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A mosque is a place for worship and religious activities that are traditionally built with a typical design and shape with a dome and minaret as its traditional symbols. The most basic design of a mosque is a simple single-storey rectangular-shaped building with a prayer hall inside it. Design in the past was influenced by social and cultural aspects. However, regional and climatic differences have led to thermal discomfort and unnecessary energy use if the mosque is not properly designed. Therefore, there is a need to consider comprehensive planning and review for passive design to avoid thermal discomfort and excessive use of energy. Assyafaah Mosque in Singapore is one example that considers sustainable elements in its design. While Singapore is located very near to the hot equatorial line, many passive and green features have been integrated into the design and construction of the mosque, and this made it possible to achieve an acceptable thermal condition according to the adaptive and PMV thermal comfort model. The design maximizes the potential of naturally ventilated design with other passive strategies which allow for both thermal comfort and energy saving. This paper aims to study the impact of natural ventilation and other passive design decisions on the thermal comfort of the Assyafaah mosque in a hot and humid climate.

The increasing demand of reducing energy consumption in buildings has led to the implementation of insulation material in roof assemblies to reduce heat gain through the roof. This paper investigates the thermal performance of reflective insulation and radiant barrier systems in a gable roof assembly by using computational fluid dynamics (CFD) simulation. In the first part of the paper, the experimental measurements using test huts under actual outdoor environment were detailed. The CFD simulation was then conducted and the results obtained from the simulation were validated against the experimental measurements. In the second part paper, the validated CFD model was then used to evaluate the reduction of heat flux transmission through the roof and the thermal resistance (RSI value) of the roof assemblies for various roof configurations, which are the thickness of reflective air space, the roof pitch and the roof material. The study showed that increasing the reflective air space thickness from 25 mm to 100 mm has increased the total RSI by 26% for both roof pitch of 30° and 45°. Besides that, increasing the roof pitch of the roof from 30° to 45° showed that biggest impact on the thermal performance of the roof, as the RSI value increases by 30%. In terms of roof tiles material, only small difference was observed in terms of thermal resistivity when switching the roof tiles material between clay tiles and concrete tiles.

In this paper, a performance analysis of a photovoltaic (PV) tracking system is conducted, to evaluate its performance based on field data measurement. A dual-axis tracker with smart algorithms called maximum light detection (MLD) applied in the solar energy generation system is analyzed. In a tropical country that having a massive cloud cover throughout the year, the sky condition is categorized as sunny, intermittent and gloomy. The comparative results show that the system with MLD tracker improved the energy generation significantly all sky conditions.

Hospital buildings are the main energy users among government facilities which require substantial energy reduction to save its annual operational costs . At the same time, the Ministry of Health Malaysia has set a policy for all hospitals to achieve green building certification, which in line with its global commitment to conserve the environment. Energy efficiency is an important component in every green building rating tool because of its high potential on point scoring. Thus, there is a need to find the most appropriate method to explore energy saving opportunities as much as possible. The overall aim of this article is to evaluate the potential for energy saving in public hospital using a systematic approach. Three methods are applied in this approach which involved energy audit, empirical evidence and simulation works. Energy audit predicts that the chiller system provides the highest energy saving amount of 1,535,175.40 kWh/year (45.54 %) with discounted payback period of 7.15 years. A chiller retrofit measure was implemented as pilot project and the predicted energy savings were validated by empirical evidence. The actual energy saving of 1,688,347.02 kWh/year (50.08 %) was obtained from the chiller system retrofit and slightly higher than what was predicted with discounted payback period of 6.29 years. Apart from active measures, many more energy saving potentials can still be explored through passive strategies. Simulation method is used to establish energy baseline as the basis for predicting energy saving potential for passive strategies that cannot not be measured through energy audit. The combination of these methods is essential to optimize the potential of energy saving through active and passive strategies that have so far has never been implemented in any public hospital in Malaysia.

The objective of this research was to obtain thermal performance data for reflective insulations in a South East Asia environment. Thermal resistance data (RSI, m2 ⋅ K/W) for reflective insulations are well established from 1-D steady-state tests, but thermal data for reflective insulation in structures like those found in South East Asia are scarce. Data for reflective insulations in South East Asia will add to the worldwide database for this type of energy-conserving material. RSI were obtained from heat flux and temperature data of three identical structures in the same location. One unit did not have insulation above the ceiling, while the second and third units were insulated with reflective insulation with emittance less than 0.05. RSI for the uninsulated test unit varied from 0.37 to 0.40 m2 ⋅ K/W. RSI for a single-sheet reflective insulation (woven foil) varied from 2.15 to 2.26 m2 ⋅ K/W, while bubble-foil insulation varied from 2.69 to 3.09 m2 ⋅ K/W. The range of RSI values resulted from differences in the spacing between the reflective insulation and the roof. In addition, the reflective insulation below the roof lowered attic temperatures by as much as 9.7° C. Reductions in ceiling heat flux of 80 to 90% relative to the uninsulated structure, due to the reflective insulation, were observed.

One of the effective measures to save cooling energy in countries with an equatorial climate like Malaysia is through the use of roof thermal insulation. This paper focuses on the economic evaluation of commonly used thermal insulation solutions for a typical hypermarket roof in Malaysia. Eight commonly used thermal insulation systems have been identified and evaluated. In order to find the most cost-effective thermal insulation measure, three types of economic evaluation methods i.e. life-cycle savings, discounted payback period and internal rate of return have been used. All the eight thermal insulation systems were ranked accordingly to these three methods It has been found that insulation system using small bubble aluminium foil ranked first with the highest life-cycle savings, internal rate of return and the shortest payback period. Sensitivity analyses have also been carried out to identify the effects of changes in the key parameters for example cost of capital and lifetime period have on the evaluation results. The analyses show that small bubble aluminium foil is least susceptible to fluctuation of these two parameters relative to other examined insulation materials.

The price of carbon emitted by thermal plants has always been a favorite topic of researchers and policy makers. A substitute price for CO2 is calculated in this study based on real-time payments through government tariffs. These payments aim to mitigate CO2 emission caused by unregulated electricity generation. The total CO2 produced by the thermal plants of 10 European countries is shown in this study. The government's payment for each technology is utilized to clear the final CO2 abatement cost. The substitute price of avoiding CO2 emission (SPAC) for each technology and country is estimated. SPAC is basically the price that each country pays to avoid producing CO2. The conducted survey shows that the SPAC of the 10 European countries ranges from 63 to 2951 Euros depending on the type of technology used and the country's policy. Results confirm a competitive payment by governments only for German and UK hydro and UK wind technologies. Comparison of the countries’ payments for renewable energies and CO2 market price shows that governments incurred an inefficient payment of liquidity as a carbon mitigation policy.

Rapid growing of energy use has raised critical concerns over energy supply difficulties and negative environmental impacts globally and among ASEAN countries. Malaysia is experiencing a high average annual energy demand growth rate of approximately 2.3% which large portion of that energy is used by office buildings. Under the hot-humid climatic conditions in Malaysia, high-rise office buildings with large or fully glazed facades are facing a major problem of overheating due to high solar radiation through the glazed facades. This has caused high cooling energy requirements. The aim of this study is to investigate the potential of three types of shading devices on cooling energy savings when applied at different facade orientations. The aim also extends to investigations on different cooling energy savings when shading devices are applied on facade glazing with different configurations and thermal performances. This was done through a case study of a high-rise office building in Kuala Lumpur, Malaysia using IES (VE) building thermal simulation software. Twenty simulation building models were applied with different shading devices at different facade orientations and with high and low performance facade glazing. The simulation results indicate that high-rise office buildings in Malaysia use approximately 45.9% of total building energy for cooling purposes. The results also suggest that use of various shading devices on low-e double glazed facades will result between 1.0% and 3.4% annual cooling energy savings, depending on the types of shading devices and facade orientations. The estimated annual cooling energy savings increase to between 5.0% and 9.9% when the shading devices are applied to all orientations of low-e double glazed facades. The estimated annual cooling energy savings further increase to between 5.6% and 10.4% when the facade glazing is replaced by single clear glazing. This study recommends prioritizing shading devices on the East and West facades for optimized annual cooling energy savings. The simulation results show that egg-crate shadings are able to produce the highest annual cooling energy savings compared to vertical shadings and horizontal shadings. It is recommended to use shading devices on low performance glazing compared to high performance glazing since the energy savings are more significant when shading devices are used on low performance glazing. In conclusion, the use of shading devices is more effective in achieving cooling energy savings compared to the use of high performance glazing under the hot-humid climate of Malaysia.

The concerns over depletion of fossil fuel resources and negative environmental impact arising from energy generation have prompted increasing attention on the use of thermal insulation in building energy conservation. This article strives to make an overall review of reflective thermal insulation system which focuses on radiant barrier and reflective insulation. The main parameters in evaluating the performance of radiant barrier system are reduction of heat flux, thermal load and attic air temperature. Based on studies, radiant barrier is effective in reducing heat flux, thermal load and attic air temperature during summer and to a lesser extent during winter. Researchers found that on average radiant barrier installed on attic space could reduce heat flux by 26% to 50% and cooling load by 6% to 16% during cooling seasons. Fundamentally, reflective insulation system works under enclosed reflective airspace(s) and thus its key thermal performance is usually measured by level of thermal resistance produced by the enclosed air cavity. Although many research works have been conducted on reflective insulation, there are still many uncertainties exist in predicting the correct resistance value. The most commonly used method to measure the resistance value is guarded hot box which can simulate large-scale assemblies that are closer to real conditions. Heat flow meter was used to test smaller specimen. Calculation using theoretical approach provides a more simplified method to predict the resistance value. However, this method may tend to over predict the value given the limitations from which its basis was formed. It was discovered that emittance of upward facing reflective foil used in both radiant barrier and reflective insulation system are also susceptible to degradation due to dust accumulation, moisture condensation and corrosion. Hence, it is imperative to ensure a low-emittance surface for a sustainable performance of both insulation systems in the long run.

The Philippines is located in Southeast Asia characterized by a tropical weather and high level of rain which makes this country as a high potential in generating electricity by hydro-power and wind.Solar potential at this country is one of the highest in the world.All these opportunities help the country to replace clean and green renewable energies instead of fossil sources which will reduce the amount of produced carbon dioxide significantly.This study illustrates the Philippines attempts for encouraging investors for investing in renewable energies.Meanwhile the cost of avoiding carbon by generating electricity by solar panels estimated and compared with the other parts of the world.The conclusion shows despite of all opportunities in the country still cost of avoiding CO2 by using solar panels in the Philippines is higher than average world price.

Increasing the country population and the trend of industrialization caused increasing Malaysia’s electricity consumption. Light Emitting Diode (LED) is a new sustainable technology that has taken over the conventional lighting in built and environ ment in a few developed counties in the recent years. However, Malaysia is left behind in using th is technology due to unfamiliarity of the decision makers on its advantages. The research is using a m ixed qualitative and quantitative method for finding advantages of LED for lighting the streets and built and environment. A group of scholars traveled to Canada and USA and observed seven factories and interviewed 40 professional of LED and discussed use of this technology in the context of Malaysia. The result of those observation and interview is synthesized and presented in this pape r. The conclusion of this research confirms despit all LED advantages, it is very high cost in term of rep lacement, primary investment and maintenance.

Quantum dots (QDs) semiconductors exhibit size-dependent Opto-electronic properties and customizable bandgaps that can be engineered to match the solar spectrum [. Organometallic synthetic approach relies on the injection of organometallic precursor into a pyrolyphic mixture at elevated temperature sufficient enough to initiate particle growth. This approach entails precise control of temperature gradient [. Organometallic reagents injected into a heated non-coordinating octadecene (ODE) were compatible with oleic acid (OA) that was used to protect the CdSe QDs against oxidation and emission loss. ODE is stable in air and has a low melting point (below 20 oC) making it easier to be handled at room temperature. Its high boiling point (about 360 oC) coupled with its inert nature, less toxicity, low cost and good dissolving power makes it an ideal solvent for the growth of CdSe QDs [3,4,5 and 6]. However, QDs synthetic methods differ and relies on how the thermodynamic properties of the reactant mixtures are varied. QDs nucleation growth depicted the underlying processes occurring in aqueous solution and the need to control thermodynamic variables such as reaction time and temperature of the reactants as well as non-thermodynamic variable such as stirring speeds.

Malaysia envisages becoming a developed nation by 2020. To sustain industrial expansion and attract investments Malaysia must introduce new energy strategies. These strategies should also moderate carbon footprint. The new energy strategies introduced by the government are (i) installation of nuclear power plant by 2021, (ii) import of Sarawak hydropower from 2015 and (iii) enhancement of use of renewable energy from 2015. In this paper we analyze the cost and resulting carbon footprint of energy expansion for 12 energy scenes (inclusive of new strategies) to produce electricity for Peninsular Malaysia for the period 2009–2030. We use a computer model MESSAGE to provide optimization. The best strategy is for the following accumulated percentage of energy resource in the fuel mix: 49.3% (natural gas), 28.4% (coal), 4.06% (nuclear), 2.98% (hydropower), 4.45% (renewable), 10.82% (import hydropower). The minimum cost of expanding this strategy from 2009 until 2030 is USD6.090B. The CO 2 emission index of this strategy is 0.329 t/MWh. The accumulated carbon dioxide emission for this period is 1825.96 Mton CO 2 eq.

Located in Southeast Asia, Indonesia and the Philippines are characterized by a tropical climate and high amounts of rainfall that render their high potential for hydro-power and wind energy deployment. The volcanic geography of both countries also indicates their high geothermal potential compared with that of other countries, and their high solar radiation level makes them suitable areas to establish power plants. The present study is an archival-statistical overview of the potential generation of renewable energy in Indonesia and the Philippines and the implementation of the Feed-in-tariff (FiT) policy. This research focuses on the challenges encountered by politicians and policymakers and confirms the insufficient production of energy from wind, solar, and bio-gas sources despite the potential and the attempts to deploy FiT. Results show that the role of the government in providing support to investors is not clear in both countries. In addition, inflation rates have not been calculated. However, FiT has benefitted both countries by preventing degression during the primary years.

A field study on thermal comfort assessment was carried out in a large-scale hospital in a tropical climate. To evaluate thermal comfort, both subjective and objective measurements were performed. The data were collected from 10 various thermal zones of a hospital. In each zone the predicted mean vote (PMV) was calculated based on the Fanger theory. In addition, the thermal sensation vote (TSV) was calculated according to the survey to find the relationship between the Fanger model (PMV) and the occupants’ votes. In this study a strong relationship between PMV and TSV was found when R 2 = 0.88. According to this correlation the neutrality point shifted to +0.7 on the seven-point ASHRAE scale. Moreover, the neutral effective temperature (ET*) was calculated based on the TSV and PMV of 23.4 °C and 21.3 °C, respectively, indicative of compatibility with the adaptive theory. The results also demonstrate that the preferred effective temperature according to subjective assessment in this case study is 20.2 °C. This analysis revealed that to the respondents of this study in 10 thermal zones the neutral temperature point is higher than global standards, while the preferred temperature is lower than standards and the neutrality point.

Hospital energy consumption is relatively high, while saving energy and reducing cost comprise one of the most important challenges considered by the majority of building designers, engineers, and decision makers. An end-use energy analysis was conducted in a large-scale hospital in Malaysia to identify energy apportioning and energy end use in the areas of air conditioning, lifts, lighting, equipment, and others. The analysis was carried out by assessing the collected desktop and field data as well as some calculations. The Building Energy Index (BEI) was calculated to compare the consumption levels in the selected hospital, which is a typical hospital building, with other hospitals in Malaysia as well as low energy buildings and Malaysian standards. The main energy source in this case study was electricity with a supply of around 75 % of total energy consumption. The current average annual electricity consumed by this hospital was 44,637,966 kWh, out of which 63 % was used by air conditioning systems and 17 % by lighting. The BEI comparison revealed that the calculated BEI of 384 kWh/m2/year is significantly higher than Malaysian rating systems and standards which recommend 200 kWh/m2/year for hospitals, 135 kWh/m2/year for commercial sectors, and is higher than previously observed hospitals with a BEI of less than 300 kWh/m2/year.

Wind-induced natural ventilation tower is one of the effective devices in enhancing indoor air quality. It can be designed and integrated as part of building components. This paper investigates the performance of various design configurations of a wind-induced natural ventilation tower with the focus on Venturi-shaped roofs and towers. The Venturi-shaped roofs and towers are used to create negative pressure in order to enhance the extraction air flow rates of the wind-induced natural ventilation tower. The computational fluid dynamics (CFD) method is used to analyse each of the design configurations. The different design configurations are based on roof tilt angles, roofs' shapes, tower heights and shapes of the wind-induced natural ventilation tower. The parameters analysed are extraction air flow rates and air flow pattern. Based on the CFD simulation results of various design configurations, the ‘biconcave’-shaped wind tower has the best design configuration with 14 568.66 m3/h extraction air flow rates at 0.8 m/s external wind velocity.

Sustainable energy system design offers credible and innovative strategies to overcome environmental energy crises. Solar walls offer feasible technique for the exploitation of directional flow of heat in buildings. This article reviewed state-of-the-art concepts, applications and significance of solar walls for energy savings in buildings. Detailed operational framework of various solar-wall configurations, technology and efficiency as building component was discussed. Need for this sustainable energy design in buildings and constraints associated with their realisation were reported to aid proposed future research work.

Thermal energy storage is very important to eradicate the discrepancy between energy supply and energy demand and to improve the energy efficiency of solar energy systems. Latent heat thermal energy storage (LHTES) is more useful than sensible energy storage due to the high storage capacity per unit volume/mass at nearly constant temperatures. This review presents the previous works on thermal energy storage used for air conditioning systems and the application of phase change materials (PCMs) in different parts of the air conditioning networks, air distribution network, chilled water network, microencapsulated slurries, thermal power and heat rejection of the absorption cooling. Recently, researchers studied the heat transfer enhancement of the thermal energy storage with PCMs because most phase change materials have low thermal conductivity, which causes a long time for charging and discharging process. It is expected that the design of latent heat thermal energy storage will reduce the cost and the volume of air conditioning systems and networks.

Green building and sustainable architecture are new techniques for addressing the environmental and energy crises. Trombe walls are regarded as a sustainable architectural technology for heating and ventilation. This article reviews the application of Trombe walls in buildings. The reviews discuss the characteristics of Trombe walls, including Trombe-wall configurations, and Trombe-wall technology. The advantages and disadvantages of this sustainable architectural technology have been highlighted, and future research questions have been identified.

A field study on assessing thermal comfort has been performed on one of the large-scale hospitals in Malaysia, a country where the climate is classified as hot-humid. The main objective of this study was to examine the comfort criteria by American Society of Heating, Air conditioning & Refrigeration Engineers, US (ASHRAE) standards in hot-humid regions and also to find the correlation between predicted mean vote (PMV) according to Fanger’s theory and thermal sensation vote (TSV) according to occupant votes. Therefore, both objective and subjective data was collected in this hospital, and this study’s results have confirmed that the preferred temperature is not necessarily in compliance with a neutral temperature, and people in hot-humid areas would prefer cooler environment to neutral temperature. In addition, by analyzing linear regression, a strong correlation between PMV and TSV was found while R2 = 0.950, and also the neutral temperature point in this field study was around +0.75 on the seven-point ASHRAE thermal sensation scale.

A field study on energy efficiency by lighting retrofitting has been carried out in one of the large-scale hospitals in Malaysia. The main objectives of this study were to find energy and cost savings after light-emitting diode (LED) tubes replacement in the hospital as well as the emission reduction and payback period time. The results have showed that, by applying this strategy, the energy cost saving will be almost US $ 2 million after 3 years with more than 5000 t of CO2 reduction per year as well as 2.9 years is resulted as payback period time.

The modeling of the performance of a one refrigeration ton (RT) solar assisted adsorp-tion air-conditioning refrigeration system using activated carbon fiber/ethanol as theadsorbent/adsorbate pair has been undertaken in this study. The effects of hot water,cooling water, chilled water inlet temperatures, and hot water and chilled water flowrates were taken into consideration in the optimization of the system and in the design ofthe condenser, evaporator, and hot water storage tank. The study includes analysis of theweather data and its effect on both the adsorption system and the cooling load. This isthen followed by estimation of the cooling capacity and coefficient of performance (COP)of the adsorption system as a function of the input parameters. The results of the modelwill be compared to experimental data in a next step. [DOI: 10.1115/1.4027964]Keywords: solar energy, adsorption air conditioning, activated carbon fiber/ethanol,cooling load