Tetsu Kubota

Wind Environment Evaluation of Neighborhood Areas in Major Towns of Malaysia

Abstract This paper discusses planning methods of neighborhood residential areas in Malaysia, focusing on the effect of wind flow. This study aims to determine strategies that reduce energy consumption at the neighborhood scale, targeting especially a reduction in the use of air-conditioners. For naturally ventilated buildings, the wind flow around the structure strongly affects the air change rates within the building. This paper presents the evaluations of the wind environment in selected case study areas, under the respective climatic conditions in major Malaysian towns. The evaluations in towns on the west coast and inland of Peninsular Malaysia showed results that, the majority of terraced house cases did not meet the required criteria, under the respective local climatic conditions. This was mainly due to the weak wind conditions in these towns. It was considered that the location of towns was a key factor in determining such weak wind conditions. High-rise housing was suggested as an effective means of utilizing stronger winds at elevated floor levels in urban Malaysia.

Energy Consumption and Air-Conditioning Usage in Residential Buildings of Malaysia

This study provides the detailed information on household energy consumption in residential buildings of Malaysia. A survey was conducted in Johor Bahru in 2009 to analyze electricity consumption due to airconditioning. The results showed that the air-conditioner ownership was 65% and its daily usage time was 6 hours on average. The yearly electricity consumption caused by air-conditioning recorded the largest amount among household appliances. Another survey was carried out in 2004 to reveal the detailed usage patterns of cooling appliances in the same housing estates. The results showed that most of the air-conditioner owners have installed them in bedrooms and operate them during the whole night for sleeping. 61 【Report】 Journal of International Development and Cooperation, Vol.17, No.3, 2011, pp. 61-69 Energy Consumption and Air-Conditioning Usage in Residential Buildings of Malaysia Tetsu KUBOTA Associate Professor Graduate School for International Development and Cooperation, Hiroshima University 1-5-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8529, Japan E-mail: tetsu@hiroshima-u.ac.jp Sangwoo JEONG Graduate Student Graduate School for International Development and Cooperation, Hiroshima University 1-5-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8529, Japan Doris Hooi Chyee TOE Graduate Student Graduate School for International Development and Cooperation, Hiroshima University 1-5-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8529, Japan Tutor Faculty of Built Environment, Universiti Teknologi Malaysia 81310 UTM, Skudai, Johor, Malaysia Dilshan Remaz OSSEN Senior Lecturer Faculty of Built Environment, Universiti Teknologi Malaysia 81310 UTM, Skudai, Johor, Malaysia 62 Tetsu KUBOTA, Sangwoo JEONG, Doris Hooi Chyee TOE and Dilshan Remaz OSSEN

Analysis of Wind Flow in Residential Areas of Johor Bahru City

Abstract Most cities in Malaysia experience hot and humid climate during most part of the year. In large metropolitan cities such as Johor Bahru, the use of air conditioners to cool dwelling units has been increasing sharply partly due to continuing rise in disposable income brought about by recent high economic growth. This has resulted to significant rise in non-renewable energy consumption, thus does not contribute toward sustainability. Natural wind flow is one of the most effective energy-saving methods to improve the thermal environment at the neighborhood level. This paper presents the results of several wind tunnel tests on selected residential areas in Johor Bahru Metropolitan City. By comparing the average of wind velocity of each case studies, the paper discusses the planning methods at the residential neighborhood level area in order to create sufficient wind flow and help achieve energy saving and sustainability objectives in Malaysia.

Field investigation of indoor thermal environments in traditional Chinese shophouses with courtyards in Malacca

This study investigates indoor thermal conditions in traditional Chinese shophouses (CSHs) in Malacca, Malaysia, using field measurements and focuses on the cooling effects of courtyards. The results indicate that the indoor air temperature in the living rooms of CSHs was approximately 5-6°C lower than the outdoor temperature during the day primarily due to structural cooling effects with night ventilation, whereas the indoor air temperature at night was similar to the outdoor temperature. If the thermal adaptations of the occupants were considered, then the thermal conditions in the living rooms were acceptable for most of the day. The results indicate that the front courtyards functioned as a cooling source for the surrounding spaces in the CSHs.

Potential of Passive Cooling Techniques for Modern Houses in the Tropical Climate of Malaysia - Analysis of the Indoor Thermal Environment for Various Ventilation Strategies

Abstract This paper discusses the potential of passive cooling techniques for Malaysian modern houses with the aim of reducing air–conditioning usage. A full–scale field experiment was carried out to reveal the detailed indoor thermal environment for various ventilation strategies. Night ventilation was found to be better than daytime ventilation, full–day ventilation and no ventilation in terms of air temperature reductions during the day and night. Night ventilation improves thermal comfort more than the other ventilation conditions based on operative temperature. However, further measures to lower indoor humidity, such as by dehumidification, or to increase indoor air velocity, such as by the use of a fan, are required to improve the thermal condition in the night ventilated room, especially in the daytime. In fact, the peak standard effective temperature (SET*) in the night ventilated room was decreased by 4.0°C mainly through the use of a ceiling fan. Thus night ventilation, with the use of a ceiling fan, was considered to be the superior option to the other conditions when the evaporative heat loss is taken into account in SET*. Several other potential passive cooling techniques are also proposed for achieving acceptable thermal comfort in modern Malaysian houses.

Life Cycle Energy and CO2 Emissions of Residential Buildings in Bandung, Indonesia

This study aims to develop a simplified life cycle assessment model for residential buildings in Indonesia, which can be used under relatively poor data availability conditions. In order to obtain material inventory data and household energy consumption profiles for constructing the above model, a survey was conducted in Bandung in 2011. This paper analyzes life cycle energy and CO2 emissions employing an input-output analysis-based method within unplanned houses (n=250), which are classified into three categories, namely simple, medium and luxurious houses. The results showed that the average embodied energy of simple, medium and luxurious houses was 36.3, 130.0 and 367.7 GJ respectively. The cement consumed the largest energy and emitted the most CO2 emissions among all materials. The annual average operational energy of simple, medium and luxurious houses varied widely at 11.6, 17.4 and 32.1 GJ/year respectively. The energy consumption for cooking accounted for the largest percentage of operational energy. The profiles of life cycle CO2 emissions were similar with those of life cycle energy. The factors affecting embodied, operational and life cycle energy were also studied.

Urban Climate Challenges in Hanoi: Urban Heat Islands and Global Warming

Urban climate of rapidly growing cities such as Hanoi will alter not only owing to land use changes but also global warming effect. This chapter investigates the contributions of land use changes and global warming to the future increases in urban temperature in Hanoi for 2030 through a numerical simulation using the Weather Research and Forecasting (WRF). The future climate data utilized the fifth phase of the Coupled Model Intercomparison Project (CMIP5) projected by the Model for Interdisciplinary Research on Climate Version 5 (MIROC5) through a direct dynamical downscaling method. In the 2030s, the average air temperature increase in the existing urban areas was projected to be up to 2.1 °C, of which up to 1.5 and 0.6 °C are attributable to global warming and land use changes, respectively. The future increase in urban temperature will likely exceed the cooling effects of any urban heat island (UHI) mitigation measures.

Thermal Function of Internal Courtyards in Traditional Chinese Shophouses in Malaysia

This study aims to identify the thermal functions of internal courtyards in traditional Chinese shophouses (CSHs) located in the hot-humid climate of Malaysia with the aim of providing useful passive cooling strategies for modern urban houses. This chapter investigates the detailed thermal environments of the selected two traditional CSHs with different courtyard types to discuss the thermal function of the courtyards. As a result, it was suggested that closed, cross-ventilated courtyards be embedded to achieve indoor thermal comfort and avoid excessive humidity in hot-humid climates. Meanwhile, it was also recommended that a staggered form of courtyard with V-shaped roofs should be designed as a nocturnal cooling source.

Indonesia: Dutch Colonial Buildings

This chapter starts with a brief history of Dutch colonial architecture in Indonesia. The arrival of Europeans in the early fifteenth century had a great impact on building construction in Indonesia. The material and spatial concepts of European buildings were completely different from those of the Indonesian indigenous people. With the passage of time, it proved that building designs imitated from existing European buildings could not be used directly in the tropical climate of Indonesia. This led to the development of buildings that were adapted to the local context. Secondly, this chapter shows the results of a field measurement conducted in a Dutch colonial building in the city of Bandung. The results showed that, overall, daytime indoor air temperatures in the building maintained relatively low values compared to the corresponding outdoor temperature mainly due to the thermal mass effect. Other passive cooling strategies found from the measurement include night ventilation, use of corridor spaces, high ceilings, and permanent openings above windows/doors.

Indoor Thermal Environments in Apartments of Surabaya, Indonesia

This chapter presents the results of detailed field investigations of thermal conditions and occupants’ window-opening behaviour in several apartments located in the city of Surabaya, Indonesia. In the public apartments, almost all of the respondents did not use air-conditioning, and approximately 70–80% opened their windows/doors on both front and rear sides, while 20–40% of them kept the rear opening opened at night. Meanwhile, most of the respondents in the high-rise private apartments depended on air-conditioning, and about 20% of them opened the rear window only during daytime. The results of field measurement showed that under the naturally ventilated conditions, the old public apartment unit provided better thermal conditions compared to those in the other types of apartments. It was difficult to achieve the thermal comfort without relying on air-conditioning in the high-rise private apartments.