Steve Kardinal Jusuf, Wong Nyuk Hien and Nedyomukti Imam Syafii
Presented in iNTA-SEGA 2009 - Bridging Innovation, Technology and Tradition, 2-4 December 2009, Bangkok, Thailand
ABSTRACT
Water features, in urban areas, have a good effect on the micro-climate of surrounding with its cooling effect from the evaporative process. Thus, evaporative cooling maybe is one of the most efficient ways of passive cooling for building and urban spaces.
This paper describes the result of field measurement on the micro-climate around a water-wall at One-North Park, Singapore. Continuous measurements were conducted at eight points near this water-wall and one reference point outside the area for two month. Two typical days between 11th March 2008 and 23rd June 2008 represent clear sunny day and rainy day was chosen to get more understanding on the performance of evaporative cooling from the Water-wall at One-North, Park.
The cooling benefits from the Water-wall are shown not only from the cooler air temperature near the Water-wall but also to the lower air temperature in the nearby environment. The presence of water-wall at One-North Park obviously improves the thermal environment in hot sunny day by cooling the air. But the cooling effect is limited to its surrounding. The field measurement found that on 10am and 1pm, when the Water-wall is operated, the temperature drop was relative to the distance from the water-wall. The nearer to the water-wall, the cooler the ambient air temperature will be. The air temperature near the Water-wall were found 1.7-1.8K cooler than the reference point. These result shows that the temperature drop is induced by evaporation of water from the Water-wall. However, the apparent relative humidity profiles reveal that the water-wall tends to moisten the air through transfer of moisture from the evaporation process, which may influence the human outdoor thermal comfort in some extent.
Keywords: influence, water wall, air temperature, hot humid climate, Singapore.
Sunday, November 29, 2009
Wednesday, September 16, 2009
Development of empirical models for an estate level air temperature prediction in Singapore
Steve Kardinal Jusuf and Wong Nyuk Hien
Second International Conference on Countermeasures to Urban Heat Islands (SICCUHI)
21-23 September 2009 in Berkeley, California.
Environmental Energy Technologies Department
E.O. Lawrence Berkeley National Laboratory
ABSTRACT
Urban heat island (UHI) phenomenon has become a common problem in many major cities worldwide including Singapore. As a small island state, it is very important for Singapore to carefully plan its urban development. However, urban planners have no assessment tool to evaluate their planning impacts on the environment, especially the impact on air temperature due to the change of land use. This paper discusses the development of an empirical model for air temperature prediction to evaluate the impact of estate development by means of Geographical Information System (GIS).
Empirical models of minimum (Tmin), average (Tavg) and maximum (Tmax) air temperature for Singapore estate have been developed and validated, based on the long-term field measurement between the period of September 2005 and March 2008. The independent variables that were used in the models are daily minimum (Tmin-r), average (Tavg-r) and maximum (Tmax-r) temperature at reference point, average of daily solar radiation (SOLAR), percentage of pavement area over radius 50m surface area (PAVE), average height to building area ratio (HBDG), total wall surface area (WALL), Green Plot Ratio (GnPR), sky view factor (SVF) and average surface albedo (ALB).
Sensitivity analyses were carried out to observe the dependence of the air temperature due to the variations of each variable. An ideal type of urban canyon was used to simplify the variation of building, pavement and greenery distributions. The sensitivity analyses were carried out by varying some of the following important parameters: the greenery density (GnPR), which may affect the SVF; the building height, which affects the SVF, WALL and HBDG values; and canyon width, which affects the SVF, PAVE and HBDG values.
The Screening Tool for Estate Environment Evaluation (STEVE) was developed with the motivation to bridge between research findings, especially the air temperature prediction models and the urban planners.
Full paper:
http://heatisland2009.lbl.gov/docs/221410-jusuf-doc.pdf
Second International Conference on Countermeasures to Urban Heat Islands (SICCUHI)
21-23 September 2009 in Berkeley, California.
Environmental Energy Technologies Department
E.O. Lawrence Berkeley National Laboratory
ABSTRACT
Urban heat island (UHI) phenomenon has become a common problem in many major cities worldwide including Singapore. As a small island state, it is very important for Singapore to carefully plan its urban development. However, urban planners have no assessment tool to evaluate their planning impacts on the environment, especially the impact on air temperature due to the change of land use. This paper discusses the development of an empirical model for air temperature prediction to evaluate the impact of estate development by means of Geographical Information System (GIS).
Empirical models of minimum (Tmin), average (Tavg) and maximum (Tmax) air temperature for Singapore estate have been developed and validated, based on the long-term field measurement between the period of September 2005 and March 2008. The independent variables that were used in the models are daily minimum (Tmin-r), average (Tavg-r) and maximum (Tmax-r) temperature at reference point, average of daily solar radiation (SOLAR), percentage of pavement area over radius 50m surface area (PAVE), average height to building area ratio (HBDG), total wall surface area (WALL), Green Plot Ratio (GnPR), sky view factor (SVF) and average surface albedo (ALB).
Sensitivity analyses were carried out to observe the dependence of the air temperature due to the variations of each variable. An ideal type of urban canyon was used to simplify the variation of building, pavement and greenery distributions. The sensitivity analyses were carried out by varying some of the following important parameters: the greenery density (GnPR), which may affect the SVF; the building height, which affects the SVF, WALL and HBDG values; and canyon width, which affects the SVF, PAVE and HBDG values.
The Screening Tool for Estate Environment Evaluation (STEVE) was developed with the motivation to bridge between research findings, especially the air temperature prediction models and the urban planners.
Full paper:
http://heatisland2009.lbl.gov/docs/221410-jusuf-doc.pdf
Tuesday, June 23, 2009
Air temperature distribution and the influence of sky view factor in a green Singapore estate
Wong Nyuk Hien1 and Steve Kardinal Jusuf2
Accepted for publication in Journal of Urban Planning and Development
Abstract
This paper investigates, firstly, the influence of vegetations to the air temperature distribution and secondly, 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
Friday, April 18, 2008
An Assessment Method for Existing Greenery Conditions in a University Campus
Wong Nyuk Hien and Steve Kardinal Jusuf†
Published in: Architectural Science Review 2008, 51 (3), 212-220
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.
Keywords: GIS, Greenery mapping framework, Greenery condition assessment, Planning, Urban environments
Published in: Architectural Science Review 2008, 51 (3), 212-220
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.
Keywords: GIS, Greenery mapping framework, Greenery condition assessment, Planning, Urban environments
STUDY OF ROOF GARDENS IN NUS
Wong Nyuk Hien, Lin Huimin, Nedyomukti* & Steve Kardinal Jusuf
2nd Building Research Student Network Symposium, National University of Singapore, Singapore.
28 March 2007
ABSTRACT:
Singapore has undergone rapid urbanization. Study shows that the huge concentration of thermal mass (building) contributes to environmental problems such as the Urban Heat Island (UHI) Effect. Heat accumulated within the urban landscape during the day is released at night resulting in higher night temperatures than normal. As the temperature in an urban area rises, more cooling energy is needed to maintain comfort levels in building structures. In addition, the UHI effect is compounded by air pollution, which reduces night-time terrestrial radiation, and by the low humidity which results from the lack of vegetation. A heat island is developed during calm conditions; winds disperse heat.
The object study of this research is inside the premises of National University of Singapore (NUS). With the introduction of new buildings to NUS Master Plan 2005, it might lead to the development of UHI. Urban greenery, such as planting of grass, trees, and shrubs could minimize the impact of the UHI effect. The potential of roof gardens within the campus was quantified and studied to further improve the urban greenery. The aim of this research seeks to study the way greenery helps in mitigating the UHI effect and determine the direct and indirect effects of the two types of rooftop garden (intensive type and extensive type).
Keywords: urban greenery, roof garden, NUS
2nd Building Research Student Network Symposium, National University of Singapore, Singapore.
28 March 2007
ABSTRACT:
Singapore has undergone rapid urbanization. Study shows that the huge concentration of thermal mass (building) contributes to environmental problems such as the Urban Heat Island (UHI) Effect. Heat accumulated within the urban landscape during the day is released at night resulting in higher night temperatures than normal. As the temperature in an urban area rises, more cooling energy is needed to maintain comfort levels in building structures. In addition, the UHI effect is compounded by air pollution, which reduces night-time terrestrial radiation, and by the low humidity which results from the lack of vegetation. A heat island is developed during calm conditions; winds disperse heat.
The object study of this research is inside the premises of National University of Singapore (NUS). With the introduction of new buildings to NUS Master Plan 2005, it might lead to the development of UHI. Urban greenery, such as planting of grass, trees, and shrubs could minimize the impact of the UHI effect. The potential of roof gardens within the campus was quantified and studied to further improve the urban greenery. The aim of this research seeks to study the way greenery helps in mitigating the UHI effect and determine the direct and indirect effects of the two types of rooftop garden (intensive type and extensive type).
Keywords: urban greenery, roof garden, NUS
STUDY OF ENVIRONMENTAL WIND PROFILE ON NEW UNIVERSITY TOWN @ WARREN
Wong Nyuk Hien, Goh Siew Ling, Steve Kardinal Jusuf* & Nedyomukti Imam Syafii
2nd Building Research Student Network Symposium, National University of Singapore, Singapore.
28 March 2007
ABSTRACT:
This research presents the adoption of wind tunnel modeling to study the environmental wind profile to enhance the performance of natural ventilation on New University Town @ Warren. Wind tunnel experiments were conducted with the use of scaled model to determine the natural ventilation performance in terms of wind velocity. The regions with low wind velocity were identified and examined.
The study also explored the impact of variations of the design parameters, which classified into four divisions, namely, openings of buildings, height of buildings, orientation of greenery and spacing between presences of greenery on environmental wind conditions. A total of eleven stages of experiments were performed in this study. The results indicated that the values of wind velocity were significantly affected by the variation of design parameters. Openings and heights of buildings in relation to prevailing wind direction can notably enhance the wind velocity. The presence of greenery in the prevailing wind direction influences the magnitude of wind velocity by producing shielding effect, which can be proven to serve as an effective windbreak. Furthermore, tree spacing played a part in modifying the wind velocity. As trees spacing increased, the values of wind velocity increased.
Keywords: wind profile, wind tunnel study, New University Town @ Warren
2nd Building Research Student Network Symposium, National University of Singapore, Singapore.
28 March 2007
ABSTRACT:
This research presents the adoption of wind tunnel modeling to study the environmental wind profile to enhance the performance of natural ventilation on New University Town @ Warren. Wind tunnel experiments were conducted with the use of scaled model to determine the natural ventilation performance in terms of wind velocity. The regions with low wind velocity were identified and examined.
The study also explored the impact of variations of the design parameters, which classified into four divisions, namely, openings of buildings, height of buildings, orientation of greenery and spacing between presences of greenery on environmental wind conditions. A total of eleven stages of experiments were performed in this study. The results indicated that the values of wind velocity were significantly affected by the variation of design parameters. Openings and heights of buildings in relation to prevailing wind direction can notably enhance the wind velocity. The presence of greenery in the prevailing wind direction influences the magnitude of wind velocity by producing shielding effect, which can be proven to serve as an effective windbreak. Furthermore, tree spacing played a part in modifying the wind velocity. As trees spacing increased, the values of wind velocity increased.
Keywords: wind profile, wind tunnel study, New University Town @ Warren
Monday, July 23, 2007
GIS-Based Greenery Evaluation on Campus Master Plan
Wong Nyuk Hien and Steve Kardinal Jusuf
Published in: Landscape and Urban Planning Volume 84, Issue 2, 6 February 2008, Pages 166-182
Abstract:
In the previous study, it was found that urban heat island intensity in National University of Singapore (NUS) campus as high as 4oC at around 13:00. It is also concluded that the presence of dense greenery in NUS environment is very important in keeping low ambient temperature.
National University of Singapore has announced its new master plan in 2005, entitled NUS Master Plan 2005. Many new buildings will be built and in some areas existing greenery will be removed. Geographical Information System (GIS) was use to evaluate the greenery condition. It was found that the greenery rate of NUS Master Plan 2005 will drop by about 3% from 55.10% of NUS current condition to 52.31%. In order to have a sustainable environment, the greenery condition should be at least maintain at the same rate or even make it better.
For this purpose, potential of increasing greenery area by rooftop greenery application was also done. The target is to maintain the green rate of different zones at the same rate with current condition. In total, there will be more than 56% new buildings in NUS Master Plan 2005. Therefore, there is a good opportunity to plan and introduce the rooftop greenery or vertical greenery since in the early design stage
The ENVI-Met simulation predicts that the ambient temperature in NUS environment will increase about 1oC when NUS Master Plan 2005 is completed. It is due to the reduction of greenery rate.
Keywords: NUS Campus, GIS, master plan evaluation, potential of rooftop greenery, ENVI-Met simulation, temperature prediction.
Published in: Landscape and Urban Planning Volume 84, Issue 2, 6 February 2008, Pages 166-182
Abstract:
In the previous study, it was found that urban heat island intensity in National University of Singapore (NUS) campus as high as 4oC at around 13:00. It is also concluded that the presence of dense greenery in NUS environment is very important in keeping low ambient temperature.
National University of Singapore has announced its new master plan in 2005, entitled NUS Master Plan 2005. Many new buildings will be built and in some areas existing greenery will be removed. Geographical Information System (GIS) was use to evaluate the greenery condition. It was found that the greenery rate of NUS Master Plan 2005 will drop by about 3% from 55.10% of NUS current condition to 52.31%. In order to have a sustainable environment, the greenery condition should be at least maintain at the same rate or even make it better.
For this purpose, potential of increasing greenery area by rooftop greenery application was also done. The target is to maintain the green rate of different zones at the same rate with current condition. In total, there will be more than 56% new buildings in NUS Master Plan 2005. Therefore, there is a good opportunity to plan and introduce the rooftop greenery or vertical greenery since in the early design stage
The ENVI-Met simulation predicts that the ambient temperature in NUS environment will increase about 1oC when NUS Master Plan 2005 is completed. It is due to the reduction of greenery rate.
Keywords: NUS Campus, GIS, master plan evaluation, potential of rooftop greenery, ENVI-Met simulation, temperature prediction.
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