Indoor and Built Environment

The impact of air pollution in crowded indoor environments, such as schools, has received considerable interest over the past decades. Classrooms are environment where children, one of the most vulnerable population groups, spend a lot of their time and poor indoor air quality (IAQ) can negatively affect their respiratory health. Several reviews in literature address the topic of IAQ, but there is scarce evidence focusing specifically on the challenges posed by school environment on childhood respiratory health. Following the PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews) checklist, systematic research was conducted in Pubmed, Scopus and Web of Science databases. 15 narrative reviews and systematic reviews were included, selected according to specific inclusion/exclusion criteria. The collected information about the consequences of indoor air pollutants on breathing health of children always reported a worsening of respiratory symptoms (cough, wheeze, irritation of the respiratory tract, viral respiratory infections) related to respiratory allergies and diseases, such as asthma. The evidence highlights the need for targeted mitigation strategies and policies to reduce pollutant levels in schools. These strategies should consider building design, ventilation systems and maintenance practices, thereby minimizing the short- and long-term adverse effects and protecting children's respiratory health.

In contemporary society, escalating stress and competition in workplace have posed significant challenges to the mental health of office workers. Within built environments dominated by concrete and steel, olfactory stimulation through aromatic environments has emerged as a promising approach to enhancing emotional well-being. This study examines the emotional and physiological impacts of rosemary, lemon and peppermint on office workers. Participants were exposed to varying odour types, concentrations and release frequencies over a 2.5-h period. The results demonstrate that exposure to aromatic environments during work could effectively enhance emotional states and alleviates stress, with the impact varying based on odour type and release conditions. Rosemary was shown to reduce heart rate and lower the low-frequency to high-frequency ratio (LF/HF) of heart rate variability, thereby supporting cardiac autonomic regulation. Lemon could significantly decrease skin conductance levels (SCLs), with heightened exposure doses and olfactory perception leading to improved subjective emotional states, reduced LF/HF and increased percentage of successive RR intervals that differ by more than 50 ms (pNN50). Peppermint also reduced the SCLs, and moderate exposure intensity was associated with a decline in LF/HF during work periods. These results provide evidence-based recommendations for the design of aromatic environments to support emotional well-being in office settings.

The computational fluid dynamics method has been widely used in the field of subway tunnel research. The simulation of the train's motion is always implemented through dynamic mesh models. However, the computational cost of dynamic mesh methods is high, and the methods adopted by researchers are different. Comprehensive simulation performance analysis of various dynamic mesh models in tunnel flow field applications has not been thoroughly conducted. In this study, based on four different dynamic mesh models (remeshing, smoothing and remeshing (S & R), layering and overset mesh) provided by ANSYS Fluent, comparing them in reduced-size, full-size and real train models. The mesh generation complexity, computational efficiency, application feasibility and accuracy in tunnel flow simulations were analysed. The results show the layering method has the highest calculation accuracy and simulation efficiency, the error was only 4.9% and the simulation time was only 25% of the other three methods. The study has provided new ideas for the simulation of complex models and has established a key reference basis for selecting the optimal dynamic mesh models. In addition, the study has significantly improved the simulation accuracy of tunnel flow mechanics and provides practical technical specifications for the application of metro tunnel engineering applications.

In the high-density building complex, the non-uniform distribution of surface temperature caused by building shading could directly affect the wind–thermal environment. Additionally, the periodicity of meteorological parameters and stochastic nature of the heterogeneous characteristics of the building complex further exacerbate the non-uniform distribution. However, previous studies have often simplified this process by assuming uniform conditions, resulting in inaccurate wind–thermal predictions. Therefore, this study aimed to quantify the ventilation performance characteristics of complex building layouts under different meteorological conditions using a transient numerical simulation method coupling radiation and convection. The results of the flow ratio analysis demonstrated that the ventilation flow ratios fluctuate with the intensity of direct solar radiation, and the amplitude of these fluctuations was shown to decrease with increasing wind velocity. The recirculation flow ratio in the enclosed layout was notably higher, ranging from 1.12 to 2.21 times that of the dotted layout. In addition, the proportion of static wind areas in the dotted layout was reduced by up to 14% in summer and up to 15% in winter for incoming wind velocities between 1 m/s and 3 m/s compared to the enclosed layout.

The building sector significantly contributes to global energy consumption and carbon emissions, making retrofitting a crucial strategy to reduce these impacts. Despite the availability of various retrofit technologies, identifying the most suitable ones for specific projects poses a major technical challenge. To address this, the current study has introduced a multi-stage, multi-objective optimization approach, integrating R, Energyplus and Excel for energy/thermal simulations, sensitivity analysis, optimization iterations and financial decision-making. Objective functions include thermal comfort, thermal energy demand, global cost, primary energy consumption and carbon emission equivalent. The functionality of the proposed framework was tested using the energy model of a residential reference building in Northern Cyprus. Cost-optimal recommendations included applying external wall thermal insulation, independently or with photovoltaics and energy-efficient air-conditioners, necessitating an initial investment of up to 46.40 €/m². This yields potential benefits with up to 56.10% primary energy savings and a 35.17% reduction in global cost. Another option, replacing windows independently or with external shutters, applying thermal insulation and installing photovoltaics and energy-efficient air-conditioners, requires an initial investment of up to 536.70 €/m², offering potential benefits with up to 58.52% primary energy savings. However, a substantial 89.49% increase in global costs is noted due to high initial investment costs.

Oxygen enrichment is essential for worker safety for high-altitude tunnel construction. To improve the design of oxygen-enrichment system, this study conducted a validated simulation to investigate the effect of diffuse terminal parameters on oxygen concentration at the tunnelling face. Relationships amongst terminal parameters, ventilation duct height and oxygen concentration were analysed. Results show that with variations in the terminal parameters, the fraction of the breathing zone meeting the oxygen-enrich criteria fluctuated between 11.76% and 76.47%. Analysis of variance was taken to quantify the relative influence of each terminal parameter on oxygen concentration. A correlation was proposed to predict local oxygen concentration within the workers’ breathing zone in the high-altitude tunnel. The findings can provide guidance for improving practical oxygen-enrichment system design during high-altitude tunnel construction.