No description available.

<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.

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.

Indoor air quality (IAQ) has a direct impact on our health, as more than half the air we inhale throughout our lifetimes is indoor air. With an increasing trend in dampness in modern buildings due to urban expansion into wetland environments and increased use of gypsum board in construction, hydrolysis in indoor surface films has been suggested to be an important chemical process in the indoor environment. Several synthetic esters (SEs) found in building materials, electronics, and consumer products may undergo hydrolysis to produce harmful volatile organic compounds (VOCs) to which building occupants may be exposed. In this dissertation, the impact of hydrolysis on indoor air quality is explored by experiments on alkaline hydrolysis kinetics and ventilation, followed by simulations of VOC production from hydrolysis. Alkaline hydrolysis kinetics of four SEs, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (TMPD-MIB), butylparaben (BP), bis (2-ethylhexyl) adipate (DEHA), and butyl benzyl phthalate (BBzP), in bulk solutions are investigated in chapter 2. With concentration decay profiles following pseudo first-order kinetics, the second order-rate constants were determined from measured pH values. The determined rate constants of the aforementioned SEs are compared with those of respective ester categories (e.g., parabens, phthalates), and the steric/polar effects of the ester substituents are discussed in detail. The results of this study contributed to the completion of the indoor chemistry box model GAMMA-CIE which was used for simulation studies in chapter 4. Room-level ventilation measurements in educational spaces across different US regions (e.g., Northeastern, Southeastern, Western) are presented in chapter 3. In the wake of COVID-19 pandemic, ventilation data on a room-by-room basis were critical in planning a safe reopening in schools and universities. Three major approaches to ventilation measurements are outlined in this chapter: direct flow measurement, controlled release, and passive/in-situ monitoring. The application of these approaches is presented in case studies across various educational institutions, showcasing their advantages and disadvantages. The frequently observed range of 0.5-5.5 ACH in this study is taken into account in simulation conditions in chapter 4. The predicted indoor generation of VOCs from alkaline hydrolysis of SEs occurring in surface aqueous films is discussed in chapter 4. Simulations were performed using GAMMA-CIE, which considers aqueous hydrolysis kinetics, interphase mass transport, and loss by ventilation. Three different scenarios were studied: (1) installation of PVC flooring on concrete; (2) coating of latex paint on concrete; and (3) uptake of airborne SEs by surface aqueous films. The simulation results suggested that: (1) the rate of hydrolysis of DEHA and DEHP from PVC flooring is not fast enough to generate high concentrations of 2-ethylhexanol observed during episodes of sick building syndrome (SBS); (2) fresh application of latex paint may cause acute exposure to 2,2,4-trimethyl-1,3-pentanediol (TMPD); and (3) hydrolysis of SEs diffused from indoor air is unlikely to produce significant amounts of alcohols associated with SBS.

No description available.

No description available.

Syftet med arbetet var att samla in mätdata för att kontrollera luftkvalitén ombord på två svenska fartyg, för att sedan jämföra resultaten med Arbetsmiljöverkets hygieniska gränsvärden och den svenska normalbefolkningens exponering för olika ämnen. Resultatet från studien var också tänkt att vara till hjälp för att utforma nya råd och rekommendationer för att minimera exponeringen och även till att bidra med material för fler framtida studier. Under cirka en vecka ombord på fartygen samlades data in med hjälp av passiva provtagare för att registrera halter av bensen, kvävedioxid och polycykliska aromatiska kolväten. Resultaten visade att luftkvalitén ombord på de två fartygen generellt sett är god. Samtliga uppmätta halter låg långt under Arbetsmiljöverkets gränsvärden och det skiljde sig inte mycket varken mellan fartyg eller jämfört med den svenska normalbefolkningens exponering. Därför är inte svensk sjömän ombord på svenskflaggade fartyg i större fara för toxiska luftföroreningar ombord jämfört med när de är hemma. / The main purpose of this study was to measure and evaluate the air quality onboard two Swedish ships, and compare the results with the exposure limits laid out by the Swedish Work Environment Authority (Arbetsmiljöverket) and the Swedish population’s exposure to various substances. The results of this study were also meant to be helpful to form new advice and recommendations to minimize exposure and also to provide material for future studies. During approximately one week onboard the two ships data were collected using passive samplers to register levels of benzene, nitrogen dioxide and polycyclic aromatic hydrocarbons. The results indicated that the air quality onboard the two ships were generally good. All measured concentrations were well below safety applications and it did not differ very much neither between ships nor compared with the Swedish population’s exposure. In conclusion, Swedish sailors onboard Swedish ships are not in greater danger of toxic air pollutants onboard compared to when they are at home.

Abstract: The aim of the study was to evaluate the indoor air quality (IAQ) of a semi-airtight (the building only utilises mechanical means to ventilate the occupied spaces however an airtight seal is not established as a result of infiltration due to building design) office building that is situated in central Johannesburg that exclusively uses a heating, ventilation and air-conditioning (HVAC) system for ventilation. This implies a system that only utilises mechanical ventilation to heat, cool, humidify and clean the air for comfort, safety and health of employees. This includes the control of odour levels, and also the maintenance of carbon dioxide (CO2) below stipulated levels. Methods: The building is divided into two sections; west and east. Each section has its own ventilation supply. A randomisation process was used to ascertain which offices needed to be sampled, in which section as well as on which floor. For this study, five offices per section were measured. Thus, ten offices per floor were measured and measurements were taken on every second floor. All measurements were done in accordance with the specific requirements of the manufacturer of any specific instrument used and measurements were taken over an eight hour period (full work shift). Results were compared to the available standard, as well as compared to the ambient concentrations. Results: None of the monitored contaminants’ concentration were above the provided standards (ASHRAE or ACGIH). Where standards were unavailable, the HVAC system maintained an indoor contaminant concentration that is substantially lower when compared to the outdoor air concentrations. Conclusion: The buildings’ HVAC system maintains indoor air quality at a healthy level it is unlikely that any one of these contaminants may lead to SBS amongst the employees. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014

La qualité microbienne de l’air intérieur représente un enjeu sanitaire important, notamment dans le secteur professionnel. Ces travaux de thèse ont permis d’étudier les conditions favorisant le développement des espèces microbiennes collectées sur des médias fibreux utilisés dans des CTA, ainsi que leur réentrainement an aval de la filtration, susceptible de dégrader la qualité de l’air. La première partie de l’étude s’est déroulée en laboratoire à partir de la filtration d’un consortium bactérien – fongique composé de Staphylococcus epidermidis et Penicillium oxalicum. L’influence de trois paramètres a été étudiée sur la croissance microbienne : le taux d’humidité relative (HR) de l’air, la nature du média fibreux, la présence/absence de flux d’air. Les résultats ont révélé notamment que quelles que soient les conditions,S. epidermidis n’arrive pas à croître. En revanche, lorsque l’HR de l’air approche 100%, P. oxalicum se développe sur les filtres et des spores sont relarguées en aval des filtres après une reprise de la filtration. Une seconde partie de l’étude a consisté à travailler avec un aérosol atmosphérique semi urbain. Deux unités de filtration d’air ont fonctionné pendant 5 mois en parallèle. La ventilation d’une des deux unités a été stoppée chaque week-end et redémarrée en début de semaine. Un suivi de la température, de l’humidité de l’air, de la perte de charge des filtres et de la concentration des particules totales dans l’air en amont de la filtration a été assuré tout au long de l’étude. Les concentrations en microorganismes cultivables ont été mesurées chaque semaine en amont et en aval de chaque filtre, notamment au redémarrage de la ventilation. En fonction des variations saisonnières de la concentration des microorganismes, les résultats ont montré en particulier des efficacités de filtration vis-à-vis des particules bactériennes faibles, voire négatives, dans l’unité de filtration fonctionnant en continu. / Microbial indoor air quality is an important issue in particular in the professional sector. This thesis aims to investigate the conditions leading to microbial development on to fibrous filters and to microbial release down stream of filters that could decrease air quality. The first part of the thesis was realized on laboratory and consisted in the filtration of a microbial consortium composed with Staphylococcus epidermidis (bacterium specie) and Penicillium oxalicum (fungi specie). The effects of three parameters on the microbial behavior were studied : the relative humidity (RH) of the air, the filter material, the airflow presence/absence. Whatever conditions, S. epidermidis did not grow up. However, P. oxalicum has demonstrated its ability to develop itself when RH was close to 100% and some P. oxalicumspores were released downstream of filter after growth, when ventilation was restarted. The second part of the thesis consisted in working with a semi-urban outdoor air. Two air handling unit (AHU) have operated during 5 months. The ventilation of one AHU was stopped each week-end and restarted each beginning of week. Temperature and RH of the air, filters pressure drop and total concentration of PM in air before filtration were monitored. Concentration of total cultivable microorganisms upstream and downstream of both filters was also measured each week, in particular at the restart of ventilation for one AHU. According to seasonal variations of microbial concentrations, results have revealed for instance that the filtration efficiency of cultivable bacteria was particularly weak, and sometimes negative, for the AHU operating continuously.