Download or read book Modelling of Volatile Organic Compound VOC Emissions from Building Materials furnishings written by J. S. Zhang and published by . This book was released on 1997 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Volatile Organic Compounds Emissions and Sinks from Building Materials written by Hongyu Huang and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volatile Organic Compounds (VOC) emitted from building materials have been recognized as major problems affecting human comfort, health and productivity. Building materials not only are main VOC sources but also are main VOC sinks in buildings. Therefore, accurate modeling of building material VOC emissions and sinks is important for predicting contaminant concentrations, occupant exposures and design of mechanical ventilation systems. This thesis describes three new modeling approaches to predict building material VOC emissions and sinks. First, a numerical and an analytical VOC emission model have been developed to predict VOC emission rates of a single-layer dry building material and VOC concentrations in a well-mixed room. Second, an integrated IAQ model has been developed to predict VOC emission rates of a multi-layer material, VOC sink rates of a material, VOC concentrations in a well mixed room with both VOC source and sink materials. Third, a zonal model has been integrated with air jet and material VOC emission/sink models to predict the transient VOC distribution in a ventilated room. In addition, a systematic parametric study has been carried out to study the impacts of model input parameters and their interactions on VOC emissions from building materials. These three models have been validated with available experimental results and/or CFD simulation results. The comparisons with the experimental results and the predictions of the CFD models indicate that there are generally good agreements between the proposed model predictions, the experimental results and the CFD results. Moreover, these three models have been applied to analyze building material VOC emission/sink behaviors and to examine ventilation system efficiency. Results show that the developed models can provide useful information for building owners or designers in selecting proper building materials, designing efficient ventilation systems and assessing indoor air quality.

Download or read book Study of Building Material Emissions and Indoor Air Quality written by Xudong Yang and published by . This book was released on 1999* with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building materials and furnishings emit a wide variety of indoor pollutants, such as volatile organic compounds (VOCs). At present, no accurate models are available to characterize material emissions and sorption under realistic indoor conditions. The objective of this thesis is to fill that gap. Using the emission data measured in small-scale and full-scale environmental chambers, this investigation has developed a numerical model for simulating emissions of "wet" materials applied to porous substrates. This model considers VOC mass transfer processes in the air, material-air interface, material film, and the substrate. The model can predict "wet" material emissions under different environmental conditions (i.e., temperature, velocity, turbulence, and VOC concentration in the air) with reasonable accuracy. We developed two models for simulating VOC emissions from dry materials. One is a numerical model for short-term predictions, the other is an analytical model for long-term predictions. The models have been successfully used to examine the VOC emissions from two particleboard samples and a polypropene Styrene-Butadiene Rubber (SBR) carpet. A VOC sorption model has also been developed to analytically solve the VOC sorption rate as a function of air-phase concentrations. The model has been validated using an analytical solution as well as data obtained from sorption experiments. The emission and sorption models that we developed have been further used to study indoor air quality (IAQ) in a small office with different ventilation systems. The results show that displacement ventilation may not provide better IAQ than mixing systems if the VOC sources are from the floor. Further, our study shows sink effects from internal walls of gypsum board.

Download or read book VOC Emissions from Building Products written by Chuck Yu and published by . This book was released on 2002 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Digest describes sources of VOCs in indoor environments, methods to control the amount of emissions from building products and the available VOC guideline values for assessing indoor air quality in buildings. Part 1 of this Digest summarises the VOCs and the range of TVOC emission rates from some typical wall and flooring materials used in buildings. Environmental chamber test methods for measuring VOC emissions from building materials were briefly described. Part 2 describes the air quality guidelines and the emission databases used for assessing the impact of VOC emissions in the indoor environment; also labelling schemes for controlling VOC emissions from building materials.

Download or read book Measurement of Diffusion and Partition Coefficients of VOCs in Dry Building Materials written by Zhong-Hong Zhang and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building materials, as a source of contaminant, such as volatile organic compounds (VOCs), and a sink of those pollutants, can significantly affect indoor air quality (IAQ). Physical models have been developed to predict volatile organic compound emissions from building materials. These results are helpful in adopting strategies to control the pollutant source. Therefore, experimental methods have been established for measuring input parameters to these models, such as diffusion coefficient (D), partition coefficients (K). However, currently available data of diffusion and partition coefficients are limited. Moreover, the effects caused by the physicochemical properties of VOC are not completely observed. Hence, it is requisite that a comprehensive investigation on the relationship between diffusion and partition coefficients, and the physicochemical properties of VOC be conducted. The twin chamber method was chosen in this research. The effects caused by physicochemical properties of VOC, such as molecular weight, vapor pressure, boiling point, and polarity, were investigated.

Download or read book VOC Emissions from Wastewater Treatment Plants written by Prakasam Tata and published by CRC Press. This book was released on 2003-03-26 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: VOC Emissions from Wastewater Treatment Plants: Characterization, Control, and Compliance provides comprehensive information on the subject of Volatile Organic Compound (VOC) emissions from publicly owned treatment works (POTWs). It describes models of emission factors so that readers will know what to expect when models need to be used for the est

Download or read book Modeling Airflows and VOC Source Strengths for an Occupied School written by and published by . This book was released on 2020 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volatile organic compounds (VOCs) are a group of air pollutants that can adversely impact human health, engage in chemistry indoors, and meaningfully degrade indoor and outdoor urban air quality. While extensive research with regard to VOC emission rates from indoor sources has been conducted, it was not until recently that this work began to focus on characterizing emissions from humans and human activity in depth. As buildings are constructed to be increasingly airtight, and the materials utilized are chosen to reduce VOC emissions, it follows that human contributions are poised to become increasingly important indoor sources of VOCs. Utilizing data extracted from a three-month campaign conducted at Harriet Tubman Middle School in Portland, Oregon, this study modeled airflows through the school and quantified source strengths for VOCs over the course of two days. Emission rates for seven compounds that are traditionally associated with human metabolism and activity were calculated, as were source strengths for BTEX compounds (benzene, toluene, xylenes, and ethylbenzene), which are typically associated with traffic-related air pollution (TRAP). In terms of per-person VOC emission rates, it was found that the values determined for some of the chosen compounds were in close agreement with the limited literature that exists on the subject, and that some varied greatly, likely due to differences in the buildings themselves, the occupants and their activities, and dissimilar experimental designs across studies. In terms of BTEX compounds, source apportionment revealed that the majority of their presence was due to supply air, which was expected considering the elevated levels of outdoor TRAP constituents in the near-roadway building. Comparing source apportionment percentages of BTEX compounds to another study that took the same approach, similar distributions were found--an outcome that suggested that despite the school's proximity to a roadway and elevated outdoor BTEX levels, the air-cleaning system was effective.

Download or read book Emissions of Volatile Organic Compounds VOC from Building Materials written by and published by . This book was released on 1997 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Emissions of Volatile Organic Compounds from New Carpets written by and published by . This book was released on 1993 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: A simple model is proposed to account for observed emissions of volatile organic compounds (VOCs) from new carpets. The model assumes that the VOCs originate predominantly in a uniform slab of polymer backing material. Parameters for the model (the initial concentration of a VOC in the polymer, a diffusion coefficient and an equilibrium polymer/air partition coefficient) are obtained from experimental data produced by a previous chamber study. The diffusion coefficients generally decrease as the molecular weight of the VOCs increase, while the polymer/air partition coefficients generally increase as the vapor pressure of the compounds decrease. In addition, for two of the study carpets that have a styrene-butadiene rubber (SBR) backing, the diffusion and partition coefficients are similar to independently reported values for SBR. The results suggest that predictions of VOCs emissions from new carpets may be possible based solely on a knowledge of the physical properties of the relevant compounds and the carpet backing material. However, a more rigorous validation of the model is desirable.

Download or read book Modeling of Indoor Air Quality and Exposure written by Niren Laxmichand Nagda and published by ASTM International. This book was released on 1993 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification and Quantification of Volatile Organic Compound Emissions from Buildings and Heating Ventilating and Air Conditioning Systems written by Chiung-Yu Peng and published by . This book was released on 1998 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Volatile Organic Compounds VOCs In Indoor Air written by Todd A. Wetzel and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Indoor air concentrations of volatile organic compounds (VOCs), including many with documented adverse health effects, vary widely but are generally higher than found outdoors. Volatile organic compounds can enter indoor environments via internal (e.g. paints, paint strippers, fuels, cleaning supplies, pesticides, building materials, adhesives) and external sources (e.g. vapor intrusion (VI) from contaminated soil and/or groundwater and ambient air from automobiles and industrial facilities). Since many consumer products contain volatile organic compounds (VOCs) that are also the focus of soil and groundwater cleanup projects, emissions of these VOCs can lead to false source identifications during VI investigations. Laboratory-measured emissions of VOCs from several consumer products were used with a standard box model to predict indoor air concentrations. The predicted concentrations were compared to measured values generated by introducing the same consumer products into an actual residence. The screening level agreement between measured and estimated air concentrations suggests that a standard box model can be used with laboratory measured emission rates to show if an emission source can cause a potential health risk or lead to false assumption during VI investigations. The use of plant leaves as a simple, cost-effective and sustainable approach to sampling indoor air concentrations of VOCs was also investigated in three studies: 1) a headspace approach; 2) a flow-through glass and stainless steel plant growth chamber, and 3) a house-scale study where plant leaf and air concentrations of VOC were simultaneously measured. Similar relationships between the leaf and air concentrations observed in the three studies suggest that plant leaf concentrations can be used as a surrogate for indoor air concentrations of VOCs.

Download or read book Study of Air Velocity and Turbulence Effects on Organic Compound Emissions From Building Materials Furnishings Using a New Small Test Chamber written by JM. Kanabus-Kaminska and published by . This book was released on 1996 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new small chamber (1.0 by 0.8 by 0.5 m) test system was developed to investigate the effect of local airflow conditions on the emission rates of volatile organic compounds (VOCs) from commonly used building materials and furnishings. The uniqueness of the new chamber is that it can provide controlled mean air velocity and turbulence level over the surface of the tested material in addition to air temperature, relative humidity, air change rate, and chamber loading as in small test chambers. This paper presents the design, construction, and performance data of this new test chamber system. In addition, VOC emissions from a wood stain were tested using the new small chamber under two different air-velocity conditions. A new procedure was developed to determine the interfacial mass transfer coefficient based on the concentration data measured at the outlet of the chamber. The results indicated that the interfacial mass transfer coefficient and hence the emission rate increased with the air velocity over the material surface when other parameters, such as air temperature, relative humidity, chamber loading, and air change rate were kept unchanged. This confirms the importance of controlling the local velocity and turbulence level over the material surface in conducting emission tests using small-scale environmental chambers in order to better understand and interpret the test results.

Download or read book Handbook of Indoor Air Quality written by Yinping Zhang and published by Springer Nature. This book was released on 2022-11-23 with total page 2182 pages. Available in PDF, EPUB and Kindle. Book excerpt: People live in indoor environment about 90% of lifetime and an adult inhales about 15 kg air each day, over 75% of the human body’s daily mass intake (air, food, water). Therefore, indoor air quality (IAQ) is very important to human health. This book provides the basic knowledge of IAQ and highlights the research achievements in the past two decades. It covers the following 12 sections: introduction, indoor air chemicals, indoor air particles, measurement and evaluation, source/sink characteristics, indoor chemistry, human exposure to indoor pollutants, health effects and health risk assessment, IAQ and cognitive performance, standards and guidelines, IAQ control, and air quality in various indoor environments. It provides a combination of an introduction to various aspects on IAQ studies, the current state-of-knowledge, various advances and the perspective of IAQ studies. It will be very helpful for the researchers and technicians in the IAQ and the related fields. It is also useful for experts in other fields and general readers who want to obtain a basic understanding of and research advances in the field of IAQ. A group of experts in IAQ research have been recruited to write the chapters. Their research interests and experience cover the scope of the book. In addition, some experienced experts in IAQ field have been invited as advisors or reviewers to give their comments, suggestions and revisions on the handbook framework and the chapter details. Their contribution guarantees the quality of the book. We are very grateful to them. Last but not least, we express our heartfelt thanks to Prof. Spengler, Harvard University, for writing the foreword of the current Handbook of Indoor Air Quality both as a pioneer scientist who contributed greatly to indoor air science and as an Editor-in-chief of Handbook of Indoor Air Quality 2001, 1st ed. New York: McGraw-Hill. In addition to hard copies, the book is also published online and will be updated by the authors as needed to keep it aligned with current knowledge. These salient features can make the handbook fresh with the research development.

Download or read book Volatile Organic Compounds in New Homes written by and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling VOC Sorption of Building Materials and Its Impact on Indoor Air Quality written by Jinsong Zhang and published by . This book was released on 2001 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sorption of volatile organic compounds (VOCs) by building materials can have significant effect on the indoor VOC concentration levels and indoor air quality in buildings. The objective of this study was to investigate experimentally the effects of environmental conditions (temperature, humidity and air velocity) on the sorption rate and capacity of three typical types of building materials (carpet, ceiling tile and painted drywall), and to evaluate existing sorption models with experimental data. A small-scale chamber test system has been developed in this study to conduct sorption tests under different environmental conditions. The sorption data collected were analyzed by three different analysis methods: the integration method, the linear Langmuir model method and the diffusion model method. The results of the integration method indicated that for the painted drywall, the differences among different environmental conditions were so small compared with the experimental uncertainties that no statistically significant environmental effect could be observed at 95% confidence level. The sorption of VOCs on ceiling tile decreased with the increase of the air velocity and temperature, but did not change significantly with the relative humidity. The sink strength of benzaldehyde under high humidity was much stronger than any other conditions. The sorption of VOCs on carpet appeared to be a diffusion-controlled process. With the increase of temperature, the diffusion coefficient increased while the partition coefficient decreased. A higher air velocity increased the sink capacity of dodecane on carpet. The relative humidity had no significant effect on the sorption of VOCs on carpet. Based on the model evaluation conducted in this study, the linear Langmuir model appeared to be suitable for painted drywall and ceiling tile while the diffusion model is more suitable for carpet.

Download or read book WHO Guidelines for Indoor Air Quality written by and published by World Health Organization. This book was released on 2010 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents WHO guidelines for the protection of public health from risks due to a number of chemicals commonly present in indoor air. The substances considered in this review, i.e. benzene, carbon monoxide, formaldehyde, naphthalene, nitrogen dioxide, polycyclic aromatic hydrocarbons (especially benzo[a]pyrene), radon, trichloroethylene and tetrachloroethylene, have indoor sources, are known in respect of their hazardousness to health and are often found indoors in concentrations of health concern. The guidelines are targeted at public health professionals involved in preventing health risks of environmental exposures, as well as specialists and authorities involved in the design and use of buildings, indoor materials and products. They provide a scientific basis for legally enforceable standards.