Bioenergy is expected to play an increasingly significant role in the global energy budget. In addition to the use of liquid energy forms such as ethanol and biodiesel, electricity generation using processed energy crops as a partial or full coal alternative is expected to increase, requiring large-scale conversions of land for the cultivation of bioenergy feedstocks such as cane, grasses, or short rotation coppice. With land-use change identified as a major contributor to changes in the emission of biogenic volatile organic compounds (BVOCs), many of which are known contributors to the pollutants ozone (O3) and fine particulate matter (PM2.5), careful review of crop emission profiles and local atmospheric chemistry will be necessary to mitigate any unintended air-quality consequences. In this work, the atmospheric consequences of bioenergy crop replacement are examined using both the high-resolution regional chemical transport model WRF/Chem (Weather Research and Forecasting with Chemistry) and the global climate model CESM (Community Earth System Model). Regional sensitivities to several representative crop types are analyzed, and the impacts of each crop on air quality and climate are compared. Overall, the high emitting crops (eucalyptus and giant reed) were found to produce climate and human health costs totaling up to 40% of the value of CO2 emissions prevented, while the related costs of the lowest-emitting crop (switchgrass) were negligible.

No description available.

No description available.

The purpose of this thesis work was to study the airflow patterns and the particle distribution in a generic car cabin in order to evaluate the air quality and find how it can be improved. A 3D CAD model was created using the Solidworks software program and meshed using ICEM CFD software. The ICEM CFD software was used to generate the mesh and ANSYS FLUENT was adapted for the simulation. In total, 12 different cases were simulated by considering different inlet velocities and vent setup. The predicted results were further used to analyze the airflow and particle distribution in the entire car cabin. With higher inlet velocity there were more particles being transported to the rear part of the cabin. In general, the particle concentration was higher in the front of the cabin when they were introduced through the inlets, especially with low inlet velocities. Opening the recirculation vents resulted in a slight reduction of the flow to the rear side and reduced the particle distribution accordingly. When smoke particles were introduced in the rear seats, they mostly stayed in the rear of the cabin, especially with low inlet flow velocities as the air did not mix sufficiently. Overall a higher inlet airflow velocity reduced the number of particles that were trapped on the front and rear seats. However, an increase in the number of particles that were trapped on the ceiling, floor and walls were obtained. / Syftet med den här avhandlingen var att studera luftflödesmönster och partikelfördelningen i en generell bilkabin för att utvärdera luftkvaliteten och se hur man kan förbättra den. En 3D CAD-modell skapades med hjälp av Solidworks och ett rutnät skapades med hjälp av ICEM CFD. ICEM CFD användes för att generera rutnätet och ANSYS FLUENT användes för simuleringarna. Totalt simulerades 12 olika fall bestående av olika inflödeshastigheter och ventilinställningar. De beräknade resultaten användes sedan för att analysera luftflödet och partikelfördelningen i hela bilkabinen. Med högre inloppsflöde var det fler partiklar som transporterades till bakre delen av bilkabinen. Överlag var partikelkoncentrationen högre i framdelen av kabinen när partiklarna introducerades i inloppsventilerna, särskilt vid låga inloppshastigheter. Att öppna recirkulationsventilerna resulterade i en liten minskning av luftflödet till bakdelen av kabinen och även så partikelfördelningen. När rökpartiklar introducerades i baksätena, stannade de för det mesta i bakdelen av kabinen, särskilt vid låga inloppsflödeshastigheter då luften inte blandades tillräckligt. Överlag innebar en högre inloppsflödeshastighet reducerade mängden av partiklar som fastnade på fram- och baksätena, men ökade mängden partiklar som fastnade på taket, golvet och på väggarna.

<p>Clean indoor air is a necessity, in the past opening a window or supplying outdoor air would suffice for removing indoor contaminated air. As humans live in more dense neighborhoods or urban areas, the need for energy efficient clean indoor air is important. As outdoor air pollution increases, a Biowall is a device to improve aesthetics and clean indoor air by pulling air through the root zone of plants in a loosely packed growth media. The Biowall is a sustainable supplement to a single use air filter. For this research a small Biowall was designed, fabricated, tested, and installed in the Children’s wing of a public library. The airflow simulation and watering for the Biowall was explored using Autodesk CFD to simulate the airflow through growth media and identify a hole pattern to distribute airflow evenly through the plant trays. Various watering line designs were also tested until the rectangular design proved to be more balanced at distributing the water evenly to the growth media. Finally, the air cleaning ability of the Biowall was tested using a Clean Air Delivery Rate (CADR) test to quantify the cleaning rate. The Biowall provided 12 cfm of clean air, or about 2 cfm/sq ft of plant tray area.  </p>

Indoor air quality is a critical determinant of physical and mental health. Despite evidence linking poor indoor air quality to adverse health outcomes, this issue is understudied in the context of First Nations children and youth health and wellbeing. The objectives of this study were to (1) characterize indoor air quality, housing conditions, and respiratory health of children living in the Kanesatake First Nation and (2) evaluate the feasibility of using remote community-based participatory methods in the context of First Nations health research. Community-assisted data collection occurred between June 2021 and February 2022 in the Kanesatake First Nation, Quebec. Indoor air data were collected from 31 randomly selected houses. Results showed elevated levels of contaminants, including particulate matter, benzene, toluene, and xylene, compared to the Canadian averages. Houses generally lacked adequate ventilation, and over one-quarter were reported to be in need of major repairs. We developed instruction tools for air sampling and house inspection to facilitate off-site data collection. High rates of participant completion (95%) and low attrition rates (5%) indicated the feasibility of remote community-based participatory research methods. Lessons learnt are summarized and important recommendations are made for adaptation to improve future data collection. This research served as a pilot project for a multi-year, cross-Nation study, as well as the first study to evaluate the indoor air environment in the Kanesatake First Nation.

No description available.

No description available.

More than 50 % of EU’s yearly energy demand is spent on heating and cooling systems with which most of its source is generated from non-renewable fossil fuel [1]. Furthermore, half of the EU buildings are heated with a non-efficient boiler of about 60% or less efficiency [1]. The report released by EU from 1990 to 2007 revealed that fuel combustion and fugitive emission contribute to about 79.3% of total greenhouse gas emissions in CO2 equivalents [1]. The EU-EBPD long-term renovation strategy is to improve the energy performance of all residential and non-residential buildings in its member countries through supporting the renovation of the existing buildings into highly energy efficient and decarbonised buildings [2]. Despite all these EU policies and efforts to replace these non-efficient heating systems, the main challenge is price comparison of different solutions and their efficiency in retrofitting of the heating old systems together with the lack of information about the functioning of those old systems [1]. Thus, the development of an easy to install heating system in retrofitting with low exergy heat supply is a significant contribution to a sustainable solution in minimizing energy resources depletion and environmental emission. Furthermore, efficient system control of these easy to install heating systems, hybrids combinations solution for retrofitting building could be a sustainable solution for the preservation of the existing building. The main objective of this work was to design an easy to install hybrid low-temperature floor heating system in retrofitting buildings and compare its results on energy performance, thermal comfort and indoor air quality with other conventional heating mainly used in the Mediterranean climate. This study was performed in two existing radiators heated buildings located in Sant Cugat del vallès in Catalonia, Spain.The results showed that the hybrid low-temperature heating system has the highest energy performance and energy saving of 48 % and 52% compared to that of existing radiator heating and all air heating, respectively. However, hybrid low-temperature floor heating showed a slow heating response, and consequently, it showed lower operative temperature compared to others even though it was within the recommended standards limits. The hybrid low-temperature heating system with demand-controlled ventilation also showed a better indoor air quality, while as existing radiator with its natural ventilation showed the worst indoor air quality. All three compared heating systems showed a better coefficient of performance with low-temperature heat supply and were able to operate with low-temperature heat supply. / Mer än 50% av EU:s årliga energibehov spenderas på värme- och kylsystem där de flesta av deras källor genereras från icke-förnybart fossilt bränsle [1]. Dessutom värms hälften av EU:s byggnader upp med en ineffektiv panna med cirka 60% eller mindre effektivitet [1]. EU:s rapport från 1990 till 2007 avslöjade att bränsleförbränning och flyktiga utsläpp bidrar till cirka 79% av de totala utsläppen av växthusgaser i koldioxidekvivalenter [1]. EU:s och EBPD:s långsiktiga renoveringsstrategi är att förbättra energiprestanda för alla bostäder och andra byggnader i dess medlemsländer genom att stödja renovering av befintliga byggnader till mycket energieffektiva byggnader [2].Trots alla dessa EU-policyer och ansträngningar för att ersätta dessa ineffektiva värmesystem, är den största utmaningen prisjämförelse av olika lösningar och deras effektivitet i renovering av de gamla värmesystemen tillsammans med bristen på information om hur de gamla systemen fungerar [1]. Därför är utvecklingen av ett installationsenkelt värmesystem med låg värmeförsörjning av exergi ett viktigt bidrag till en hållbar lösning för att minimera energiresurser och miljöutsläpp. Dessutom kan effektiv systemkontroll av dessa värmesystem med olika kombinationslösningar för renovering av byggnaden vara en hållbar lösning för att bevara den befintliga byggnaden.Huvudsyftet med detta arbete var att utforma ett lågtemperaturgolvvärmesystem att använda vid renovering av byggnader och jämföra dess resultat på energiprestanda, termisk komfort och inomhusluftkvalitet med annan konventionell uppvärmning som huvudsakligen används i medelhavsklimat. Denna studie utfördes i två befintliga radiatoruppvärmda byggnadet i Sant Cugat del vallès i Katalonien, Spanien. Resultaten visade att hybridsystemet med låg temperatur har den högsta energiprestandan och energibesparingen på 48% och 52% för den befintliga radiatorvärme respektive luftvärme. Emellertid visade lågtemperaturgolvvärme ett långsamt uppvärmningssvar, och följaktligen visade det lägre driftstemperatur jämfört med de andra systemen trots att det låg inom de rekommenderade standardgränserna. Lågtemperaturvärmesystem med efterfrågningsstyrd ventilation visade också en bättre inomhusluftkvalitet, medan befintliga radiatorer med sin naturliga ventilation visade den sämsta inomhusluftkvaliteten. Alla tre jämförda värmesystemen visade bättre prestanda med lågtemperaturvärmeförsörjning och kunde fungera med lågtemperaturvärmeförsörjning.

Ground-level ozone is harmful to the human respiratory system, as well as the environment. The national EPA 8-hour ozone standard for ground-level ozone was reduced from 85 parts per billion (ppb) to 75 ppb in 2008, and trends from previous years show that some of the counties in Central Florida could be in danger of violation. Violation means "non attainment" status; in which the county is ordered by EPA to develop specific implementation plans to reduce its emissions. The objective of this study was to compile an emissions inventory of volatile organic compounds (VOCs) and nitrogen oxides (NOx) from nonroad equipment in Osceola, Seminole, and Orange Counties (OSO) in Central Florida, and to develop possible action steps to reduce those emissions. This is important because VOC and NOx emissions are precursors to ground-level ozone. Thus, compiling emissions inventories is important to identify high VOC and NOx emitters. Mobile and point sources have long been the highest emitters of VOC and NOx and have therefore been targeted and monitored since the Clean Air Act of 1970, but the nonroad sources (such as construction and lawn equipment) have only been regulated since the 1990s. Using the NONROAD and NMIM modeling programs, the highest nonroad emitters of VOC for Central Florida were found to be lawn/garden equipment, and boating equipment, emitting a combined percentage of 77% of the total nonroad mobile source VOC. Construction equipment contributed 67% of the total nonroad mobile source emissions of NOx in Central Florida. The components of these categories were also analyzed to find the largest individual sources of VOC and NOx. Of the individual sources, lawn mowers and outboard boat engines were found to be the largest sources of VOCs. Of the NOx sources, all the construction equipment components had a relatively similar level of NOx emissions. Next, action steps were developed to reduce emissions, focusing on the high emitters, along with an estimated cost and feasibility for each measure. Of these steps, implementing a ban on leafblowers, and reducing use of lawn mowers, edgers, trimmers, etc. seemed to be the most effective for reducing VOCs. Although these are effective measures, the cost and feasibility of both pose challenges. The best action step for reducing NOx emissions in construction equipment seemed to be by simply reducing idling of equipment on job sites. This also poses challenges in feasibility and enforcement by management. Further, constant on/off cycles could result in decreasing the useful life of the older construction equipment. Finally, a survey was conducted with various construction managers and companies to find out the typical equipment and quantity needed for land clearing/grubbing, as well as the typical use, idling time, and total project time for each piece of equipment on a 10-acre site, under various conditions. The purpose of the study was to develop a rough estimate for the average amount of VOC and NOx emissions that will be produced per acre of land clearing activities, and to estimate the emissions reductions and cost savings if idling of the equipment was reduced.