Abstract

A passive skylight system is a significant building design element that provides an ideal condition for interior spaces. However, the use of this system is limited to specific climatic regions because of its considerable effect on the indoor environment. Malaysia is a tropical country that has favorable natural benefits, such as solar geometry and natural light, which can brighten building interiors throughout the year. However, harnessing this benefit affects spaces, especially those in single-story buildings, because of excessive natural loads. This study reviews a concept to understand the passive behavior of solar radiation in the form of light and heat that falls on, interacts with, and is emitted from a skylight system in a single-story building. The study method is theoretically based on descriptive analysis to assess design requirements. The review shows that designs grounded on the physical aspects of climate (influenced variables), materials (design variables), and human comfort (affected variables) in one process (ESI) can develop the architectural way of thinking rather than estimate the condition based on a limited perspective. This assumption indicates that the adoption of this concept in the preliminary design stage will enable designers to balance the building environment effectively.

Abstract

This work aimed to find the best possible solution for transparent façades. The evaluation was formulated to assure the highest user comfort criteria corresponding to energy efficiency—two criterion optimisation. The analyses were based on BESTEST, south-oriented zone geometry. Computer model was designed using Finite Control Volume Techniques with assumptions for applied materials and specified boundary conditions, plus reference year for energy calculation (WYEC2). The natural ventilation façade system was designed to determine airflow network inside the façade. The adjustable size of openings (inlets and outlets) was selected at the level of 80% for the cold season and totally closed during the hot season. Environmental parameters for thermal comfort evaluation were: zone resultant temperature and solar radiation in zone space. Energy efficiency was assessed based on heat flux between the zone with controlled temperature and external environment. Results showed that well selected design of buffer zone section could improve energy efficiency of adjacent zones for both winter and summer periods. The most profitable Double Skin Façade solution is DGC (double glazing with low-e coating) combined with single glazing with internal blinds (SGB) or coloured glazing.

Abstract

In recent years, research about the application and optimization of PV panels has grown rapidly. Especially for stand-alone solar systems there have been some problems related to first stages of design and application. Finding the optimum slope of PV panels in order to maximize the absorbed solar radiation is considered as one of the major obstacles. Although in Malaysia there have been some research works about finding of optimal tilt angle, however, this research work aims to start investigation about slope of PV panels for three villages without electricity and prior research. The Liu and Jordan model is applied to find the monthly optimal tilt angle and fixed tilt angle for the application of solar energy in these rural locations. The results demonstrate that the optimal tilt angle in these locations is less than 5°.

Abstract

The energy supply characteristic of a proton-exchange membrane fuel cell for houses is strongly influenced in a hydrogen supply unit. Therefore, a bioethanol reforming system (FBSR) with a sunlight heat source is developed as a potential fuel supply system for distributed fuel cells. However, the temperature distribution of a catalyst layer in the reactor is not stable under conditions of unstable solar radiation and unstable outside air temperature, as a result, it is thought that the inversion ratio (the percentage of hydrogen obtained from ethanol) of a reforming reaction will decrease. In this paper, heat transmission analysis was used in the catalyst layer of the reformer of FBSR, and the fundamental performance of FBSR was investigated. Fluctuations of the solar insolation over a short period of time affect the hydrogen-generating rate of FBSR. Moreover, the amount of hydrogen production of FBSR was simulated using meteorological data from a day in March and a day in August in a cold region (Sapporo in Japan). In this research, the relation between the collected area of a solar collector and the energy supply to an individual house was obtained.

Abstract

In this work, results of efficiencies for first and second law of thermodynamics applied to four box-type solar cookers with internal reflectors are shown. The solar cooker has two glasses on its cover to diminish the losses of heat for radiation and convection, besides creating the effect hothouse inside the cooker. The interior of the cooker has flat mirrors placed at different angles to reflect the solar radiation toward a recipient with water inside the cooker. The obtained results are based on heating water temperatures which were obtained by means of numeric simulation, allowing comparison under identical conditions of four solar cookers. The treatment of the results revealed that the quantity of energy that impacts on the solar cookers is not used in right way for the heating water ends. Most of the profitable energy is stored in the glasses of the cover, what evidences the necessity to work in the development of better materials to diminish such situation.