Wong Nyuk Hien and Steve Kardinal Jusuf
Architectural Science Review 53 (2010) 196-212
ABSTRACT
The research on urban canyon in the tropics is still very limited. Currently the research focus has been in the temperate climate especially in the development of 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 was 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, the pedestrian thermal comfort was also calculated. The calculated Mean Radiant Temperature (MRT) and Physiologically Equivalent Temperature (PET) show that mature trees are able to provide thermal comfort to the pedestrian due to their ability to provide sufficient shading.
Keywords: Microclimate condition, Impact of trees, Green pedestrian canyon, Outdoor thermal comfort, Singapore
http://www.scribd.com/doc/33126543/Study-on-the-Micro-Climate-Condition-Along-Green-Pedestrian-Canyon-in-Singapore
Sunday, November 29, 2009
STEVE TOOL: A WEB APPLICATION OF SINGAPORE AIR TEMPERATURE PREDICTION MODEL
Steve Kardinal Jusuf and Wong Nyuk Hien
Presented in iNTA-SEGA 2009 - Bridging Innovation, Technology and Tradition, 2-4 December 2009, Bangkok, Thailand
RECEIVED THE BEST PAPER AWARD
ACCEPTED FOR PUBLICATION in Journal of Green Building
ABSTRACT
Empirical models of minimum (Tmin), average (Tavg) and maximum (Tmax) air temperature for Singapore estate have been developed and validated. The independent variables that were used in the models are daily minimum (Ref Tmin), average (Ref Tavg) and maximum (Ref Tmax) temperature at reference point, average of daily solar radiation (SOLAR), percentage of pavement area over R 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).
However, these models are far too complicated for educated non-scientists, such as urban planners. At the end, these models are often kept in the shelves until the scientists are engaged to do the assessment.
The Screening Tool for Estate Environment Evaluation (STEVE) was developed with the motivation as mentioned above, which is to bridge between research findings, especially the air temperature prediction models and the urban planners. STEVE is a web application that is specific to an estate and it calculates the Tmin, Tavg and Tmax of the point of interest for the existing condition and future condition (proposed master plan) of the estate. This paper describes the STEVE tool and some examples of its application on a Singapore green estate.
Keywords: STEVE tool, web application, Singapore, air temperature prediction model.
Presented in iNTA-SEGA 2009 - Bridging Innovation, Technology and Tradition, 2-4 December 2009, Bangkok, Thailand
RECEIVED THE BEST PAPER AWARD
ACCEPTED FOR PUBLICATION in Journal of Green Building
ABSTRACT
Empirical models of minimum (Tmin), average (Tavg) and maximum (Tmax) air temperature for Singapore estate have been developed and validated. The independent variables that were used in the models are daily minimum (Ref Tmin), average (Ref Tavg) and maximum (Ref Tmax) temperature at reference point, average of daily solar radiation (SOLAR), percentage of pavement area over R 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).
However, these models are far too complicated for educated non-scientists, such as urban planners. At the end, these models are often kept in the shelves until the scientists are engaged to do the assessment.
The Screening Tool for Estate Environment Evaluation (STEVE) was developed with the motivation as mentioned above, which is to bridge between research findings, especially the air temperature prediction models and the urban planners. STEVE is a web application that is specific to an estate and it calculates the Tmin, Tavg and Tmax of the point of interest for the existing condition and future condition (proposed master plan) of the estate. This paper describes the STEVE tool and some examples of its application on a Singapore green estate.
Keywords: STEVE tool, web application, Singapore, air temperature prediction model.
INFLUENCE OF WATER FEATURE ON TEMPERATURE CONDITION IN HOT HUMID CLIMATE
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.
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.
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
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