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Building energy simulations often rely on abstract assumptions when it comes to natural ventilation, such as ‘windows always open [or closed]’ or ‘windows open when outdoor temperature is below a certain threshold.’ However, simulations based on these assumptions fail to fully exploit the cooling potential of natural ventilation, as its effectiveness can be enhanced or diminished by various factors, including the presence of thermal mass. This issue also extends to smart home controls, where determining the window schedule becomes challenging without information about the building's response to outdoor conditions. To address these issues, this study has developed an analytical model for window operation schedules that leverages the passive cooling from natural ventilation. The analytical model was validated against a Modelica simulation. A case study utilizing the BESTEST model of ANSI/ASHRAE Standard 140 underwent validation with EnergyPlus simulations, showing strong concordance. The algorithm provides window schedule recommendations adapted to various airflow rates, thermal masses, and climate variations. The case study demonstrated that proper window scheduling could reduce indoor temperature by up to 8 °C under the given simulation settings, thereby improving resilience and indicating potential energy savings. Furthermore, the paper explores the potential opportunities and challenges this approach presents, especially for building simulation and smart home applications.

The COVID‐19 pandemic has prompted renewed interest in indoor air quality (IAQ). Poor ventilation habits, energy obsolescence, and the lack of cooling equipment in schools, combined with increasing temperatures due to climate change, are leading to situations of thermal stress in classrooms. Changes in school operation, following the COVID pandemic, have made it necessary to establish an accurate understanding of the current situation. This research work presents an assessment of winter and summer IAQ and thermal comfort (TC) for a sample of 7 archetypal secondary schools in 5 Mediterranean climate variants in southern Spain in a postpandemic situation. IAQ was assessed through CO2, PM2.5, PM10, and CH2O, while static and adaptive models were used in the case of TC. Surveys were also used to assess both of these. The main novelty is the use of IAPI (indoor air pollution index) and IDI (indoor dissatisfaction index) objective global dimensionless indices to optimize the joint assessment of both variables. Poor objective IAQ results, especially for CO2 and PM2.5, were obtained for both seasons and all climate variants. Global IAPI is between 6.2 and 8.1, with an index of 10 considered unacceptable, while time percentages exceeding established limits are more variable in winter, ranging from 7% to 31.9%, than in summer, ranging from 14.3% to 20.9%. TC objective results varied, and the summer percentage of hours outside the comfort bands reached 40%–47% due to excess heat in the hottest regions. This discomfort was reported by 58.3% of users. [ABSTRACT FROM AUTHOR]

The growing concerns over climate change and energy scarcity have highlighted the need for building energy conservation. Windcatchers, renowned for their effective ventilation capabilities, have emerged as a pivotal solution for saving energy and improving indoor thermal comfort. Serving as rooftop installations, windcatchers harness high-altitude airflow to provide fresh indoor air while expelling stale air. This comprehensive review encompasses over 96 studies published between 2000 and 2024, examining the performance of various types of windcatchers. The review reviews previous articles and concludes that using different types of wind catchers in hot and arid areas can increase indoor air velocity by about 10–50%, reduce building energy consumption by about 20–50%, and increase thermal comfort duration by about 25–50%. The article combines the perspectives of multiple disciplines such as architecture, environmental engineering, and sustainable design, providing a new perspective for the study of windcatchers. The article not only summarizes the design and performance of existing wind catchers, but also provides 13 suggestions for the design of wind capture towers, while also identifying areas for future research, such as combining wind capture machines with other passive cooling technologies and evaluating their performance under different climate and urban conditions. [ABSTRACT FROM AUTHOR]

Natural ventilation has become a focal point due to its positive impact on indoor air quality, expanding its role in addressing thermal comfort issues in schools. Despite previous studies exploring various approaches to enhance natural ventilation, factors such as classrooms facing non‐windward directions and optimal window opening sizes have not been adequately considered. This lack of consideration poses challenges for implementation in school environments. To address this issue, this study employed response surface methodology, back‐propagation neural network, and multiple linear regression to investigate the effects of different factors on natural ventilation. Experiments were conducted in classrooms facing nonwindward directions, measuring indoor air changes per hour (ACH) during peak noon temperatures. Thermal comfort was assessed using the predicted mean vote (PMV). The experimental results showed that single window openings provided better thermal comfort compared to cross window openings while maintaining indoor CO2 concentrations below 1000 ppm. Furthermore, subsequent analysis revealed that the opening size (open and open/gap) increases the range of ACH, suggesting avenues for future research to enhance natural ventilation practices. This underscores natural ventilation's potential in maintaining indoor thermal comfort and CO2 levels under challenging conditions. [ABSTRACT FROM AUTHOR]

Accurate air temperatures underpin environmental research. Most professional meteorological air temperature measurements still expose thermometers within traditional, naturally ventilated screens. Their representation of true air temperature depends on screen airflow, and therefore local winds. Accuracies of daily maximum (Tmax) and minimum (Tmin) air temperatures are assessed by comparison between a naturally ventilated large conventional screen and a co‐located aspirated reference screen. In over 1200 days' data, the naturally ventilated Tmin and Tmax both showed small (median < 0.06°C) cold bias, but, in 1% of cases, warm Tmax bias and cold Tmin bias >|1°C|. The Tmin cold bias is associated with calm clear nights, and the Tmax warm bias events with calm winter days at low sun angles, allowing solar heating of the screen. The prevalence of poor natural ventilation, potentially affecting Tmin and Tmax, is estimated across European sites. Poor ventilation occurred at Tmin for 12% of values, and at Tmax for 4%. Climatological averaging will reduce these effects, but, without corroborating wind data, statistical changes in Tmin or Tmax, including identifying "Tropical Nights" (Tmin > 20°C) or occurrences of winter extremes, may have limited value. Wider adoption of aspirated thermometer screens, with an initial overlap period, will largely eliminate these effects. [ABSTRACT FROM AUTHOR]

In order to understand the dispersion of hydrogen (H2) leaked in packed beds of nonporous/porous particles in a partially open space practically, the dispersion of H2 in the particle layers of glass beads and soil was analytically studied using a computational fluid dynamics code to be compared with the experiments and to elucidate the effects of the particle layer. The packed beds in the partially open space can be considered as a basic model for all processes of transfer, treatment, storage, and disposal of radioactive materials containing fuel debris in the decommissioning of nuclear facilities after a severe accident. The H2 flowing out from a single leak point in the particle layer of nonporous glass beads was affected by buoyancy around the leak point and diffused directly above the leak point in an elliptical shape faster than in the horizontal direction. After that, when it reached the air layer in the head space above the particle layer, the H2 spread horizontally, formed a large concentration gradient near the boundary between the particle layer and the air layer, and further diffused in the air layer until the H2 concentration became about 1/3 or less of the concentration near the surface of the particle layer. When the particle diameters were 512 μm and 1200 μm, this tendency was more pronounced when the porosity was the same and the particle diameter was smaller. The calculations largely reproduced the experimental concentration distributions. When the particle layer was porous decomposed granite soil, the diffusion behavior of H2 in the particle layer proceeded in the same manner as in the case of the glass beads. However, a large concentration gradient was formed near the boundary between the particle layer and the air layer, and then H2 diffused in the air layer until the H2 concentration became below the lower combustion limit. It was suggested through sensitivity analysis that the air permeability coefficient had a large effect on the time course of the H2 concentration distribution. Based on this information, we further simulated H2 behavior in the vessel containing the H2 leaked particle layer. By inserting multiple vent pipes without considering H2 generation distribution and particle properties in the particle layer, H2 accumulated from one pipe was discharged by buoyancy without depending on the H2 generation distribution and particle properties in the particle layer and air flowed in from the other pipe. It was suggested that such a natural ventilation process would reduce the H2 concentration in the container. [ABSTRACT FROM AUTHOR]

Confluences are essential nodes in natural and artificial networks of open channels, where the merging of flows creates a complex flow and scour pattern. The present study is an experimental investigation on the zero-degree confluence of rigid and mobile bed channels. Excessive scouring at the confluence of the channels leads to the failure of the common wall and floor of the rigid channel. Experimental studies show that primarily two scour holes develop, one at the confluence point of the channels and a second downstream of the rigid (primary) channel. Results are presented for scour patterns and maximum scour depth for varied ratio of the discharge in the primary channel and total discharge and for varied tailwater depth. Experiments were also carried out for three length of the solid apron provided in the primary channel beyond the divide wall to examine the effect of the apron on the flow and scour pattern. Scour holes formed downstream of the primary channel and at the confluence point decreases with an increase in tailwater depth and solid apron length but increases with an increase in the ratio of discharge in the primary channel and total discharge. One scour hole formed at the confluence of the two channels and another hole formed downstream of the primary channel. The scour hole formed at the confluence was extending in the secondary channel. Equations are developed to compute the maximum scour depths of the two scour holes and extension of the scour hole in the mobile (secondary) channel. Sensitivity analysis shows that the Densimetric Froude number of flow downstream of the confluence is the most sensitive parameter that affects maximum scour depth of the scour holes and extension of scour hole in the secondary channel. [ABSTRACT FROM AUTHOR]

This paper presents the global research landscape and scientific progress on occupant thermal comfort in naturally ventilated buildings (OTC-NVB). Despite the growing interest in the area, comprehensive papers on the current status and future developments on the topic are currently lacking. Hence, the publication trends, bibliometric analysis, and systematic literature review of the published documents on OTC-NVB were examined. The search query "Thermal Comfort" AND "Natural Ventilation" AND "Buildings" was designed and executed to recover related documents on the topic from the Elsevier Scopus database. Results showed that 976 documents (comprising articles, conference papers, reviews, etc.) were published on the topic from 1995 to 2021. Further analysis showed that 97.34% of the publications were published in the English language. Richard J.de Dear (University of Sydney, Australia) is the most prolific researcher on OTC-NVB research, while Energy and Buildings has the highest publications. Bibliometric analysis showed high publications, citations, keywords, and co-authorships among researchers, whereas the most occurrent keywords are ventilation, natural ventilation, thermal comfort, buildings, and air conditioning. Systematic literature review demonstrated that OTC-NVB research has progressed significantly from empirical to computer-based studies involving complex mathematical equations, programs, or software like artificial neural networks (ANN) and computational fluid dynamics (CFD). In general, OTC-NVB research findings indicate that physiological, social, and environmental factors considerably influence OTC in NVBs. Future studies will likely employ artificial intelligence or building performance simulation (BPS) tools to examine relationships between OTC and indoor air/environmental quality, human behavior, novel clothing, or building materials in NVBs. [ABSTRACT FROM AUTHOR]

In high-altitude tunnels, due to the ambient pressure and density of air being different from those under normal pressure, the convection and heat radiation in tunnels are also different when fires occur. As a result, the smoke exhaust capacity varies under different pressures. This work aimed to numerically explore the impact of ambient pressure on the smoke exhaust efficiency at high-altitude shallow tunnels with natural ventilation by shaft. The numerical results demonstrated that the smoke exhaust capacity is enhanced with increasing ambient pressure. This is because of the increase in the air entrainment coefficient and air density, and it causes plug-holing more easily to occur under higher ambient pressures. Once the plug-holing has taken place, the fresh air can be directly exhausted through the shaft, which results in a poor smoke exhaust capacity. By accounting for the factors of the smoke layer thickness, ambient pressure, the exhausted smoke temperature and heat release rate, the Richardson number was introduced as the criterion for determining whether plug-holing occurs. As ambient pressure was increased, the critical Richardson number for plug-holing was observed to decrease, a finding supported by existing research. [ABSTRACT FROM AUTHOR]

The assessment of indoor environmental conditions of educational buildings is not only essential to ensure the correct performance of heating, cooling and ventilation systems but it is also fundamental to guarantee a suitable environment. This study aims to analyse the thermal comfort of students in teaching–learning spaces in university buildings with natural ventilation. A field measurement campaign and a questionnaire survey were carried out from September 2021 to June 2022 in educational buildings in southern Spain. The collected data were analysed and the neutral temperature in each season was obtained, based on the thermal sensation votes of 1966. The neutral temperatures found in this study were 23.5°C, 23.1°C, 23.3°C and 23.9°C, for autumn, winter, spring and summer, respectively. The ranges obtained for 90% acceptability in the winter season (21.1°C–25.1°C) provided lower temperature limits than the ranges obtained in the summer months (22.6°C–25.3°C). The highest values for clothing insulation were found in the autumn (0.90 clo) and winter (0.75 clo) seasons, compared to the spring (0.5 clo) and summer (0.4 clo) seasons. An adaptive thermal comfort model was applied. These findings could be used to improve thermal comfort and to optimise energy consumption according to the students' actual thermal perception. [ABSTRACT FROM AUTHOR]

According to the most recent climate projections, urban settings and historic centres will be affected by considerable increases in temperature extremes and heat waves as a result of climate change. For this reason, the issue of energy efficiency and indoor comfort in historic buildings has become a topic of major interest for the significant number of buildings in the national and European territories. The performance redevelopment of architectural heritage, particularly religious buildings, requires accurate design, through a careful assessment of the occupants' needs and the historic building's characteristics, to guarantee adequate levels of thermal comfort and ensure an indoor climate suitable for safeguarding the cultural asset. In this regard, the study investigates, through a data-driven approach and building performance analysis, the indoor comfort level of a religious building in the historical centre of Rome that presents phenomena of excessive indoor overheating. The objective is to identify passive cooling strategies, through the optimization of natural ventilation levels and reduction of surface temperatures of the envelope exposed to solar radiation, in order to propose different design scenarios. The results show how a data-driven process in a digital environment can significantly contribute to the identification of optimal and integrated design strategies and solutions. [ABSTRACT FROM AUTHOR]

This study addresses the critical issue of indoor air quality (IAQ) and pathogen transmission within enclosed spaces at high altitudes, focusing on university classrooms in Quito, an Andean city in South America. The aim is to establish safety thresholds for room occupancy and permissible durations of exposure, tailored to this unique environmental context. Through an experimental approach conducted at an elevation of 2900 m above sea level, various natural ventilation strategies were evaluated for their efficacy in mitigating pathogen transmission risks. The study employs the Concentration Decay Test Method to characterize air changes per hour (ACH) and utilizes the Bazant mathematical model to predict occupancy levels based on ventilation, dimensions of the room, respiratory activity, infectiousness rates, and other parameters. Findings highlight the significant impact of ventilation strategies on room occupancy. Notably, higher infectiousness rates and large exposure times drastically reduce permissible occupancy levels, underscoring the importance of effective ventilation in maintaining safety. This research contributes valuable insights for informed decision‐making regarding classroom capacity and safety protocols in Andean higher education settings. [ABSTRACT FROM AUTHOR]

Over the past two decades, the joint manifestation of global warming and rapid urbanization has significantly increased the occurrence of heatwaves and the formation of urban heat islands in temperate cities. Consequently, this synergy has amplified the frequency and duration of periods with tropical nights (TNs) in these urban areas. While the occurrences of such extreme events demonstrate irregular and nonlinear annual patterns, they consistently manifest a discernible rising decadal trend in local or regional climatic data. In urban regions situated amidst hilly or mountainous landscapes, changing wind directions--often associated with uphill or downhill thermal flows--profoundly impact the spread and dispersion of heat-related pollution, creating unique natural ventilation patterns. Using the Lausanne/Pully urban area in Switzerland as examples of hilly and lakeshore temperate cities, this study explores the influence of wind patterns and natural urban ventilation on the nonlinearity of recorded climatic data within an urban environment. This study integrates a mesoscale numerical weather prediction model (COSMO-1), a microscale Computational Fluid Dynamics (CFD) model, field observations, variational mode decomposition technique, and statistical analysis to investigate how wind speed and direction critically influence the nonlinearity of recorded long-term trends of extreme events, specifically focusing on the frequency and duration of TNs in lakeshore and hilly cities. The results strongly indicate a direct correlation between the frequency of TNs and the occurrence of specific moderate wind patterns. These wind patterns are exclusively captured by the microscale CFD model, unlike the mesoscale model, which neglects both urban morphology and complex hilly terrains. The impact of temporal and spatial variability of the wind field on long-term observations at fixed measurement stations suggests that caution should be exercised when relying on limited spatial measurement points to monitor and quantify long-term urban climate trends, particularly in cities located in complex terrains. [ABSTRACT FROM AUTHOR]

This study employed the CFD to evaluate the characteristics of hydrogen leakage, dispersion and explosion via activation of Thermally Activated Pressure Relief Devices (TPRDs) when HFCVs parking in a confined or ventilated parking space. The impact of varying leak diameters (2, 3, and 4 mm), natural ventilation and vehicle count on the formation of flammable gas clouds, their concentration distribution, and the generation of overpressure after the explosion were explored. The results showed that larger TPRD diameters resulted in more extensive clouds of highly concentrated hydrogen which dispersed more rapidly. Ventilation decreased both the volume and concentration of flammable clouds. In addition, large leak diameters resulted in larger pressure peaks after the explosion, in contrast, the danger was minimized in the single-vehicle case. Additionally, pressure peaks were higher in the parking lot's corners. This study offers theoretical support for safely parking HFCVs in confined spaces. • FLACS was used to simulate hydrogen leakage, diffusion and explosion in a garage. • Smaller TPRD diameters restricted the hydrogen diffusion range initially. • Overpressure increased with the size of the leak diameter. • Natural ventilation affected hydrogen concentration and reduced explosion pressure. • Surrounding vehicles intensified localized hydrogen concentrations as obstacles. [ABSTRACT FROM AUTHOR]

There are many different factors affecting indoor air quality: environmental ones such as temperature, humidity, human activities within the building, smoking, cooking, and cleaning, but also external pollutants such as particulate matter, biological contaminants, and viruses or allergens. This study investigated the indoor air quality (IAQ) of a primary-school classroom in Cracow, Poland, based only on CO2 concentration levels exhaled by occupants. In the 1960s, over a thousand schools were built in Poland using similar technology. Most of them are still in use, and in many cases, modernization works are being carried out to improve their building envelope and the comfort of their use. The analyzed school is one of several hundred similar ones in southern Poland. Therefore, analyzing the possibilities of improving IAQ is an important topic, and the results can be used in the modernization process for many other buildings. Measurements indicated that the CO2 levels significantly exceeded acceptable standards, signaling poor air quality during usage time. This problem was connected mainly with the low efficiency of the natural ventilation system being used in the classroom. It is worth emphasizing that this type of ventilation system is the most commonly used ventilation solution in Polish schools. To address this problem, the classroom environment was simulated using CONTAM software, and the model was validated by comparing the simulated measurement data against the collected measurement data. Next, simulations for the entire heating season in Cracow were conducted, revealing that the IAQ remained consistently poor throughout this period. These findings highlight the persistent problem of inadequate ventilation in the classroom, which can have adverse effects on the health and performance of students and teachers. This article shows the usefulness of CONTAM for modeling not only gravity ventilation but also the window-opening process. The validated CONTAM model will be subsequently utilized to simulate annual IAQ conditions under various ventilation strategies in order to identify the most effective methods for maintaining acceptable IAQ while minimizing energy consumption. In our future analysis, the validated model will be used to test the following systems: demand-controlled ventilation (DCV), exhaust ventilation, and DCV/balanced ventilation with heat recovery. [ABSTRACT FROM AUTHOR]

This research aimed to quantify concentrations of ammonia (NH3), carbon dioxide (CO2) and methane (CH4), estimate emissions, and analyze the factors influencing them during warm periods in an open dairy barn equipped with two cooling systems in a Mediterranean climate zone. Gas distribution within the barn was observed to vary both vertically and horizontally, with the highest gas concentrations observed in the central area of the barn. NH3, CH4 and CO2 ranged in 1.7--7.4, 7--18, 560--724 μg·g-1, respectively. Natural ventilation through openings and the operation of cooling systems induced changes in indoor microclimate conditions, influencing cow behavior and, consequently, gas production. Gas concentrations were the highest at air velocities below 0.5 m·s-1humidity index (THI) was > 72 and ≤ 78; and CO2 and CH4 concentrations were the highest with THI ≥ 72 and decreased with THI ≤ 72. NH3 concentrations when barn management included three daily milkings were higher than those measured when barn management was based on two daily milkings, and lower for CH4 and CO2. NH3 and CH4 emissions were the highest during barn cleaning, while the lowest NH3 emissions occurred during activity of the cows (i.e., feeding, walking). [ABSTRACT FROM AUTHOR]

The natural ventilation model plays a crucial role in greenhouse environmental control. It has been extensively studied by previous researchers, but it is limited to low-altitude areas. This study established a numerical model of single-span plastic greenhouses in high-altitude areas. The model was validated using measured data, showing a good agreement between the measured and simulated values. By setting boundary conditions based on on-site monitoring data, ventilation rates were extracted under different conditions for numerical simulations. Through nonlinear fitting, an empirical formula for natural ventilation rates, with a determination coefficient (R2) of 0.9724, was derived. The formula was validated through an energy balance analysis of indoor air. Different ventilation opening sizes were simulated to derive an empirical formula for natural ventilation rates based on opening size. Building on this, the relationship between plant height and ventilation rate was analyzed. As the dominant factors of natural ventilation change with environmental fluctuations, this study also proposed the threshold wind speed for wind pressure ventilation, thermal pressure ventilation, and coupled ventilation, filling the knowledge gap in relevant ventilation rate calculations. This is the first time that a natural ventilation model of single-span plastic greenhouses in high-altitude areas has been proposed, providing the basis in terms of modeling for the further development of local facility agriculture. [ABSTRACT FROM AUTHOR]

Objectives: Prior to the advent of low-carbon travel, the air pollution arising from vehicle exhaust emissions within the urban canopy layer has remained a significant challenge in the governance of urban atmospheric environments. Methods: This paper presents a series of three-dimensional physical models representing typical urban streets, with varying street interface density (SID). The models employ the computational fluid dynamics (CFD) simulations to assess the impact of SID on airflow patterns and pollutant dispersion. Metrics such as air exchange rate, purging flow rate, average residence time, and pollutant concentration in pedestrian areas are utilized to evaluate the natural ventilation performance and pollutant diffusion capacity across urban streets with different SIDs. Results: The findings illustrate that the CFD simulation approach is an effective means of elucidating the intricate details of airflow and pollutant dispersion within urban street spaces. A reduction in SID on both sides of urban streets has been demonstrated to enhance natural ventilation and air quality. Notably, a decrease in the upstream SID has a more pronounced effect on improving air quality compared to that of the downstream. The arrangement of buildings adjacent to urban streets significantly impacts the overall ventilation performance and pollutant dispersion capacity under different SIDs, with a critical upstream SID value of approximately 0.8. Conclusions: The proposed CFD simulation method can facilitate a comprehensive understanding of airflow and pollutant dispersal mechanisms, thereby enabling more scientific planning and design control of urban street spaces. Further-more, it helps to provide proactive strategies for residents residing near urban streets to cope with traffic-related air pollution risks. [ABSTRACT FROM AUTHOR]

Mine ventilation is crucial for ensuring safe production in mines, as it is integral to the entire underground mining process. This study addresses the issues of high energy consumption, regulation difficulties, and unreasonable regulation schemes in mine ventilation systems. To this end, we construct an optimization model for mine ventilation network regulation using mixed-integer nonlinear programming (MINLP), focusing on objectives such as minimizing energy consumption, optimal regulation locations and modes, and minimizing the number of regulators. We analyze the construction methods of the mathematical optimization model for both selected and unselected fans. To handle high-order terms in the MINLP model, we propose a variable discretization strategy that introduces 0-1 binary variables to discretize fan branches' air quantity and frequency regulation ratios. This transformation converts high-order terms in the constraints of fan frequency regulation into quadratic terms, making the model suitable for solvers based on globally accurate algorithms. Example analysis demonstrate that the proposed method can find the optimal solution in all cases, confirming its effectiveness. Finally, we apply the optimization method of ventilation network regulation based on MINLP to a coal mine ventilation network. The results indicate that the power of the main fan after frequency regulation is 71.84 kW, achieving a significant energy savings rate of 65.60% compared to before optimization power levels. Notably, ventilation network can be regulated without adding new regulators, thereby reducing management and maintenance costs. This optimization method provides a solid foundation for the implementation of intelligent ventilation systems. [ABSTRACT FROM AUTHOR]

The thermal performance of windows is an important area of research to reduce the energy consumption of buildings and improve indoor comfort. The application of innovative glazing technologies can improve the energy performance of windows and transparent facades, resulting in significant energy savings. This paper presents research results on the energy performance of electrically heated windows. A comprehensive CFD and experimental analysis of the heat transfer processes in a window space depending on the size, power, and location of an electric heater was performed. The convective gas flows in the gas gaps and in the boundary layer were also analysed, and it is shown that a window with an electric heater can reduce the energy consumption of a room by 10–12%. This study is a pilot study to assess the feasibility and cost-effectiveness of electric local heating of a window or facade to minimise heat loss before full-scale implementation. The results of numerical modelling and experimental studies confirm the potential of the new technologies. [ABSTRACT FROM AUTHOR]

Energy efficiency in the context of building design is a significant concern in Morocco. This paper offers a comprehensive analysis of how various design variables can impact both energy consumption and thermal comfort in the Moroccan context. Rather than isolating individual design variables, we investigate synergistic combinations of these variables. To achieve this, we develop multiple building design scenarios, each employing different combinations of design options, focusing on building orientation, window-to-wall ratio, building envelope construction, and window shading. We use EnergyPlus to conduct energy simulations for all scenarios under the hypothesis of air-conditioned houses and free-running houses with and without natural ventilation. Our results reveal that building design has the potential to significantly enhance energy efficiency and thermal comfort, but not for the same design strategies. In comparison to the most energy-efficient design scenario, the least favorable design scenario can lead to an increase in energy consumption between 237% in Agadir and 130% in Ifrane. Meanwhile, design scenarios favoring comfort can increase the number of comfortable hours by 85% in Agadir and 59% in Ifrane. We identify optimal building design scenarios that simultaneously offer the highest comfort levels with the lowest energy requirements. The findings provide valuable guidance for architects, allowing them to design high-performance buildings in all climate zones in Morocco. [ABSTRACT FROM AUTHOR]

Mixed-mode ventilation system (MMVS) can significantly decrease the energy consumption of Egyptian office buildings while meeting indoor air quality requirements and thermal comfort of occupancy. This paper studies the effect of using mixed-mode ventilation system (MMVS) in achieving both energy efficiency and thermal comfort in office buildings. The research specifically focuses on investigating the energy-saving potential and thermal performance of existing office buildings in Egypt by merging natural ventilation (NV) with mechanical ventilation (MV) to reach an effective mixed-mode ventilation system (MMVS). Additionally, an energy performance simulation was used to study how to achieve thermal comfort and the building's indoor temperature. Firstly, a selected office building in Cairo was used as a case study, and its thermal performance was studied by simulation. Secondly, site measurements were conducted to record the real thermal performance of the tested office building. These measurements were used for the validation phase. The validation demonstrated a satisfactory agreement between the building simulation and measurement data for air temperature (T) and relative humidity (RH). Thirdly, building energy simulations and analysis were used for testing the energy performance and thermal comfort of the tested scenarios that have different alternatives in the operation settings. The results revealed that it is possible to increase the thermal comfort hours by merging natural ventilation and applying the mixed-mode ventilation system only by changing the operation settings on the MMVS performance. The building's annual energy consumption was reduced by approximately 27 % compared with the use of HVAC in the building. Natural Ventilation hours increased by approximately 27 % to reach 427 hours (h) and the HVAC hours decreased by 17 % to reach 898 hours (h). [ABSTRACT FROM AUTHOR]

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In order to build energy-efficient commercial buildings in bustling urban centers and utilize passive means such as natural ventilation and natural lighting as much as possible to improve indoor environmental quality, the author proposes a green environment design optimization algorithm based on artificial intelligence. Taking Building A as an example, simulation technology was used to optimize the performance of the enclosure structure, anti condensation in the glass atrium, and natural ventilation during the transition season. The sunlight and shadow simulation software BSAT was used to simulate the mutual occlusion and self occlusion of the building. It was found that external rolling shutters were not required for shading the facade between axes L2-L5 and 3-9. Using DeST-C, the energy consumption and investment of south facing, east facing, and west facing envelope structures were compared when using different types of glass. Combining economic efficiency and energy-saving effects, the optimal southbound enclosure structure scheme for this building is to use Low-e membrane coated hollow double glass with ten horizontal louvers for external shading; It is recommended to adopt the scheme of hollow double glass (Low-e membrane) or hollow double glass (Lowe membrane)+external roller shutter in the east-west direction. It is worth noting that for east-west oriented glass, the Lowe film should be low permeability, mainly to improve the thermal performance in winter and reduce the radiation heat gain in summer. Using DeST-C for simulation 2 calculation, it was found that when the thermal performance of windows increased from 3.0W/(m². K), shading coefficient 0.7 to 2.0W/(m º K), and shading coefficient 0.5, the maximum cold and heat load of the building and the cumulative consumption of cold and heat throughout the year were significantly reduced, providing an effective reference for solving problems. [ABSTRACT FROM AUTHOR]

Natural Ventilation Effectiveness (NVE) is a performance metric that quantifies when outdoor airflows can be used as a cooling strategy to achieve indoor thermal comfort. Based on standard ventilation threshold and building energy simulation (BES) models, the NVE relates available and required airflows to quantify the usefulness of natural ventilation (NV) through design and building evaluation. Since wind is a significant driving force for ventilation, wind pressure coefficients ( C p ) represent a critical boundary condition when assessing building airflows. Therefore, this paper investigates the impact of different C p sources on wind-driven NVE results to see how sensitive the metric is to this variable. For that, an experimental house and a measurement period were used to develop and calibrate the initial BES model. Four C p sources are considered: an analytical model from the BES software (i), surface-averaged C p values for building windows that were calculated with Computational Fluid Dynamics (CFD) simulations using OpenFOAM through a cloud-based platform (iia,b,c), and two databases—AIVC (iii) and Tokyo Polytechnic University (TPU) (iv). The results show a variance among the C p sources, which directly impacts airflow predictions; however, its effect on the performance metric was relatively small. The variation in the NVE outcomes with different C p 's was 3% at most, and the assessed building could be naturally ventilated around 75% of the investigated time on the first floor and 60% in the ground floor spaces. [ABSTRACT FROM AUTHOR]

In rapidly urbanizing regions, enhancing passenger comfort in subway systems through sustainable methods is a critical challenge. This study introduces an innovative exploration of the impact of subway entrance geometry on natural ventilation and its subsequent effects on the thermal environment within Cairo's subway system. The primary objective is to identify optimal entrance configurations that maximize natural airflow, thereby improving passenger comfort and reducing energy consumption. Focusing on the newly constructed segments of the Cairo subway, the research employs a mixed-methods approach that integrates computational fluid dynamics (CFD) simulations with a questionnaire survey to evaluate interactions between various entrance designs and urban wind flow patterns. This dual approach allows for a comprehensive assessment of how different geometrical configurations influence the capture and distribution of prevailing winds. The results indicate that specific entrance geometries can significantly enhance ventilation efficiency by optimizing wind capture and distribution. The most effective designs demonstrated substantial improvements in air quality and thermal comfort, providing practical insights for subway systems in similar hot arid climates. The novelty of this research lies in its detailed analysis of architectural elements to leverage natural environmental conditions for improving indoor air quality and thermal comfort in public transit systems. The significance of this study is its contribution to the field of sustainable urban transport, offering a valuable framework for urban planners and engineers. By demonstrating how thoughtful design can lead to energy savings and enhanced passenger experiences, this research advances the discourse on sustainable urban infrastructure. This work not only enhances theoretical understanding but also provides actionable recommendations for creating more sustainable and comfortable public transit infrastructures. [ABSTRACT FROM AUTHOR]

School buildings are essential in catering to children's psychological and educational needs. They enable children to learn, teach, play, and interact with peers. The corridor space within a school's structure is also significant, serving multiple purposes. The community in Erbil, Iraq, has expressed concerns about the economic challenges of constructing and designing new school buildings. Therefore, this research aimed to identify unused spaces in these corridors to ensure usability and flexibility while reducing the cost of building construction. A comprehensive approach was taken to achieve this, employing both qualitative and quantitative analysis techniques. The qualitative analysis was conducted through surveys and documentation to provide an intense understanding of the issues. This research employed two distinct quantitative methods: first, the study used the Revit engineering software to compare the circulation ratio of pre-existing buildings with that recommended by the BB 103 guidelines, and second, student feedback was collected through a questionnaire to provide a holistic view of the situation. This study found that the built-up corridor area in the L-shaped school accounted for 34% of the total area, 11.5 percentage points more than the BB 103 guideline. Meanwhile, the built-up corridor area in the O-shaped school was 20.5 percentage points higher than the recommendation. According to the student feedback, the extra corridor space in the selected schools is not being efficiently utilized. Therefore, the proposed redesigns for the L-shaped and O-shaped schools focus on eliminating traditional corridors and integrating outdoor spaces to create functional areas, enhancing natural lighting and ventilation. These redesigned concepts ensure cost-effective, adaptable, and engaging educational spaces that support the well-being and academic success of students. This paper recommends that school designers and architects re-evaluate existing school designs with a focus on reducing corridor spaces and prioritizing outdoor learning areas. By adopting these strategies, schools can improve space utilization, foster healthier and more efficient learning environments, and promote sustainability. [ABSTRACT FROM AUTHOR]

Low-carbon development in the field of buildings is an important means to achieve the goal of "carbon peaking and carbon neutrality". In public buildings, the operation of science and technology museum buildings (TMB) has high carbon emissions, and the application of green building technology for energy saving and carbon reduction has great potential. In this paper, typical TMB in cold areas are selected and built, and energy consumption is simulated by Designbuilder. The calculation boundaries and carbon emission factors of carbon emissions are set according to current standards, and the carbon reduction potential of green science and technology museum buildings (GTMB) under different levels is compared. The results show that compared with the benchmark building based on GB 55015-2021, the carbon emission of the GTMB is significantly reduced, and the carbon emission reduction rates of silver, gold, and platinum TMB are 7.9%, 13.4%, and 29.6%, respectively. Based on the existing optimization design of passive measures such as natural ventilation and natural lighting, the GTMB should pay more attention to the realization of its optimal control strategy and automatic control. [ABSTRACT FROM AUTHOR]

The incorporation of physical environmental performance as a primary consideration in building design can facilitate the harmonization of the built environment with the surrounding site and climate, enhance the building's environmental adaptability and environmental friendliness, and contribute to the achievement of energy-saving and emission-reduction objectives through the integration of natural lighting and ventilation. General computational fluid dynamics (CFD) can help architects make accurate predictions and effectively control the building's wind environment. However, CFD integration into the design workflow in the preliminary stages is frequently challenging due to program uncertainty, intricate parameter settings, and substantial computational expenses. This study offers a methodology and framework based on machine learning to overcome the complexity and computational cost barriers in simulating outdoor wind environments of buildings. In this framework, the machine learning model is trained using an automated CFD simulation system based on Butterfly and implemented within the Rhino and Grasshopper environment. This framework provides real-time simulation feedback within the design software and exhibits promising accuracy, with a Structural Similarity Index Measure (SSIM) ranging from 90–97% on a training dataset of 1200 unique urban geometries in Xinjiekou Area of Nanjing, China. Furthermore, we programmatically integrate various parts of the simulation and computation process to automate multiscenario CFD simulations and computations. This automation saves a significant amount of time in producing machine-learning training sets. Finally, we demonstrate the effectiveness and accuracy of the proposed working framework in the design process through a case study. Although our approach cannot replace CFD simulation computation in the later design stages, it can support architects in making design decisions in the preliminary stages with minimal effort and immediate performance feedback. [ABSTRACT FROM AUTHOR]

When exposed to light sources, photochromic (PC) materials change their optical properties and can lessen the transmission of UV and infrared radiation. This results in optimal thermal comfort and a pleasing visual contrast between the internal and external settings. This study uses computer modeling to analyze the annual energy usage in a home with natural ventilation in order to compare the effectiveness of photochromic films with commercial glass. The study is carried out using the EnergyPlus program in the cities of São Carlos and Cuiabá ‐ Brazil. Experiments and numerical simulations with data from doped and undoped tungsten trioxide (WO3) PC films are used in the study. Given the rise in energy usage and the pursuit of thermal comfort, this method is essential for assessing the thermal performance of buildings. Evaluations included a comparison of air conditioner performance and energy savings analysis, which leads to a noteworthy annual reduction in energy usage of up to 216.55 kWh and a 40% improvement in visual comfort. It is determined that PC film's dynamic behavior is the best option for comfort in terms of heat, illumination, and visual comfort. [ABSTRACT FROM AUTHOR]

This paper describes a two-year high-fidelity dataset for an ultra-low energy office building and living laboratory called HouseZero®. The building integrates multiple low-energy technologies, such as natural ventilation with automatic windows, ground source heat pump, and thermally activated building systems. The building's performance is continuously monitored with an extensive sensor network. The dataset consists of breakdown energy end uses, photovoltaic (PV) production, zone-level indoor environment including indoor air temperature, CO2 concentration, and relative humidity, micro-climatical conditions, building façade temperature, and detailed system operations including zone-level BTU meter, valve status, slab temperature, window/skylight opening status, heat pump, and geothermal well operations. The data can be used to support data analytics of ultra-low-energy building operations, and data-driven modeling of low-energy building systems. [ABSTRACT FROM AUTHOR]

One of the technical solutions to improve indoor thermal comfort and reduce energy consumption in buildings is the use of demand-controlled ventilation (DCV) systems. The choice of the control method becomes more important when the walls in the room are finished with moisture-buffering materials. This study explores the impact of four DCV system control scenarios (control of temperature, relative humidity, and carbon dioxide concentration for two different supply airflows to the room) combined with various indoor moisture-buffering materials (gypsum board and cement–lime plaster) on the variability of indoor air quality parameters, thermal comfort, and energy. The analysis was performed by computer simulation using WUFI Plus v.3.1.0.3 software for whole-building hydrothermal analysis. Control-based systems that maintain appropriate relative humidity levels were found to be the most favourable for localised comfort and were more effective in terms of energy consumption for heating and cooling without humidification and dehumidification. This research also revealed that the moisture-buffering effect of finishing materials can passively contribute to enhancing indoor air quality, regardless of the room's purpose. However, higher energy consumption for heating was observed for better moisture-buffering materials. [ABSTRACT FROM AUTHOR]

This study presents the potential of using a natural ventilation system integrated with different combinations of enhancement techniques. The focus was on the perspective of using such configurations of passive ventilation systems (PVSs) in buildings located in different European cities. This work presents the results of obtaining the level of volumetric air flow rate for considering natural ventilation systems. Furthermore, the influences of local weather conditions (temperature, solar radiation, wind speed) were analyzed. Moreover, the year-round operation of all systems was presented. Also noted was the limitation of using PVSs based on the natural draft effect, additionally assisted by wind turbine ventilators in all European localizations. However, for the cities located in the northern part of Europe, it was confirmed that such a system can still meet minimum hygienic recommendations. It was also noted that a system additionally supported by a solar chimney is a much better solution. The best system was a PVS supported by a wind turbine ventilator and solar chimney integrated with PCM accumulation mass. The system should be additionally supported by waste heat from low-temperature sources. In the presented study, a high potential to reduce CO2 emission from building stock by the recommended system is additionally highlighted. However, there is still a need to analyze the proposed solutions by additional field tests and experimental investigations. [ABSTRACT FROM AUTHOR]

Vertical shaft natural ventilation is a common smoke exhaust method in highway tunnel fires. This study investigated the vertical shaft natural smoke exhaust work in highway tunnel fires with the effect of multiple factors through numerical simulation. Using the analysis of the flow field of smoke in nearby areas of the vertical shaft and the quantitative calculation of the gas exhausted through the vertical shaft, considering the impact of shaft division and board height, an optimal vertical shaft arrangement was proposed, and the working conditions of this arrangement in low-pressure environments were discussed. The results show that dividing a single large vertical shaft into multiple small vertical shafts and appropriately adjusting the board height can reduce the incidence of vertical shaft plug holes and significantly enhance the vertical shaft smoke exhaust performance. Meanwhile, the board-coupled shaft (BCS) has excellent working ability in low-pressure environments, and when pressure drops, smoke exhaust efficiency will improve. This research offers a foundation and reference value for improving the vertical shaft smoke exhaust system in highway tunnels. [ABSTRACT FROM AUTHOR]

This paper evaluates the influence of natural ventilation on the longitudinal temperature attenuation of cable tunnel wall fires. It took into account the effects of different fuel quantities, cable types, cable layers, and the number of cables per layer. Experimental tests were carried out in a cable tunnel. Results indicated that under natural ventilation the cable burns well. The cable total mass loss rate varies under different conditions. Moreover, under natural ventilation, cable combustion was affected by many factors. This paper analyzed the effect of natural ventilation on longitudinal dimensionless temperature attenuation. A mathematical model was proposed for longitudinal dimensionless temperature attenuation under natural ventilation cases. In addition, a predictive model for maximum temperature rise below the ceiling was proposed to address the effects of heat release rate (HRR) and ventilation on cable tunnel fires. The experimental results were compared with previous research results. Finally, this paper established a calculation equation for dimensionless fire source heat release rate. This paper provides guidance for the fire prevention of cable tunnels. [ABSTRACT FROM AUTHOR]

From a public health perspective, it is necessary to improve indoor air quality (IAQ) in schools. This study aims to assess the state of perceived IAQ in Slovenian school classrooms and its association with the selected IAQ factors to improve the understanding of perceived IAQ for designing public health interventions aimed to improve IAQ in schools. A national cross-sectional study was performed in all 454 Slovenian primary schools in the school year 2019/2020. The questionnaires were filled out by the 3rd-grade teachers with the support of the caretakers. Teachers rated the IAQ in the classroom as the worst in winter. We found that the teachers' perceived IAQ in the classroom is statistically significantly associated with the micro location of the school and some of the IAQ factors. Poor IAQ is associated with reduced manual airing of classrooms due to the thermal comfort of the occupants. Interventions should be aimed at improving occupants' adaptive behaviors to increase the frequency of natural ventilation in classrooms. [ABSTRACT FROM AUTHOR]

In South Korea, environmental complaints related to livestock odors continue to increase, and various efforts are underway to overcome them. An objective of this study is to monitor indoor concentrations of ammonia and sulfur-based odorous substances emitted from laying hen houses in South Korea through on-site visits for one year to understand their temporal emission patterns. The highest concentration was found in ammonia (NH3), at 6.92 ppmv, followed by hydrogen sulfide (H2S), at 8.98 ppbv. The concentrations of methyl mercaptan (CH3SH), dimethyl sulfide (DMS), and dimethyldisulfide (DMDS) ranged from sub ppbv to 10 ppbv. In general, there was no consistent concentration distribution of ammonia and sulfur-based odorous substances in laying hen houses between those with forced ventilation and natural ventilation. Regarding the seasonal distribution of odorous compounds, their concentrations in winter season (December to February) when the ventilation rate in laying hen houses decreased were generally higher than those in the summer season (June to August) when the ventilation rate in poultry buildings was relatively high, which is applied to properly maintain the thermal environment in laying hen houses. The limitation of this study is that unexpected conditions such as clearance of laying hen houses, chicken shipments, and disorders of exhaust fans were not controlled for intentionally due to on-site investigations. [ABSTRACT FROM AUTHOR]

The province of Gauteng in South Africa has a rich history of gold mining, which has driven economic growth and urbanization. Gold mining has also created over 270 gold mine tailings (GMT), now surrounded by human settlements due to a housing shortage. These GMT pose a health risk as they harbor elevated uranium, which over time undergoes radioactive decay to produce radon, a known lung carcinogen. This study aimed to investigate the potential correlation between the proximity to gold mine tailings (GMT) and indoor radon concentrations in Gauteng's residential dwellings. Volume activity of radon (VAR) inside 330 residential dwellings was measured in residential dwellings located proximally (<2 km) and distally (>2 km) to gold mine tailings using AlphaE radon monitors during winter. An interviewer-administered questionnaire was utilized to obtain data on factors that may influence indoor radon activities. Descriptive statistics and bivariate logistic regression analyzed the influence of proximity to gold mine tailings and dwelling characteristics on VAR. Furthermore, VAR was compared to the World Health Organization (WHO) radon reference level of 100 Bq/m3. Residential dwellings near gold mine tailings had significantly higher average indoor radon concentrations (103.30 Bq/m3) compared to the control group (65.19 Bq/m3). Residential dwellings proximal to gold mine tailings were three times more likely to have VAR beyond the WHO reference level of 100 Bq/m3. Furthermore, they had estimated annual effective doses of 2.60 mSv/y compared to 1.64 mSv/y for the control group. This study highlighted a concerning association between proximity to gold mine tailings and elevated indoor radon levels. Public health interventions prioritizing residential dwellings near gold mine tailings are crucial. Educational campaigns and financial assistance for radon mitigation systems in high-risk dwellings are recommended. Residents near gold mine tailings are encouraged to ensure continuous natural ventilation through frequent opening of windows and doors. [ABSTRACT FROM AUTHOR]

The wind movement is a crucial factor in enhancing thermal comfort, forming an essential part towards friendly and sustainable urban environment. Air movement, as a prominent climatic factor, reduces heat stress with improving ventilation quality. Effective natural ventilation and heat stress mitigation can be achieved by orientation, planning and shaping the urban blocks in urban environments. Air movement represents the most important element in improving environmental adaptation, as the rapid airflow reaching buildings can significantly reduce their temperature. Site planning requires precise knowledge of the main wind directions and speeds. The research utilized the ENVI-met Models program for modeling urban environments and predicting thermal effects in the built environment. This program plays a crucial role in understanding and analyzing environmental conditions and their impact on thermal comfort. The research addressed the knowledge gap and lack of local studies in highlighting the role of wind movement in enhancing thermal comfort in urban environments using ENVI-met Models. The research aimed to provide specific knowledge in measuring wind movement and its role in enhancing thermal comfort in urban environments using the program. The research hypothesized that analyzing and modeling wind movement with ENVI-met Models can effectively contribute to understanding and improving thermal comfort in urban environments. One of the key findings is that studying the impact of wind movement with this program is essential for providing scientific and technical foundations to improve urban design and enhance thermal comfort in urban areas, promoting sustainability and environmental quality in cities. [ABSTRACT FROM AUTHOR]

Prior studies have attributed the heightened positive thermal response during summer to perceived control. The process through which perceived control is cultivated in the built environment has been scarcely explored. A field study was conducted in a dormitory building operating successively in natural ventilation and mixed-mode in the cold region of China. A total of 922 valid samples were obtained. The data analysis indicated that the building's operation mode impacted both perceived control and its influencing factors. In natural ventilation mode, occupants perceived less control than in mixed-mode, and perceived control was shaped by both thermal stimulus and exercised control. Conversely, in mixed-mode, the occupants' perceived control was solely influenced by exercised control. Reflecting on this result, this study is the first to suggest a method for determining 'perceived effectiveness' by assessing occupants' thermal sensations and preferences. Only air conditioning was perceived as effective, amplifying occupants' perceived control, while other controls diminished it. In mixed-mode, control combinations incorporating air conditioning were judged to have perceived effectiveness. On this basis, further combining psychological adaptation with behavioural adaptation, active and passive technology was used to play the role of behavioural adaptation, and the upper limit of acceptable temperature for occupants was increased to 31.1°C. [ABSTRACT FROM AUTHOR]

This study addresses the pressing need for energy-efficient greenhouse management by focusing on the innovative application of natural ventilation. The primary objective of this study is to evaluate various ventilation strategies to enhance energy efficiency and optimize crop production in agricultural greenhouses. Employing advanced numerical simulation tools, the study conducts a comprehensive assessment of natural ventilation's effectiveness under real-world conditions. The results underscore the crucial role of the stack effect and strategic window positioning in greenhouse cooling, providing valuable insights for greenhouse designers. Our findings shed light on the significant benefits of optimized ventilation and also offer practical implications for improving greenhouse design, ensuring sustainable and efficient agricultural practices. The study demonstrated energy savings in cooling from November to April, with a maximum saving of 680 kWh in March, indicating the effectiveness of strategically positioning windows to leverage the stack effect. This approach enhances plant growth and reduces the need for costly cooling systems, thereby improving overall energy efficiency and lowering operational expenses. Graphic Abstract [ABSTRACT FROM AUTHOR]

Natural ventilation is a critical method for reducing energy consumption for heating, cooling, and ventilating buildings. Recent research has focused on utilizing environmental IoT data from both inside and outside buildings for NVR prediction based on a deep learning model. To design an accurate NVR prediction model while considering individual building environments, various knowledge-sharing methods can be applied, such as transfer learning and ensemble models for cross-building prediction. However, the characteristics of learning data and model parameters should be considered when applying transfer learning and ensemble models to predict NVR with different spatial and temporal domains. In this paper, we propose a way to design an NVR prediction model for a cross-building environment by normalizing the training data, selecting transfer learning layers that are well-suited to the data environment, and augmenting NVR knowledge via ensemble methods. Based on the experimental results, we confirm that the proposed knowledge-sharing deep learning approach, while considering the normalizing of training data, the selecting transfer learning layers, and augmenting the NVR knowledge approach, can improve the accuracy up to 11.8% in the two different offices and seasons. [ABSTRACT FROM AUTHOR]

Evaluation of the suitability of university ladder classroom environment on humans is an effective approach to improve the quality of the indoor environment and protect human health. However, there are unresolved issues regarding the suitability of university ladder classroom environment for humans. For example, the design of enclosure structure and heating ventilation and air conditioning (HVAC) system is unreasonable, and the indoor air quality does not meet the required standard. In this study, the suitability of university ladder classroom environment on humans was considered the research object. The evaluation indices of indoor environment were selected from indoor air quality, indoor thermal and humid environments, light environment, and sound environment. And the health and comfort of users were taken as the evaluation indices of users. According to the results of expert investigations and case measurements, the index weight was determined by the expert-entropy weight method, and a complete evaluation system of indices was built. There were two first-level, six second-level, and fourteen third-level indices in the evaluation system. The evaluation indices of each level with the largest weight were indoor environment (0.5940), user health (0.2530), and indoor temperature (0.1175) respectively. By comparing the actual learning effect to the evaluation results, the applicability of the evaluation system was determined. The evaluation system of the suitability of university ladder classroom environment on humans is convenient for operators to identify the weak points between humans and the environment. The evaluation system is endowed with important theoretical and practical significance to realize the green development of colleges and universities and build an environment-friendly campus. [ABSTRACT FROM AUTHOR]

Representative weather data are fundamental to characterizing a place and determining ideal design approaches. This is particularly important for large countries like Brazil, whose extension and geographical position contribute to defining diverse climatic conditions along the territory. In this context, this study intends to characterize the Brazilian territory based on a 15-year weather record (2008–2022), providing a climatic assessment based on a climatic and bioclimatic profile for the whole country. The climate analysis was focused on temperature, humidity, precipitation, and solar radiation, followed by a bioclimatic analysis guided by the Givoni chart and the natural ventilation potential assessment. In both situations, the results were analyzed using three resolutions: country-level, administrative division, and bioclimatic zones. This study also identified representative locations for the Brazilian bioclimatic zones for a building-centered analysis based on the thermal and energy performance of a single-family house with different envelope configurations. The results proved that most Brazilian territories increased above 0.4 °C in the dry bulb temperature and reduced relative humidity. The precipitation had the highest reduction, reaching more than 50% for some locations. The warmer and drier conditions impacted also the Köppen–Geiger classification, with an increase in the number of Semi-Arid and Arid locations. The bioclimatic study showed that ventilation is the primary strategy for the Brazilian territory, as confirmed by the natural ventilation potential results, followed by passive heating strategies during the year's coldest months. Finally, building performance simulation underlined that, in colder climates, indoor thermal comfort conditions and air-conditioning demands are less affected by solar absorptance for constructions with low U-values, while in warmer climates, low solar absorptance with intermediary U-values is recommended. [ABSTRACT FROM AUTHOR]

Indoor air quality determines the comfort, health, and wellbeing of people in buildings. Windows are the optimal elements for providing natural ventilation and fresh air, but the outside contains suspended particles that can be harmful in high concentrations. This work presents an openable and double-glazed façade component with a cavity that includes a series of slats that filter the air and depurate it by means of a photocatalytic reaction (TiO2). This component integrates the functions of ventilation, solar protection, and air purification, which were analysed in the slat and the façade component to approve a preliminary design. To this end, it was applied to a specific case, a non-residential building at a latitude 41° N in a Mediterranean climate. The results show the optimal dimensions according to solar radiation and ventilation in this specific case and the method used to obtain them, along with the increase in the temperature of the incoming air with respect to the outside (10 °C). Finally, the results obtained from a photocatalytic coating sample show that the NOx degradation can be up to 9%. All these results confirm the applicability of this component in buildings and pave the way for further research. [ABSTRACT FROM AUTHOR]

The immediate vicinity of buildings of different floors causes damages of the smoke and ventilation channels work of the low-rise buildings. This is dangerous for the resident's health and lives. To determine the impact of high-rise buildings on the operation of air channels of a nearby two-story building, experimental research has been carried out in a wind tunnel. Charts and analytical formulas have been designed for determining the buildings aerodynamic coefficients depending on wind directions and the channels height. An increase of the channel height results in an increase in static rarefaction in smoke and ventilation channels. Increasing rarefaction increases the efficiency of the natural ventilation system and ensures the residents health and life. [ABSTRACT FROM AUTHOR]

This study evaluates thermal sensitivity, expectations, and adaptability in mixed-mode ventilated buildings by subjective and objective assessments. A field study of simultaneous measurements of physical environmental parameters and right-here-right-now surveys was conducted in three office buildings from summer to winter in humid subtropical climates. The study confirmed previous findings that thermal adaptability and preferences changes as the ventilation system switches between natural ventilation (NV) and air-conditioning (AC). Occupants in this study showed more sensitivity to temperature changes than previously reported by ASHRAE Standards, yet thermal sensitivity was the same under different modes of operation. The neutral temperature was 0.5 oC higher than the predicted neutral temperature by ASHRAE 55 under both modes of operation. Thermal expectations were 1.5 oC warmer than the neutral temperature estimated by ASHRAE 55 when the building was operated by AC, while thermal expectations were almost the same as predicted by ASHRAE 55 under NV mode. Thermal comfort range was 0.75 oC wider than those predicted by ASHRAE 55 under NV operation, and the same as ASHRAE 55 under AC operation. The findings of this research provide a better understanding of mixed-mode building operations and perspectives from occupants, important for building designers and building operation managers. [ABSTRACT FROM AUTHOR]