Validation and Application of the Mass Balance Model To Determine the Effectiveness of Portable Air Purifiers in Removing Ultrafine and Submicrometer Particles in an Apartment

Lee, Wan-Chen; Catalano, Paul J.; Yoo, Jongman; Park, Chan Jung; Koutrakis, Petros

doi:10.1021/acs.est.5b03126

Cited by 15 publications

(5 citation statements)

References 24 publications

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“…There is empirical evidence that air movement reduces PNC indoors [23, 42, 43]. While this effect could be due to tightness of the building envelop, which can reduce indoor pollution of outdoor origin depending on the infiltration rate rather than sham filtration, we doubt this is the case because most apartments opened windows (Table 1).…”

Section: Discussionmentioning

confidence: 95%

Lessons from in-home air filtration intervention trials to reduce urban ultrafine particle number concentrations

Brugge

Simon

Hudda

et al. 2017

Building and Environment

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Background Exposure to airborne ultrafine particle (UFP; <100 nm in aerodynamic diameter) is an emerging public health problem. Nevertheless, the benefit of using high efficiency particulate arrestance (HEPA) filtration to reduce UFP concentrations in homes is not yet clear. Methods We conducted a randomized crossover study of HEPA filtration without a washout period in 23 homes of low-income Puerto Ricans in Boston and Chelsea, MA (USA). Most participants were female, older adults who were overweight or obese. Particle number concentrations (PNC, a proxy for UFP) were measured indoors and outdoors at each home continuously for six weeks. Homes received both HEPA filtration and sham filtration for three weeks each in random order. Results Median PNC under HEPA filtration was 50–85% lower compared to sham filtration in most homes, but we found no benefit in terms of reduced inflammation; associations between hsCRP, IL-6, or TNFRII in blood samples and indoor PNC were inverse and not statistically significant. Conclusions Limitations to our study design likely contributed to our findings. Limitations included carry-over effects, a population that may have been relatively unresponsive to UFP, reduction in PNC even during sham filtration that limited differences between HEPA and sham filtration, window opening by participants, and lack of fine-grained (room-specific) participant time-activity information. Our approach was similar to other recent HEPA intervention studies of particulate matter exposure and cardiovascular risk, suggesting that there is a need for better study designs.

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Section: Discussionmentioning

confidence: 95%

Lessons from in-home air filtration intervention trials to reduce urban ultrafine particle number concentrations

Brugge

Simon

Hudda

et al. 2017

Building and Environment

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“…The temperature of the coil in the heating chamber was set at 350 °C to provide a buoyant plume to simulate that from cooking activities. We maintained the air exchange rate using the CO 2 constant injection method at 2 per hour by manually adjusting the openings of the study zone [29]. Detailed measurement procedure of air exchange rate can be found in SI (SI-2).…”

Section: Methodsmentioning

confidence: 99%

Effects of Window Position and Exhaust Flow Rate on Residential Kitchen Hood Performance: A Validated Numerical Approach

Lin,

Chan,

Lee

2024

Indoor Air

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Previous studies showed that opening windows could help with kitchen ventilation in pollutant removal. However, no studies have systematically examined the impacts of window positions on kitchen hood performance, and there is insufficient information on indoor airflow characteristics and pollutant distribution from makeup air through open windows. Therefore, the objective of this study was to use a validated computational fluid dynamics approach with CO2 as an indoor air quality indicator (a surrogate for cooking emissions) to understand the impacts of exhaust flow rate and the window opening position on the flow characteristics, concentration distribution, and capture efficiency (CE) of the hood. We conducted four-point validation tests of the numerical models based on CO2 concentration and temperature measurements under steady-state conditions. The validated models were subsequently used in simulations to understand the effects of six different window opening positions and the two exhaust flow rates on exposure. We found that the CO2 concentration could be better reduced by having windows open at the higher location. Generally, the front windows were more effective with CE>80%, followed by the back and the side windows, respectively. We also found that as the exhaust flow rate increased from 6.72 to 12.16 m3/min, CE reached >75% for all window positions, where the most significant increase was 1.58 times for the lower side window. To sum up, changing the relative position of the window and the exhaust hood could help disperse the incoming airflow from the window, improve the kitchen’s overall ventilation, and reduce pollutant concentration.

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“…The steady‐state approach has been used by many studies 9,11,26‐28 to facilitate the integration of Equation 1 9 . This implies that the outdoor concentration is assumed to have not changed considerably with time and that steady outdoor conditions prevail long enough to allow indoor concentrations to reach steady state.…”

Section: Methodsmentioning

confidence: 99%

Infiltration of fine particles in urban daycares

2020

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Singapore is a tropical country with a high density of day‐care facilities whose indoor environments may be adversely affected by outdoor fine particle (PM2.5) air pollution. To reduce this problem requires effective, evidence‐based exposure‐reduction strategies. Little information is available on the penetration of outdoor PM2.5 into day‐care environments. Our study attempted to address the following objectives: to measure indoor infiltration factor (Finf) of PM2.5 from outdoor PM2.5 and to determine the building parameters that modify the indoor PM2.5. We collected indoor/outdoor 1‐min PM2.5 from 50 day‐care classrooms. We noted mean Finf ± SD of 0.65 ± 0.22 in day‐care rooms which are naturally ventilated and lower Finf ± SD values of 0.47 ± 0.18 for those that are air‐conditioned: values which are lower than those reported in Singapore residences. The air exchange rates were higher in naturally ventilated rooms (1.47 vs 0.86 h−1). However, fine particle deposition rates were lower for naturally ventilated rooms (0.67 ± 0.43 h−1) compared with air‐conditioned ones (1.03 ± 0.55 h−1) presumably due to composite rates linked to the filters within the split unit air‐conditioners, higher recirculation rates, and interior surfaces in the latter. Our findings indicate that children remaining indoor in daycares where air‐conditioning is used can reduce their PM2.5 exposures during outdoor pollution episodes.

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Validation and Application of the Mass Balance Model To Determine the Effectiveness of Portable Air Purifiers in Removing Ultrafine and Submicrometer Particles in an Apartment

Cited by 15 publications

References 24 publications

Lessons from in-home air filtration intervention trials to reduce urban ultrafine particle number concentrations

Lessons from in-home air filtration intervention trials to reduce urban ultrafine particle number concentrations

Effects of Window Position and Exhaust Flow Rate on Residential Kitchen Hood Performance: A Validated Numerical Approach

Infiltration of fine particles in urban daycares

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