liu, S., Wehner, B., and Wiedensohler, A. (2008). Particle Number Size Distribution in the Urban Atmosphere of Beijing, China. Atmos. Environ., 42:7967–7980.

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Hussein, T., Puustinen, A., Aalto, P. P., Mäkelä, J. M., Hämeri, K., and Kulmala, M. (2004). Urban Aerosol Number Size Distributions. Atmospheric Chemistry and Physics, 4(2): 391–411.

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