Investigation of Volatile Organic Compounds Emissions in Different Stages of HVAC System

Simple item page
dc.contributor.advisorDeCarlo, Peter
dc.contributor.advisorKoehler, Kirsten
dc.creatorLi, Tianyi
dc.date.accessioned2023-02-10T21:28:11Z
dc.date.available2023-02-10T21:28:11Z
dc.date.created2022-12
dc.date.issued2022-08-22
dc.date.submittedDecember 2022
dc.date.updated2023-02-10T21:28:11Z
dc.description.abstractEfficient heating, ventilating, and air-conditioning (HVAC) systems are essential for improving indoor air quality and human health. However, HVAC systems those days typically rely on mechanical ventilation and filters to reduce air pollution. Volatile organic compound (VOC), a common type of gas phase air pollution, is usually neglected but is considerably higher indoors than outdoors and can cause severe health problems. This research explored how the VOC concentrations changed in different steps of the HVAC system and investigated the relation between VOCs and the HVAC system, building, and occupants. This research aimed to 1) identify and quantify health-related VOC concentrations within the building and compare them with current guidelines; 2) compare VOC concentrations in separate steps of the HVAC system; 3) explore temporal tendencies and source apportionment of VOCs. VOCs were monitored and quantified using a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) with additional measurements of CO, CO2, CH4, NH3, and CH2O using cavity ringdown spectroscopy instrumentation from Picarro through a four-valve switching chamber. This process allowed us to sample multipoint pollutants in mixed air, post-filter air, supply air, and return air in a frequent switching sequence. Our observations show that long-term exposure to some health-related VOCs in the sampled building, such as benzene, formaldehyde, and trimethylbenzene, can potentially cause health problems. The average VOC concentrations were highest in the return air and lowest in the mixed air for most indoor source VOCs. The unexpected VOC concentration increase in supply air suggested a leak in the HVAC system. This study will fill fundamental knowledge gaps in the HVAC system and offer quantitative evidence of how HVAC systems influence chemistry in indoor environments by heating, cooling, and filtering the air. With an improved understanding of the association among indoor VOCs, HVAC systems, buildings, and occupants, engineers can design more effective ventilation systems for buildings that minimize indoor VOCs and reduce the risk of health concerns for occupants.
dc.format.mimetypeapplication/pdf
dc.identifier.urihttp://jhir.library.jhu.edu/handle/1774.2/68056
dc.language.isoen_US
dc.publisherJohns Hopkins University
dc.publisher.countryUSA
dc.subjectHVAC
dc.subjectVOC
dc.subjectindoor air quality
dc.titleInvestigation of Volatile Organic Compounds Emissions in Different Stages of HVAC System
dc.typeThesis
dc.type.materialtext
thesis.degree.departmentEnvironmental Health and Engineering
thesis.degree.disciplineEnvironmental Health & Engineering
thesis.degree.grantorJohns Hopkins University
thesis.degree.grantorBloomberg School of Public Health
thesis.degree.levelMasters
thesis.degree.nameSc.M.
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
LI-THESIS-2022.pdf
Size:
1.91 MB
Format:
Adobe Portable Document Format
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
LICENSE.txt
Size:
2.67 KB
Format:
Plain Text
Description:
Download
Collections
ETD -- Graduate theses