Buildings In Tropical Climate Research Articles

Optimation of Electrical Energy Generation for Low Rise Office Building with Folding-BIPV Concept

AbstractBIPV is an architectural concept that related to energy contribution. The system has functions of producing electricity as well as building form giver. The effectivity of BIPV depends on solar radiation received. Meanwhile, the solar radiation received depends on numbers of solar receiving area and environmental shading. Environmental shading will decrease the effectivity of BIPV. But, integrated configuration of folding-BIPV is expected to create more numbers of solar receiving area. The integrated configuration of folding-BIPV will create optimum BIPV, both in electrical generation and building form giver. Experiment to low rise office building in tropical climate is done by giving folding treatment. The experiment also considers about environmental shading. Evaluation is done by analyzing and optimizing the numbers and uniformity of solar radiation received. Simulation with ARCHIPAK 5.1 is used as experimental research tool. The simulation is used to calculate annual radiation received (kWh/m2) from folding-BIPV configuration. Manual calculation is used to calculate total annual radiation received (kWh) and uniformity percentage. Gradient diagram is used to do the optimation. Result of this research is an optimation of electrical energy generation in low rise office building which use folding-BIPV concept.

Investigating the feasibility of positive energy residential buildings in tropical climates

Positive energy residential buildings are houses that generate more energy from renewable sources than they consume while maintaining appropriate thermal comfort levels. However, their design, construction and operation present several critical challenges. In particular, the considerable load reductions are not always compatible with the increased level of comfort expected in modern houses. Tropical climates, meanwhile, should be more amenable to the implementation of positive energy houses for two reasons. Firstly, negligible heating is generally required as compared to colder climates, where the heating energy requirements are considerable. Then, renewable energy resources are usually abundant in tropical climates. This paper investigates the feasibility of positive energy residential buildings in the tropical island of Mauritius. A baseline model representing a typical Mauritian house is designed using DesignBuilder software. The energy efficiency of the model is then optimised by investigating a whole range of passive building design strategies, many of them adapted from vernacular architecture. Results reveal that the application of passive strategies such as shading, insulation and natural ventilation have precluded the need for artificial cooling and ventilation in the positive energy (PE) house. The resulting electricity consumption of the house decreases from 24.14 to 14.30 kWh/m2/year. A 1.2 kW photovoltaic system provides the most cost-effective solution to exceed the annual electricity requirements of the house.

Light Pipe Transporter for High-rise Office Building in Tropical Climate

Daylight has known to bring benefits for human, psychologically and physiologically. It also provides better indoor environment quality and thus increase the performance and productivity of office workers as stated by Paevere (2009). However, due to economic reasons, the current practice of using deep open plan building has cause a dent to having daylight in the interior spaces, which cause a dependency on artificial lighting. Hence, to provide daylight in deep interior, light distribution system is needed. Although so, according to Hansen (2003), most of the systems can only illuminate up to 8m-10m depth. Therefore, light pipe (LP) plays an essential role where it can illuminate up to 20m depth. LP’s efficiency depends on the 3 main components; collector, transporter and extractor. This research explores the effectiveness of horizontal LP through different type of transporter’s shapes which includes rectangular, triangular, square and semi-circle. Previous studies have shown differences of efficiency on the shaped while using vertical LP. This research’s analysis was done using a computer simulation, Integrated Environment Solution: Virtual Environment (IESVE), where DF of each shapes were compared to MS 1525:2007 benchmark. The viability of the software was also validated though an assessment with a physical scaled-model experiment that was conducted in an open car park in Universiti Teknologi Malaysia, Johor, Malaysia. The results from the simulation showed that semi-circle shaped transporter offered the same efficiency as rectangular shaped. These findings will promote the usage of LP in buildings as it decreases the costing for LP.

The fieldwork and control engineering studies on thermal comfort of occupants in a conventional office building in the tropics

This paper presents the fieldwork and the control system studies to examine and improve the thermal comfort of the occupants in a typical office building in Malaysia. The proposed control system works as the basis of adjusting the thermostat setting at a certain period of time with the degree of using the fuzzy logic. The thermostat of the central AC system has its set point fixed between 21℃ and 22℃, slightly below the range of 23–26℃ as recommended by Malaysian Standard MS1525. In order to maintain the room comfort, the occupants choose to switch OFF the central AC system for a certain period of time before it is switched back ON. It has been repeated at least once per working days. Therefore, the proposed control system is designed to overcome this practice. Pre- and post-comfort surveys have been conducted where the thermal comfort level of the occupants throughout this study is investigated. The air temperature ( Ta), globe temperature ( Tg), air velocity ( V) and relative humidity ( RH) in the occupied area were data-logged for continuous five working days. These data are used to compute the operative temperature ( Top) before new thermostat set points are generated, which indicates possible adjustment from the recommended set-point (24℃). The proposed thermostat setting has an error tolerance of 2.9% or less. As a result, the simulation results show an adjustment of the thermostat setting from 24℃ to 25.5℃, which successfully maintained the room temperature of the main office between 23.3℃ and 25℃. The relative humidity is maintained between 54.3% and 59.8%. Also, these outcomes have indirectly promoted an average increase of 22.6% in the thermal comfort satisfactory level of the occupants. Practical application: The new conclusions from the simplified thermostat control strategy, which can be customised according to the environment variables in the air-conditioned space (in this case the operative temperature and the relative humidity) or based on the preferences of the occupants, such as the level of thermal comfort that suits the current thermal environment in tropical climates, could be applied as an important guide for building services engineers and researchers. Their aims are to reduce energy usage in HVAC systems in the non-green office buildings in tropical climates while maintaining an adequate thermal comfort level, and thus, the performance and well-being of the office workers are improved.

Solvothermal synthesis of Sb:SnO2 nanoparticles and IR shielding coating for smart window

The buildings in tropical climate like Singapore get excessive heat gain throughout the year. Passive cooling can be achieved with IR-shielding coating by blocking the IR radiation from solar light. In this work, antimony-doped tin oxide (ATO) nanocrystals with diameter of 10nm were synthesized by solvothermal method. The Sb dopant concentration in ATO nanoparticles was optimized towards enhanced IR shielding properties. Sol–gel precursor was formulated with silanes and ATO nanocrystals. Transparent IR shielding coatings were coated on glass for smart window. The optical and IR shielding performance of the coatings were evaluated. By incorporating smaller ATO nanocrystals synthesized by solvothermal synthesis, the IR shielding performance of the coating was greatly improved as compared to that using larger commercial ATO nanoparticles. The IR shielding coating with synthesized ATO nanocrystals can block more than 90% IR while it can maintain more than 80% transmittance at the visible range. The solar heat gain coefficient (SHGC or G-value) of the coating with 10wt.% synthesized ATO nanocrystals is 0.68 for single layer structure, and decreases to 0.53 with double glazing structure while maintaining good visible transmittance of 60%.

A case study on feasible performance of a system combining an airbox convector with a radiant panel for tropical climates

This study presents feasible performance of a system that combines an airbox convector unit with a radiant chilled ceiling panel for application in tropical climates. This combined system offers the potential for effective cooling and dehumidification for buildings in tropical climates because the airbox convector not only dehumidifies indoor air but also enhances the mixed convective effect, which combines natural convection with mechanical forced convection, in indoor conditions with moisture gains caused by high infiltration rates or internal heat and moisture gains. This paper presents a case study that demonstrates the enhanced mixed convection effects of the combined system as well as the cooling and dehumidification performance of the system. This novel system not only reduces the moisture condensation risk but also contributes to maximizing the temperature of the cooling system as a low exergy technology.

Potential energy savings by radiative cooling system for a building in tropical climate

Abstract Nowadays, almost every building required a cooling system and most of them use active cooling, which normally operates using electricity generated from non-renewable fossil fuel. To achieve comfort, it is possible to utilize the natural environmental conditions to partially replace the active cooling energy requirements. This research attempts to investigate the correlation between the radiative cooling power and the temperature difference between the ambient and the sky. The potential of a radiative cooling system in Malaysia is evaluated as well. The radiative cooling system operates by using a flat-plate rooftop as a radiator to reject heat to the cooler nocturnal sky for cooling purposes. In addition, the radiative cooling potential is determined by using the climate data of 10 different locations in Malaysia. The study found that radiative cooling can save up to 11% of the power consumption for cooling purposes. This value is the same for all 10 locations in this country.

Strategy for Energy Efficient Buildings in Tropical Climate

Residential, commercial and industrial buildings share nearly one-fourth of the total electrical energy consumption in Thailand. The design of energy efficient buildings relies on a selection of appropriate techniques that complement the local climate. The two important elements to be considered carefully in tropical climate are the cooling technology and the electrical appliances (including the lighting system). In this paper, the focus is on the design of residential and commercial buildings in a tropical climate. The literature data and the results from a case study in Thailand are gathered and a strategy for energy efficient buildings is proposed. In short, the design of the building envelope, the cooling technology and the efficiency of the appliances are the crucial factors in reducing energy consumption. This investigation shows that building energy demand could be reduced by as much as 28% through the use of low thermal conductance material alone for a building wall.

Radiant Cooling with Dehumidified Air Ventilation for Thermal Comfort in Buildings in Tropical Climate

Radiant cooling is an alternative air-conditioning that havs been implemented successfully in high latitude regions. In tropical region as Thailand, radiant cooling is quite challenge due to its cooling performance being limited by high-moisture ambient air. This paper reports an investigation of radiant cooling in a tropical building. The study comprises full-scale experiments of a radiant cooling system with cool panels installed in a room of a laboratory building. A separate fan coil unit was installed to remove humidity of the ventilation air before suppluying it into the room. A software namely TRNSYS was used to model the systems in order to determine the heat extraction rate of the cool panels. Thermal comfort level in the room was evaluated by predicted mean vote (PMV) index. The results show that the radiant cooling is able to use for air conditioning for human comfort in tropical buildings. However, a sophistical system to control temperature of the chilled water supplied to the cool panels and the fan coil unit for the ventilation air dehumidification is inevitably required.

Assessment of Mould Growth for Library Buildings in Tropical Climates

This paper attempt to give a brief insight into the importance of studying mould growth in library building that relates to human health and causes of material deterioration to library materials. It’s significant to conduct this research because no similar study has carried out for a library building in Malaysia. Recent literature on the topics reviews to gain insight into developing a theoretical framework and research method. Likewise, the study also supports through pilot study questionnaires with 30 respondents from two different university libraries. The finding revealed to further investigation and mould growth assessment to be conducted that useful in protecting library materials and users health effects through environmental control.

Design and Simulation of Positive Net Energy Building in Tropical Climate

Design and Simulation of Positive Net Energy Building in Tropical Climate

Thermal design of air-conditioned building for tropical climate using admittance method and genetic algorithm

The present work proposes a methodology by combining building thermal model (admittance procedure) and an optimization technique (genetic algorithm) to allow a rapid energy efficient design for air-conditioned building in tropical climate. The developed model is meant for initial design stage of building, when the designer experiments with various ideas of forms and materials. Genetic algorithm (GA) is found a suitable optimization tool for design, because of its capability to handle different kinds of building design variables simultaneously and its approach towards the global optimum solution. The optimum solution, given by GA is further processed and validated through the building simulation software TRNSYS16.

The Environmental Performance of Air Conditioning Systems in Heritage Buildings in Tropical Climates

This paper examines the performance of retrofitting climate control systems focusing on air conditioning systems in refurbished old buildings in tropical climates. Data was gathered by means of investigation in the sequential steps of condition survey, space audit, ventilation systems, indoor/outdoor temperature reading and relative humidity (RH) measurement. The study raises several important issues relating to indoor environmental quality. Beyond the obvious aesthetical issues that are addressed here, the installation of air conditioning systems tends to create thermal instabilities and indoor environment imbalances in refurbished buildings. Furthermore, there is also a gap between the necessities of conserving the precious features of old buildings and the demand for better thermal comfort by the occupants. This study outlines the risks as well as making recommendations for future strategies.Keywords: Climate control, indoor environment, heritage buildings, Malaysia

A performance-based method for energy efficiency improvement of buildings

Building energy standards provide control over excessive use of energy in buildings, promoting energy efficiency and mitigating detrimental environment impacts brought by high energy consumption. The central objective of this paper is to develop correlations that will predict building heat gains and cooling energy consumption for commercial buildings in tropical climates. The energy performance index OTTV was first revised to obtain a new performance index, ETTV for commercial buildings. We developed new correlations to investigate the impact ventilation rates and building aspect ratios had on building cooling energy consumption. Comparing estimated and simulated results, we demonstrated good agreement, even for buildings having different aspect ratios. A study was further conducted to investigate the impact of weather conditions on the developed methodology for estimating the energy consumption of buildings. We employed a design-day weather file to provide simplicity, flexibility and greater ease of use. The design day concept is pivotal in providing key inputs to the cooling energy-estimating methodology yielding good agreement with DOE-2.1E simulated results. We believe that the results presented in this study will benefit building authorities in their pursuit of developing and refining stringent building energy standards in order to realize better energy efficient buildings.

An investigation of atmospheric turbidity of Thai sky

An investigation of atmospheric turbidity has been undertaken for tropical Thai sky. Values of turbidity indices, namely, Linke factor ( T L), Angstrom coefficient ( β) and illuminance turbidity factor ( T il) are derived directly from measurements taken by pyrheliometer, Volz sunphotometer and beam illuminance meter. Monthly mean values and frequency of occurrence of the value of each turbidity index are used to characterize variations of atmospheric turbidity. Simple polynomial equations are developed for computing values of Linke factor and illuminance turbidity factor as functions of solar altitude angle. Using the values of Linke factor and illuminance turbidity factor obtained from the models developed, values of beam normal irradiance and illuminance can be calculated accurately under clear sky conditions. Values of daylight illuminance are useful for daylighting application that contributes to energy conservation for buildings. Knowledge of the size of beam normal irradiance is useful for calculation of cooling load in air-conditioning buildings in tropical climate.

Bringing scientific knowledge from research to the professional fields: the case of the thermal and airflow design of buildings in tropical climates

The need for construction projects to be sustainable is becoming more widely recognised, partly because of diminishing world energy resources, and partly because recent world developments (for example, global warming and increasing oil prices) have made those involved in construction more aware of a new approach to building. We often hear now of buildings with a high environmental rating, of sustainable development, and of improved comfort. The stated objective is to construct comfortable buildings, which use little energy and produce little pollution. This desire on the part of construction project leaders has led to some problems amongst architects, engineers and university researchers who tend to work in isolation from each other. However, the only way to achieve an overall improvement in building design is by close collaboration between the various participants, from when the first sketch of the future building is made. Of course, this task appears difficult because these participants have different approaches, training and ‘tools of the trade’. This article aims to show that efficient cooperation between the professionals involved is possible. We will see that by producing an instructive working document, understandable by all and based on expert rules, it is possible to produce buildings which are adapted to the climate, and to spread the scientific knowledge to the more practical professions. We will illustrate our ideas by describing the methodology we used for a building project in the tropics. Finally, we will present a summary for the period 1997–2001 and will show the impact that such collaborations have had on the design of buildings in tropical climates.

Case Study of Building Diagnostics: Acoustic Post-Occupancy Evaluation of Buildings in Tropical Climates

A re-examination of traditional procedures for evaluation of occupied buildings, marrying objective evaluation and subjective judgement of acoustic quality, has pointed to a wide range of areas where architectural planning could be improved. Systematic methods were used to assess acoustical problems: interviews, technical observation, objective measurements, and computer simulation. From an extensive report of the findings, some results of a survey in Rio de Janeiro, a typical tropical region in Brazil, are highlighted. Data obtained from the reaction to environmental noise and those related to building acoustics are considered. The results underscore the importance of adequate architectural planning in regard to climate conditions and particular social-cultural and economic characteristics.

Bringing simulation to implementation: presentation of a global approach in the design of passive solar buildings under humid tropical climates

In early 1995, a DSM pilot initiative was launched in the French islands of Guadeloupe and La Reunion through a partnership between several public and private partners (the French Public Utility EDF, the University of Reunion Island, low cost housing companies, architects, energy consultants, etc…) to set up standards to improve thermal design of new residential buildings in tropical climates. This partnership led to defining optimized bio-climatic urban planning and architectural designs featuring the use of passive cooling architectural principles (solar shading, natural ventilation) and components, as well as energy efficient systems and technologies. The design and size of each architectural component with regard to internal thermal comfort in buildings has been assessed with validated thermal and airflow building simulation software (CODYRUN). These technical specifications have been edited in a reference document which has been used to build over 800 new pilot dwellings through the years 1996–2000 in Reunion Island and in Guadeloupe. Monitoring experiments were held in these first ECODOM dwellings in 1998 and 1999. This resulted in experimental validation of the impact of the passive cooling strategies on the thermal comfort of occupants leading to the modification of specifications when necessary. The paper presents all the methodology used for the application of ECODOM, from the simulations to the experimental results. This follow up is important, as the setting up of the ECODOM standard will be the first step towards the introduction of thermal regulations in the French overseas territories, by the year 2002.

Behaviour of museum buildings in tropical climates

The long-term preservation of collections relies above all on the environment in which they are stored and displayed. The museum building is the first line of defence, and often the only line of defence for a majority of museums worldwide. Temperature and relative humidity are major problems which need to be addressed by tropical museum buildings, and reliable monitoring can be of assistance in making informed decisions to overcome these problems. This paper describes the monitoring and evaluation of two museum buildings in the tropics: comparing the behaviour of air-conditioned and non air-conditioned storage spaces at the Fiji Museum, and determining the contribution of moisture rising through the floor at the Vanuatu Cultural Centre.

Efficient energy performance of large commercial buildings in tropical climates

In this paper, we present the approach to develop energy targets for large commercial buildings in Singapore. The approach involves energy surveys and audits conducted on selected buildings and an analysis of their energy indices. We incorporate the use of computer simulations in order to assess the benefits of several energy conservation opportunities. The results of this study show that, for large commercial buildings, a three-tier classification is needed to account for the differing operating performances. Finally, we recommend the application of two sets of energy targets to achieve near- and long-term energy efficiency.