Experimental evaluation of in-duct electronic air cleaning technologies for the removal of ketones

Lee, Chang-Seo; Shayegan, Zahra; Haghighat, Fariborz; Zhong, Lexuan; Bahloul, Ali; Huard, Mélanie

doi:10.1016/j.buildenv.2021.107782

Cited by 11 publications

(4 citation statements)

References 52 publications

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“…(4) All cleaners tested emit a range of VOCs, including formaldehyde, at least initially. These results are in broad agreement with previous studies of oxidation-based, consumer-grade portable air cleaners and larger-scale air cleaning technologies, ,, although the present results provide a more comprehensive characterization of the emitted VOCs and oxidation byproducts than in previous work.…”

Section: Discussionsupporting

confidence: 93%

Real-Time Laboratory Measurements of VOC Emissions, Removal Rates, and Byproduct Formation from Consumer-Grade Oxidation-Based Air Cleaners

Krechmer

Shutter

et al. 2021

Environ. Sci. Technol. Lett.

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Levels of volatile organic compounds (VOCs) in the indoor environment can be decreased by the use of "air cleaners", devices that remove VOCs by sorption and/or oxidative degradation. However, efficacies of these technologies for removing VOCs tend to be poorly constrained, as does the formation of oxidation byproducts. Here, we examine the influence of several oxidation-based air cleaners, specifically ones marketed as consumer-grade products, on the amounts and composition of VOCs. Experiments were conducted in an environmental chamber, with a suite of real-time analytical instruments to measure direct emissions, VOC removal efficacies (by the addition of either limonene and toluene), and byproduct formation. We find that the air cleaners themselves can be a source of organic gases, that removal efficacy can be exceedingly variable, and that VOC loss is primarily driven by physical removal in some cleaners. When oxidative degradation of VOCs was observed, it was accompanied by the formation of a range of oxidation byproducts, including formaldehyde and other oxygenates. These results indicate that some consumer-grade portable air cleaners can be ineffective in removing VOCs and that the air delivered may contain a range of organic compounds, due to direct emission and/or byproduct formation.

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Section: Discussionsupporting

confidence: 93%

Real-Time Laboratory Measurements of VOC Emissions, Removal Rates, and Byproduct Formation from Consumer-Grade Oxidation-Based Air Cleaners

Krechmer

Shutter

et al. 2021

Environ. Sci. Technol. Lett.

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“…Several recent experimental characterizations of EAC performance have included (i) large chamber and in-situ field tests of an in-duct bipolar ionization device, which suggested that ionization led to a decrease in some gas-phase organic compounds but an increase in others, most prominently oxygenated VOCs (e.g., acetone and ethanol), with minimal impacts on particles, O 3 , and NO 2 [29], (ii) evaluations of the VOC removal effectiveness and potential for forming gas-phase organic products of a variety of EACs (including two oxidizing plasma air cleaners) in a test duct [30], (iii) demonstration of the formation of oxidized gases and secondary organic aerosols from a commercial oxidantgenerating EAC that generates OH radicals and hydrogen peroxide (H 2 O 2 ) in an office [31], (iv) assessment of the efficacy of bipolar ionization devices for microbial disinfection in air and on surfaces in a variety of test locations [32][33][34], and (v) measurements of primary emissions, VOC removal efficacies, and VOC byproduct formation of portable oxidationbased air cleaners in an environmental chamber [35]. Each of these showed a variety of mixed results for air cleaner efficacy and/or demonstrated the potential for forming chemical or particle byproducts during operation of some EACs.…”

Section: Introductionmentioning

confidence: 99%

Experimental Evaluations of the Impact of an Additive Oxidizing Electronic Air Cleaner on Particles and Gases

et al. 2022

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Electronic air cleaning (EAC) technologies have garnered significant attention for use in buildings. Many EAC technologies rely on the addition of reactive constituents to indoor air to react with gas-phase compounds, enhance particle deposition, and/or inactivate microorganisms. However, limited data are available on the efficacy of many EAC technologies and their potential to form chemical byproducts during operation. Here we experimentally evaluate the indoor air quality impacts, specifically targeting particles and gases but not microbial constituents, of a commercially available additive oxidizing EAC that generates positive and negative ions and hydrogen peroxide (H2O2). Tests were conducted in a large unoccupied test chamber in Chicago, IL and an unoccupied laboratory in Portland, OR under a combination of natural conditions (i.e., without pollutant injection) and perturbation conditions (i.e., with pollutant injection and decay). A combination of integrated and time-resolved measurements was used across both test locations. Chamber tests at lower airflow rates demonstrated that operation of the EAC: (i) had no discernible impact on particle concentrations or particle loss rates, with estimated clean air delivery rates (CADRs) for various particle measures less than ±10 m3/h, (ii) was associated with apparent decreases in some volatile organic compounds (VOCs) and increases in other VOCs and aldehydes, especially acetaldehyde, although a combination of high propagated uncertainty, limitations in test methods (e.g., lack of replicates), and variability between repeated tests limit what quantitative conclusions can be drawn regarding gas-phase organics; (iii) did generate H2O2, assessed using a crude measure, and (iv) did not generate ozone (O3). Laboratory tests at higher airflow rates, which involved injection and decay of particles and a single VOC (limonene), both simultaneously and separately, demonstrated that: (i) pollutant loss rates for both particles and limonene were slightly lower with the EAC on compared to off, yielding slightly negative pollutant removal efficiencies (albeit largely within propagated uncertainty) and (ii) there was a change in observed concentrations of one potential limonene degradation product, m/z 59 (putatively identified as acetone), with steady-state levels increasing from 10 ppb (air cleaner off) to 15 ppb (air cleaner on). No increases or decreases beyond measurement uncertainty were observed for other analyzed gaseous limonene degradation products. Overall, both chamber and laboratory tests demonstrated negligible effectiveness of this device at the test conditions described herein for removing particles and mixed results for VOCs, including decreases in some VOCs, no discernible differences in other VOCs, and apparent increases in other compounds, especially lower molecular weight aldehydes including acetaldehyde.

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“…Further reviews tried to organize the design and operational parameters of NTP reactors [35,264]. Examples of relevant studies include the comparison of three metal-organic frameworks (MOFs) as catalysts for the NTP process [265], the comparison of VOC's modular structures and their removal efficiency [266], and the comparison of three electronic air-cleaning technologies (i.e., PCO, NTP, and ozonation) using a test rig similar to a filter section of an air-handling unit [267].…”

Section: Removal Of Gaseous Contaminantsmentioning

confidence: 99%

Review of Engineering Controls for Indoor Air Quality: A Systems Design Perspective

2023

Sustainability

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This paper aims to review the engineering controls for indoor air quality (IAQ) from a systems design perspective. As a result of the review, we classify the literature content into three categories: (1) indoor air treatments, (2) dissemination control strategies, and (3) information technology. Indoor air treatments can be generally interpreted as the “cleaning” aspect, which covers ventilation and contaminant removal techniques. Dissemination control focuses on how contaminants generated in an indoor space can be transmitted, where four types of dissemination are classified. The category of information technology discusses IAQ sensors for monitoring, as well as the applications of the Internet of Things and IAQ data. Then, we further analyze the reviewed engineering controls by performing systems and functional analysis. Along with a discussion of IAQ functions, we suggest some systems design techniques, such as functional decoupling and design for flexibility/resilience, which are expected to promote more systems thinking in designing IAQ solutions.

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Experimental evaluation of in-duct electronic air cleaning technologies for the removal of ketones

Cited by 11 publications

References 52 publications

Real-Time Laboratory Measurements of VOC Emissions, Removal Rates, and Byproduct Formation from Consumer-Grade Oxidation-Based Air Cleaners

Real-Time Laboratory Measurements of VOC Emissions, Removal Rates, and Byproduct Formation from Consumer-Grade Oxidation-Based Air Cleaners

Experimental Evaluations of the Impact of an Additive Oxidizing Electronic Air Cleaner on Particles and Gases

Review of Engineering Controls for Indoor Air Quality: A Systems Design Perspective

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