The simultaneous impact of a building's electricity consumption and thermal performance is analyzed in this paper by taking a thermal model of a retail building located in Ranchi, India. A Baseline ...design of retail building having a rectangular footprint area is compared with four buildings with different footprint areas (Rectangular, T, L, H and U), in the South-West orientation. The thermal models for lighting of retail building are developed using eQuest software, and results obtained were validated experimentally. Intensity of light is reduced by 35% in baseline building corresponding to the amount of energy saved by upgrading to a T8 fluorescent fixture from a T12 fluorescent fixture. Average daylight factor of retail building in hot summer was found to be 34.80% experimentally and 28.98% through simulation. Based on energy consumption it is found that, for temperate buildings with rectangular footprints, buildings with L footprints, and buildings with H footprints are preferable when targeting net-zero energy status. The results encourage architects and engineers to work out an effective framework to enhance the use of natural illumination energy and suitable lighting according to buildings layout.
•Optimal Window-to-Wall Ratios were recommended for various building orientation.•Integrated models with different glazing area and orientation combinations were proposed.•Daylight factor, air ...temperature and air velocity were computed for each test scenario.•Three optimal intervals of Window-to-Wall Ratio were determined respectively.•Intersection interval of the three subsets is the optimal interval of Window-to-Wall Ratio.
Since the ratio of glazing and opaque areas on building facade has significant impact on the indoor visual and thermal comforts as well as energy consumption, the optimal Window-to-Wall Ratio is necessary to be explored for the rural residences with a large quantity in China. Due to the traditional dwellings has been representative of housing samples among rural residences, Sizhai traditional dwellings situated in Zhejiang Province were chosen as the study buildings in this paper. The building model is rotated to 20° increments clockwise to create 18 building orientation intervals. Furthermore, the Window-to-Wall Ratio of front facade for the building model was divided into 8 intervals at increments of 0.1, from 0.1–0.2 to 0.8–0.9. Through indoor environment simulation, the daylight factor, air temperature and air velocity were computed for the test scenarios with different building orientation and Window-to-Wall Ratio combinations. Three optimal intervals of Window-to-Wall Ratios at a series of building orientations corresponding to the daylight factor, mean maximum indoor temperature and mean indoor air velocity are determined respectively, based on the criteria of national codes and thermal comfort ranges. The intersection interval of the three subsets is the optimal interval of Window-to-Wall Ratio for the study building. In addition, for verifying the accuracy of research results, two validation techniques (i.e., comparison of experimental measurement data, and comparison of computational results from other simulation tools) were adopted in this paper.
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•Evaluation of daylight factor inside hostel room in Ranchi city analytically and experimentally.•Determination of best and worst building orientation for thermal ...performance.•Analysis and evaluation of minimum number of hours a building requires thermal gain.•Optimization of room temperature using HVAC.•Overall heat transfer coefficients through walls and roofs through simulations.
This work focuses on daylighting performance analysis and its energy savings potential for residential building by using dynamic simulation and its experimental validation. The thermal performance of nano building material and its comparison with conventional building material has also been analyzed. The daylight factor was found in between 1 and 11% and 1–21% for the floor and wall, which is within the thermal comfort limit. The theoretical model results are compared with experimental values. The best building orientation was found to be 180° from the north or towards the south. Wind speed was found to be more than 30 kmph, which is used effectively in the natural ventilation of the building envelop. It leads to optimization of the room temperature. The heat transfer parameters, including the quantity of heat lost and gained through fabrics, thermal properties of nanomaterial have been compared with conventional building materials. The U value (heat loss coefficient) of building material defines building performance at a particular orientation. The U- values decreased to 8 times in-wall and 8.67 times in the roof of the building envelope compared to conventional building material. The model was experimentally validated, and there is close agreement between simulated and experimental daylight factor values with root mean percentage error of 1.24%. The total uncertainty in experimental measurement was found out to be 0.1421%, which is within the expectable range. Present study can be implemented in any building design with minimum modifications in any part of the world.
Solar heat gains contribute widely to the overheating in buildings, specifically in extreme climates. Climates which require large amounts of cooling energy during summer as well as heating energy ...during winter need to be carefully designed. Reducing solar transmittance through windows and improving building details/types can help minimize surface heat transfer. The use of shading to minimize solar transmission and heat gains through glazed and opaque surfaces is a strong method to reduce solar gains and can be an appropriate method to also improve thermal comfort in such extreme weathers. In the following paper, a method was followed in order to ensure thermal comfort without compromising the daylight factors inside. IESVE was used for the energy and daylighting analysis. Initially, a selected case study of a school building in Minneapolis was analyzed. Afterwards, a study was conducted using climate consultant to select the appropriate shading systems to be adopted. Next, selected classrooms were analyzed for the average daylight factor and solar heat gains pre and post applying the shading systems. The cooling hours were compared after the strategies were applied, a reduction up to 4% of cooling hours was seen post applying the shading devices. The correct study and application of shading devices can help reduce energy needs in summer, without increasing the heating loads in winter.
•In this paper we studied the daylight performance metrics in Canton, south China.•Studied the DA metric under the real daylight climate in Canton, which is seldom accepted in China now.•Analyzed the ...criteria of DF for a north facing façade in canton through vigorous experiment.•Comparing the DA and DF for four cardinal façade orientation in canton, the results should be a guide for the daylighting and sustainable design of buildings.
To ensure sufficient daylight in rooms, daylight performance metrics are the basic references to guide building design or to benchmark a building against another in terms of daylighting in a room. Daylight factor (DF) is the most commonly accepted daylight performance metric, but it has limitations in evaluating the daylighting of a room space in a real daylight climate, as defined under CIE standard overcast sky, while daylight autonomy (DA) is a climate-based performance metric which takes into consideration the regional daylight climate. Based on long-term continuous measurements of daylight illuminance in a test room under real climate, combined with scale model tests under an artificial sky and computational simulations, the quantitative relationship between monthly average daylight illuminance, DF and DA are holistically analyzed in this paper. The result shows that a monthly average daylight illuminance above 300lx in a room located in Canton requires a DF of no less than 1.8% for north-facing space. Finally, the depth of DA300lx 50% daylit area for four cardinal directions was proposed in comparison with DF.
Considering that reading and research are the main functions of use in libraries of all educational facilities, proper lighting becomes a crucial factor in the overall success of a library design. In ...this framework, daylight is essential for both energy saving and improvement of the quality of life in newer buildings where visual tasks are more diverse, and technology poses new types of lighting requirements. Furthermore, emphasis on the importance and methods used to utilize energy will be implemented; provided by nature as the first step in achieving optimum energy saving and reducing our dependence on fossil fuels. Thus, this study will examine the conditions of indoor daylight and the library’s energy performance in the faculty of Architecture, Design and Built Environment, Beirut Arab University with various architectural elements including space depth, window size, external obstruction angle, and glazing visible transmittance. This is done by first analysing the existing situations of daylighting (using Autocad Ecotect software), the situation of the artificial lighting inside the space (using Dial DIALux software), and the behavior of the users throughout the day (using Hobo loggers). Then, the outcomes will be analyzed to specify the challenges, therefore providing solutions related to environmental, technological, and energy saving as well as sustainable and green building designs. As a result, daylight designs based on hollow prismatic light guides are proposed. These designs act as luminaires increasing guide efficiency and uniformity distribution of natural light into the library spaces. The proposed designs are configured and analyzed by ray-tracing simulations for achieving high illumination levels and uniform lighting in the working plane of the library.
Global attention is currently focussed on developing techniques to improve the thermal performance of buildings to provide indoor comfort with minimum reliance on energy load. Several studies have ...investigated building facade, materials used and other factors involved in building design. The aim of this study is to examine the impact of thermal insulation, shading devices, window-to-wall ratio (WWR) and a combination of these factors in a prototype school building design in the warm climate city of Taif, Saudi Arabia. The study used various methods classified into two main phases. The first phase involved on-site observation where both thermal imaging and regular cameras were used to examine the influence of orientation on glazing as a baseline. The second phase involved advanced software investigations with 2D AutoCAD, 3D Revit and computer modelling for energy evaluation and daylight factor. A detailed framework was introduced to examine current school buildings and to improve the future designs of prototype school buildings. The study revealed that a combination of applying thermal insulation along with minimising WWR is required in existing buildings within hot and dry regions. Furthermore, it was recommended that WWR should not exceed 35%, 25% and 20% for northwest, southeast and southwest building facades, respectively.
Kernel density estimation (KDE) approximates the distribution of statistical data similar to the histogram. The histogram of data is a special kind of the Kernel density. In the reconstructed ...building of stall in Oponice (Slovakia), we measured the values of daylight factor. The obtained data proved a bimodal distribution, so it was not appropriate to use some of the usual parametric distributions. This paper describes how Kernel density can be applied to measured results. We find out the values of the cumulative distribution function of such density, by probability procedures, that serves us comparison with the prescribed values of the daylight factor in the standard, on the one hand for animals (1.0%) and on the other hand for the people (1.5%) who care for animals. The results obtained from the measurements and the same ones approximated by KDE are in good agreement.
Based on a new approach for the prediction of the Daylight Factor (DF), using existing empirical models, this research work presents an optimization of window size and daylight provided by the glazed ...apertures component for a building located in a hot and dry climate. The new approach aims to improve the DF model, considering new parameters for daylight prediction such as the orientation, sky conditions, daytime, and the geographic location of the building to fill in all the missing points that the standard DF, defined for an overcast sky, presents. The enhanced DF model is considered for the optimization of window size based on Non dominated Sorting Genetic Algorithm (NSGA II), for heating and cooling season, taking into account the impact of glazing type, space reflectance and artificial lighting installation. Results of heating and cooling demand are compared to a recommended building model for hot and dry climate with 10% Window to Wall Ratio (WWR) for single glazing. The optimal building model is then validated using a dynamic convective heat transfer simulation. As a result, a reduction of 48% in energy demand and 21.5% in CO2 emissions can be achieved. The present approach provides architects and engineers with a more accurate daylight prediction model considering the effect of several parameters simultaneously. The new proposed approach, via the improved DF model, gives an optimal solution for window design to minimize building energy demand while improving the indoor comfort parameters.
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