ORCID Profile
0000-0002-5324-9091
Current Organisation
Universiti Putra Malaysia
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Publisher: SAGE Publications
Date: 08-07-2009
Abstract: Conventional tropical building designs are experiencing a new paradigm in their environmental response to improve lighting ambiance and occupants’ visual comfort through the exploitation of daylighting. However, it is important for architects to understand that flaws in daylighting strategies could lead to disadvantages as they could hinder vision, cause discomfort, increase interior heat gain, and result in excessive energy demands. The objective of this study was to assess how occupants’ perceived their visual conditions through daylight ratio and luminance level measurements. Measurements were conducted throughout a 2-month period starting from 12th May to 3rd July 2007. Three case studies were conducted at typical Malaysian hostels located in the Klang Valley. Those selected were: the Twelfth Residential College, Universiti Malaya (H1) the Eleventh Residential College, Universiti Putra Malaysia (H2) and Murni Student Apartments, Universiti Tenaga Nasional (H3). The daylighting source in all these case studies were from side-lit windows. Overall, the findings suggested that occupants were at ease with the level of daylighting available in their rooms even though rooms that were shaded by projecting balconies (i.e.,: H1) were dimmer than the rooms that were not shaded (i.e.,: H2 and H3).
Publisher: SAGE Publications
Date: 08-2008
Abstract: The need to design for low energy consumption dwellings has induced Malaysian architects to design naturally ventilated high-rise hostels (HH), near the capital, Kuala Lumpur. Objective and subjective measurements for thermal comfort investigations were conducted in two high-rise university hostels located in Universiti Malaya, Petaling Jaya (HH1) and Universiti Putra Malaysia, Serdang (HH2) from May 12 to June 19 in 2007. Eighteen rooms located at first, fifth, and top floor of each HH were measured for different orientations. The measured rooms were naturally ventilated with ceiling fans. Thermal comfort variables were measured prior to the subjective measurement. A total of 208 student occupants responded to the questionnaire. Subjects with 6 months and over living experience in those HH were selected randomly. This study was aimed: (1) to assess the indoor microclimate of each naturally ventilated HH, (2) to identify student occupants' thermal sensation during rainy and clear day, and (3) to simulate the neutral operating temperature for rooms in naturally ventilated high-rise hostels. Findings revealed that room in HH1 which is located on high land and shaded has a more constant operating temperature distribution than rooms in HH2 that is located on lower land and un-shaded. Operating temperature ranges for HH1 and HH2 were 27—31°C and 26—41°C, respectively. Results suggested that there is also a possibility that thermal comfort is achievable in shaded naturally ventilated hostels with a window-to-wall ratio of 0.35 where the internal—external relative humidity is above 70% RH, especially in south-facing rooms.
Publisher: Elsevier BV
Date: 10-2014
Publisher: Elsevier BV
Date: 10-2009
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.APERGO.2015.12.008
Abstract: The study was done to identify affective and sensory responses observed as a result of hysteresis effects in transient thermal conditions consisting of warm-neutral and neutral - warm performed in a quasi-experiment setting. Air-conditioned building interiors in hot-humid areas have resulted in thermal discomfort and health risks for people moving into and out of buildings. Reports have shown that the instantaneous change in air temperature can cause abrupt thermoregulation responses. Thermal sensation vote (TSV) and thermal comfort vote (TCV) assessments as a consequence of moving through spaces with distinct thermal conditions were conducted in an existing single-story office in a hot-humid microclimate, maintained at an air temperature 24 °C (± 0.5), relative humidity 51% (± 7), air velocity 0.5 m/s (± 0.5), and mean radiant temperature (MRT) 26.6 °C (± 1.2). The measured office is connected to a veranda that showed the following semi-outdoor temperatures: air temperature 35 °C (± 2.1), relative humidity 43% (± 7), air velocity 0.4 m/s (± 0.4), and MRT 36.4 °C (± 2.9). Subjective assessments from 36 college-aged participants consisting of thermal sensations, preferences and comfort votes were correlated against a steady state predicted mean vote (PMV) model. Local skin temperatures on the forehead and dorsal left hand were included to observe physiological responses due to thermal transition. TSV for veranda-office transition showed that no significant means difference with TSV office-veranda transition were found. However, TCV collected from warm-neutral (-0.24, ± 1.2) and neutral-warm (-0.72, ± 1.3) conditions revealed statistically significant mean differences (p < 0.05). Sensory and affective responses as a consequence of thermal transition after travel from warm-neutral-warm conditions did not replicate the hysteresis effects of brief, slightly cool, thermal sensations found in previous laboratory experiments. These findings also indicate that PMV is an acceptable alternative to predict thermal sensation immediately after a down-step thermal transition (≤ 1 min exposure duration) for people living in a hot-humid climate country.
Publisher: Penerbit UTM Press
Date: 31-10-2016
DOI: 10.11113/.V78.8041
Abstract: Vernacular houses using indigenous building materials have shown to be a good strategy for sustainable energy consumption without compensating the occupant’s indoor thermal comfort. Bamboo has been identified as the most used building material for vernacular houses in South-East Asia region. However, very little investigation has been conducted to study the passive performance of a bamboo house in maintaining indoor thermal comfort. This study compares the indoor microclimate conditions using thermal comfort Predicted Mean Vote and Predicted Percentage of Dissatisfied models (PMV-PPD) developed by American Society Heating, Refrigerating and Air-conditioning Engineers (ASHRAE) between indigenous bamboo house (H1) and modern brick house (H2) at a village located in the Ulu Gombak Forest Reserve, Selangor. Observations on environmental factors and predicted thermal comfort satisfaction level between day and night times were also taken into consideration. The findings suggest that the use of bamboo plus other vernacular house design features such as raising a house on stilts, located on hilly site and providing air permeability in H1 can lead to a thermally comfortable indoor environment, particularly during night time.
Publisher: Emerald
Date: 05-11-2022
DOI: 10.1108/SASBE-08-2020-0122
Abstract: Recent studies have found that the high demand for air-conditioning usage in tropical countries has affected the thermal adaptability of building occupants to hot weather, and increased building energy consumption. This pilot study aims to investigate the effects of transient thermal environment changes on participants' sensory and physiological responses. The change of thermal perceptions, skin temperatures and core temperatures when exposed to transient thermal environments (cool-warm-cool) from 10 college-aged female participants during a simulated daily commute by foot to class in a tropical university c us were investigated. Subjective measurements were collected in real-time every 5 min. The main finding suggests that participants were acclimatised to cool air-conditioned indoor environments, despite exhibiting significant mean skin temperature differences ( p 0.05). In addition, exposure to uniform air conditioning from 17 to 18°C for 20 min was thermally unacceptable and reduced concentration during given tasks. The study focused on thermal comfort conditions in a uniform air-conditioned lecture hall, and the findings may not be applicable for residential and other private building spaces. The distinct temperature difference between indoor and outdoor in the tropical built environment resulted in high dependence on air-conditioning usage. The building occupants' well-being and energy conservation implications of the findings are discussed. This study provides the platform for discussion on the dynamics of occupants' comfort level and adopting a more variable thermal environment in tropical spatial transient thermal environments among architects and building management system managers. The findings from this study may contribute to the Malaysian Standards for Energy Efficiency and Use of Renewable Energy for Non-Residential Buildings (MS1525). A knowledge gap in adaptive thermal comfort due to exposure from transient conditions in tropical university c us for energy efficiency revision has been investigated.
Publisher: Elsevier BV
Date: 02-2011
Publisher: Public Library of Science (PLoS)
Date: 29-11-2018
Publisher: Elsevier BV
Date: 09-2013
Publisher: Penerbit UTM Press
Date: 25-06-2023
DOI: 10.11113/JURNALTEKNOLOGI.V85.15124
Abstract: With over a third of global energy used for building construction and operation, an optimum design for building envelopes is essential to improve the energy performance of the existing buildings. This study revealed that typical government high-rise office buildings in Malaysia have an average Building Energy Intensity (BEI) of 161 kWh/m2/year before any upgrading works on the air-conditioning and mechanical ventilation (ACMV) systems were conducted. This value is higher than the recommended value in Green Building Index (GBI) for commercial office buildings (150 kWh/m2/year) and the Economic Planning Unit (EPU) standard for public buildings (140 kWh/m2/year). Therefore, this study employed a case study approach combined with calibrated computer simulation to determine the optimal building envelope retrofit strategies and identify the three levels of interventions (minor, moderate and major levels) with corresponding energy reduction. A validated model representing a typical existing government high-rise office building in Malaysia was chosen as the base case model for energy evaluation studies. The effectiveness of each level of intervention and its energy retrofit measures (ERMs) were evaluated compared to the actual electricity bills. The results showed that all levels of interventions provided between 4% to 7% savings in annual energy consumption. The proposed interventions demonstrated compliance with the BEI benchmark margins of the GBI and EPU standard, namely 116 kWh/m2/year (minor intervention level), 113 kWh/m2/year (moderate intervention level), and 110 kWh/m2/year (major intervention level).
Publisher: SAGE Publications
Date: 15-10-2015
Abstract: Investigation of occupant’s indoor environment influences can be identified through perceptive-cognitive aspects. Such an investigation leads to affective responses such as satisfied or dissatisfied, annoyed or not annoyed and hot or cold. This study investigates the perceptive-cognitive aspects of indoor environment among students who are staying in multi-storey accommodations in Klang Valley area, Malaysia. The students were asked to participate in the subjective survey in order to gather their indoor environment satisfaction votes. The objectives of this study are (1) to know how does the occupant of naturally ventilated multi-storey student accommodations respond to their indoor comfort whilst staying in an uncontrollable indoor atmosphere and (2) to identify what are the design features that contribute to the achievement of occupant’s overall indoor environment satisfaction. The main findings suggest that the uncontrollable indoor condition which occurred when occupants open their windows resulted in a more significant dissatisfaction vote toward indoor noise level in conjunction with warmer thermal sensation incidences. Moreover, despite the increasing indoor noise level recorded in rooms at higher floor levels, the findings show that room location, room orientation and shading ratio are not considered to influence the occupants’ overall indoor environment satisfaction and dissatisfaction.
Publisher: Elsevier BV
Date: 08-2013
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Nur Dahlan.