A review of human thermal comfort in the built environment

Utilising green and bluespace to mitigate urban heat island intensity.

Energy use in cities has attracted significant research in recent years. However such a broad topic inevitably results in number of alternative interpretations of the problem domain and the modelling tools used in its study. This paper seeks to pull together these strands by proposing a theoretical definition of an urban energy system model and then evaluating the state of current practice. Drawing on a review of 219 papers, five key areas of practice were identified – technology design, building design, urban climate, systems design, and policy assessment – each with distinct and incomplete interpretations of the problem domain. We also highlight a sixth field, land use and transportation modelling, which has direct relevance to the use of energy in cities but has been somewhat overlooked by the literature to date. Despite their diversity, these approaches to urban energy system modelling share four common challenges in understanding model complexity, data quality and uncertainty, model integration, and policy relevance. We then examine the opportunities for improving current practice in urban energy systems modelling, focusing on the potential of sensitivity analysis and cloud computing, data collection and integration techniques, and the use of activity-based modelling as an integrating framework. The results indicate that there is significant potential for urban energy systems modelling to move beyond single disciplinary approaches towards a sophisticated integrated perspective that more fully captures the theoretical intricacy of urban energy systems.

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A review of urban energy system models: Approaches, challenges and opportunities

Cities occupy 2% of the earth's surface but their inhabitants consume 75% of the world's energy resources. Under certain conditions, the heat from solar radiation and different urban activities can make city temperatures rise in certain areas, simply because of the way in which a city is structured. This effect is known as the urban heat island (UHI). This article provides a review of recent research on the urban heat island as well as of the strategies that can be applied to mitigate its adverse effects. Such strategies can be applied in the project design phase of urban planning and thus directly affect city temperatures on a local scale. The elements analyzed in this paper include green spaces, trees, albedo, pavement surfaces, vegetation, as well as building types and materials. The discussion of this research clearly reflects the impact of urban morphology on local temperatures and how urban design can be modified to reduce energy consumption and CO2 emissions into the atmosphere. This study is useful for professionals who are responsible for decision-making during the design phase of urban planning.

The city and urban heat islands: A review of strategies to mitigate adverse effects

The abundant availability and accessibility of plant fibres are the major reasons for an emerging new interest in sustainable technology. While focusing on the composite materials, the main points to be considered are environment friendliness and light weight, with high specific properties. This century has witnessed remarkable achievements in green technology in the field of materials science through the development of high-performance materials made from natural resources is increasing worldwide. Plant fibres are a kind of renewable resources, which have been renewed by nature and human ingenuity for thousands of years. The greatest challenge in working with plant fibre reinforced composites (PFRCs) is their large variation in properties and characteristics. A PFRCs properties are influenced by a number of variables, including the fibre type, environmental conditions, processing methods, and modification of the fibre. A detailed systematic review on these sustainable and renewable green materials is presented in this paper. The overall characteristics of plant fibres used in bio-composites, including source, type, structure, composition, as well as properties, will be reviewed. Finally, the review will conclude with recent developments and future trends of PFRCs as well as key issues that need to be addressed and resolved.

Plant fibre based bio-composites: Sustainable and renewable green materials

Thermal evaluation of vertical greenery systems for building walls

Energy simulation of vertical greenery systems

Acoustics evaluation of vertical greenery systems for building walls

The objective is to discover the current perception of vertical greenery systems and barriers to their widespread adoption in Singapore. It can be concluded that the energy saving property of vertical greenery systems make them suitable for the local conditions as Singapore depends heavily on air conditioning. In addition, vertical greenery systems will also enhance the aesthetic of a building. Moreover, the installation of vertical greenery system is part of the effort to reduce the increasing serious air and noise pollution. Lastly, vertical greenery system is able to bring nature closer to humans. As with all greenery, constant clearing of the residue of dead leaves as well as periodical replacement and trimming cannot be avoided. These may become a barrier in convincing building owners to adopt vertical greenery systems. Furthermore, there is a lack of technical information, maintenance instructions, and information on plants suitable for vertical greenery systems locally. Lastly, there is lack of awareness of the benefits and performance of vertical greenery systems as well as a lack of grants and subsidies for implementation of vertical greenery systems.

Alex Yong Kwang Tan

Papers

Thermal evaluation of vertical greenery systems for building walls

Energy simulation of vertical greenery systems

Acoustics evaluation of vertical greenery systems for building walls

Perception Studies of Vertical Greenery Systems in Singapore

Natural ventilation performance of classroom with solar chimney system