In-situ measurements and GIS-based analysis of the microclimate at the Universiti Teknologi Malaysia, Kuala Lumpur

Developing tropical countries are expecting a large number of population in the near future, thus, environmental degradation issues due to excessive economic development and urban climate change are becoming a major threat to modern society. In order to improve urban design and sustainable architecture, in accordance with this specific tropical climate, a quantitative grasp of the microclimate in a developed city is highly desirable. Moreover, only a few studies have been carried out on the aforementioned issues in a low-latitude tropical urban region. Therefore, this study aims to provide a better insight into the use of in-situ microclimatic measurements and Geographical Information Systems (GIS), particularly in analysing the effect of greenery coverage and morphological aspects, i.e. height to width ratio of built-up features, for understanding the microclimate pattern at the university campus. The study area is situated at the Universiti Teknologi Malaysia, Kuala Lumpur, (UTM KL), which is a local-scale city campus environment, located near the Kuala Lumpur city centre. The urban microclimate was observed for the duration of one year. The climatic data were mapped and spatially analysed in relation to different land cover types in the GIS environment. Moreover, the effect of green areas and building morphology are critically evaluated with regards to the changes made to the local climatic variables in the campus. As a result, this study reveals that the effects of greenery coverage and the morphological characteristics on the campus providing a good indicator of the microclimate pattern in a developed city campus. In conclusion, with the support of in-situ measurements and GIS analysis, the campus temperature properties were quantitatively evaluated, and this directly contributed to a better understanding of climate change in the city of Kuala Lumpur

Analysis of controllers in suppressing the structural building vibration

Two degree of freedom (2 DOF) mass spring damper system is used in representing as building structure that dealing with the earthquake vibration. The real analytical input is used to the system that taken at El Centro earthquake that occurred in May 1940 with magnitude of 7.1 Mw. Two types of controller are presented in controlling the vibration which are fuzzy logic (FL) and sliding mode controller (SMC). The paper was aimed to improve the performance of building structure towards vibration based on proposed controllers. Fuzzy logic and sliding mode controller are widely known with robustness character. The mathematical model of two degree of freedom mass spring damper wasis derived to obtain the relationship between mass, spring, damper, force and actuator. Fuzzy logic and sliding mode controllers were implemented to 2 DOF system to suppress the earthquake vibration of two storeys building. Matlab/Simulink was used in designing the system and controllers to present the result of two storeys displacement time response and input control voltage for uncontrolled and controlled system. Then the data of earthquake disturbance was taken based on real seismic occurred at El Centro to make it as the force disturbance input to the building structure system. The controllers proposed would minimize the vibration that used in sample earthquake disturbance data. The simulation result was carried out by using Matlab/Simulink. The simulation result showed sliding mode controller was better controller than fuzzy logic. In specific, by using the controller, earthquake vibration can be reduced

Turbulence effect of urban-canopy flow on indoor velocity fields under sheltered and cross-ventilation conditions

Understanding the characteristics of natural, wind-induced ventilation of buildings is essential for accurate predictions of ventilation flow rates; however, indoor ventilation is significantly influenced by surrounding buildings. Therefore, a series of wind-tunnel experiments were performed to clarify the relationship between outdoor and indoor air flows around and within a target cube model with several openings. Two surrounding building arrangements, namely square (SQ) and staggered (ST), were placed under the condition of a building coverage ratio of 25%. The results indicated that the wind speed near the windward openings on the streamwise faces showed 0.3 to the reference wind speed, whereas those on the lateral faces were less than 0.1; these numbers indicate that the opening positions significantly affect the mean indoor wind speed. Furthermore, the temporal fluctuations of velocities near the opening demonstrated that the introduction of the flow is significantly affected by turbulent flow due to the surrounding buildings. In addition, correlation between the outdoor and indoor air flows was observed. The highest correlations were obtained for both opening conditions with a certain temporal delay. This result indicates that indoor air flows become turbulent because of the turbulent flows generated by the surrounding outdoor buildings; however, slight temporal delays could occur between indoor and outdoor air flows. Although the present study focuses on the fundamental turbulent characteristics of indoor and outdoor air flows, such findings are essential for accurately predicting the ventilation flow rate due to turbulent air flows for sheltered buildings

Modulation of the atmospheric turbulence coherent structures by mesoscale motions

The precise modeling of turbulence is indispensable for weather forecasting and environmental heat-removal and pollution-dispersion assessment. Models rely on correlations derived from field measurements. Unfortunately, the readings are usually contaminated with mesoscale motions which alter turbulence statistics and mislead the characterization of turbulence coherent structures, the drivers of the heat and mass transport process. This article depicts the interference of the mesoscales in turbulence statistics and coherent structure detection. Atmospheric measurements were taken at EKOMAR on the east coast of Malaysia. Two ultrasonic anemometers at heights of 1.7 and 12 m were utilized. Twelve samples from the convective atmospheric boundary layer were analyzed. Spectral and auto-correlation analysis were conducted to assess the weight of the mesoscales relative to the shear coherent structure scales. The structure inclination angle and timescale were calculated for the wind speed signal with and without the mesoscale scales filtered out. It was found that these interfering structures largely shifts the calculated length- and time-scales of the coherent structures. The improper filtration of the signal may delete part of the coherent structures and hence worsen the situation

Spatiotemporal analysis on the squatter development: a case study in Kampung Baru, Kuala Lumpur

As a Malay Agricultural Settlement gazetted in 1900, Kampung Baru (Kuala Lumpur) has been subjected to prolonged national interests (e.g. economic, social, environment and politic) and it is pressured by modern and future development. Theoretically, the Urban Heat Island (UHI) phenomenon is prevailed in the area, but only few studies have been carried out to address the issues in a quantitative manner. Therefore this study aims at providing better insight the UHI phenomenon in Kampung Baru (Kuala Lumpur) and explicitly examining the temperature pattern and its vicinity effects. The field survey was conducted to collect the temperature and relative humidity using mobile survey method. Additionally, the fixed weather station had been installed starting from October 2013 in the study area and the data were compared with the rural area data from the Malaysia Meteorological Department. Thus, the intensity of UHI was estimated based on the difference between urban and rural temperature. In conclusion, this research quantified the UHI in Kampung Baru, and it can be a critical input to the urban development planning in a changing environment

In-situ Measurement of Pedestrian Outdoor Thermal Comfort in Universities Campus of Malaysia

The present study is intended to evaluate an outdoor thermal comfort at two universities campus in Malaysia. Field measurement and questionnaire survey were conducted simultaneously to assess the microclimatic condition and pedestrian thermal sensation. A total of 3033 samples were collected at seven different sky view factor (SVF) values that range from 0.2 to 0.9. The physiological equivalent temperature (PET) was estimated to evaluate outdoor thermal comfort. It was observed that at a highly shaded area (SVF < 0.35) the respondent’s thermal sensation vote (TSV) are neutral (> 25%), acceptable for thermal acceptance vote (TAV) (> 50%) and no change (> 50%) for thermal preference vote (TPV). For moderate shaded (0.35 ≤ SVF ≤ 0.70) TSV was voted as hot (> 25%), acceptable for TAV (40%), and prefer slightly cooler for TPV (>50%). For less shaded area (0.70 < SVF ≤ 1), TSV was voted as hot and very hot (> 25%), acceptable for TAV (>40%) and prefer slightly cooler for TPV (> 40%). Moreover, the PET value increases simultaneously with the increase of SVF. Results thus suggest that at any given activities such as sitting, walking, and standing also caused effects slightly on the way people thermally perceive it during the on-campus daytime

Design and fabrication of FIV apparatus for classroom lecture demonstration

Flow induced vibrations (FIVs) of a cylinder commonly occur where a cylindrical body is exposed to a flow. However, their appearance and behavior are widely diverging depending on flow condition and characteristics of cylinder with its supporting structure, making their prediction quite difficult. Hence, many serious accidents have been caused so far for structures and machines. Most typical and well-known FIVs in this category are the Karman vortex induced vibration (KVIV), the galloping and the torsional flutter. In this work, a very simple and convenient apparatus is designed and made to reproduce these three vibrations. This apparatus will be effective in a classroom lecture of fluid mechanics by demonstrating how easily the FIVs can be induced by a simple apparatus, even though their prediction remains to be important but difficult problems to be solved in practical engineering

Load and Household Profiles Analysis for Air-Conditioning and Total Electricity in Malaysia

Load profile of household air-conditioning (AC) and total electricity consumption is essential to increase the stability of the energy demand on the grid. Therefore, field measurements on time series data of total and AC electricity consumption from 20 households were conducted from March 2016 to August 2017. The questionnaire survey was carried out simultaneously to grasp the profile of each family. The average total daily and AC consumption were 14.5 kWh/day and 3.9 kWh/day, respectively. The average hourly electricity consumption for total was 0.6 kWh/hour, meanwhile for AC was 0.2 kWh/hour. About 20% of the total peak demand was contributed by the consumption of AC. The indoor air temperature was measured in the bedroom (BR) when AC was switched ON and OFF with an average of 27 ∘C and 29 ∘C, respectively. However, the indoor air temperature in the living room (LR) was 2∘C and 1∘C higher if compared to BR for both conditions. Based on the questionnaire survey, 92% of the occupants preferred a temperature setting below than the level recommended by the Malaysian standard i.e., 24 ∘C. These results might be beneficial to understand the occupant behavior of electricity demand in Malaysia for designing smart grid energy systems in the future

Short-Term Measurements of Household Electricity Demand During Hot Weather in Kuala Lumpur

The aim of this study was to conduct short-term measurements on household electricity demand under hot weather conditions in a residential area in Kuala Lumpur. The measurements included total and air conditioner (AC) electricity consumption of 10 households in an apartment building as well as outdoor air temperatures, which were collected from March to May 2016. Results indicated that the average AC electricity consumption contributed to a major portion of total household electricity consumption, which ranged from 19.4 to 52.3% during the measurement period. Additionally, 1-minute interval time series data indicated household energy consumption more accurately than 30- or 60-minute interval

A review of cross-cultural analysis on energy behaviour consumption in residential building between Malaysia and Japan

Energy saving behaviour is unique and complex. The role of culture in shaping energy usage patterns in Japanese and Malaysian households is focused in this review study. The Japanese is much better in terms of energy savings behaviour in order to decrease the emission of the country. It will help to sort out energy usage patterns that are rooted in the Japanese culture and thus resistant to rapid changes in technological aspect of buying household appliances. The Japanese daily use of appliances is more effective and efficient than Malaysians who make up one-third of the Japanese population. The impact of occupant behaviour on energy consumption is therefore crucial to be investigated. The findings from this investigation can develop an improved green technology usage for sustainable development in Malaysia