26 research outputs found
Visual effects of wood on thermal perception of interior environments
There is a general consensus, supported by preliminary evidence, that exposed wood improves human perception of thermal comfort, though this idea has yet to be supported by meaningful effect sizes. This study sought to quantify human perception of thermal comfort of wood materials in a controlled laboratory setting. Participants experienced one of two wall treatments: exposed wooden wall panels and white-painted walls in a thermal environment set directly between "neutralâ and "slightly warmâ (81.5°F, 4Q%RH, PMV +Q.5). We hypothesized that participants exposed to the wood walls would gauge their thermal preference to be closer to neutral than that of participants who experienced the same thermal environment but with the white wall treatment. Wood was found to have a significant and moderate effect on thermal comfort, with the mean response of the participants who received the wood wall treatment being thermally preferable over that of the white wall (wood wall: M = Q.46, SD = Q.56; white wall: M = Q.68, SD = Q.51; p<Q.Q1)
Evaluating Volatile Organic Compound Emissions from Cross-Laminated Timber Bonded with a Soy-Based Adhesive
Volatile organic compound (VOC) emissions from indoor sources are large determinants of the indoor air quality (IAQ) and occupant health. Cross-laminated timber (CLT) is a panelized engineered wood product often left exposed as an interior surface finish. As a certified structural building product, CLT is currently exempt from meeting VOC emission limits for composite wood products and confirming emissions through California Department of Public Health (CDPH) Standard Method testing. In this study, small chamber testing was conducted to evaluate VOC emissions from three laboratory-produced CLT samples: One bonded with a new soy-based cold-set adhesive; a second bonded with a commercially available polyurethane (PUR) adhesive; and the third assembled without adhesive using dowels. A fourth commercially-produced eight-month-old sample bonded with melamine formaldehyde (MF) adhesive was also tested. All four samples were produced with Douglas-fir. The test results for the three laboratory-produced samples demonstrated VOC emissions compliance with the reference standard. The commercially-produced and aged CLT sample bonded with MF adhesive did not meet the acceptance criterion for formaldehyde of â€9.0 ”g/m3. The estimated indoor air concentration of formaldehyde in an oïŹce with the MF sample was 54.4 ”g/m3; the results for the soy, PUR, and dowel samples were all at or below 2.5 ”g/m3
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2019 Novel Coronavirus (COVID-19) Pandemic: Built Environment Considerations To Reduce Transmission.
With the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that results in coronavirus disease 2019 (COVID-19), corporate entities, federal, state, county, and city governments, universities, school districts, places of worship, prisons, health care facilities, assisted living organizations, daycares, homeowners, and other building owners and occupants have an opportunity to reduce the potential for transmission through built environment (BE)-mediated pathways. Over the last decade, substantial research into the presence, abundance, diversity, function, and transmission of microbes in the BE has taken place and revealed common pathogen exchange pathways and mechanisms. In this paper, we synthesize this microbiology of the BE research and the known information about SARS-CoV-2 to provide actionable and achievable guidance to BE decision makers, building operators, and all indoor occupants attempting to minimize infectious disease transmission through environmentally mediated pathways. We believe this information is useful to corporate and public administrators and individuals responsible for building operations and environmental services in their decision-making process about the degree and duration of social-distancing measures during viral epidemics and pandemics
Evaluating Volatile Organic Compound Emissions from Cross-Laminated Timber Bonded with a Soy-Based Adhesive
11 pagesVolatile organic compound (VOC) emissions from indoor sources are large determinants
of the indoor air quality (IAQ) and occupant health. Cross-laminated timber (CLT) is a panelized
engineered wood product often left exposed as an interior surface finish. As a certified structural
building product, CLT is currently exempt from meeting VOC emission limits for composite wood
products and confirming emissions through California Department of Public Health (CDPH) Standard
Method testing. In this study, small chamber testing was conducted to evaluate VOC emissions
from three laboratory-produced CLT samples: One bonded with a new soy-based cold-set adhesive;
a second bonded with a commercially available polyurethane (PUR) adhesive; and the third assembled
without adhesive using dowels. A fourth commercially-produced eight-month-old sample bonded
with melamine formaldehyde (MF) adhesive was also tested. All four samples were produced with
Douglas-fir. The test results for the three laboratory-produced samples demonstrated VOC emissions
compliance with the reference standard. The commercially-produced and aged CLT sample bonded
with MF adhesive did not meet the acceptance criterion for formaldehyde of â€9.0 ÎŒg/m3. The estimated
indoor air concentration of formaldehyde in an office with the MF sample was 54.4 ÎŒg/m3; the results
for the soy, PUR, and dowel samples were all at or below 2.5 ÎŒg/m3.This research was funded by the U.S. Department of Agricultureâs Agricultural Research Service [USDA
ARS Agreement 58-0204-6-002]
A Novel VOC Breath Tracer Method to Evaluate Indoor Respiratory Exposures in the Near- and far-fields; implications for the spread of respiratory viruses
Background
Several studies suggest that far-field transmission (\u3e6âft) explains a significant number of COVID-19 superspreading outbreaks. Objective
Therefore, quantifying the ratio of near- and far-field exposure to emissions from a source is key to better understanding human-to-human airborne infectious disease transmission and associated risks. Methods
In this study, we used an environmentally-controlled chamber to measure volatile organic compounds (VOCs) released from a healthy participant who consumed breath mints, which contained unique tracer compounds. Tracer measurements were made at 0.76âm (2.5âft), 1.52âm (5âft), 2.28âm (7.5âft) from the participant, as well as in the exhaust plenum of the chamber. Results
We observed that 0.76âm (2.5âft) trials had ~36â44% higher concentrations than other distances during the first 20âminutes of experiments, highlighting the importance of the near-field exposure relative to the far-field before virus-laden respiratory aerosol plumes are continuously mixed into the far-field. However, for the conditions studied, the concentrations of human-sourced tracers after 20âminutes and approaching the end of the 60-minute trials at 0.76âm, 1.52âm, and 2.28âm were only ~18%, ~11%, and ~7.5% higher than volume-averaged concentrations, respectively. Significance
This study suggests that for rooms with similar airflow parameters disease transmission risk is dominated by near-field exposures for shorter event durations (e.g., initial 20â25-minutes of event) whereas far-field exposures are critical throughout the entire event and are increasingly more important for longer event durations
The Impact of School Facilities on Student Learning and Engagement
83 pagesThis document outlines, catalogs, and summarizes a framework of literature that highlights the impact of school of facilities and classroom environments on student engagement and learning. The NetZED Laboratory at the University of Oregon commenced this project following a Request for Proposals from the California School Facilities Research Initiative (CSFRI) which sought to identify elements of the built environment of Kâ12 schools that result in higher levels of student engagement and learning. CSFRIâs goal was to summarize existing literature regarding the effects that physical organizational environments and furnishings within classrooms, makerspaces, laboratories, and interior ancillary facilities, as well as space at the exterior of the building that contribute to student engagement and learning. The overall intent of this white paper is to draw upon published evidence and original research to support the design planning and process for facility planners/managers, architects, educator, and community members who will seek funding to renovate and build new schools in California. With learning and engagement at the center, we developed a diagram of relationships of the schoolâs physical environment that includes three categories: indoor environment, spatial environment, and the people/community in relation to the school and classrooms. The review initially captured more than 750 peer-reviewed papers, reports, dissertations, books and literature reviews using framework, key word searches, and relevancy criteria, and stored through shared referencing software (Mendeley). Approximately 500 publications were selected to become an annotated bibliography and form the basis for this white paper. The review included studies from around the world, though most studies are applicable to conditions in the U.S
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Revealing Occupancy Patterns in Office Buildings Through the use of Annual Occupancy Sensor Data
Energy simulation programs like DOE-2 and EnergyPlus are tools that have been proven to aid with energy calculations to predict energy use in buildings. Some inputs to energy simulation models are relatively easy to find, including building size, orientation, construction materials, and HVAC system size and type. Others vary with time (e.g. weather and occupancy) and some can be a challenge to estimate in order to create an accurate simulation. In this paper, the analysis of occupancy sensor data for a large commercial, multi-tenant office building is presented. It details occupancy diversity factors for private offices and summarizes the same for open offices, hallways, conference rooms, break rooms, and restrooms in order to better inform energy simulation parameters. Long-term data were collected allowing results to be presented to show variations of occupancy diversity factors in private offices for time of day, day of the week, holidays, and month of the year. The diversity factors presented differ as much as 46% from those currently published in ASHRAE 90.1 2004 energy cost method guidelines, a document referenced by energy modelers regarding occupancy diversity factors for simulations. This may result in misleading simulation results and may introduce inefficiencies in the final equipment and systems design
Understanding Flow of Energy in Buildings Using Modal Analysis Methodology
It is widely understood that energy storage is the key to integrating variable generators into the grid. It has been proposed that the thermal mass of buildings could be used as a distributed energy storage solution and several researchers are making headway in this problem. However, the inability to easily determine the magnitude of the buildingâs effective thermal mass, and how the heating ventilation and air conditioning (HVAC) system exchanges thermal energy with it, is a significant challenge to designing systems which utilize this storage mechanism. In this paper we adapt modal analysis methods used in mechanical structures to identify the primary modes of energy transfer among thermal masses in a building. The paper describes the technique using data from an idealized building model. The approach is successfully applied to actual temperature data from a commercial building in downtown Boise, Idaho
Comparing Whole Building Energy Implications of Sidelighting Systems with Alternate Manual Blind Control Algorithms
Currently, there is no manual blind control guideline used consistently throughout the energy modeling community. This paper identifies and compares five manual blind control algorithms with unique control patterns and reports blind occlusion, rate of change data, and annual building energy consumption. The blind control schemes detailed here represent five reasonable candidates for use in lighting and energy simulation based on difference driving factors. This study was performed on a medium-sized office building using EnergyPlus with the internal daylight harvesting engine. Results show that applying manual blind control algorithms affects the total annual consumption of the building by as much as 12.5% and 11.5% for interior and exterior blinds respectively, compared to the Always Retracted blinds algorithm. Peak demand was also compared showing blind algorithms affected zone load sizing by as much as 9.8%. The alternate algorithms were tested for their impact on American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) Guideline 14 calibration metrics and all models were found to differ from the original calibrated baseline by more than the recommended ±15% for coefficient of variance of the mean square error (CVRMSE) and ±5% for normalized mean bias error (NMBE). The paper recommends that energy modelers use one or more manual blind control algorithms during design stages when making decisions about energy efficiency and other design alternatives