Search Results (9)

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

As a result of environmental and human influences, several types of surface deterioration emerge on historic buildings, resulting in a decline in the quality of these structures and even threats to their safety. In the conventional approach, assessing the surface damage on a structure involves the time-consuming and labor-intensive judgment and evaluation of trained professionals. In this study, it is suggested that the YOLOv4 machine learning model be used to automatically find five types of damage to historical gray-brick buildings. This would make the job go more quickly. This study uses the gray-brick wall buildings in the buffer zone of the global cultural heritage in Macau as an example. In total, 1355 photographs were taken on-site of the gray-brick walls, and the five most common types of damage were identified. By slicing and labeling the photos, a training set of 1000 images was created, and through 200-generation model training, the model can accurately identify and effectively identify the damage state of the gray bricks and enhance the quality judgment and evaluation of the exterior walls of historical buildings. Experiments allow us to reach the following conclusions: (1) The damage to the gray-brick ancient buildings in Macau is affected by the subtropical maritime climate. Missing paint, stains, and cracks are the main contributors to gray-brick wall damage. (2) Machine learning can help determine the type of damage to old gray-brick buildings, which is useful for managing and protecting historical buildings. (3) The model in this study can identify five types of damage: missing, cracking, plant or microbial erosion, yellowing, and pollution on the exterior walls of ancient gray-brick buildings. It is helpful to accurately identify and evaluate the damaged condition of the gray-brick wall and formulate corresponding protection schemes. Full article

Based on an extensive literature review on passive building designs for tropical climates, seven energy-efficient building design principles for tropical climate areas were deduced. These are: 1. To orientate a building design in such a direction that it protects from excessive solar radiation; 2. To accommodate for indoor natural ventilation; 3. That it makes maximal use of indirect instead of direct natural light; 4, That it reduces the amount of heat transmission through the roof as much as possible by natural ventilation between roof and ceiling and by lowering the roof surface temperature; 5. By preventing the use of high thermal mass materials; 6. By reducing through the exterior walls as much as possible heat transmission by e.g., preventing direct sunlight on the external walls and applying reflective paints on the external walls and; 7. By creating outdoor and transition spaces such as balconies, terraces atriums and corridors. The insights from the literature review were used as input to conduct a field study to evaluate the practice of applying passive building design principles. To this end, for 626 buildings on the Caribbean island Curaçao, it was investigated to what extent the recommended passive design principles for tropical climates were actually applied. Based on the results of the field study, several recommendations are made to improve the practice of applying passive building principles. Full article

The Alhambra Monumental Ensemble (Granada, Spain) is a unique well-preserved palatine city from the medieval Islamic period, and it constitutes the best example of Nasrid architecture. In this work, we focus on the study of one of its most unknown decorations: Wall paintings with the appearance of red bricks. These faux-brick decorations are found in many different locations within the Alhambra complex, including both exterior and interior walls, arches and vaults. We have considered locations from different Nasrid reigns to gain information about their characteristics in terms of materials, execution techniques and conservation state. They have been studied combining a non-invasive methodology using portable equipment (X-ray fluorescence (XRF) and Raman spectroscopy) with complementary studies on selected samples (Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS) and Raman microimaging). In general, those located in the exterior are poorly preserved, in contrast with the good conservation state of the interior motifs. The red rectangles of these decorations were painted over a white finishing layer, which acted also as the edge lines between these false bricks. The red colour was always due to hematite (α-Fe₂O₃), as revealed by its characteristic Raman bands. The use of a natural red ochre pigment (very abundant in the region) could be hypothesised considering XRF and SEM-EDS results. In general, the white layer was made of lime mortar and the presence of CaCO₃ in the painting layers suggests the use of lime-based techniques (either fresco or mezzo fresco). Only in one of the indoor locations, a different execution technique, based on gypsum (CaSO₄·2H₂O) plaster, was used. The identification of calcium oxalate in this location, in the form of weddellite (CaC₂O₄·2H₂O), can be interpreted as the result of organic binder degradation. Furthermore, superficial contamination with gypsum was always detected in outdoor locations. Full article

In recent years, with the rapid development of the building industry in western cities during the period of “Western Development” in China, the paints industry has developed rapidly and become more mature. In addition, waterborne inorganic exterior wall paints have been a great choice in the building industry because of their reduced volatile organic compounds (VOCs) and less toxicity and odor. However, the problem of stain resistance for exterior wall paints in western cities has not been solved, which has become a major obstacle to the application and promotion of exterior wall paints in western cities in China. Therefore, effective measures should eventually be carried out for improving the stain resistance of exterior wall paints in western cities in China. In this paper, an experimental study on improving stain resistance for exterior wall paints in a typical western city in China, Chongqing, is reported. In the three defined designs, the effects of the paint structure type, the pigment volume concentration (PVC), thickeners, cosolvents and wetting and dispersing agents on the stain resistance of exterior wall paints in a typical western city in China, Chongqing, were examined. The experimental results suggest that the stain resistance of silicone–acrylic paint was the most suitable among the three kinds of tested paints (silicone–acrylic paint, styrene–acrylic paint and pure acrylic paint). In addition, the PVC had a great influence on the stain resistance of the exterior wall paints. The compactness, water absorption and stain resistance of the paint’s film were the most suitable when the PVCs of the paints reached 45%. Furthermore, the tested wetting and dispersing agents made the same contributions to the paints’ stain resistance, as their decline rates for reflectivity were similar. The reflectivity of the film significantly decreased when the ratio of associating thickener to non-associating thickener reached 4:1, and also significantly declined when the content of propylene glycol reached 5%. Full article

White building components, whether decorative or the overall structure, are susceptible to extreme weathering conditions, which affect the durability of the building’s external surface. In particular, white natural stone materials can provide buildings with beauty, durability, and sustainability, but this beauty is affected by key factors determining their weather resistance, namely physical properties such as porosity and acid and alkali resistances. As indicated by a past study, marble used as the exterior wall of a building in a similar environment will exhibit tarnishing after six months of weathering. Taiwan is a subtropical island, so the weather resistance of building materials to this environment is worthy of attention. As pointed out by the study, raw stone materials containing zirconium and silica can have greater weather resistance, do not easily change color, and possess good stress resistance properties. Focusing on this, this study attempted to identify stone materials with such compositions and sent samples to SGS (Societe Generale de Surveillance S.A., New Taipei City, Taiwan) for testing of weather resistance. This paper uses Spanish artificial stones for the study and observes the changes in the surface cleanliness on two buildings in Yilan County and Taipei in Taiwan after exposure to sun and rain. The experiments were conducted over two years. The study results showed that the artificial stones displayed no change in outward appearance under both rainy and acid rain environments. In Yilan, construction of an exterior wall was carried out in February 2018. The exterior wall used the white artificial stone directly from the manufacturer, and the black artificial stone with added paint for stone protection. After two months, the black artificial stone covered with paint exhibited a change in color and stains appeared on the surface, while the white artificial stone not covered with paint maintained the same cleanliness after two years. In Taipei, white Spanish artificial stone was used for the exterior wall of an entire building block in February 2020. After the frame was dismantled in September 2020, the color was found to be unaffected, being as pure white as it was when new. Therefore, this study selected Spanish artificial stone for the design of a building’s exterior wall, as the cleanliness of the stone surface is not affected and it has good applicability in rainy and acid rain island environments. Full article

A one-dimensional transient hygrothermal model was used to simulate eight different wood-frame wall assemblies. Simulations were compared with measured results from a two-year field study exploring the effects of exterior insulation on wall moisture performance in a cold-climate. The field study documented the moisture content, temperature, and relative humidity measurements in wall assemblies using oriented strand board (OSB) sheathing. Simulations were performed using generic design input values as well as input values based on measurements or sensitivity analysis. Laboratory material property measurements informed the choice of material property values in the improved model for OSB, asphalt-coated kraft paper, and interior latex paint. Simulations using improved input values typically agreed with field measurements within measurement error. The most significant model improvements were all related to vapor permeance. The vinyl siding used an effective permeance much lower than typically recommended. However, both the extruded polystyrene insulation and the asphalt-coated kraft paper facing on the cavity fiberglass insulation had higher permeance than literature values. Full article

The amount and market size of apartment complex exterior wall painting work continues to increase each year in South Korea. Nevertheless, there are difficulties with the supply and demand of human resources due to the high risks associated with conventional painting work. To resolve these issues, research and development has recently been conducted on a Gondola-type Exterior Wall Painting robot (GEWPro). The aims of this study were to develop a performance evaluation and life cycle cost (LCC) analysis model for a GEWPro and deduce its performance and economic efficiency through a case study. According to the results, the performance of the automated method was 16.8% higher than that of the conventional method, and the economic efficiency was also superior (benefit/cost ratio 6.39). These results show that the proposed performance evaluation and LCC analysis model can predict the productivity and economic efficiency of automated methods. Full article

Long-term moisture performance is a critical consideration for design and construction of building envelopes in energy-efficient buildings, yet field measurements of moisture characteristics for highly insulated wood-frame walls in mixed-humid climates are lacking. Temperature, relative humidity, and moisture content of wood framing and oriented strand board (OSB) structural panel sheathing were measured over a period from mid-November 2011 through March 2013 in both north- and south-facing orientations in test structures near Washington, DC, USA. Wall configurations varied in exterior cladding, water-resistive barrier, level of cavity insulation, presence of exterior continuous insulation, and interior vapor retarder. The combination of high interior humidity and high vapor permeance of painted gypsum board led to significant moisture accumulation in OSB sheathing during winter in walls without a vapor retarder. In contrast, wintertime moisture accumulation was not significant with an interior kraft vapor retarder. Extruded polystyrene exterior insulation had a predictable effect on wall cavity temperature but a marginal impact on OSB moisture content in walls with vinyl siding and interior kraft vapor retarder. Hygrothermal simulations approximately captured the timing of seasonal changes in OSB moisture content, differences between north- and south-facing walls, and differences between walls with and without an interior kraft vapor retarder. Full article