Supplementary material for: Effects of microclimatic and human parameters on outdoor thermal sensation in the high-density tropical context of Dhaka

The supplementary material has a separate DOI generated from ResearchGate: DOI: 10.13140/RG.2.2.30599.4496

Impact of urban geometry on indoor air temperature and cooling energy consumption in traditional and formal urban environments

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the URI link.This study explores the effect of outdoor microclimatic environment on indoor conditions in a tropical warm-humid climate. An indoor air temperature and building energy performance analysis is carried out for the real case-study areas to examine the impact of urban geometry on building indoor conditions. The study incorporates microclimatic data from CFD, micro-climatic tool ENVI-met into building energy performance analysis using IES-VE. Findings reveal that diversity in urban geometry in deep urban canyons is helpful in reducing the indoor air temperature and cooling load. On average, cooling load in model rooms in the formal area is 21% higher for 1st floors (40% for top floors) compared to the corresponding rooms in the traditional area. In terms of solar gains, the difference was 30% for the 1st floors and 91% for the top floors, with rooms in the formal area having the higher ranges. Furthermore, the room air temperature in the traditional area was found to be 0.6-1.6 Deg C lower than those in the formal area

Effects of microclimate and human parameters on outdoor thermal sensation in the high-density tropical context of Dhaka

open access articleA thermal comfort questionnaire survey was carried out in the high-density, tropical city Dhaka. Comfort responses from over 1300 subjects were collected at six different sites, alongside meteorological parameters. The effect of personal and psychological parameters was examined in order to develop predictive models. Personal parameters included gender, age, activity, professiontype (indoor or outdoor-based), exposure to air-conditioned space and sweat-levels. Psychological parameters, such as ‘the reason for visiting the place’ and ‘next destination is air-conditioned’, had statistically significant effects on thermal sensation. Other parameters, such as ‘body type’, ‘body exposure to sun’, ‘time living in Dhaka’, ‘travelling in last_30 min’, and ‘hot food’ did not have any significant impact. Respondents’ humidity, wind speed and solar radiation sensation had profound impacts and people were found willing to adjust to the thermal situations with adaptive behaviour. Based on actual sensation votes from the survey, empirical models are developed to predict outdoor thermal sensation in the case study areas. Ordinal linear regression techniques are applied for predicting thermal sensation by considering meteorological and personal conditions of the field survey. The inclusion of personal and weather opinion factors produced an improvement in models based on meteorological factors. The models were compared with the actual thermal sensation using the cross-tabulation technique. The predictivity of the three models (meteorological, thermos-physiological and combined parameter) as expressed by the gamma coefficient were 0.575, 0.636 and 0.727, respectively. In all three models, better predictability was observed in the ‘Slightly Warm’ (71% in meteorological model) and ‘Hot’ (64.9% in combined parameter model) categories—the most important ones in a hot-humid climate

Post-occupancy evaluation of architecturally-designed low-income housing in Ahmadabad, India

This paper presents post-occupancy evaluation of low-income houses that have been built through the DMU: Square Mile India Programme in Ahmedabad, India. Questionnaire and interviews were conducted which elicited information on respondents’ socio-cultural and environmental experiences in the new houses compared to the existing dwellings in the community. Findings include: 1. increased expectations and higher demands for space and facilities in the new houses, 2. discontent with integrated courtyard/ open spaces, 3. prioritising flood protection over environmental quality and thermal comfort conditions in the existing houses and 4. Significant change in the perception of social status of families in the new homes. The findings highlight residents’ need for adequate sleeping area, thermal comfort, safety from animals and security. These aspects must be critically considered in future design of similar houses. The paper produces empirical evidence on users’ perception that will provide better knowledge and understanding to the designer and policy-makers to identify important factors to improve residents’ quality of life in a low-income housing context

A Comparative Study of Sustainable Urban Forms: Compact City and Short Cycle Strategy

The file attached to this record is the author's final peer reviewed version. Open accessThis paper aims to identify the urban form and design issues that are concerned with the sustainable development of a new settlement. Drawing on the theoretical literature, it recognizes eight key issues to achieve a sustainable urban form which includes compact and mixed use development, high density, social wellbeing, design excellence, renewable energy sources, sustainable built environment, efficient transport network and preservation of open space and ecosystems. It explains the two most important but opposing theories to achieve a sustainable urban form: compact city and short cycle city. Then it argues that while considering the metropolitan scale, a comparatively recent development of sustainable urban form: the strategy of decentralised concentration is more appropriate for contemporary European cities. The suitability of the third strategy which is basically a combination of compact and dispersed city with an emphasis on greening will be examined through a case study. Based on a practical study of issues, opportunities and constraints the paper will try to identify the urban form that is the most sustainable and environmentally sound for Hackney wick, London which forms a significant part of the Legacy site for the Olympic Games 2012

Understanding traditional comfort practices: case-study of a low-income community in Ahmedabad, India

An indoor thermal comfort study was carried out in a low-income community during the hot summer in 3 different categories of houses: Type-1: New_builds, Type-2: DMU_new_builds and Type-3: Old_houses. The performance of Type-2 houses (architecturally designed with passive strategies) were significantly better than Type-1 and Type-3 houses with the former being 1.00C cooler on average than the later. All respondents of the study expressed little concern for indoor thermal comfort as they are accustomed to sleep outdoors, either in the courtyard, roof, or balcony as a cultural practice. During daytime, they spend most of the time in outdoor shaded conditions. This is a unique example of how people can adapt through behaviour that makes us rethink the impact of immediate outdoor conditions rather than focusing solely on indoor conditions in a low-income residential context. However, the residents still use indoor spaces for cooking, eating and other social and household practices and for sleeping during the other seasons. It means there is a balance to be made. However, the attempts to incorporate courtyard in the design by the architect for improved social and environmental performance were mostly unsuccessful due to opposition from the residents. This identifies a challenge for local designers to design low-income houses in a high-density context while providing for the socio-cultural and environmental needs of the residents