Applied Mechanics and Materials Vols. 178-181

Abstract: The main objective of this study is to present low energy building and design process using building energy analysis tools, designing a practical office building. EnergyPlus and ECO2 were selected as primary and second tools. The peak heating and cooling load of the designed office building were simulated by EnergyPlus. And the peak load values were applied to ECO2 as HVAC and plant system's capacity. The second objective of this study is to investigate the tendency of simulation results by ECO2 using various input parameters, because ECO2 is a newly proposed energy rating tool for office building by KICT. The passive and active parameters were selected, such as U-factor, shading, orientation, system capacity, and so on. The primary energy usages were calculated by ECO2 and the results and their tendency were analyzed.

Abstract: According to the features of energy utilization in campus buildings, a hybrid system based on heat sink form with solar energy and ground source heat pump is introduced in this paper. By theoretical calculation and experimental validation for heat transfer effect of the heat sink and economic analysis of fuel cost, it was confirmed that the system could efficiently match solar energy with ground heat. Renewable energy storage was realized and operation cost was saved.

Abstract: Forty-seven influential factors of green residential costs were identified in this study, and then four categories of respondents estimated their influential degrees through a questionnaire survey. In order to analyze these factors more accurately, a fuzzy factor analysis model (FFAM) was proposed while the classical one has often been affected by interference information. After calculating fuzzy eigenvalues, fuzzy correlation cofficients and factor loadings matrix in the model, eight different common factors were extracted. Finally, the author put forward several effective measures for controlling green residential costs based on these common factors.

Abstract: According to statistics and field investigation, analyses of the energy consumption (EC) level are on the basis of three low-energy office building cases. These cases locate in three typical cities of different climate zones (North China region-Cold zone, East China region-Hot summer and cold winter zone, South China region-Hot summer and warm winter zone) in China. In conclusions, the energy consumption index (ECI) of these three cases is between 41.06~65.7 kWh/(m2•a). The percentage of EC used for cooling is more than 26.43%, and the outdoor climate conditions influence the total EC level of the whole building.

Abstract: It's an important topic that how to improve the illumination but decreasing or no increasing the electricity loads. The energy-efficient lighting equipment in the study was T5 lighting fixture combining with High-efficiency Reflector and Low-loss Diffuser Plate. The High-Efficiency Reflector could reflex the luminous energy above 97%. The illuminance could be improved largely through using the High-Efficiency Reflector without additional power. The High-Efficient Equipment illuminated the environment with low glare by the lights through the plate. Saving electricity was 47.5% and the measured illumination was increased more than 2 times in case one. The saving electricity was 30% and the measured illumination was increased about 1.5~2 times in case two. The specific benefits using energy-efficient lighting equipment were saving energy and enhance illumination. Cost of the investment achieved balance about 9.5~13.3 months. The additional value was a lighting environment with uniformity and low-glare. The energy-efficient lighting equipment could be an option of green construction.

Abstract: The lighting performance of top lighting solar light pipe in the meeting room in winter in Beijing has been measured under sunny and cloudy conditions to analyze whether the top solar light pipe can satisfy the general jobs lighting or not. The results showed that the indoor maximum and minimum illuminance were 163.2 lux and 115.4 lux respectively and the average illuminance was 147.8 lux in one day. The simulated average illuminance is 113lx in the same experimental time. It can satisfy the design criteria requirements and generally meet the basic for the meeting rooms. The light pipe can be the accessorial illuminance equipment to substitute partial or total artificial light sources in daily life to decrease the energy consumption of lighting.

Abstract: Courtyard sunspace passive solar house is designed according to architecture structure characteristics of rural courtyard, which is a composite of direct absorption, collected wall and attached greenhouse solar house. Architectural optimization design is carried out in order to improve energy saving effect of courtyard sunspace passive solar house, and evaluation standard of thermal performance test and energy consumption of building test is determined to analyze indoor thermal environment of courtyard sunspace passive solar house. It will provide theoretical foundation to construct courtyard sunspace passive solar house in rural area.

Abstract: Exergy analysis is used as a tool to analyze the performance of a refrigeration system. In this paper, it is based on the following conditions: the solar radiation is set as 750 W/m2, the refrigerating capacity is 10 kW, R141b is fixed as the refrigerant in the refrigeration cycle and ambient temperature to be the reference temperature is 31°C. The exergy analysis results of the solar ejector refrigeration system shows that irreversible loss comes from all components and depends on the operating temperatures. The exergy efficiency increases with the condensation temperature’s decrease or the evaporation temperature’s increase. In the specific evaporation temperature and condensation temperature, the optimum generating temperature can be get when the system exergy efficiency is at its maximum. For the operating conditions in this paper, the optimum generating temperature is 95°C.

Abstract: Green building is building that the focus is to maximize the energy efficiency and resources used. While, retrofitting is the process of renovate or refurnish the existing building. Therefore by retrofit existing buildings that comply with green building requirement, it improves the environmental attributes of the buildings. In Malaysia, existing buildings and its communities contribute over 40% of green house gases to the environment. This paper describes a study that explores the potential to retrofit existing campus buildings that response to sustainable green building standard. A validation survey was carried out and the data collected was analysed using SPSS in order to confirm the significance of retrofitting Universiti Teknologi Malaysia (UTM) buildings toward green building initiative. The results show that all the twenty eight identified green elements recorded average index of higher than 3.5 which means that there is significant needs to retrofit the existing buildings to green buildings. This study concludes that it is urgently need for the campus to response to green building requirements in order to achieve higher energy effeciency and this can be done through effective etrofitting of existing buildings.