Window Area Research Articles

Energy efficiency of solar shading structures of the rectangle type in the climate conditions of Hanoi and Moscow

Introduction. The article presents the results of calculating the energy efficiency of windows using a sun protection structure (SZK) of the rectangle type for buildings facing the southeast direction in the climatic conditions of the cities of Hanoi and Moscow, using the new proposed method described in Evaluation of the energy efficiency of a window system with a П-type sunshade. In the conditions of Vietnam, for buildings with a southeast orientation (southwest orientation), the use of a rectangular SZK is considered the most appropriate.
 
 Materials and methods. the calculations are based on the projection of the sunbeam when calculating a part of the window area in the shade, considering the coefficient of reducing the irradiance of diffuse solar radiation by a shading device. In the presence of the shading device, there is a reduction in the intensity of diffuse solar radiation, which is represented by the coefficient Kbt. This coefficient was determined by experiments and proposed by regression equations. A computer program for calculating SZK was created to facilitate evaluation and design practice.
 
 Results. The article analyzes the effectiveness of rectangular sun protection divice, compared with a egg-crate shaped structure. Solar heat gain q through the southeastern window was calculated for the two types of SZK mentioned above with solar radiation data from Hanoi and Moscow.
 
 Conclusions. The results of the study show that the energy efficiency of the egg-crate shaped SZK is marginally better than the rectangle-type SZK for both cities. Rectangle-type SZK prove to be a good solution for building windows oriented to the east and south-east directions due to their simplicity.

Preliminary Evaluation of the Heating and Cooling Capability of an Insulating Glass Unit

AbstractIn order to achieve maximum transparency of the buildings, architects plan large facades and large window areas. These glass surfaces have the disadvantage that they form a cold surface in winter and the sun heats the room in summer. It is desirable to use the potential of the huge surfaces of the glass for controlled heating and cooling. To be able to use an insulating glass unit as a heater, the temperature must be distributed uniformly over the glass. Existing solutions rely on heating wires between the panes of a laminated glass, but these are visible for the user. To create an invisible system, the cavity of the insulating glass can be used. The idea is to fill the cavity with helium instead of argon or krypton. Due to the good thermal conductivity of helium, temperatures in the cavity can be distributed over the whole glass. Content of this paper is the basics research, experimental research of the gas tightness with helium in the cavity and the first functional tests for heating and cooling with helium. The results give a first look at the heating and cooling capability of and insulating glass unit and include the basics for further researches on this topic. These are the first results of a current research project of the Institute of Building Construction at the TU Dresden.

Optimization of the Selected Parameters of Single-Family House Components with the Estimation of Their Contribution to Energy Saving

Knowledge of the influence of factors determining energy consumption in buildings is very important for the possibility of effective energy saving. This article describes the results of an original study on the analysis of the annual energy demand for heating (QH;nd), cooling (QC;nd), and annual usable energy demand (QH/C;nd = QH;nd + QC;nd) assumed as objective functions of a designed single-family building, which can be classified as a typical representative of currently built houses in Poland. It was assumed that the object of study was located in the climatic conditions of north-eastern Poland. The study takes into consideration three groups of selected parameters: architectural/spatial, structural, and physical properties of windows. The research was carried out in a single-family building, as energy consumption in residential buildings accounts for a significant part of the total energy consumption in buildings. In the group of architectural/spatial parameters, the height of rooms in the building (h) and the window area change coefficient (k) were taken into consideration. The design parameters pertained to the solutions of building components: the density of the material of the inner layer of the external walls (ρ1), the density of the material of internal walls (ρ2), and the thickness of internal walls (d). In the third group of parameters, the heat transfer coefficient of the glazing (Ug) and the total solar transmittance of the glazing (g) were considered. Deterministic mathematical models of these dependencies were developed on the basis of the results of a computational experiment, obtained by performing a simulation with the use of the DesignBuilder software, based on the EnergyPlus computational engine. The models allowed the authors to estimate the degree and nature of the influence of the examined factors on the building’s energy demand. As a result of the optimization of parameters according to the energy criterion, the contribution of each of the three groups of parameters to energy saving was determined. Deterministic numerical optimization using MATLAB was applied. It turned out that the factors from the first group played the most important role in energy savings (40.0%), and the factors from the third group contributed slightly less (25.7%). The contribution of the characteristics from the second group was 4.2% of the total value of energy saving. This information can be useful to scientists, as well as engineers and policymakers, in making correct decisions when designing new residential buildings.

Ventilation performance of solar chimney integrated into a multi-storey building

Previous studies have mainly focused on solar chimneys in single-chamber/zone or single-story buildings. Its theoretical development in multi-chamber or multi-story buildings is lagging, which hampers its practical applications in multi-storey buildings. This study investigated ventilation capacity characterized by volume flow rates numerically and theoretically for a multi-storey building with a solar chimney. Three mathematical methods based on simplified models were introduced to predict the ventilation rates for each floor. By comparing the three methods, Method 1, based on the bifurcation hypothesis, was found suitable for two-storey or single-storey cases; and Method 3, based on empirical flow equations, is practical for those cases greater than two-storey. To optimize the ventilation rate, a wider cavity gap and a higher stack height for a multi-storey solar chimney were the most effective ways compared to the single-zone/floor cases. A larger window area and air inlet size promoted the ventilation capacity, where the growth rate of volume flow was small and critical values exist. It was observed that the solar chimney dimensions show a more significant effect on the volume flow rates than the solar radiation intensity. The main contribution of this study is that it establishes the links between the single-zone and the multi-storey theoretical models and proposed practical mathematical methods to obtain acceptable prediction accuracy of ventilation rates for a solar chimney in a multi-storey building.

The Use of Daylighting Rules of Thumb in Libraries Across Different Eras

This study investigates the use of daylighting rules of thumb in four libraries across different eras and aims to outline different guides, methods and strategies used by architects in applying daylighting design in this building typology. Two historical libraries prior to the 20th century were selected to identify the use of daylighting strategies during the times when electrical lighting was not yet available in buildings. In the other hand, two post 20th centruy libraries were also selected for a similar daylighting rules of thumb appraisal. The study reveals that three daylighting rules of thumb were commonly used in all of the library buildings appraised which include the limiting floor depth rule, window area to wall area ratio and window area to floor area ratio. It was found that the most consistent daylighting rule of thumb is the limiting floor depth whereby the depth of typical floor plan is within the range of approximately 6 meters for unilateral and 12 meters for bilateral daylighting. Each sampled library building was found to utilise a combination of daylighting rules of thumb in it’s design. This demonstrates that simple daylighting guides have been used to design library buildings in different climates, sites and eras. It also indicates that daylighting rules of thumb or simple guides have been timelessly used by architects to design well daylit library buildings.

Energy efficiency of residential buildings in Tehran climate by saving energy

This paper examines and compares energy consumption in a sample building to reduce energy consumption and obtain the best performance in reducing energy consumption. Energy Plus software has done the modeling and simulation of energy consumption for a hypothetical five-story building in the climate of Tehran. The hypotheses used in this study include the use of four types of phase-change materials (PCMs) with different melting temperatures and specific latent temperatures in the Interior and exterior walls of the building, use of four different types of insulation, including glass wool (fiberglass), rock wool, elastomer and polyurethane in the outer walls of the building, the effect of the ratio of window area to exterior walls of the building on energy consumption, the use of various HVAC terminal systems including air conditioners, radiators and fan coils in the building. This study shows that, in general, the highest energy consumption with an increase of 71% compared to the reference building was related to the use of 90% of the area of the window to the external walls of the building, and the lowest energy consumption with a decrease of 20.81% compared to the reference building was related to the use of polyurethane thermal insulation.

Sporters' visual comfort assessment in gymnasium based on subjective evaluation & objective physiological response

Visual comfort is affected by the light environment of interior spaces. However, relatively few studies have combined subjective and objective indicators of visual comfort in the assessment of indoor sport facilities. Thus, the purpose of this was to determine the factors influencing visual comfort and establish corresponding thresholds by combining subjective evaluation, objective physiological indicators, and photometric light environment assessment. The experiment was conducted at a university gymnasium in Harbin, located in the northeast of China, during summer, autumn, and winter. The visual comfort of the participants was assessed via subjective evaluation via questionnaires, and objective physiological indicators were recorded using biosensors. Additionally, high-dynamic-range images were used to assess the light environment. Subjective evaluation revealed that visual comfort was affected by the glare intensity, target clarity, and emotional state. Objective physiological indicators showed that emotional arousal and alertness were higher in autumn and winter than in summer. Furthermore, the physiological indicators and subjective evaluation of visual comfort were highly consistent with each other. In summer, acceptable ranges of the luminance ratio of the window area to the field of view were less than 5 and greater than 10, and comfortable ranges were less than 3 and greater than 12. In winter, the upper acceptable and comfortable thresholds were 42 and 13, respectively. This study provides a reference point for optimizing gymnasium light environment design.

Time-dependent effect of intense capsule-coffee and bleaching on the color of resin-infiltrated enamel white spot lesions: an in vitro study.

Background and ObjectivesWhite spot lesions (WSLs) are a common problem that can be conservatively managed by resin infiltration. Consumption of dark beverages such as coffee causes staining of dental hard tissues, which can deteriorate the esthetic qualities of treated WSLs. The aims of this study were to investigate the effect of dark coffee heavy consumption on ICON® resin infiltrated WSLs and the influence of bleaching on them after staining.MethodsTwenty surfaces from sound human extracted third molars were used in the study. Two square-shaped buccal and lingual window areas had artificially created WSLs (received buccal resin infiltration afterward). Using VITA Easyshade, the baseline ΔE was recorded. Espresso coffee was used to immerse all surfaces for 8 days. The color coordinates according to CIE LAB were recorded for all surfaces at 2, 4, 6, and 8 days of immersion, and ΔE was calculated at each timepoint. After 8 days, in-office bleaching was applied to all surfaces according to the manufacturer’s instructions and the color. Coordinates and ΔE were recorded. For statistical analysis, an independent sample t-test was used to compare each group. A general linear mixed model (GLMM) repeated measure ANOVA was applied for statistical analysis of L*and changes due to staining over time.ResultsAnalysis of time as a main effect on the L values of surfaces was statistically highly significant (p < 0.01). The interaction of time with surfaces under investigation and type of surface (test vs. control) as a main effect were non-significant (p = 0.47 and p = 0.35, respectively). Bleaching showed a significant difference in color lightness in both test and control surfaces compared to the mean L value at 8 days of staining (p < 0.01).ConclusionCapsule-coffee consumption gradually influences the esthetic of resin infiltration on treated teeth. However, bleaching materials might restore an esthetic shade.

Implementation of a Dynamic Thermal and Illuminance Control System in Responsive Facades: Shading Study

This study evaluates three shading configurations designed and tested in a preliminary stage of responsive shading device development. The strategy is based on trigonometric relationships focused on solar angles at any given moment. The configurations are thus related to the ratio of the window area shaded by a responsive brise-soleil that provides 0%, 50%, or 100% shading of the indoor space, based on the daylight needs and the indoor thermal control realized. Shading simulations were performed for Pomona, California (latitude 34.04°) for different seasons of the year. Simplified thermal simulations were run in EnergyPlus to estimate the effectiveness of the method in a full-scale environment of three shading modes (static shading device, seasonal shading, and responsive brise soleil). Comparisons were made relative to a ‘no shading’ condition to improve indoor comfort conditions. The results of the visual analysis demonstrated a higher shading efficiency for lower solar angles between the equinoxes and winter. In terms of comfort, the response brise soleil was found to be promising in locations with seasonal variations. The response was low in predominantly tropical climates. Therefore, the strategy can be used to better control indoor conditions. The extent of solar heat gain and the degree of work-task illuminance can be improved to improve comfort in naturally conditioned spaces. The extent of energy consumption can be reduced.

Analisis Kesenjangan Keuntungan Usaha Bunga Krisan Di Show Window Dan Di Tingkat Petani Kelurahan Kakaskasen II, Kec. Tomohon Utara Kota Tomohon

This research aims to analyze the profit gap of chrysanthemum business in “Show Window” Land and Farmers' Land in Kakaskasen II Village, North Tomohon District, Tomohon City. This research was conducted from December to April 2022. The selection of respondents was done intentionally. The data collection method is a survey method. Interview data collection techniques using a questionnaire. The data used are primary data and secondary data. Primary data were collected through interviews based on questionnaires, to four farmers. Secondary data were obtained from related institutions, namely the Head of the Show Window Center and the Kelurahan Office. The results showed that the profit of the chrysanthemum flower business in the Show Window area was greater than that of the farmer, namely Rp. 13,635,049, while in the Farmer's Land, it was Rp. 7,705.822. The value of the gap in the profit of chrysanthemum business between the potential performance in the Show Window Land and the actual performance in the Farmer's Land is Rp. 5,891,726. The profit gap that occurs is caused by the cost factor incurred and the resulting revenue factor. Costs that can affect fixed costs are depreciation costs, and variable costs consisting of medicine costs, labor costs, and other costs (electricity and water). Costs that can affect fixed costs are depreciation costs, and variable costs consisting of medicine costs, labor costs, and other costs (electricity and water). Acceptance at the Show Window is greater than that of farmers because production is influenced by land use, chrysanthemum production, cultivation methods, and competent workers.

Air Quality and Thermal Environment of Primary School Classrooms with Sustainable Structures in Northern Shaanxi, China: A Numerical Study

In northern Shaanxi, China, the air quality and thermal insulation properties of primary school classrooms should be given more attention due to the relatively low temperatures in the winter, which are significant to the learning processes of students in classrooms. Some sustainable building measures have been designed and constructed to improve the air quality and thermal comfort of classrooms in this region; however, is still unclear how these measures influence air quality and temperature. This study investigated the indoor air quality and thermal environment of a typical primary school classroom in Yulin city, Shaanxi Province, China. The classroom was characterized by sustainable structures, including double-sided corridors and an underground ventilation pipe, for better thermal insulation. By conducting on-site monitoring in the classroom and performing various numerical simulations based on finite element software, the variations in the indoor air quality (carbon dioxide, water vapor concentration) and temperature over time, and under different conditions, were investigated. Moreover, influences (i.e., of corridors, ventilation pipes, window areas, classroom areas, and the number of students) on the air quality and temperature were analyzed. It was proven that double-sided corridors, underground ventilation pipes, and windows with heights/widths equaling 1 could provide energy-efficient and livable building structures for primary school classrooms in the northern Shaanxi region of China.

Evaluation of Urban Green Building Design Schemes to Achieve Sustainability Based on the Projection Pursuit Model Optimized by the Atomic Orbital Search

The popularization and use of green buildings are of great significance for reducing the carbon emissions of buildings and achieving sustainable development. Scientific evaluation of the green building design scheme is the key factor in ensuring the popularization and use of green buildings. To overcome the shortage of a systematic evaluation index system and comprehensive evaluation method, an evaluation index system of green building design schemes and an evaluation method based on the projection pursuit model were developed. First, according to the needs of green building development, an evaluation index system of green building design schemes was systematically constructed from the five aspects of the economy, the resource utilization index, environmental impacts, technical management, and social impacts. The calculation methods of all secondary indexes are provided in detail. Then, a novel evaluation method based on the projection pursuit model optimized by the atomic orbital search was constructed. This method searches for key influencing factors and determines the evaluation grade from the evaluation data structure, and realizes the scientific and objective evaluations of green building design schemes. Finally, the Nanchang Hengda Project was selected to conduct a detailed empirical study. The research results show that the incremental net present value of the investment, the energy consumption of the air conditioning system, and the ratio of the window area to the indoor area are the most important secondary indexes. Moreover, the environmental impact index was found to be the most important primary index. Via comparisons with different optimization algorithms and evaluation methods, the superiority of the proposed model is proven.

An Analytical Study of the Key Physical Factors that Affect the Health Status of the Home Isolated Residents under COVID-19

The indoor living environment has an important impact on human health, which is more obvious at home segregation under COVID-19. This paper discussed some key factors that affect the health status, including the physical and mental aspects, of people isolated at home during COVID-19. In particular, the indoor temperature, the mass concentration, including the humidity and density of contaminants, were thoroughly studied. The measurement methods and related factors under different situations were also presented. Moreover, the interaction among different factors, showing how the whole ventilation system works, was also illustrated in the paper. Those results show that temperature and concentration (humidity, CO2, and fungus) levels should be controlled in a suitable range. People could use different ventilation systems in different situations or open a proper area of windows to keep healthy. It is also important to keep distance between people.

Quality Of Lighting In Regular And Fullday Class Tsanawiyah Miftahul Huda Tayu Pati

An analysis of the quality of the lighting level in the classroom needs to be carried out to determine the existing lighting level. If the level of lighting is below the specified standard, it can cause eye damage. Meanwhile, if the level of lighting is above the standard, the classroom will be too bright. The purpose of this study was to determine the level of lighting in the Regular and Full Day classroom of MTs. Miftahul Huda Tayu. The tools and materials used in this experiment are lux meter, roller meter and thermohygro. The experiment was carried out in the Regular class school building and the Full Day classroom building with a sample of three rooms per building with each room representing each floor. The experiment was carried out during the day for three consecutive days. There are two types of the intensity measured in this experiment, namely natural intensity (lights off) and natural artificial intensity (lights on). In each room, 9 points were taken. The floor area and window area were measured using a roller meter. From the experiments that have been carried out, it can be concluded that the lighting in the Regular class (17-73 lux) and Full Day class (97-181 lux) buildings do not meet Indonesian National standards (Standar Nasional Indonesia, SNI).

Efficient electrochemical degradation of X-GN dye wastewater using porous boron-doped diamond electrode

Surface porous Ti substrates were obtained by electrodeposition–hot melt–alkali etching. Porous-Ti/BDD and flat-Ti/BDD electrodes were prepared for comparative study. The results of SEM, Raman, and XRD analyses show that the BDD films of these two electrodes had good uniformity and stable quality. The electrochemical window (EW) and electrochemical-active surface area (EASA) of the porous-Ti/BDD electrode is as high as 4.21 V and 22.78 cm2 (11.39 cm2/cm2), respectively. Furthermore, the electrochemical catalytic performance and degradation mechanism of porous-Ti/BDD electrode as the anode were studied by the electrolysis of Active Orange dye X-GN (X-GN), and the optimal electrochemical degradation operating parameters were obtained. The results show that when the degradation time was 50 min, the X-GN was completely decolorized. The TOC removal rate reached 69.24%, and the energy consumption was 5.62 kWh m−3. The contribution rate of •OH and SO4•− was calculated to be 91.40% and 1.26% by radical quenching experiments, respectively, indicating that the active substances in the degradation system were mainly •OH and SO4•−. The high specific surface characteristics of porous-Ti/BDD electrode enhanced its electrochemical oxidation advantages, and it showed a high degradation efficiency and low energy consumption for the treatment of X-GN simulated wastewater.

The Real-World Effects of Route Familiarity on Drivers' Eye Fixations at Urban Intersections in Changsha, China.

A crucial factor, route familiarity, can affect traffic safety. Nevertheless, focus on the influence of route familiarity on drivers’ eye fixations at urban intersections has received less attention. Identifying the real-world effect of route familiarity on drivers’ eye fixations at urban intersections in Changsha, China, was the objective of this study. Their visual fixation indicators were recorded while unfamiliar drivers and familiar drivers drove a 9 km-long route with nine intersections in an urban environment, but their effectiveness was indicated by the data collected 150 m before the lane stop and 50 m after the lane stop at these intersections. From the analysis of the extracted data, the results indicated that route familiarity could influence drivers’ processing times in the left window (LW) and other areas (OT). Compared with familiar drivers, unfamiliar drivers had longer processing times and higher mental workloads for the right front (RF). For the vehicle’s front (RF, FL, FR), the sampling rates and mental workloads of unfamiliar drivers were higher than those of familiar drivers, but it was the opposite for the driver’s sides (LW, RW) and rear (LM, RM, ReM). It was also indicated that the phenomenon said to increase familiarity with the route and make drivers more likely to be distracted in urban intersections had not been found. From the present findings, the effect of route familiarity on drivers’ eye fixations at urban intersections was confirmed. The high accident risk of familiar drivers could be partly explained by the decrement in drivers’ eye fixation strategies. However, the strategies could not account for the phenomenon that more familiar drivers are involved in rear-end accidents. Therefore, the reason can be investigated based on drivers’ visual scanning strategies, their physiological signals and driving behavior in the future.

Identification of ARX Model for Thermoelectric Cooling on Glass Windows

Thermoelectric cooling (TEC) is a solid-state heat pump that uses the Peltier effect to dissipate the heat generated by the electronic packaging system. TECs are widely used in aerospace, military, scientific work and industry due to small size, lack of moving parts, and ease of integration. In this study, a cooling system integrated with TEC is developed in a testing area (lecturer’s office) with the aim to reduce the temperature of the hot glass window area due to solar radiation that passes through it. This cooling system used direct TEC, for keeping the cooling temperature on the window to about 26 °C which is equivalent to an air conditioning setting temperature of 26 °C set during the experiment. This work includes experimental and modelling studies conducted on cooling systems integrated with TEC. The main target of this study is to develop a dynamic model of a cooling system integrated with TEC. The black box modelling approach in producing a mathematical model was selected based on the ARX model that corresponds to the actual dynamic state of the cooling system. The best model was finalized based on the best match on curve patterns when comparing the real and estimated models using the system identification tools in MATLAB, and also had the least error. The accuracy of the models was compared and analysed. The results showed that the 4th order of the ARX model produced a higher best fitting and standard deviation values of 78.14% and 0.030769. This system accuracy is almost within the acceptable range for most error calculations in the validation method. In addition, the ARX model is found incapable of achieving the highest fitting due to the losses from the dynamic environment and losses from the TEC itself. Still, the use of this black box model used in this study is a significant variation where system parameters can be identified even offline.

Uncertainty in model prediction of energy savings in building retrofits: Case of thermal transmittance of windows

Energy saving in buildings is an important measure for mitigation of climate change. There exists a large potential for energy saving in buildings by improving the thermal performance of windows. For decisions on energy saving window retrofits, accurate estimation of the energy saved and its uncertainty is of importance. The ISO 15099 standard, which is normative for thermal modelling of windows within the building sector, does not give uncertainty estimates. The main novelty of this study was to provide uncertainty analysis for model prediction of the thermal transmittance of windows, in the perspective of decisions on window retrofits. For this purpose, we proposed a new simplified model, which facilitated uncertainty analysis, and still was similar to the ISO 15099 window model. The model was validated by application of a benchmark validation procedure to a set of previously performed validation experiments. Main conclusions were: (i) The model was accurate within a prediction uncertainty equal to 0.20 Wm−2K−1; (ii) The domain where the model is valid was described using existing well-documented validation experiments. This domain was restricted to windows with glazing thermal transmittance corresponding to 2-layer glazing, and to windows where the frame area is a minor part of the total window area. (iii) The prediction uncertainty was mainly determined by the measurement uncertainty in the validation experiments; (iv) If a window retrofit is based on reduction of window thermal transmittance, then this reduction has to be larger than 0.56 Wm−2K−1 in order to yield energy savings above the uncertainty limit.

Stable Sn-doped In2O3 films coated on Al2O3 for infrared transparent and electromagnetic shielding conductors

The transparency of most electromagnetic shielding conductors is limited to the visible regime. Here, we demonstrate the high infrared transmittance (>50% at 4-μm-wavelength), low sheet resistance (<200 Ω □−1 at room temperature), and high shielding effectiveness (∼16.2 dB at 10 GHz for the X-band) of 20–90-nm-thick Sn-doped In2O3 films deposited on an (0001)-oriented Al2O3 substrate. The phase persists even at 700 °C in air. Thus, multifunctional Sn-doped In2O3 films on Al2O3 substrates will advance technology in the areas of military applications, invisible circuitry, smart windows, infrared sensors, and transparent solar cells working in extreme environment.

THE VALUE OF A RATIONAL ROOF OVERHANG OVER A STAINED-GLASS FACADE USING BIM TECHNOLOGIES

Problem statement. These days, the issue of reducing energy consumption is relevant, including due to the roof overhang formation in winter, when the sun is below the horizon and can use solar heat for heating, and in summer, when the sun rises high above the horizon and solar radiation is maximum. The issue of roof overhangs value therefore becomes relevant in reducing energy consumption. The purpose of the article is to determine the rational roof overhang value to reduce energy consumption and the dependence between stained-glass system height and roof overhang value using Revit software. Conclusions. The roof overhang value can make a significant difference to a building's energy consumption during the heating period, allowing solar radiation to enter the house due to the large open areas of the stained-glass windows. In the summer, for example, the roof overhang can provide shade inside the house during the hottest times of the day, thereby reducing the energy consumption for air-conditioning cooling. The dependence between the height of the stained-glass window and the rational roof overhang value, which provides shade inside the room in summer and does not prevent the sun's energy from entering the room in winter, was determined.