Steve Kardinal Jusuf

Air Temperature Distribution and the Influence of Sky View Factor in a Green Singapore Estate

This paper investigates, first, the influence of vegetations to the air temperature distribution and, second, the correlation between air temperature and sky view factor (SVF) to understand whether the trees have adverse impact especially to the nighttime air temperature since trees reduce the SVF values. Air temperature and SVF measurements were conducted in a green Singapore estate, One-North, from November 1, 2007 to March 31, 2008. The field measurement results show that daytime air temperature difference between dense greenery area and less greenery area is 2.4 K and the nighttime air temperature difference is 1.1 K. The temperature maps study provides a clear picture on the air temperature distribution across the One-North estate and concludes that parks or clusters of trees are able to maintain both daytime and nighttime air temperature at a cool level. Statistical analysis was conducted to analyze the correlation between air temperature and SVF. During daytime, there is a significant and good correlation between air temperature and SVF. The higher the SVF, the higher is the air temperature. Trees reduce the sky openness and provide shading to the environment. At nighttime, there is a weak correlation between air temperature and SVF. Thus, there is no adverse impact, i.e., reduction of nighttime net long-wave loss, due to the reduction of SVF by trees.

Study on the microclimate condition along a green pedestrian canyon in Singapore

The research on urban canyons in the tropics is still very limited. Currently, the research focus has been on the temperate climate, especially in the development of the urban canyon temperature prediction model. In the Singapore context, the cooling impacts of greenery in the form of parks and rooftop gardens have been well established. However, the cooling effects within the different green canyon forms have not yet been explored. Experimental data were therefore collected in this study to examine the issues. Firstly, the microclimate condition and the thermal effects along two pedestrian canyons with different greenery and building distribution conditions were investigated. The results show that the cooling effects inside the canyons vary as a function of vegetation cover and shading effect from trees and buildings. Planting vegetation within the canyon can be an effective passive measure to improve the microclimatic condition. Secondly, pedestrian thermal comfort was also calculated. The calculated mean radiant temperature and physiologically equivalent temperature show that mature trees are able to provide thermal comfort to the pedestrian due to their ability to provide sufficient shading.

An Assessment Method for Existing Greenery Conditions in a University Campus

Abstract It is widely known that greenery has positive impacts to the environment. It is necessary to consider greenery as an important element in any contemporary urban planning. However, planners, estate managers and property managers are not able to asses existing greenery conditions in terms of quantitative data in order to achieve their goals in maintaining or improving the greenery condition. Thus, it is impossible to set a framework or plan to improve the environmental quality. The objective of this research is to develop a framework for planners to evaluate and to improve the greenery conditions in planning the urban environment.

A Climatic Responsive Urban Planning Model for High Density City: Singapore's Commercial District

Local climate condition and urban morphology affect air temperature generated within urban canopy layer which related to urban heat island (UHI) intensity and later impacts on outdoor thermal comfort and urban energy usage. Climatic responsive urban planning by careful consideration on urban morphology parameters of urban corridor width, building height, urban surface materials, sky view factor (SVF) and vegetation help to improve urban environment quality. This study mainly focuses on commercial district and observes impacts of various urban structures configurations towards air temperature by interpolating climatic and urban morphology predictors. The urban structures indeed show relation with level of air temperature generated although vegetation also contributes in reducing air temperature through its evapotranspiration process. Therefore the understanding of relation between urban morphology with thermal performance and UHI benefits in future urban planning and development.

Influence of Water bodies on Outdoor Air Temperature in Hot and Humid Climate

Water features, within an urban area have a positive effect on the microclimate of the surrounding areas when natural cooling from evaporative process is needed in the hot sunny day. The increased availability of water usually enhances evaporation, and the associated uptake of latent heat provides and additional daytime cooling effect. The water bodies of the river operate as the cooling source on the microclimate of the surrounding area. Air temperature near or over bodies of water is much different from that over land due to differences in the way water heat and cool. Water bodies are noted to be about the best absorbers of radiation, but on the other hand, they exhibit very little thermal response. Many other researches argued that evaporative cooling from water bodies or water features is yet one of the most efficient ways of passive cooling for building and urban spaces. However, evaporative cooling may not work optimally in a hot humid tropical country due to its relatively high humidity. This paper studies the evaporative cooling performance of a waterway of approximately 70m to its surrounding micro-climate. The waterway is situated in Kallang, Singapore. The air temperature and relative humidity are measured continuously for five months, May and September 2010, to find the clear extent of the cooling effect from the waterway horizontally. There is a total of 10 measurement points in each location, where five points of measurement are located along the waterway and another five points of measurement are located moving away from the waterway in order to observe the extent of its cooling effect.

Mitigation Methods of Climate Change Impact on the Cooling Load of Public Residential Buildings in Singapore

AbstractBuildings have time-varying interactions with the local climate condition for the heating or cooling systems; changes of the surrounding climate condition affect building energy consumption. Based on the thermal envelope approach, which considers the heat gain by conduction and radiation through the wall and fenestration, the cooling load simulation study was conducted to see the impact of climate change on the cooling load of public residential buildings in Singapore and propose mitigation methods to bring the predicted increase of the cooling load in the future back to the current level. From the simulation results, climate change is predicted to increase the cooling load of current public residential models for 11.8–55.8% through three different time frames. Based on the parametric study of mitigation methods proposed, changing the material of the wall, material of the glass, and the surface properties show a smaller increase in the predicted cooling load compared with other methods because of ...

Comparison of STEVE and ENVI-met as temperature prediction models for Singapore context

In urban areas, natural land soil has been replaced by asphalt roads and concrete buildings, which absorb and retain more heat during the day, creating the Urban Heat Island (UHI) phenomenon. Current studies show that UHI impact mitigation strategies are to increase the open spaces to allow urban ventilation and plant green cover. To complement this, a temperature prediction model could be effective for simulating and quantifying the temperature reduction for every developed strategy. This paper will look into two prediction methods: STEVE and ENVI-met. Screening Tool for Estate Environment Evaluation (STEVE) is a prediction tool which is able to calculate the T min , T avg and T max of the point of interest for certain urban settings. The temperature at that particular point is the result of its surrounding environment within the buffer zone. Output data from STEVE will be used as a database for a Geographic Information System (GIS) to produce temperature maps. ENVI-met is a Computational Fluid Dynamics ...

THE STUDY OF VARIATION IN GROSS BUILDING COVERAGE RATIO ON ESTATE-LEVEL OUTDOOR VENTILATION

Unstructured & improper planning of urban morphologies (geometry & placement) is common in urbanization & the buildings’ roughness & geometry within have caused a host of ventilation-related problems. This study postulates that there is an association between certain morphological variables & urban wind flow & one of the morphological variables Gross Building Coverage Ratio (GBCR) has been singled out for a preliminary parametric numerical study here. From the results of the study, interesting trends can be garnered & this supports the high possibility of development of an overall ventilation potential model using the various morphological variables (in form of indices) as independent variables for input. This will be useful for development of climate-responsive design & planning regulations specific to highdensity residential estates in tropical Singapore.

Simulation of the Impact of the Climate Change on the Current Building's Residential Envelope Thermal Transfer Value (ETTV) Regulation in Singapore

Buildings have time-varying interactions with local climate condition for its heating or cooling systems; changes on the surrounding climate condition affects building energy consumption. Building envelope therefore plays a critical role in reducing heat gained/ lost, thus energy consumption. Singapore’s building regulations currently requires new residential buildings to have a minimum envelope thermal transfer value of 25 W/m 2 base on the Residential Envelope Transmittance Value (RETV) formula. However, as ambient temperature continues rising with global warming, buildings designed under these criteria might be affected in terms of thermal performance. This paper presents the potential impacts of climate change on building energy consumption, in terms of RETV parameter. Existing local weather data is modified using CCWorldWeatherGen, and entered into TAS building energy simulation. Results showed that there is an increase in building energy consumption of 54% and 75% in 2080 for point and slab block respectively. Hence, current RETV regulations may have to be revised in the future.

STEVE Tool: Bridging the Gap between Urban Climatology Research and Urban Planning Process

In the past decades, urban heat island (UHI) phenomenon in the city and its corresponding issues including the mitigation methods have become the main research topics in the area of urban climatology. Researchers have conducted various investigations and measurements in which as the results, they have come out with various prediction models for different purposes. Nevertheless, these prediction models are too complicated for educated non-scientists, in this case the urban planners. At the end, these models remain in the academic domain, unless the scientists are engaged and involve in the urban planning process. There is a gap between scientists and planners. The Screening Tool for Estate Environment Evaluation (STEVE) has been developed as an effort to bridge between urban climatology research, in this case the urban temperature, and urban planning process. In the near future, the STEVE Tool will become an interactive design tool where the urban planners design the building massing and do the urban temperature prediction at the same platform and time. This paper also discusses the prospective of urban climatic analysis tool that lies on how to analyze the interaction between buildings and their surrounding environments as an integrated urban design process.