Skylights or light wells are an integral part of the design of low-and high-depth buildings. The design of these Skylights in different areas is based on specific criteria. According to Hamedan's criteria, only the dimensions of these Skylights and the ratio of Skylight area to height of the Skylight are enough to design Skylights. The purpose of this study was to evaluate the accuracy of Skylights designed according to the existing regulations in Hamadan city and to estimate the optimum Skylight dimensions to achieve the required space illumination and thus reduce the electrical energy consumption for illumination. To achieve this goal, studies were first conducted on daylight, solar energy, climate characteristics of the area, and standards on lighting. Then three buildings were selected as samples and in four seasons of the year, the illumination received in the spaces overlooking the Skylight was harvested by a lux meter. Based on the studies, the amount of illumination was analyzed. Next, using simulator software, the dimming dimensions, modeled to achieve standard illumination, were modified. Finally, by changing the height parameter, the optimum dimensions of the Skylight for one-to nine-story buildings were determined by the software. The results of this study showed that the existing criteria in Hamadan were not efficient and the light received by this system was not sufficiently implemented and new dimensions were introduced in this study.

One of the main architectural characteristics in the central area of Iran is the relation between life and climatic conditions; e. g., the four-seasonal house which is a typical kind of the central-yard house. As the climate of Isfahan is more pleasant than other desert regions in the central part of Iran, wind towers are replaced with Skylights to ventilate the pool area of hozekhane. So far, several researches have been carried out to study the stack effect characteristics and to review wind tower performance. In this paper, a case study is carried out to investigate the effect of the Skylight of Mosaver-al-Molki house on the flow pattern and natural ventilation. The performance of Skylight on the internal air flow patterns as an effective tool in improving the natural ventilation is investigated by using the Ansys Fluent software. Other elements which have been discussed in this paper are the vault and the columns. These elements have a distinguished effect on distribution of inlet streams in different parts of the hoze-khane. Analysis of the simulation results were obtained for wind velocities of 2. 5 m/s and 8 m/s. The numerical results show that wind speed of 2. 5 m/s has better performance than wind speed of 8 m/s in terms of ventilation.

Daylight is one of the most influential parameters of visual quality, especially in spaces like art exhibitions. Skylights are proper choices to provide daylight, improve visual comfort, and reduce artificial lighting energy consumption. In this paper, the effect of the main design parameters of Skylights on the visual quality is studied using DesignBuilder software. An 81 m2 exhibition area is assessed as a test case. The design variables are the Skylight form, orientation, location, glazing type, and splay angle. Also, luminance uniformity, spatial daylight autonomy (sDA), and useful daylight illuminance (UDI) are used as evaluation metrics. The north-oriented curved Skylight leads to the best visual quality among the studied cases based on the results. Installing the Skylight on the north side of the exhibition roof is better to provide the best luminance uniformity. Besides, the results showed that triple Low-E glazing provides the most uniform and the least maximum luminance. However, it may slightly reduce sDA. Finally, although the effect of splay angle on the visual comfort indexes depends on the intended time, 45° to 60° angles work satisfactorily.

Atrium is referred to a wide-open space, which often has several floors and is covered with glass ceilings or large windows, or both. Atria are often used when the built-up area of the building is too high or the building's southern facades are inaccessible or limited for lighting, so using sunlight should be the main consideration of their design. There are four types of atrium: centralized, semi-enclosed, attached, and linear. In this research centralized type is reviewed and a square plan atrium is chosen according to the studies. The dimensions of the selected plans for atriums are 4*4, 6*6, 8*8, and 10*10 meters and the height of the atrium is constant )9 meters(. Since the form and structure of the Skylight can affect how the atrium receives sunlight, this paper seeks to study the effect of the type and shape of the Skylight on the amount of light received in the inner space of the atrium. This research has been carried out in the cold climate of Tabriz in Iran so the conditions of cloudy skies according to the climate of Tabriz are considered for simulation. In order to fulfill the objective of this study, first, the atrium and components which affect the design and the theoretical reviews were investigated and then the proportions of the model were obtained. In order to perform more detailed analysis, the effect of five different atrium Skylights )1. flat roof with lighting from the top, 2. flat roof with lighting from sides, 3. roof with light scoops, 4. single-sided sloped roof, and 5. double-sided sloped roofs( on the interior lighting of the atrium have been compared. Also changing the amount of glazing surface of these Skylights is another main variable of this research. Daylight Factor, Autonomy, Brightness )lux(, and Sky Component are the factors that were measured by Ecotect Analysis and Radiance software. The results are compared and analyzed and have been illustrated in tables and graphs. The results demostrate that the shape of the Skylight has a significant effect on the amount of light received inside the atrium. Suitable daylight factor and brightness for the atrium are achieved by a single-sided sloped roof with 90 percent of glazing and a double-sided sloped roof with 80-90 percent of glazing while the dimensions of the atrium are 4m. For the atrium with dimensions of 6m, it is achieved by flat roof with lighting from the top, single-sided and double-sided sloped roof with 50-60 percent of glazing and finally roof with light scoops with 50-70 percent of glazing. There is a very high possibility of glare in larger atriums with this low, two-story height. It should be noted, however, that the results achieved are only affected by the changes in the roof shape, the proportions of the atrium and the amount of glass in the Skylight, and factors such as the reflection of surfaces, the transmission of the surfaces, shading, height, and shape of the atrium and the effect of other conditions of the sky have not been considered.

In the architecture of the mosque, the light entering into the dome is a functional necessity and due to the structure, the weight of the dome and its one or more shells has caused limitations in any kind of Skylights to be encumbered. The research main question is that due to the mechanism of the dome parts, how the creation and the entering of Skylights to the dome were done. The research method is a combination of both quantitative and qualitative methods. Initially, based on library studies, researcher's opinions were investigated and by analyzing 14 types of mosques from the Seljuk to the Qajar era in Iran, analyzes on how to create Skylights through the dome were accomplished. This research answer two essential questions which are what principles had been followed for locating Skylight in the dome? Moreover, how did light enter through the dome, in one-shell and two-shell domes? The findings show that in the one-shell domes, the position of the Skylight is variable. In detached two-shell domes, the Skylights are placed merely in 45° areas and are not limited in terms of numbers. Conclusions state that one-shell domes had a restriction to the number of Skylights, in comparison to the two-shell domes. In detached twoshell domes, lighting was possible until the 22. 5° area and considering no limitations, there has been no Skylight in the area between 67. 5° to 90° apart from a few exceptions.

Atrium, as a passive light absorbing solution, in addition to having positive psychological effects due to creating a connection between indoor and outdoor space, may increase the heat in the hot season of the year and increase the cooling load if there is no ventilation and shading on the glass surfaces. Therefore, the atrium should be measured with criteria and patterns of energy consumption reduction, otherwise, it will impose a significant energy load on the building. Many studies on the daylighting of atriums have been investigated and have shown that the daylighting performance of an atrium largely depends on its geometrical characteristics. The main features of atriums can be categorized into three parts: (1) Skylight system (Skylight height, shape, scale); (2) atrium form (well height, shape, scale); and (3) surrounding interface (corridors, windows, etc.). In this research, two important components of the atrium form and the geometry of the roof Skylight have been investigated. The purpose of this study is to compare the different forms of the atrium body and its Skylight roof in an educational space in order to optimize energy consumption. For this purpose, Design Builder software has been used for data simulation and analysis, as well as Energy Plus engine for calculations. In this regard, the initial model with three different plans of the atrium was simulated in the design-builder software and the optimal plan was determined according to the amount of energy consumption, and then three types of Skylight roofs were added to the atrium and the amount of energy consumption in them was checked again. In this project, the dimensions of the plans are considered so that they have the same area. In the first stage of the research, three plans with the same areas with three forms of circle, square, and rectangle are simulated and the amount of energy consumption in each is obtained. At this stage, the energy analysis results obtained from three atrium forms are compared, then the most optimal form is selected in terms of energy consumption. Calculations related to energy consumption have been evaluated separately and the amount of energy consumed by equipment, lighting, heating, cooling, and the amount of energy for hot water consumption have also been determined. The results show that in different atrium plans with the same area, in the circular plan, the total energy consumption is 215.5 (MWh), and this amount is 215.9 (MWh) in the square plan and 216.77 (MWh) in the rectangular plan. Therefore, the atrium plan form with a circular plan has the best function and the rectangular form has the weakest energy efficiency. In the second step, three forms of spherical, flat, and cylindrical Skylights with a height of 1.20 were simulated. The results showed that the amount of energy consumption in the building with a flat Skylight is 207.1 (MWh), in the atrium with a spherical Skylight is 222.83 (MWh), and in the atrium with a cylinder Skylight is 215.5 (MWh). Therefore, it can be concluded that the atrium with a circular plan form and a flat Skylight has a more effective energy efficiency than other forms.

Background and Objective: In recent decades, atriums have been installed in public buildings to optimize energy consumption and provide thermal comfort, and therefore have always been of interest to mechanical engineers, architects and designers. Atrium also created different microclimates with different thermal layers in its lower space, which affected the cooling load and thermal comfort inside the building. Therefore, the purpose of this research, is to find the most suitable form and height of atrium for reducing energy consumption and heat stratification in commercial buildings of Mashhad city with cold and dry climate. Method: This research has used fluent software and Mathematical equations. Initially, Almase Shargh commercial building in Mashhad with central atrium in a spherical form of 5 m height was selected and after field measurements and data recording by dataloggers, the common atrium forms (spherical, prismatic, parabolic and flat at 3 m, 5 m, 7 m and 10 m) were replaced and in order to measure the heat stratification, the Mathematical formulas was used. Findings: According to field observations and data measurements, the fifth floor and attic of the indoor Skylight due to the influence of sunlight and lack of air conditioning, are critical areas of heat stratification and are out of range of thermal comfort throughout the year. Therefore, the amount of energy consumption during the year to provide thermal comfort in these floors is high, which can be reduced by reducing the levels of light-absorbing interior walls and using materials with high thermal capacity. Discussion and Conclusion: The results show that the flat form with a height of 3 meters, due to the reduction of light levels in the interior wall and the temperature difference between the floors is the most appropriate form of atrium for reducing energy consumption and cooling load up to 7% and reducing heat stratification in commercial complex in cold and dry climate of Mashhad city.

Light wells are extensively used in high-rise buildings as an integrated part of the building for daylighting. Since the solar illuminance is usually higher on horizontal surfaces than the vertical ones, roof Skylights transmit more daylight than vertical windows. For proper design of daylighting, a parametric study on the effective parameters in daylighting is required. In this study, the effects of these parameters are investigated for a four-story building.  Attenuation of the daylight in the floors, effects of reflectivity of the surfaces of the light well, as well as effects of the reflectivities of light well floor and room walls, effects of the dimensions of the Skylight, and the slope of Skylight to horizon have been studied,. The daylight factor for the three situations of the lightwell: four-sided, three-sided, and in the corner of the building have been obtained. The radiosity method or point by point algorithm has been used for daylighting calculations. Results of the present study can be used in improving the daylighting of the buildings.

Due to demographic changes and the growing trend of urbanization and the consequent increase in energy demand in recent decades, energy supply has become one of the main concerns of human societies. The use of passive solutions and renewable resources for sustainable design, especially in the construction sector, is one of the ways to deal with the consequences of the crisis due to limited fossil fuels and greenhouse gas emissions. Among renewable energy, solar energy plays an important role in meeting the needs of the building, especially lighting. Daylight is one of the basic components of a passive solar building design. Proper integration of daylight with architectural design is considered one of the most effective means of reducing energy and the environmental problems and improve the quality of visual comfort and health. Among the various daylight systems available today, toplighting is used because of its ability to provide uniform daylight in spaces without facades or in deep rooms. The use of Skylights in large stores, due to the high energy demand of this type of building and also the potential of using natural light, can reduce energy consumption and introduce daylight to deeper spaces. The purpose of this study is primarily to investigate the thermal and lighting performance of the installation of Skylights in store buildings and in particular the Shahrvand Al-Ahmad branch store in Tehran. To achieve this goal, after defining the parameters affecting energy and light performance, the process of simulating daylight and energy was done in two stages: 1) Skylight, and 2) clerestory. Models with parameters including the dimensions of the Skylight, the height of the north and south curb, the type of glass in the model with Skylights, and the height and type of glass in the model with clerestory were simulated, so that an appropriate solution in terms of light and energy can be achieved with the help of multi-objective optimization process,. The objectives are energy use intensity (EUI) and spatial useful daylight illuminance (sUDI), which were evaluated after the optimization process with the help of Pareto front diagrams. Finally, in the two mentioned models, sensitivity analysis was performed to evaluate the effect of the studied variables on the outputs.  According to the results, the Skylights with SFR of 4.97% to 6.09% with the lowest curb height and double glazing with 0.10 emission coefficient, and high clerestories on the north and south walls and low clerestories on the east and west walls with double glazing with 0.10 emission coefficient have the best performance in terms of daylight and energy. Also, the Skylight provides the same level of daylight with more uniformity compared to the clerestory in the same conditions, with 35% less glass area but with 12 kWh/m2 of higher energy consumption. According to the results of sensitivity analysis, the dimensions of the Skylight and the height of the southern clerestory have the greatest impact on daylight and energy use in the model with Skylights and clerestories, respectively.

One of Kashanchr('39')s historical architectural achievements has been the use of Skylights in historic houses. Research has shown that these Skylightschr('39') quality and performance are related to factors such as their type, distance from other openings, size, and materials, cut-off Angle, area of illumination created, number, and amount of their efficiency. The article used these factors for evaluating the impact of these Skylightschr('39') performance. The present study, based on library and field studies, analyzes the effect of Skylightschr('39') performance on the architecture of the house of Boroujerdi as a selected example. The results show that Skylightschr('39') performance has been influential on architectural proportions through the number, size, and area of the space illuminated by it. Also, the three-component structure of Skylights determined the geometry and architectural form of related spaces, and formalization was a part of the design of Skylights in Kashan, which was a solution to direct light into the building; Also; the distance of the Skylights from each other shows that the scale and dimensions of the space have been formed in relation to them and the efficiency factor of 50% of the Skylights shows the acceptable performance and correct choice of their materials in providing light.