Determination of Particle Penetration Coefficient, Particle Deposition Rate and Air Infiltration Rate in Classrooms Based on Monitored Indoor and Outdoor Concentration Levels of Particle and Carbon Dioxide

Particle deposition and penetration in buildings has been widely studied, but the effect of indoor characteristics merits further investigation, so improved experimental methods may be needed. The present study measured indoor and outdoor concentrations of PM2.5 and estimated PM2.5 deposition rates and penetration factors under a variety of different indoor situations, with a novel method (blower-door method). The blower-door method is compared with the standard decay and rebound method for an idealized room (a portable building test cell; 6.08 m [Formula: see text] 2.40 m [Formula: see text] 2.60 m) under eight testing scenarios (empty, cardboard boxes in three arrangements, terry cloth wall covering, and three sets of window holes); run three times to establish the coefficient of variation representing precision. Results show that higher induced indoor–outdoor pressure differences cause a larger variation of estimated effective deposition rate on different indoor surfaces. The deposition rate and penetration factor may be influenced by indoor surface materials. The blower-door method gives higher precision for the estimates, and detects subtle differences in penetration factors, which may be difficult using the decay and rebound method.

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Effects of Neighboring Units on the Estimation of Particle Penetration Factor in a Modeled Indoor Environment

Urban Science ◽

10.3390/urbansci5010002 ◽

2020 ◽

Vol 5 (1) ◽

pp. 2

Author(s):

Yonghang Lai ◽

Ian A. Ridley ◽

Peter Brimblecombe

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Deposition Rate ◽

Indoor Air ◽

Particle Deposition ◽

Weather Conditions ◽

Penetration Factor ◽

Particle Penetration ◽

Indoor Pm2.5 ◽

Pm2.5 Concentration

Ingress of air from neighboring apartments is an important source of fine particulate matter (PM2.5) in residential multi-story buildings. It affects the measurement and estimation of particle deposition rate and penetration factor. A blower-door method to measure the particle deposition rate and penetration factor has previously been found to be more precise than the traditional decay-rebound method as it reduces variability of PM2.5 ingress from outside. CONTAM is a multi-zone indoor air quality and ventilation analysis computer program to aid the prediction of indoor air quality. It was used in this study to model the indoor PM2.5 concentrations in an apartment under varying PM2.5 emission from neighboring apartments and window opening and closing regimes. The variation of indoor PM2.5 concentration was also modeled for different days to account for typical outdoor variations. The calibrated CONTAM model aimed to simulate environments found during measurement of particle penetration factor, thus identifying the source of error in the estimates. Results show that during simulated measurement of particle penetration factors using the blower-door method for three-hour periods under a constant 4 Pa pressure difference, the indoor PM2.5 concentration increases significantly due to PM2.5 generated from adjacent apartments, having the potential to cause an error of more than 20% in the estimated value of particle penetration factor. The error tends to be lower if the measuring time is extended. Simulated measurement of the decay-rebound method showed that more PM2.5 can penetrate inside if the PM2.5 was generated from apartments below under naturally variable weather conditions. A multiple blower-door fan can be used to reduce the effects of neighboring emission and increase the precision of the penetration estimates.

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Indoor particle dynamics in schools: Determination of air exchange rate, size-resolved particle deposition rate and penetration factor in real-life conditions

Indoor and Built Environment ◽

10.1177/1420326x15610798 ◽

2015 ◽

Vol 26 (10) ◽

pp. 1335-1350 ◽

Cited By ~ 9

Author(s):

Dinh Trinh Tran ◽

Laurent Y Alleman ◽

Patrice Coddeville ◽

Jean-Claude Galloo

Keyword(s):

Deposition Rate ◽

Particle Deposition ◽

Particle Density ◽

Real Life ◽

Particle Dynamics ◽

Ventilation Rate ◽

Rate Coefficients ◽

Particle Size Fractions ◽

Penetration Factor

Indoor and outdoor airborne particles, CO, CO2 levels and comfort parameters were monitored at two naturally ventilated elementary schools (S1 and S2). This paper studies the variation of ventilation rate during lectures, recreations, lunchtime and after class. Additionally, mass balance equations were used to estimate the particle deposition rates and penetration factors for different particle size fractions. The originality of the present work resides in taking advantage of occupants’ activities as sources of indoor particles and tracer gas CO2 used to simultaneously estimate the above-mentioned parameters in different scenarios. This simple approach makes the determination of indoor particle dynamics more effective, and allows reducing the cost of indoor air quality studies. During the class, the ventilation rates at S1 and S2 fluctuated largely from day to day, with respective average values of 10.08 m3/h/p and 7.92 m3/h/p, significantly lower than the ASHRAE acceptable value (18 m3/h/p) in classrooms. The particle deposition loss rate coefficients for 0.3–10 µm particles dramatically increased from 0.16–0.18 h−1 for the 0.3–0.5 µm fraction to 1.81–2.31 h−1 for the 7.5–10 µm fraction, while their corresponding penetration factors declined from 0.94 to 0.30, respectively. The difference in deposition rate between schools was probably associated to discrepancies in particle density.

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Gas Chromatographic/Mass Spectrometric Determination of Benzene and Its Alkyl Derivatives in Indoor and Outdoor Air in Fuji, Japan

Journal of AOAC International ◽

10.1093/jaoac/85.1.203 ◽

2002 ◽

Vol 85 (1) ◽

pp. 203-211 ◽

Cited By ~ 8

Author(s):

Takashi Amagai ◽

Takeshi Ohura ◽

Tomohiko Sugiyama ◽

Masahiro Fusaya ◽

Hidetsuru Matsushita

Keyword(s):

Mass Spectrometric ◽

Benzene Derivatives ◽

Outdoor Air ◽

Indoor Pollution ◽

Indoor Sources ◽

Alkyl Derivatives ◽

Concentration Levels ◽

Indoor And Outdoor ◽

Chromatographic Mass

Abstract An analytical method was established for the determination of benzene and 13 of its alkyl derivatives. The method was applied to a survey of indoor pollution that investigated the usefulness of the method, concentration levels, seasonal variations, profiles, correlations between compounds, and factors that affected indoor pollution by these compounds. The survey was performed in 21 houses in the summer of 1999 and 20 houses in the winter of 1999–2000 in Fuji, Japan. All the target compounds were detected in the indoor and outdoor air of all houses. Outdoor concentrations of benzene ranged from 0.779 to 3.17 μg/m3 in summer and from 1.35 to 6.04 μg/m3 in winter, whereas indoor concentrations of benzene ranged from 0.694 to 3.11 μg/m3 in summer and from 1.65 to 6.89 μg/m3 in winter. Indoor concentrations of the target compounds, except for benzene, were elevated, compared with outdoor concentrations. Because indoor and outdoor concentrations of benzene and its derivatives in summer were lower than in winter, the emission of these compounds may be increased by use of a heater and other variables present in winter. Profiles of the compounds, correlations between the compounds, and factors that affected indoor pollution (determined by multiple regression analysis) were investigated. These results suggested that indoor benzene predominantly penetrated from outdoors and that other benzene derivatives were emitted from indoor sources, such as paint solvents and kerosene heaters.

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Indoor and outdoor PM concenctration at a residential environment, in the Athens area

Global NEST Journal ◽

10.30955/gnj.000553 ◽

2013 ◽

Vol 10 (2) ◽

pp. 201-208

Keyword(s):

Population Exposure ◽

Air Exchange Rate ◽

Diurnal Cycles ◽

Indoor Sources ◽

Limit Value ◽

Pm10 And Pm2.5 ◽

Outdoor Concentration ◽

Highly Correlated ◽

Concentration Levels ◽

Indoor And Outdoor

The aim of the present work was to study exposure to PM in the indoor and outdoor microenvironment of a typical residence in the center of Athens. Simultaneous indoor and outdoor measurements of PM10 and PM2.5 were conducted, by the use of gravimetric and continuous samples, during October and November 2006. Moreover, air exchange rate was monitored continuously during the entire measurement period. The indoor and outdoor concentration levels were significant for both size fractions. Mean daily PM10 outdoor concentrations exceeded the E.U. 24-hr limit value for 84 % of the measured days, while the respective PM2.5 concentrations exceeded the 24-hr limit value set by the C.A.F.E. working group for 69 % of the measured days. PM10 and PM2.5 concentrations exhibited increased short-term variability with high peak concentrations during morning and afternoon/night rush hours. Indoor concentration levels seem to be mainly affected by PM of outdoor origin, since the calculated indoor-to-outdoor concentrations ratios (I/O) were much lower than 1.00 during all days and indoor and outdoor concentrations were highly correlated. This finding was also supported by the pattern of their diurnal cycles, which followed the outdoor ones, with a delay of approximately 1 hr. The results indicate increased PM concentration levels in the center of Athens, even in indoor microenvironments with no significant indoor sources and emphasize the need for a more extensive investigation of the Athens population exposure, for the protection of public health.

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Indoor / outdoor PM levels and EC surrogate, at typical microenvironments in the Athens area

Global NEST Journal ◽

10.30955/gnj.000693 ◽

2013 ◽

Vol 12 (1) ◽

pp. 12-19 ◽

Cited By ~ 1

Keyword(s):

Absorption Coefficient ◽

Ambient Air ◽

Ambient Atmosphere ◽

Large Contribution ◽

Outdoor Concentration ◽

Measured Absorption ◽

Athens Area ◽

Very High ◽

Concentration Levels ◽

Indoor And Outdoor

The aim of the present work was to characterize particulate matter (PM) and elemental carbon (EC) indoor and outdoor concentration levels in the Athens area and to examine the contribution of ambient air to the observed indoor levels. 24-hr simultaneous indoor and outdoor PM10 and PM2.5 measurements were conducted at a central (CR) and a suburban (SR) residence, and at an office in the commercial centre of Athens (CO), during cold and warm period of 2006. The absorption coefficient (α) was measured on the collected filters, as a surrogate for EC concentration levels. Ambient PM levels were very high at both central sites and significant at SR (mean 24-hr PM10: 87.4, 50.3 and 87.3 μg m-3 and PM2.5: 50.7, 20.2 and 42.8 μg m-3 at CR, SR and CO). The measured absorption coefficient values were very high at CR and CO for both size fractions. Indoor PM concentration and absorption coefficient values were lower than the respective outdoor ones, but still significant at the two central sites. Very good correlations were observed between indoor and outdoor data (especially for absorption coefficient values), indicating a large contribution of the ambient atmosphere to the indoor levels, more pronounced in finer particles.

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