242 research outputs found
Development of outdoor thermal comfort model for tourists in urban historical areas; A case study in Isfahan
The present study intended to evaluate thermal comfort conditions in microclimates of the urban historical areas of Isfahan, Iran during a heatwave. The thermal comfort conditions of different historical sites were compared during the daylight hours to determine the best time to visit each historical site. Using the results of this study, tourists can select the best timeframe with appropriate thermal conditions to visit the historical sites of Isfahan. Along with performing field measurements in the intended historical sites, a questionnaire was used to determine the thermal comfort range of tourists. ENVI-met is used in order to properly simulate the outdoor thermal environment of the historical touristic areas in Isfahan during the hottest as well as the most touristic month of the year. The results of questionnaire and simulations are compared with each other. It was shown that three historical sites with higher thermal stress experience an unpleasant thermal condition. The results of questionnaire show that the comfort range of tourists is within 23.06–29.73 °C PET. The thermal conditions of Si-o-Se Pol, Hasht Behesht and Naqsh-e-Jahan are within the thermal comfort range at 19,20 and 21 p.m. respectively. During the daytime, thermal comfort conditions varied from 4.9 °C PET at 8 a.m. to 8.1 °C PET at 3 p.m. Early morning hours were the most comfortable time to visit the historical sites of Menar-e-Jonban, Masjed-e-Jame and Vank Cathedral in Isfahan. During the peak hours of heat, the priority of thermal comfort goes to Masjed-e-Jame, Menar-e-Jonban and Si-o-Se Pol, respectively
Learning to Chill: The Role of Design Schools and Professional Training to Improve Urban Climate and Urban Metabolism
The increased frequency of heat-related mortality and morbidity in urban environments indicates the importance of urban climate studies. As most of the world’s population lives in cities, the education of designers, planners and policy makers is crucial to promote urban sustainability This paper, firstly, focuses on the different factors causing the urban heat islands in large cities. Secondly, it considers how these factors are reflected in higher education programmes. Examples are shown from courses in UK higher education, explaining the common software tools used for simulating urban spaces, and student field measurements are drawn on to illustrate how urban climate studies are included in higher education curricula. Urban metabolism is used to conceptualise the main approach to systemic resource-use assessments and as a holistic framework to investigate the main drivers of the urban heat island phenomenon. To sum up, this paper reflects on the importance of training climatically-aware graduates from design schools
The Relationship between Job Burnout, Organizational Citizenship Behavior, and Staff Performance in State Tax Organization
Organizational citizenship behaviors refer to optional behaviors which are not clearly defined by the organization\u27s official reward system. Overall, these behaviors improve the organization\u27s performance. Job burnout is on the other hand a psychological response to the mental pressures of a job, which includes three components of emotional burnout, depersonalization, and perceptions regarding self-inefficacy. Organizational citizenship behavior has a positive effect on organizational performance while job burnout has a negative effect on organizational performance. Accordingly, the current study evaluates the roles organizational citizenship behaviors and job burnout play in the occupational performance of the employees. The current study is a descriptive survey. In order to realize the objectives of the study, a sample of 311 participants among the staff members of the country\u27s State Tax Organization has been selected. A questionnaire was used for gathering the required data. The validity and reliability of the questionnaire were confirmed using Cronbach\u27s Alpha coefficient and confirmatory factor analysis. In order to analyze the obtained data structural equation modeling (SEM) and confirmatory factor analysis (CFA) were utilized. The findings show that job burnout and organizational citizenship behavior have a significant relationship with occupational performance. Also, the components of job burnout and the components of organizational citizenship behavior have a significant relationship with occupational performance
Energy performance and summer thermal comfort of traditional courtyard buildings in a desert climate
Courtyards have been traditionally used as a passive design strategy in desert climates. However, few studies have quantified the thermal performance of this building archetype. This paper explored the indoor and outdoor thermal conditions of a typical courtyard house in Iran. The study was performed in two phases. The first phase showed the effect of the position of the zones located in four sides of the courtyard on their indoor energy use and indoor thermal comfort. The results showed that the east and west sides of the courtyard require the highest cooling demand due to the solar radiation in summer time.
Furthermore, maximum discomfort hours occurred in the east zone. In the second phase, hourly air temperature inside and outside of the courtyard were compared during the longest day of the year (21st of June). The results showed that inside of the courtyard was 1.2 °C cooler than the outside on average. Moreover, it was observed that the
temperature fluctuations outside of the courtyard were higher than the inside. To sum up, the results showed that courtyards can provide a cooler microclimate in summer time
Energy performance and thermal comfort of courtyard/atrium dwellings in the Netherlands in the light of climate change
With increased global concerns on climate change, the need for innovative spaces which can provide thermal comfort and energy efficiency is also increasing. This paper analyses the effects of transitional spaces on energy performance and indoor thermal comfort of low-rise dwellings in the Netherlands, at present and projected in 2050. For this analysis the four climate scenarios for 2050 from the Royal Dutch Meteorological Institute (KNMI) were used. Including a courtyard within a Dutch terraced dwelling on the one hand showed an increase in annual heating energy demand but on the other hand a decrease in the number of summer discomfort hours. An atrium integrated into a Dutch terraced dwelling reduced the heating demand but increased the number of discomfort hours in summer. Analysing the monthly energy performance, comfort hours and the climate scenarios indicated that using an open courtyard May through October and an atrium, i.e. a covered courtyard, in the rest of the year establishes an optimum balance between energy use and summer comfort for the severest climate scenario
Indoor thermal comfort in urban courtyard block dwellings in the Netherlands
Global warming and elevated temperatures in the Netherlands will increase the energy demand for cooling. Studying passive strategies to cope with the consequences of climate change is inevitable. This paper investigates the thermal performance of courtyard dwellings in the Netherlands. The effects of different orientations and elongations, cool roofs and pavements on indoor thermal comfort are studied through simulations and field measurements. The results show that North-South and East-West orientations provide the least and most comfortable indoor environments. Regarding materials, the use of green on roofs and as courtyard pavement is the most effective heat mitigation strategy. It was observed that the effects of wet cool roofs are much higher than of dry roofs. Cool roofs did not show a specific negative effect (heat loss) as compared to conventional asphalt roofs in winter. Some simulation results were validated through field measurement with a 0.91°C root mean square deviation
Living with Air Pollution: Simple tips to reduce the impact of air pollution
This guide explores the nature, sources, and impacts of urban air pollution, emphasizing both outdoor and indoor environments. It highlights that air pollution, often invisible and odorless, can significantly affect health, with vehicles, especially diesel ones, being major contributors. Vulnerable groups, such as infants, children, pregnant women, and the elderly, are particularly at risk. The guide provides practical tips to minimize exposure, noting that air pollution varies by time of day and season, often worsening in colder months and during rush hours. Indoor pollution, caused by activities like cooking, cleaning, and using certain household products, also poses significant health risks. The guide advises on ventilation and safer practices to reduce indoor pollution. Special attention is given to air quality around schools and the negative impact of vehicle idling, offering strategies to protect children from pollution.
Available for download in different languages: English, Arabic, Chinese, Farsi and Hindi.
التعايش مع تلوث الهواء: نصائح بسيطة للحد من تأثير تلوث الهواء
与空气污染共存: 减少空气污染影响的简单建议
زندگی با آلودگی هوا : نکاتی ساده برای کاهش آثار آلودگی هوا
वायु प्रदूषण के साथ जीना: वायु प्रदूषण के प्रभाव को कम करने के सरल उपा
Air Pollution within Different Urban Forms in Manchester, UK
Air pollution causes millions of mortalities and morbidities in large cities. Different mitigation strategies are being investigated to alleviate the negative impacts of different pollutants on people. Designing proper urban forms is one of the least studied strategies. In this paper, we modelled air pollution (NO2 concentration) within four hypothetical neighbourhoods with different urban forms: single, courtyard, linear east-west, and linear north-south scenarios. We used weather and air pollution data of Manchester as one of the cities with high NO2 levels in the UK. Results show that the pollution level is highly dependent on the air temperature and wind speed. Annually, air pollution is higher in cold months (45% more) compared to summer. Likewise, the results show that during a winter day, the concentration of air pollution reduces during the warm hours. Within the four modelled scenarios, the air pollution level in the centre of the linear north-south model is the lowest. The linear building blocks in this scenario reduce the concentration of the polluted air and keep a large area within the domain cleaner than the other scenarios. Understanding the location of air pollution (sources) and the direction of prevailing wind is key to design/plan for a neighbourhood with cleaner air for pedestrians.</jats:p
Evaluating the ENVI-met microscale model for suitability in analysis of targeted urban heat mitigation strategies
Microscale atmospheric models are increasingly being used to project the thermal benefits of urban heat mitigation strategies (e.g., tree planting programs or use of high-albedo materials). However, prior to investment in specific mitigation efforts by local governments, it is desirable to test and validate the computational models used to evaluate strategies. While some prior studies have conducted limited evaluations of the ENVI-met microscale climate model for specific case studies, there has been relatively little systematic testing of the model's sensitivity to variations in model input and control parameters. This study builds on the limited foundation of past validation efforts by addressing two questions: (1) is ENVI-met grid independent; and (2) can the model adequately represent the air temperature perturbations associated with heat mitigation strategies? To test grid independence, a “flat” domain is tested with six vertical grid resolutions ranging from 0.75 to 2.0 m. To examine the second question, a control and two mitigation strategy simulations of idealized city blocks are tested. Results show a failure of grid independence in the “flat” domain simulations. Given that the mitigation strategies result in temperature changes that are an order of magnitude larger than the errors introduced by grid dependence for the flat domain, a lack of grid independence itself does not necessarily invalidate the use of ENVI-met for heat mitigation research. However, due to limitations in grid structure of the ENVI-met model, it was not possible to test grid dependence for more complicated simulations involving domains with buildings. Furthermore, it remains unclear whether existing efforts at model validation provide any assurance that the model adequately captures vertical mixing and exchange of heat from the ground to rooftop level. Thus, there remain concerns regarding the usefulness of the model for evaluating heat mitigation strategies, particularly when applied at roof level (e.g. high albedo or vegetated roofs)
Renaturing a microclimate : the impact of greening a neighbourhood on indoor thermal comfort during a heatwave in Manchester, UK
Higher air temperatures in large cities like Manchester, UK, reduce human thermal comfort. In this paper, the impact of land cover on microclimate, and consequently on indoor thermal comfort is studied. Through different stages, field measurements and computer modelling were carried out for a heat wave episode in summer 2017 in Manchester:
First, the urban heat island (UHI) was measured between the city centre of Manchester and the campus of the University of Salford (between May to October 2017). Maximum detected UHI was 2.3 °C at 4:00, during the hottest day of the summer. Parallel measurements within the university campus showed that the park was 0.9 °C cooler than the paved areas (maximum cooling effect was 3.6 °C at 14:45).
Finally, the impact of the current land cover of the campus, and a greener land cover (as a renaturing scenario) with more planted trees on indoor thermal comfort of a house within the campus was studied. It was found that by adding 17% more trees to the campus, indoor thermal comfort was improved by 20.8% during the hottest day of 2017 in Manchester. These showed that renaturing cities could be a solution for future warmer climates
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