Search Results (40)

This article evaluates the effectiveness of various energy retrofit solutions—both passive and active—for reducing energy demand and improving indoor thermal conditions in apartments of typical multifamily buildings in Central Europe, considering current and future climate conditions. This study combines computer-based co-simulations (EnergyPlus and CONTAM) with in situ thermal measurements to identify challenges in maintaining indoor thermal conditions and to support model validation. Key indicators include the number of thermal discomfort hours and heating and cooling demand. The evaluated strategies include passive measures (wall insulation, green or reflective roofs, roller blinds, solar protective glazing) and active solutions such as mechanical cooling. The comfort operative temperature range of the adaptive model is adopted as a measure of thermal comfort and the energy demand in individual apartments as a measure of energy efficiency. The simulation results showed that solar protective glazing combined with a reflective roof reduced thermal discomfort hours by up to 95%, while modern windows alone decreased them by 90% and lowered heating demand by 18%. In contrast, typical passive solutions such as internal blinds or balconies were significantly less effective, reducing discomfort hours by only 11–42%. These findings highlight that, while no single retrofit measure is universally optimal, well-selected passive or hybrid strategies can substantially improve summer comfort, maintain winter efficiency, and reduce long-term reliance on energy-intensive cooling systems in aging multifamily housing. Full article

This study analyzes the dynamics of temperature and moisture in a cylindrical silo with a conical roof and floor used for storing corn in the Bajío region of Mexico, considering conditions both with and without aeration. The model incorporates external temperature fluctuations, solar radiation, grain moisture equilibrium with air humidity through the sorption isotherm (water activity), and grain respiration to simulate real storage conditions. The model is based on continuity, momentum, energy, and moisture conservation equations in porous media. This model was solved using the finite element method (FEM) to evaluate temperature and interstitial humidity variations during January and May, representing cold and warm environmental conditions, respectively. The simulations show that, without aeration, grain temperature progressively accumulates in the center and bottom region of the silo, reaching critical values for safe storage. In January, the low ambient temperature favors the natural dissipation of heat. In contrast, in May, the combination of high ambient temperatures and solar radiation intensifies thermal accumulation, increasing the risk of grain deterioration. However, implementing aeration periods allowed for a reduction in the silo’s internal temperature, achieving more homogeneous cooling and reducing the threats of mold and insect proliferation. For January, an airflow rate of 0.15 m³/(min·ton) was optimal for maintaining the temperature within the safe storage range (≤17 °C). In contrast, in May, neither this airflow rate nor the accumulation of 120 h of aeration was sufficient to achieve optimal storage temperatures. This indicates that, under warm conditions, the aeration strategy needs to be reconsidered, assessing whether a higher airflow rate, longer periods, or a combination of both could improve heat dissipation. The results also show that interstitial relative humidity remains stable with nocturnal aeration, minimizing moisture absorption in January and preventing excessive drying in May. However, it was identified that aeration period management must be adaptive, taking environmental conditions into account to avoid issues such as re-wetting or excessive grain drying. Full article

The Life Cycle Cost Assessment (LCCA) methodology is widely used to determine the optimal thickness of thermal insulation for walls and roofs. The results depend on several factors, such as the degree day calculations method, the ambient or sol–air temperature, base temperature variations, and the heat capacity of the thermal envelope elements. This study aims to analyze the impact of solar radiation on mass walls with different orientations in five cities in northern Chile, which have severe solar climates. The goal is to determine the optimal thickness of expanded polystyrene insulation using the LCCA method, considering solar radiation, a varying base temperature, and validating results by analyzing the energy demand for heating and cooling of a typical house. The findings show that excluding solar radiation in the LCCA methodology can lead to an underestimation of the optimal insulation thickness by 21–39% for walls in northern Chile. It was also found that using variable monthly threshold temperatures for heating and cooling based on the adaptive thermal comfort model results in a slight underestimation (1–3%) of the optimal thickness compared to a constant annual temperature. An energy simulation of a typical house in five cities in northern Chile showed that neglecting the effect of solar radiation when determining the thermal insulation thickness for the studied wall can lead to a minor increase in heating and cooling energy demand, ranging from approximately 1% to 9%. However, this study emphasizes the importance of applying optimal insulation thickness for cities with more continental climates like Santiago and Calama, where the heating demand is higher than cooling. Full article

Urban expansion has led to two significant environmental challenges: the reduction in green spaces and the rise in urban temperatures, decreasing city livability. Green roofs have emerged as a sustainable solution to mitigate these issues, offering ecological and economic benefits while improving building energy efficiency. Some species of the genus Sedum, particularly Sedum sediforme and Sedum album, are ideal for such green infrastructure due to their non-aggressive and superficial root system, high drought tolerance, low nutrient needs, pest and disease resistance, and metabolic adaptability during dry periods. This study aims to optimize the large-scale production of two native ecotypes of S. sediforme and S. album from the Valencian Community through an efficient propagation system that enables uniform plant production in limited space. For this purpose, we have developed micropropagation systems that allow a rapid multiplication of these two species. A direct morphogenesis system was established using axenic plant shoots, and a protocol for adventitious organogenesis from leaves was also developed. These methods significantly enhance propagation speed, spatial efficiency, and plant uniformity. Notably, the metabolic plasticity of S. sediforme and S. album reduces abiotic stress during acclimatization, promoting efficient ex vitro establishment and functional integration into extensive green roof ecosystems. Full article

The intensification of extreme temperature events driven by climate change has heightened the vulnerability of urban areas to heatwaves, making it a critical environmental challenge. In this study, we investigate the spatial characteristics of urban heatwave vulnerability in Jungang-dong, Gangneung—a representative mid-sized coastal city in South Korea that experiences a strong urban heat island (UHI) effect due to the prevalent land–sea breeze dynamics, high building density, and low green-space ratio. A representative heatwave day (22 August 2024) was selected using AWS data from the Korea Meteorological Administration (KMA), and hourly meteorological conditions were applied to Computational Fluid Dynamics (CFD) simulations to model the urban microclimates. The thermal stress levels were quantitatively assessed using the Universal Thermal Climate Index (UTCI). The results indicated that, at 13:00, the surface temperatures reached 40 °C and the UTCI values peaked at 43 °C, corresponding to a “Very Strong Heat Stress” level. Approximately 17.4% of the study area was identified as being under extreme thermal stress, particularly in densely built-up zones, roadside corridors with high traffic, and pedestrian commercial areas. Based on these findings, we present spatial analysis results that reflect urban morphological characteristics to guide the optimal allocation of urban cooling strategies, including green (e.g., street trees, urban parks, and vegetated roofs), smart, and engineered infrastructure. These insights are expected to provide a practical foundation for climate adaptation planning and thermal environment improvement in mid-sized urban contexts. Full article

This study examines the climate adaptability of traditional Hani ‘Mushroom Houses’ located in the rice terrace region of Honghe Hani Autonomous Prefecture, Yunnan, China. By analyzing 30 years of meteorological data, the study identifies the local climatic characteristics of high temperatures, high humidity, and significant diurnal temperature variations. The thermal comfort voting method was used to establish a quantitative relationship between the Physiological Equivalent Temperature (PET) index and residents’ subjective thermal perceptions, thereby assessing seasonal variations in thermal comfort. Field measurements of indoor and outdoor temperature, humidity, and wind speed were conducted in May and December 2023 to evaluate thermal interactions between rooms. This study demonstrated: (1) the critical roles of building orientation (e.g., northwest-facing design), functional layout (e.g., multi-story zoning), and structural forms (e.g., thick walls, thatched roofs) in regulating temperature and humidity. (2) Confirmed that Hani ‘Mushroom Houses’ stabilize indoor environments through passive strategies, including material selection (wood, rammed earth), natural ventilation (cross-draft design), and spatial organization (climate-buffering storage layers). (3) Provided empirical evidence for optimizing traditional dwellings (e.g., enhanced insulation, ventilation improvements) and advancing sustainable practices in similar climatic regions. Full article

Due to ongoing climate change, urban areas face increasing challenges associated with rising temperatures and growing energy demand. Green roofs have emerged as a sustainable, nature-based solution to enhance urban resilience. This study presents a systematic review of the thermal and energy performance of green roofs in the Mediterranean region, and was conducted following the PRISMA framework. By identifying targeted research questions formulated using the PICO(C) structure, this review systematically evaluates the potential of green roofs to promote sustainable urban environments in Mediterranean regions. The findings highlight their effectiveness in mitigating heat stress, enhancing building energy efficiency, and counteracting urban temperature fluctuations, reinforcing their role as a key climate adaptation strategy in densely populated areas. The review also identifies critical research gaps that must be addressed to facilitate the large-scale adoption of green roofs. Specifically, the lack of long-term performance monitoring, the need for standardized assessment protocols, and the necessity of optimizing green roof configurations for Mediterranean subregions emerge as key areas for future investigation. This study bridges a crucial gap in the literature by providing a systematic, PRISMA-compliant evaluation. It offers the scientific community a robust knowledge base to inform policy, urban planning, and future research directions. Full article

Rapid urbanization and industrialization have led to great changes to the climate, such as global warming, urban heat islands, and frequent fluctuations in ambient temperature, and also a large amount of building energy consumption. Adaptive building provides an appropriate solution to maintain low energy consumption under various indoor and outdoor conditions and therefore has increasingly gained attention recently. Yet there is no clear definition on adaptive buildings and the current literature often focuses on the building envelope and overlooks buildings’ mechanical system, which is also an important part of the building system for responding to the indoor requirements and outdoor conditions. This article presents a systematic review on the research and development of adaptive buildings to address the identified research gaps. Firstly, it introduces and discusses the definition and evolution of the concept of adaptive building. Secondly, it reviews the adaptive building envelope technologies of roof, wall and window. Thirdly, it investigates the research progress on the adaptive mechanical system, especially lighting and air-conditioning systems. Lastly, it demonstrates practical applications of adaptive buildings and provides recommendations on future research directions on adaptive buildings. Full article

Green roofs are becoming common in cities around the world. Rooftop vegetation faces severe and unique conditions ranging from shallow substrates, high irradiance, water limitation, flooding, extreme temperatures, and strong winds. To benefit the most from this technology for improving urban climate, ecological interactions, and human life quality, it is important to have a toolbox of candidate plant species adapted to the rooftop environment. Herein, an effort was made to provide an overview of the global scenario of green roof plants. A quantitative and qualitative review examining 439 articles published within an approximate 14-year time window (2009 to mid-2023) was conducted to categorize plants amenable to use in green roof conditions, and to identify and discuss their key morphophysiological phenotypic features. This dataset allowed the establishment of archetypal green roof plants for use in different climates. Similar traits were recorded between temperate and continental climate species on one side and between tropical and dry climate plants on the other. The identified set of species and their archetypes within each major climate zone can be useful for readily adopting and expanding new green roofs and as a guideline for incorporating new taxa into this urban environmental technology. Full article

Adequate school buildings are essential for the development of children, young people, and adolescents, as they must provide conditions that support their well-being and health. A healthy and comfortable indoor environment is critical for students’ performance in the learning process. This study aims to evaluate the indoor environment in kindergartens located in northern Portugal, with a primary focus on thermal comfort and indoor air quality. To achieve this, five buildings with varying construction characteristics were monitored, with temperature and relative humidity measurements taken in classrooms of different orientations over time. Additionally, the outdoor climate was also monitored. Based on the collected data, thermal comfort was evaluated using the adaptive model defined by the European standard EN 16798. Continuous monitoring of carbon dioxide concentration was also conducted in three of these buildings. The results reveal significant heterogeneity among the buildings, demonstrating the influence of construction characteristics on the interior thermal conditions. The recorded temperatures ranged from 10 °C to 27 °C, highlighting a substantial variability in performance across the different buildings. Particularly, the orientation and size of glazed openings, together with the lack of thermal insulation in the building envelope, especially in the roof, were found to have an important impact on the thermal comfort of the occupants. Furthermore, a relationship was observed between the daily maximum carbon dioxide concentration and the outdoor temperature, as a result of users’ efforts to minimize uncontrolled air infiltration, by limiting the opening of doors and windows, with consequences in the air exchange between the interior and exterior. Full article

Due to climate change, population increase, and the urban heat island effect (UHI), the demand for cooling energy, especially in urban areas, has increased and will further increase in the future. Technologies such as radiative cooling offer a sustainable and energy-free solution by using the wavelength ranges of the atmosphere that are transparent to electromagnetic radiation, the so-called atmospheric window (8–13 µm), to emit thermal radiation into the colder (3 K) outer space. Previous publications in the field of textile building cooling have focused on specific fiber structures and textile substrate materials as well as complex multi-layer constructions, which restrict the use for highly scaled outdoor applications. This paper describes the development of a novel substrate-independent coating with spectrally selective radiative properties. By adapting the coating parameters and combining low-emitting and solar-reflective particles, along with a matrix material emitting strongly in the mid-infrared range (MIR), substrate-independent cooling below ambient temperature is achieved. Moreover, the coating is designed to be easily applicable, with a low thickness, to ensure high flexibility and scalability, making it suitable for various applications such as membrane architecture, textile roofs, or tent construction. The results show a median daytime temperature reduction (7 a.m.–7 p.m.) of 2 °C below ambient temperature on a hot summer day. Full article

An effective community landscape design consistently impacts thermally comfortable outdoor conditions and climate adaptation. Therefore, constructing sustainable communities requires a resilience assessment of existing built environments for optimal design mechanisms, especially the renewal of thermally resilient communities in densely populated cities. However, the current community only involves green space design and lacks synergistic landscape design for renewing the central community. The main contribution of this study is that it reveals a three-level optimization method to validate the Synergistic Landscape Design Strategies (SLDS) (i.e., planting, green building envelope, water body, and urban trees) for renewing urban communities. A typical Japanese community in central Komatsu City was selected to illustrate the simulation-based design strategies. The microclimate model ENVI-met reproduces communities involving 38 case implementations to evaluate the physiologically equivalent temperature (PET) and microclimate condition as a measure of the thermal environments in humid subtropical climates. The simulation results indicated that the single-family buildings and real estate flats were adapted to the summer thermal mitigation strategy of water bodies and green roofs (W). In small-scale and large-scale models, the mean PET was lowered by 1.4–5.0 °C (0.9–2.3 °C), and the cooling effect reduced mean air temperature by 0.4–2.3 °C (0.5–0.8 °C) and improved humidification by 3.7–15.2% (3.7–5.3%). The successful SLDS provides precise alternatives for realizing Sustainable Development Goals (SDGs) in the renewal of urban communities. Full article

This paper proposes a temperature-adaptive radiative cooling (TARC) coating with simple preparation, cost effectiveness, and large-scale application based on a thermochromic powder. To determine the energy efficiency of the proposed TARC coating, the heat transfer on the surface of the TARC coating was analyzed. Then, a typical two-story residential building with a roof area of 258.43 m² was modeled using EnergyPlus. Finally, the energy-saving potential and carbon emission reduction resulting from the application of the proposed TARC roof in buildings under different climates in China were discussed. The results showed that the average solar reflectivity under visible light wavelengths (0.38–0.78 μm) decreases from 0.71 to 0.37 when the TARC coating changes from cooling mode to heating mode. Furthermore, energy consumption can be reduced by approximately 17.8–43.0 MJ/m² and 2.0–32.6 MJ/m² for buildings with TARC roofs compared to those with asphalt shingle roofs and passive daytime radiative cooling (PDRC) roofs, respectively. This also leads to reductions in carbon emissions of 9.4–38.0 kgCO₂/m² and 1.0–28.9 kgCO₂/m² for the buildings located in the selected cities. To enhance building energy efficiency, TARC roofs and PDRC roofs are more suitable for use on buildings located in zones with high heating demands and high cooling demands, respectively. Full article

The rise in outdoor temperatures and heatwaves highlights the limitations of buildings in adapting to warming conditions, even in temperate climates. This paper analyses the indoor overheating of residential dwellings in Pamplona (a city in northern Spain, with a Cfb climate) using an urban-scale diagnostic methodology and presents different envelopes’ retrofitting scenarios as a strategy to reduce it. The results come from energy simulations conducted during an extremely warm summer in 2022, considering the microclimate effects. The residential typologies most vulnerable to overheating are those with only one orientation, built before the EPBD 2002, and located on top floors. These dwellings show a 23.7% mean of indoor overheating hours (IOH), representing approximately 870 h above the EN 16798-1:2019 adaptive threshold from May to September. Renovating building envelopes to meet current energy standards reduces the IOH by an average of 8.6% and up to 15.35% in the most vulnerable typologies. In the retrofitting scenario with green roof systems, indoor temperatures are up to 0.5 °C lower than when roofs are renovated with traditional systems. This study assists policy-makers in preventing the risk of overheating within cities and encourages them to promote nature-based solutions in order to adapt urban residential buildings and cities to warming conditions. Full article

As global warming and heat waves are becoming more frequent and severe, cities, with their different morphological districts, must be at the forefront of environmental challenges. Notably, many Mediterranean towns maintain the original medieval urban fabric and the regular one. The research focuses on the development of a methodology with the application of high-resolution 3D modelling software ENVI-met V5.1 to analyze the microclimatic effects of mitigation and adaptation strategies derived from the study of medieval and regular urban fabric. The aim is to address contemporary challenges such as heat waves and urban heat island (UHI) effects in modern cities. By studying outdoor energy behavior in a southern Italian city (Bari), the research proposes scenarios for urban settlements in the face of climate change. This approach provides recommendations for creating more climate-resilient urban environments both in the historic and modern city. The use of trees with large crowns and tall shrubs and the inclusion of fountain jets are strategies to achieve sky view factor and air temperatures in the modern city similar to those in the historical fabric. Increasing albedo values and the use of green roofs prove to be further strategies for improving outdoor climatic conditions. Full article