Shading Coefficient Research Articles

ANALIZA PARAMETRÓW MAJĄCYCH WPŁYW NA ZMIANĘ ZAPOTRZEBOWANIA NA CHŁÓD W OKRESIE LETNIM W BUDYNKU ZAMIESZKANIA ZBIOROWEGO

Artykuł przedstawia analizę problemu zapotrzebowania na chłodzenie pomieszczeń w okresie letnim wynikającego z powiększenia okien na elewacjach południowych. Celem badania jest analiza parametrów mających wpływ na zmianę zapotrzebowania na chłód i wybór najkorzystniejszych z nich. Parametry poddane analizie to: temperatura wewnętrzna w pomieszczeniu (zakres 21–24°C), współczynnik przenikania ciepła przez przenikanie dla okien U (zakres: 0,7 – 1,3 ), współczynnik zacienienia przez urządzenia przeciwsłoneczne fc (zakres: 0,15 – 0,95) oraz współczynnik zacienienia okna przez zewnętrzne elementy zacieniające Fsh,ob.,k (zakres: 0,7 – 1,0).

Optimum design and analysis of the application of the air slot on the building horizontal sun-shading board

ABSTRACTThe sun-shading board is an important way to improve the indoor thermal environment. And air slot is the critical component to improve ventilation effect of sun-shading board. It not only can promote heat dissipation of sun-shading board but also can improve ventilation effect of building window. The shading coefficient of shading board and vorticity influence of air slot are the main principles of designing configuration and size of air slot. The horizontal sun-shading board of residential building south window in Nanjing is the study object. The shading and ventilation effect of shading board with various configurations and size is analyzed quantitatively. And appropriate configuration and size are obtained on the basis of comprehensive consideration of various factors.

Quantitative research on the influence of particle size and filling thickness on aerogel glazing performance

Silica aerogel has attracted increasing interest in building glazing for energy efficiency owing to its light weight, ultra-low thermal conductivity and high visual transmittance. In this study, four types of aerogel granules with various average particle sizes (viz. 0.41, 1.03, 1.64 and 2.54 mm) were prepared by using a low-cost ambient pressure drying method. Three gaps between two pieces of glass (viz. 6, 9 and 12mm) were filled with aerogel granules, yielding 12 pieces of aerogel filling glazing. The light transmittance and reflectance of the aerogel glazing samples were experimentally measured by using a spectrometer. Based on the experimental results, the correlation between the light transmittance performance and the geometrical parameter of the aerogel glazing were established based on a proposed dimensionless geometrical parameter. It revealed that the visible light transmittance and the shading coefficient of the aerogel glazing had a positive correlation with the particle size and a negative correlation with the filling thickness. In addition, the filling thickness had a greater influence on the properties of aerogel glazing than the particle size. This opens new possibility for a multiple-objective evaluation of the aerogel glazing aiming at building energy efficiency.

Problems and Prospects of Nanometer Transparent Infrared Thermal Insulation Glass

The existing building energy-saving reconstruction has a large area in our country. If the performance indexes such as the shading coefficient, visible light transmittance and hardness of the coating heat-insulating glass are in the condition of reaching the specification, and it can meet the needs of energy conservation and reform in building, it is a suitable technology for economic application.

外付けブラインドの計画・設計に関する研究 改良した日射熱取得量測定装置の性能検証

外付けブラインドの計画・設計に関する研究 改良した日射熱取得量測定装置の性能検証

Energy Performance and CO2 Emissions of HVAC Systems in Commercial Buildings

Energy performance of buildings has attracted much attention among building physicists and engineers worldwide. The effects of building heating; ventilation; and air conditioning (HVAC) systems’ design upgrade on the building energy performance are the focus of the current study. The adopted HVAC system consisted of chilled ceiling and chilled beam systems served by a centrifugal water chiller. An energy simulation study was undertaken in accordance with the national Australian built environment rating system-rules for collecting and using data. A three-dimensional simulation study was carried out utilizing the virtual environment-integrated environmental solutions software. Results from the current study have shown the importance of utilizing energy-efficient HVAC systems and HVAC strategies for achieving a high building energy star rating. Recommended strategies in order to achieve the nominated star rating; as predicted by the simulation analysis; were presented. Moreover; the effects of solar radiation inside the building atrium were significant; which cannot be overcome by simply installing a low shading coefficient glazing type at the atrium skylight. In addition to providing chilled ceiling technology; a high efficiency chiller and low energy lighting; it is recommended that the building be well tuned during the commissioning period. The current approach could be extended to accommodate higher energy ratings of commercial buildings at different locations worldwide.

Potential reduction of energy consumption in public university library

Efficient electrical energy usage has been recognized as one of the important factor to reduce cost of electrical energy consumption. Various parties have been emphasized about the importance of using electrical energy efficiently. Inefficient usage of electrical energy usage lead to biggest factor increasing of administration cost in Universiti Tun Hussein Onn Malaysia. With this in view, a project the investigate potential reduction electrical energy consumption in Universiti Tun Hussein Onn Malaysia was carried out. In this project, a case study involving electrical energy consumption of Perpustakaan Tunku Tun Aminah was conducted. The scopes of this project are to identify energy consumption in selected building and to find the factors that contributing to wastage of electrical energy. The MS1525:2001, Malaysian Standard - Code of practice on energy efficiency and use of renewable energy for non-residential buildings was used as reference. From the result, 4 saving measure had been proposed which is change type of the lamp, install sensor, decrease the number of lamp and improve shading coefficient on glass. This saving measure is suggested to improve the efficiency of electrical energy consumption. Improve of human behaviour toward saving energy measure can reduce 10% from the total of saving cost while on building technical measure can reduce 90% from total saving cost.

STRUCTURE OF THE FLOW IN THE SYSTEM OF TURBULENCE STIMULATOR-NICHE CAVITY

One way to significantly improve the efficiency of work combustion processes in stabilizer type burners is to use various means of intensifying of heat transfer and fuel burn. Such means include as follows: preheating the air, going to the combustion, air flow twisting, organization of developed surface ignition and combustion, increasing shading coefficient burner, use of additional elements of tubulisation etc. The existing papers devoted to the study of transport processes in the application of these ways of combustion intensification in stabilizer burners do not cover many aspects of this direction of research. Thus, the further development of research of flow characteristics, which largely determine the course of work processes in burners, deserves attention. Therefore our objective is to define patterns of flow in the system of angular turbulence stimulator-niche cavity modelling the main elements of the stabilizer type burner. Studies are conducted on the operation area at the following initial data: the height of the channel was operation area of 120 mm, width – 190 mm, length – 500 mm. Length niches downstream 75 mm, height – 35 mm. To measure the flow velocity of T-shaped pneumatic probe, using cement nozzle Witoszynskyj was used. First of all, comparison of velocity profiles in various vertical sections of niche cavities in the plane of symmetry of turbulence stimulator for the present and absent of availability of turbulence stimulator of flow indicates that without of turbulence stimulator reverse flows zone is significantly pressed to the niche bottom. That is if turbulence stimulators are installed behind niche cavity reverse flows zone is visible pressed against the bottom of the niche. Secondly, there is a tendency to the emergence of forward flow near the wall stabilizer in the area of the location of the turbulence stimulator. There is a direct-flow trend outside return flows zone of turbulence stimulator, accelerated down the stream as you approach to the section x = 120 mm, which corresponds to the maximum width of said zone. Further down the stream-flow this trend is slowed. The return flows zone behind the turbulence stimulator appears more clearly on some distance from the wall of the turbulence stimulator. This fact becomes evident due to effect of the emergence of forward flow in the wall area of the stabilizer. Thus, the analysis of experimental data on flow patterns in the system of corner vortex flow is niche cavity. Setting of angle vortex flow on a section of the back wall of the niche leads to inhibition of specific areas of backward flows in the niche cavity and pressed it to the bottom of the niche.

Solar shading performance of window with constant and dynamic shading function in different climate zones

Window is a basic building element that can significantly influence the indoor thermal and lighting environment, in evaluating the shading performance of a window system with shading device, the solar heat gain coefficient (SHGC) is of key factor. This paper analyzed the optimal constant solar heat gain coefficient (SHGC) in several typical climate zones in USA and China, the SHGC values were compared according to their latitudes. Based on a grid shading configuration for window, the optimization of grid pitch for energy saving was conducted. The optimal SHGC decreases gradually with the decrease of latitude, the effect of shading device becomes more obvious. The window with optimal SHGC could reduce total building load up to 37.8% in selected USA cities and 24.8% in selected China cities. For the same city and grid pitch, more than 6 times difference emerges from summer to winter. The minimum geometrical shading coefficient (GSC) of grid shading increases with the decrease of latitude.

Exploratory Survey of Recessed Window Façade Shading in Johor Bahru Malaysia

The built environment is a major source of global energy consumption and greenhouse gas (GHG) emissions potentially exacerbating the threats of climate change. With global rising temperatures, the energy requirements for cooling and ventilating buildings in tropical nations like Malaysia will soar geometrically. Scientists around the globe are exploring several technologies to address the challenges posed by building emissions and energy consumption. One of the main methods is the application of passive design strategies such as external facade shading or self-shading. Studies indicate one of the most practical self-shading technique is recessed window facades (RWF) which can easily integrate without reducing natural light and obscuring views. However, studies on the RWF are limited in literature particularly in Malaysia. This research aimed at carrying out an exploratory survey of recessed window facade (RWF) shading in selected buildings in Johor Bahru Malaysia. The RWF buildings characteristics namely; Window-Wall Ratio (WWR), Recessed Depth (RCD), Shading Ability (SHA), Solar Heat Gain Coefficient (SHGC) and Shading Coefficient (SC) will be examined. The results indicated that the values for solar heat gain and shading coefficient are within acceptable limits. Furthermore, the high shading ability of the buildings indicated that RWF might be responsible. Further studies are required to ascertain empirical correlations between the examined characteristics. This further study will potentially improve the design of more energy efficient, low emission and thermally comfortable buildings for the future.

BEAT 프로그램을 이용한 건물에너지 retrofit 요소들 간의 에너지 절감 관계분석

Recently, Korean government is successively driving energy saving policies. Nevertheless, the use of energy is continuously increasing, and shift toward a low-energy society is somewhat out of our expectation. The major goal of building energy retrofit is to optimize energy consumption in existing buildings which are under deterioration. Many of these old buildings with lower efficiency spend more energy than newly built ones. Thus, this paper suggests a reasonable guideline for energy retrofit. A government office building located in Kangdonggu, Seoul is selected as the subject building, and a modified bin-method called BEAT(Building Energy Analysis Tool) program is used for the analysis. The primary goal of this research is to find the best combination of influencing factors that can improve energy efficiency in old buildings. Such factors stem from design components of Building, System and also Operational facets of a building. By applying the input standards from 'Green remodeling guidelines', heating energy can be reduced by 38.28% in the winter and 38.50% of cooling energy in the summer. Most of the factors contributed to reducing energy consumption except for SC(Shading Coefficient) and Internal lighting to heating energy. This is due to the blockage of solar heat gain and decrement of internal heat respectively, which results in a higher demand for heating in the winter. Finally, the total energy(HVAC+Lighting+Office equipment) on a yearly basis, can be reduced by 38.89% when all the considering factors are applied in combination. The study will further move to analyze the best solution for building energy retrofit.

建筑外窗的热工性能及其节能标识方法的研究

建筑外窗节能标识是能效标识时代下的产物。本文主要从外窗的传热系数、遮阳系数、空气渗透率以及可见光透射比四大性能参数入手，阐述了外窗节能标识的主要内容，并对外窗节能标识的等级划分作出了初步构想，这于超低能耗建筑的研究有一定的参考价值。 The energy saving labeling of building exterior window is the product of the era of energy efficiency labeling. In this paper, mainly from the external window of the heat transfer coefficient, shading coefficient, air permeability and visible light transmission ratio of the four performance parameters, the main contents of the development of energy saving logo are described. The preliminary scheme assumptions are made on the classification of the energy saving logo of the outer window. This will have a certain reference value for research of Ultra-low Energy Buildings.

Field study on energy economic assessment of office buildings envelope retrofitting in southern China

Energy consumption of buildings accounts for more than 37.3% of total energy consumption while the proportion of energy-saving buildings is just 5% in China. In this paper, in order to save potential energy, the building envelope retrofitting is considered. An office building in Southern China was selected as a test example for energy consumption characteristics. The base building model was developed by TRNSYS software and validated against the recorded data from the field work in six days out of August-September in 2013. In addition, with a design of numerical simulation, sensitivity analysis was conducted for energy performance of building envelope retrofitting; six envelope parameters were analyzed for assessing the thermal responses. Results show that significant energy savings are obtained for the thermal transmittance (U-value) of exterior walls, infiltration rate, ventilation and shading coefficient, of which the sum relative sensitivity is about 91.06%. The results are evaluated in terms of energy and economic analysis. On the other hand, it appears that the cost-effective method improves the efficiency of investment management in building energy.

Assessment of energy and economic performance of office building models: a case study

Energy consumption of building accounts for more than 37.3% of total energy consumption while the proportion of energy-saving buildings is just 5% in China. In this paper, in order to save potential energy, an office building in Southern China was selected as a test example for energy consumption characteristics. The base building model was developed by TRNSYS software and validated against the recorded data from the field work in six days out of August-September in 2013. Sensitivity analysis was conducted for energy performance of building envelope retrofitting; five envelope parameters were analyzed for assessing the thermal responses. Results indicated that the key sensitivity factors were obtained for the heat-transfer coefficient of exterior walls (U-wall), infiltration rate and shading coefficient (SC), of which the sum sensitivity factor was about 89.32%. In addition, the results were evaluated in terms of energy and economic analysis. The analysis of sensitivity validated against some important results of previous studies. On the other hand, the cost-effective method improved the efficiency of investment management in building energy.

Simulation study on energy conservation performance for integrated external louver facades

The authors previously proposed integrated-facade-systems comprising different types of external louvers integrated with buckling restraint braces. The systems can be applied to both new and existing buildings, paying attention to the building’s appearance, upgraded structural performance and indoor environment. The authors have studied indoor daylight conditions with louver facades and a research paper was published in this journal (Misawa, Hikone, Nakamura, Iwamoto, Iwata, 2014). This research study reports on the energy conservation performance of louver facades and proposes an External Shading Coefficient (ESC) for external louver systems. Situations with five external louver facades and no louvers, facing three facade orientations (East, South and West) are examined. The year-round ESC is simulated every hour using Radiance software for transient solar radiation calculations. Furthermore, by using the proposed ESC, case studies for typical Japanese offices are carried out to verify reduction effects on the annual thermal load and electrical energy consumption of an air source heat pump for each louver set-up. Simulation results are calculated in hourly increments using TRNSYS software; the results show that both thermal loads and electrical energy consumption are reduced regardless of louver types and facade orientations when integrated external louver facades are installed.

A smart building material for low/zero carbon applications: heat insulation solar glass—characteristic results from laboratory andin situtests

Heat insulation solar glass (HISG) is a recently developed smart building material to minimize energy consumption of building sector. HISG might be presumed to be a conventional photovoltaic glazing product; however, it is completely unique by having some characteristic features such as superior thermal insulation, which is competitive with triple-glazed windows using argon as inert gas, acoustic and thermal comfort, self-cleaning ability owing to TiO2 nano-coating on module surface and extraordinary energy saving potential in both summer and winter. In our previous works, comprehensive experimental and numerical works have been carried out for power generation and thermal insulation performance of HISG under various climatic conditions. Within the scope of this research, optical- and lighting-related performance parameters of this smart building material are evaluated through extensive laboratory and in situ tests. Shading coefficient, visible light intensity, and UV and IR penetration are investigated via the tests conducted in real operating conditions. It is achieved from the results that the shading coefficient of HISG is only 0.136, which yields almost 80% reduction in solar heat gain compared with ordinary glazing. It is also observed from the in situ tests that HISG has a %100 UV and 99% IR blocking rate, which is of vital importance in terms of human health and thermal comfort conditions. Glaring effects are totally resolved via HISG, which is still a challenge for the buildings with conventional glazing products, especially in summer.

Energy saving potential of heat insulation solar glass: Key results from laboratory and in-situ testing

HISG (heat insulation solar glass) is a recently developed multi-functional glazing technology to mitigate energy consumption of buildings. HISG can generate electricity similar to conventional PV (photovoltaic) glazing products when exposed to sunlight, however it differs from them by having some extraordinary characteristic features such as thermal insulation, which is competitive with Argon filled triple glazed windows, acoustic comfort, remarkable energy saving potential and self-cleaning ability owing to TiO2 nano coating. Within the scope of this research, latest results from laboratory and in-situ testing of HISG are presented in terms of its key role in mitigating heating and cooling demand of buildings as well as clean energy generation. Lighting and thermal comfort related parameters such as shading coefficient, UV, IR and visible light intensity are also investigated through the tests conducted in real operating conditions. It is achieved from the results that instant electricity generation of HISG is 16% higher than that of standard PV glazing owing to its nano layer reflective film. Shading coefficient of HISG is only 0.136, which provides almost 80% reduction in solar heat gain compared to ordinary glazing. Indoor air temperature measured from HISG test house in summer time is very close to the ambient temperature, whereas it is found to be 14.7 °C higher in ordinary glass test house due to greenhouse effect. Annual heating and cooling demand tests indicate that HISG provides 38 and 48% energy saving in heating and cooling season, respectively.

Glass Properties Selection Effect on LEED Points for Core and Shell High Rise Residential Building in Jordan

Green building concept is flourishing in developing countries due to the high-energy cost. To meet the green building requirement, this paper investigate the effect of glass properties on 4 and 20 story building total, heating and cooling, loads for variable glass-wall ratios using HAP4.5 . The ratios considered are 20%, 40%, 60%, 80% & 100% glass to wall. The simulations were carried out for both building under moderate climate, Amman, Jordan was the selected city from this climatic zone. The glass overall heat transfer (U-value) & shading coefficient (S.C) are paired in nine combinations, these pairs are called Combination Number (CN). Combination Number simulate all range of glass properties, CN 1 is the worst case to 9 the best glass properties. Results showed that the minimum impact of glass properties was on 20-percentile glass to wall ratio and maximum at 100 Percentile. On the other hand, a Maximum of 10 LEED point could be achieved in the 20-percentile and 16 point in the case of 100-persentile for both 20 and 4 story building. Data found in this paper where formulated in the following equations with R2 = 0.949. 4 Story Total Load = 915514 - (63546 * CN) + (9770 * Glass to wall) 20 Story Total Load = 7638346 - (540386 * CN) + (84090 * Glass to wall)

Study on Daylighting and Energy Conservation Design of Transparent Envelope for Office Building in Hot Summer and Cold Winter Zone

The design of transparent envelope not only affects the energy consumption of cooling and heating, but also has a great impact on indoor day lighting (lighting energy consumption), artificial lighting in office building energy consumption counts for the important proportion, and influences the energy consumption for cooling and heating, so it is necessary to study the energy-saving optimal design of transparent envelope for office building. Combined with day lighting, the effects of some parameters on overall energy consumption of cooling, heating and lighting are investigated using simulation software, such as the window to wall ratio, the heat transfer coefficient of window, shading coefficient, transmittance, shading system, and so on, the optimal design of transparent envelope is obtained for office buildings of the summer and cold winter zone. The results show that annual total energy consumption is the lowest when the window to wall ratio is 40% in different window to wall ratios, building facade facing south among different orientations, and the type is on-2/3-1/3-off in different control methods.

Development of Testing Platform for Building Shading Device

In this paper a shading coefficient test platform using artificial light sources was developed to measure the shading coefficient of some typical shading products for building. The platform consists of three testing cases and a protective case. The results show that the detection period using this method was approximately 5-6 hours, and stability of repeating test was good. The experiment results of between-glass venetian blinds are compared with the simulation results to verify the scientific feasibility of the test method.