Search Results (82)

If implemented properly in architectural design, passive measures can contribute to achieving the desired comfort in a building while reducing its energy consumption. Glazed additions in the form of sunspaces or greenhouses can influence the improvement of building energy efficiency and, at the same time, create appealing and pleasant building extensions. Through energy simulations performed using EnergyPlus software, this study aims to analyze the potential contribution of glazed additions to a detached house to reducing energy consumption and creating additional space for living. Research was performed as a case study at the following locations: Niš (Serbia), Berlin (Germany), and Tromsø (Norway). For the purposes of this study, five models (M0–M4) were developed and subjected to analysis across two different scenarios. The results of the conducted research showed that the integration of glazed elements can significantly contribute to energy savings: maximum total annual savings regarding heating and cooling go from 21% for Tromsø, up to 32% for Berlin and 40% for Niš, depending on whether the building to which the glazed element(s) is/are attached is insulated or not and the number and the position of glazed elements. Although glazed additions can create a pleasant microclimate around the house, the overheating observed in the study indicates that proper ventilation and shading are mandatory, especially in more southern locations. Full article

This research proposes an integrated lighting and solar shading strategy to improve energy efficiency and user comfort in a retrofit project in a temperate-humid climate. The study examines a future library addition to an existing faculty building in Bursa, featuring highly glazed façades (77% southwest, 81% northeast window-to-wall ratio), an open-plan layout, and situated within an unobstructed low-rise campus environment. Trade-offs between daylight availability, heating, cooling, lighting energy use, and visual and thermal comfort are evaluated through integrated lighting (DIALux Evo), climate-based daylight (CBDM), and energy simulations (DesignBuilder, EnergyPlus, Radiance). Fifteen solar shading configurations—including brise soleil, overhangs, side fins, egg crates, and louvres—are evaluated alongside a daylight-responsive LED lighting system that meets BS EN 12464-1:2021. Compared to the reference case’s unshaded glazing, optimal design significantly improves building performance: a brise soleil with 0.4 m slats at 30° reduces annual primary energy use by 28.3% and operational carbon emissions by 29.1% and maintains thermal comfort per ASHRAE 55:2023 Category II (±0.7 PMV; PPD < 15%). Daylight performance achieves 91.5% UDI and 2.1% aSE, with integrated photovoltaics offsetting 129.7 kWh/m² of grid energy. This integrated strategy elevates the building’s energy class under national benchmarks while addressing glare and overheating in the original design. Full article

Facing rapid urbanization, rising temperatures, and a residential sector that accounted for 38% of Egypt’s electricity use in 2022, middle-income housing presents a critical yet underexplored opportunity for energy efficiency improvements. This study investigates how the integration of passive design strategies and rooftop photovoltaic (PV) systems can enhance energy performance in this segment, using the Sakan Masr housing project in New Cairo as a case study. Addressing a research gap—namely the limited analysis of combined strategies in Egypt’s middle-income housing—the study follows a four-phase methodology: identifying dominant building orientations; simulating electricity demand and thermal comfort using DesignBuilder; optimizing the building envelope with passive measures; and evaluating PV system performance across south-facing and east–west configurations using PV-SOL. Results reveal that passive strategies such as improved glazing and shading can enhance thermal comfort by up to 10% and reduce cooling loads. Also, east–west PV arrays outperform south-facing ones, producing over 14% more electricity, reducing costs by up to 50%, and avoiding up to 168 tons of CO₂ emissions annually. The findings highlight that passive improvements with smart PV integration—offer a cost-effective pathway toward Net Zero Energy goals, with significant implications for national housing policy and Egypt’s renewable energy transition. Full article

In Saudi Arabia’s hot and arid climate, residential buildings account for over half of national electricity consumption, with cooling demands alone responsible for more than 70% of this use. This paper explores the hypothesis that contemporary villa designs are inherently inefficient and that current building regulations fall short of enabling adequate thermal performance. This issue is expected to become increasingly significant in the near future as external temperatures continue to rise. The study aims to assess whether passive design strategies rooted in both engineering and architectural principles can offer substantial reductions in cooling energy demand under current and future climatic conditions. A typical detached villa was simulated using IES-VE to test a range of passive measures, including optimized window-to-wall ratios, enhanced glazing configurations, varied envelope constructions, solar shading devices, and wind-tower-based natural ventilation. Parametric simulations were conducted under current climate data and extended to future weather scenarios. Unlike many prior studies, this work integrates these strategies holistically and evaluates their combined impact, rather than in isolation while assessing the impact of future weather in the region. The findings revealed that individual measures such as insulated ceilings and reduced window-to-wall ratios significantly lowered cooling loads. When applied in combination, these strategies achieved a 68% reduction in cooling energy use compared to the base-case villa. While full passive performance year-round remains unfeasible in such extreme conditions, the study demonstrates a clear pathway toward energy-efficient housing in the Gulf region. Full article

Thermal comfort in public buildings is crucial for occupant well-being and energy efficiency. This study employs TRNSYS software to simulate the effects of thermal mass, window performance, and window–wall ratio (WWR) on summer thermal comfort. The results indicate that without energy-saving measures, increased thermal mass raises daily average maximum and minimum temperatures by 0.33–0.96 °C and 0.14–0.94 °C, respectively. Enhanced WWRs lead to higher daily average maximum and minimum temperatures for double-glazed windows (0.18–0.61 °C and 0.07–0.62 °C, respectively), while single-glazed windows show increased maximum temperatures (0.18–1.86 °C) but decreased minimum temperatures (−0.01 to −0.72 °C). Thermal mass has a modest effect on indoor overheating during high outdoor temperatures. Double-glazed windows and lower WWRs effectively reduce indoor overheating, decreasing the attenuation coefficient by 2.13–28.94%. Conversely, single-glazed windows and higher WWRs enhance heat dissipation, increasing daily average temperature fluctuations by 2.33–44.18%. Notably, single-glazed windows with WWRs ≥ 50% improve thermal comfort by reducing extreme superheat temperature occurrence in heavy-thermal-mass buildings by 0.81 to 14.63%. Despite lower cooling loads with heavy thermal mass, double-glazed windows, and low WWRs, the study suggests that single-glazed windows and high WWRs can enhance summer thermal comfort. Therefore, reasonable shading measures and lighter thermal mass are recommended for such buildings. Full article

Objectives: To examine the effects of surface treatments on the color stability, surface roughness, surface gloss, and wettability of monolithic polychromatic material jetting (MJT) 3D-printed denture material. Material and Methods: Twenty-one color variants of the same denture material (TrueDent; Stratasys, Eden, MN, USA) underwent two surface treatments (polishing only or polishing and glazing), creating 42 study groups with a total of 420 samples (n = 10 per group). The samples were manufactured using a PolyJet 3D printer (J5 DentaJet; Stratasys, Eden, MN, USA), a type of MJT 3D printer. Color measurements were taken with a digital spectrophotometer before and after the surface treatments, and quantitative color differences (ΔE₀₀ and ΔC*) were calculated using the CIE2000 system. Comparisons of ΔE₀₀ were made against the 50%:50% acceptability threshold (AT) of 1.8 and the 50%:50% perceptibility threshold (PT) of 0.8 for tooth shade, as well as the 50%:50% PT of 1.72 and the 50%:50% AT of 4.08 for gingival (pink) shade. After surface treatment, the gloss was measured using a glossmeter, surface roughness was measured with optical profilometry, and wettability was measured by contact angle measurements using an optical tensiometer. The significance of surface treatment on color changes for each color variant was evaluated using one-sided, one-sample t-tests against the AT and PT. The effects of surface treatment on surface gloss, surface roughness, contact angle, and ΔC* were analyzed using t-tests for each color variant. Pairwise comparisons between groups were made using Fisher’s Protected Least Significant Differences (α = 0.05). Results: In most cases, glazing caused the color change (ΔE₀₀) to exceed the AT and PT, with a few exceptions. Most materials exhibited a more vibrant (more saturated) appearance and statistically higher chroma, with glazed surface treatments compared to polished ones, though there were some exceptions. For all materials, the glazed samples had significantly higher gloss units than the polished ones (p < 0.0001). Additionally, all materials showed significantly higher surface roughness in glazed samples compared to polished ones (p < 0.0001 for most). The polished samples had significantly higher contact angles (p < 0.0001 for most). Conclusions: Surface treatments significantly influenced the color, surface gloss, surface roughness, and wettability of MJT 3D-printed denture materials. Glazing led to increased chroma and gloss and produced more hydrophilic surfaces, although it also increased surface roughness. These results highlight the importance of surface treatment selection in optimizing the clinical performance of MJT-fabricated dentures. Full article

This study addresses daylighting to enhance the quality of indoor atmospheres, considering building skins. In the hotel industry, lighting accounts for more than 10% of energy consumption. Many highly glazed façades create visual comfort problems, resulting in increased electric lighting consumption. Ninety-four restaurants were studied in Spain; almost all cases have a window with outside views, and more than half of the cases have tables adjacent to the outside views. However, it is difficult to balance daylight use, a shading system, and the outside view. A virtual restaurant prototype is built by Rhinoceros to simulate the daylight glare index by Evalglare and daylight autonomy of a highly glazed façade with three different shading systems by Radiance through a screen and an overhang with and without a complex fenestration system. The results show that the screen system reduces the daylight glare index value to imperceptible glare (15%), while the daylight glare index for the overhang with and without a complex fenestration system increases to acceptable glare (21%). However, the daylight autonomy for the screen system is almost half (52%) the daylight autonomy for the overhang systems (95%). Although the daylight glare index for the overhang with a complex fenestration system is slightly higher, the illuminance level and its distribution performance are better without obstructing the outdoor view. Full article

This work focuses on the impact of different types of glazing and the dynamic control of shading using roller shutters on the thermal comfort and energy consumption of office buildings. Shading systems control is based on solar radiation and outdoor temperature during the winter period adapted to the Algerian climatic context. The main objective is to evaluate the efficiency of different control strategies in reducing heating demands and CO₂ emissions. The research was conducted experimentally and numerically using TRNSYS 17 (Transient System Simulation Program). A validation was done of the prototype office building and then a parametric study aimed at verifying the influence of various parameters, including glazing type, climate, and the proposed shading scenarios based on temperature or solar radiation on both energy demand and thermal comfort. Different scenarios were proposed to reduce energy consumption and environmental impact. The obtained results demonstrate that shading systems are beneficial even in winter and highlight the effectiveness of controlling shutters based on solar radiation compared to temperature control for the different studied regions for a standard building. This approach achieves reductions of up to 21% for energy consumption, along with a significant decrease in carbon footprint, contributing to the sustainability of energy management in office buildings. Full article

This paper summarizes the potential energy efficiency benefits of PV-integrated dynamic overhangs for housing units in Qatar. Specifically, the technology combines two energy benefits of shading effects of reducing air conditioning loads and generating on-site electricity generation. The analysis is performed for a prototypical dwelling unit in Doha, Qatar. Three adjustment frequencies for the positions of the PV-integrated dynamic overhangs are evaluated, including hourly, daily, and monthly. It is found that optimally operated PV-integrated overhangs can substantially reduce the annual electricity needs of the dwelling unit. For instance, southern-oriented PV-integrated dynamic overhangs can lower the annual net energy requirements for the dwelling unit by 69.7% relative to the case with no shading and by 32.2% relative to the case of deploying PV-integrated static overhangs. Higher energy use reductions can be achieved when the overhang depth and window size are increased and when more energy-efficient glazing types are installed. Full article

Railway stations are normally designed with glazing façades and skylights to achieve aesthetic requirements and facilitate visual permeability, but this design can lead to significant energy consumption. The implementation of dynamic external shading systems together with appropriate control strategies can significantly reduce the energy consumption of HVAC systems. This study numerically investigated the lighting and cooling energy consumption of railway stations equipped with external shading systems under various climatic zones, window-to-wall ratios (WWRs), skylight-to-roof ratios (SRRs) and roller-shade performance. The study shows that lighting energy consumption varies most significantly when the shading activation threshold is set between 50 and 200 W/m². The dynamic shading thresholds are influenced by natural lighting and solar heat gain, with the strategy changing from using natural light to reducing solar gain as the SRR increases. This study also provides the optimal activation thresholds and energy-saving rates for railway station buildings in different climatic zones using external roller shades for different external window scenarios. In Guangzhou, using roller shade A in a railway station under the maximum external window scenario achieves energy savings of 36.41%, while in Shanghai and Beijing, the energy savings are 18.12% and 23.13%, respectively. These results provide guidance for the use of dynamic external shading in railway stations in China and for the achievement of energy-reduction targets in the transport and building industries. Full article

This study investigates the implementation of passive design strategies to improve the thermal environment in the extremely hot climates of Brazil, Portugal, and Turkey. Given the rising cooling demands due to climate change, optimizing energy efficiency in buildings is essential. Using the Trace 3D Plus v6.00.106 software, typical residential buildings for each country were simulated to assess various passive solutions, such as building orientation, wall and roof modifications, glazing optimization options, window-to-wall ratio (WTWR) reduction, shading, and natural ventilation. The findings highlight that Brazil experienced the higher discomfort temperatures compared to Mediterranean climates, with indoor air temperatures exceeding 28 °C all year round and remaining between 34 °C and 37 °C for nearly 40% of the time. Building orientation had a minimal impact near the equator, while Mediterranean climates benefited from an up to 10% variation in energy demand. Thermal insulation combined with white exterior paint resulted in Şanlıurfa experiencing annual energy savings of up to 26%. Optimal roof solutions yielded a 19% demand reduction in Évora, while WTWR reduction and double-colored glazing achieved up to a 35% reduction in Évora and 19% in other regions. Combined strategies achieved energy demand reductions of 44% for Évora, 40% for Şanlıurfa, and 32% for Teresina. The study emphasizes the need for integrated, climate-specific passive solutions, showing their potential to enhance both energy efficiency and the thermal environment in residential buildings across diverse hot climates. Full article

Saudi Arabia faces significant challenges in managing the rising energy consumption in buildings driven largely by its hot climatic conditions. As a result, retrofitting building facades to enhance energy efficiency has become a critical strategy. This study assesses the effectiveness of various façade retrofit strategies in reducing cooling electricity consumption using a real-time case study in Dhahran, Saudi Arabia. The strategies explored include external wall upgrades, window replacements, and installation of shading devices. Each strategy was evaluated individually, considering the reduction in heat gains, cooling load, and payback period as key performance indicators. To further maximize energy efficiency, these strategies were also analyzed in combination using the genetic algorithm optimization method, yielding 224 possible facade configurations. The optimal solution included the use of an External Thermal Insulation Composite System (ETCIS) in walls, louvers in windows, and low-emissivity coating with Argon gas-filled glazing, achieving a cooling energy reduction of approximately 16% and a payback period of 14.8 years. This study provides several recommendations for improving the efficiency of retrofitting building façades in hot climatic conditions. Full article

Air renewal rate is an important parameter for both indoor air quality and thermal comfort. However, to improve indoor thermal comfort, the air renewal rate to be used, in general, will depend on the outdoor air temperature values. This article presents the modelling of indoor air quality and thermal comfort for occupants of a passive building subject to a climate with warm conditions. The ventilation and shading strategies implemented for the interior spaces are then considered, as well as the use of an underground space for storing cooled air. The indoor air quality is evaluated using the carbon dioxide concentration, and thermal comfort is evaluated using the Predicted Mean Vote index. The geometry of the passive building, with complex topology, is generated using a numerical model. The simulation is performed by Building Thermal Response software, considering the building’s geometry and materials, ventilation, and occupancy, among others. The building studied is a circular auditorium. The auditorium is divided into four semi-circular auditoriums and a central circular space, with vertical glazed windows and horizontal shading devices on its entire outer surface. Typical summer conditions existing in a Mediterranean-type environment were considered. In this work, two cases were simulated: in Case 1, the occupation is verified in the central space and the four semi-circular auditoriums and all spaces are considered as one; in Case 2, the occupation is verified only in each semi-circular auditorium and each one works independently. For both cases, three strategies were applied: A, without shading and geothermal devices; B, with a geothermal device and without a shading device; and C, with both shading and geothermal devices. The airflow rate contributes to improving indoor air quality throughout the day and thermal comfort for occupants, especially in the morning. The geothermal and shading devices improve the thermal comfort level, mainly in the afternoon. Full article

The rapid global transition toward renewable energy necessitates innovative solar PV deployment strategies beyond conventional roof installations. In this context, commercial building facades represent an expansive yet underutilized resource for solar energy harvesting in urban areas. However, existing studies on commercial rooftop solar PV predominantly focus on European contexts, neglecting the unique design constraints and performance trade-offs present in regions such as the Middle East. This study addresses this gap by specifically investigating the impact of architectural and structural features on the utilizable facade area for PV deployment in commercial buildings within the hot desert climate of Saudi Arabia. Detailed case studies of twelve representative buildings are conducted, combining architectural drawing analysis, on-site measurements, and stakeholder surveys. The methodology identified sixteen parameters across three categories—facade functionality, orientation suitability, and surrounding obstructions—that impose technical and non-technical restrictions on photovoltaic integration 3D modeling, and irradiance simulations revealed that, on average, just 31% of the total vertical facade area remained suitable for PV systems after accounting for the diverse architectural and contextual limitations. The study considered 698 kWh/m² of solar irradiance as the minimum threshold for PV integration. Shopping malls displayed the lowest utilizability, with near-zero potential, as extensive opaque construction, brand signage, and shading diminish viability. Offices exhibited the highest utilizability of 36%, owing to glazed facades and unobstructed surroundings. Hotels and hospitals presented intermediate potential. Overall, the average facade utilizability factor across buildings was a mere 16%, highlighting the significant hurdles imposed by contemporary envelope configurations. Orientation unsuitability further eliminated 12% of the initially viable area. Surrounding shading contributed an additional 0.92% loss. The results quantify the sensitivity of facades to aspects such as material choices, geometric complexity, building form, and urban context. While posing challenges, the building facade resource holds immense untapped potential for solar-based urban renewal. The study highlights the need for early architectural integration, facade-specific PV product development, and urban planning interventions to maximize the renewable energy potential of commercial facades as our cities rapidly evolve into smart solar energy landscapes. Full article

This paper investigated an application of adjustable photovoltaic (PV) slats to improve the thermal performance of an exposed glazing window and sequentially enhance the energy efficiency and thermal comfort of an office room. Solar radiation and longwave heat gains from a window fitted with PV slats were measured through experiments conducted in an outdoor chamber cooled by a radiant ceiling system. The daylight level at the workplane was also measured inside the chamber. A transient thermal model was developed and validated against experimental data. Using the experimental chamber as a demonstration case, the model revealed that adjusting the slats monthly to fully block direct sunlight could reduce the electrical energy use by 67% compared to a typical office with heat reflective glass windows. However, the electricity generated by the PV slats contributed a minor portion of the overall energy savings. To assess the thermal comfort impact of the PV slats in the room with the radiant cooling, this study utilized radiation asymmetry criteria from ASHRAE Standard 55. Simulations showed that the PV slat-shaded glazing window resulted in a lower asymmetric plane radiant temperature than the unshaded window of heat reflective glass. The adjustable slat system reduced the risk of local discomfort for occupants working near the window in the radiantly cooled office room. Full article