Indoor and Built Environment

Few studies assessed the long-term changes in the prevalence of indoor damp indicators in residences. In this paper, we tried to clarify nationwide spatial-temporal distributions of the prevalences of damp indicators in residences in the past four decades in China and compared the prevalences in other countries. A systematic review was conducted in three Chinese-language databases and two English-language databases from January 1980 to December 2020 according to the guidelines of PRISMA (preferred reporting items for systematic review and meta-analysis). After reviewing 5580 documents, 86 articles that provided specific data were retained for the review of prevalences of damp indicators in residences. Windowpane condensation was the most common damp indicator in residences (averaged: 34.1%, 95% CI: 28.1–40.1), followed by damp clothing and/or bedding (26.5%, 95% CI: 22.0–31.0), mouldy odour (13.3%, 95% CI: 10.4–16.2), water damage (12.5%, 95% CI: 8.6–16.5), visible mould spots (12.2%, 95% CI: 8.7–15.7) and visible damp stains (11.8%, 7.1%–16.5%) in dwellings in China. In the past four decades, increasing trends of window pane condensation prevalences and mouldy odour were noted and trend was then declined after 2010, whereas prevalences of water damage and visible damp stains were generally shown to produce decreasing trends in the surveys. Our findings provide comprehensive data for the evaluation of indoor damp indicators in residences in China.

The rapid development of cities has led to highly urbanized artificial environments that limit people's exposure to nature. The resulting accelerated pace of life has placed individuals under prolonged high-pressure conditions, leading to an increased incidence rate of related diseases. Recent research has shown that visual stimuli of plants have a positive impact on human physiological health. The experimental paradigm involves the presentation of visual stimuli, which encompasses a variety of modes including authentic plant landscapes, botanical imagery, videos and virtual reality simulations, amongst other modalities. In the course of the experiment, the physiological markers of human participants exhibited a favourable response to the presentation of plant landscapes, manifesting in a notable reduction in stress levels, an enhancement in immune function and a calming influence. This study critically reviews experimental literature on the physiological benefits of viewing plant landscapes, examining the effects on human brain activity, autonomic activity, secretory activity and immune activity. This review supports further research into the effects of plant landscapes on human physiological health and the development of preventive medicine in the future.

Outdoor thermal comfort affects occupants’ well-being and building energy use. A reliable thermal index tailored to diverse climates is crucial for improving outdoor conditions. Current calibration methods for the neutral thermal range typically set a Thermal Sensation Vote threshold between −0.5 and 0.5. However, this threshold was derived from the indoor-focused Predicted Mean Vote model, which may not be applicable to outdoor conditions. To address this limitation, a revised calibration framework for outdoor scenarios is proposed, taking subtropical hot-humid campus as a case study. The key aspect of this framework is refining the neutral Thermal Sensation Vote interval for outdoor settings. First, an evaluation of the original outdoor thermal comfort index identified the necessity for recalibration. Next, the correlation between Thermal Comfort Vote and Thermal Sensation Vote was established to accurately localize context-specific neutral Thermal Sensation Vote interval. Finally, the proposed framework was applied to UTCI calibration, yielding a modified neutral UTCI range of 4.5–27.2°C through localized regression analysis. This study also highlights the impact of spatial configurations on outdoor thermal comfort, finding higher thermal tolerance within natural landscapes. It provides insights into creating outdoor thermal settings in subtropical hot-humid locations, especially for campus construction or renovation.

In the present work, computational fluid dynamics (CFD) was used to study the dispersion behaviours of vehicle exhaust, including the CO and PM in a curved tunnel with a consideration of the coupling effects of tunnel radius and tilt angle of jet fan. The simulation results showed the variations in the high-speed jet area in the tunnel under different tunnel radii and tilt angles of jet fan. For the pollutant diffusion, concentrations of CO and PM were shown to be inversely proportional to the tilt angle of jet fan and tunnel radius. In the vertical direction, the PM concentration was not always decreased with the increase in the altitude, which is different from distribution of CO concentration. In the horizontal direction, CO was mainly distributed at 20 – 60 m downstream from the fan, while PM accumulation covered the entire downstream of the tunnel. A close relationship between the distribution of pollutant concentration and vortex structures was found. The present work could contribute to knowledge for reducing the energy consumption of jet fans and the pollutant concentration in the curved tunnel and would provide significant guidance for the future design of curved road tunnels.

Urban areas are significant contributors to global carbon emissions. Investigating the spatiotemporal distribution characteristics of urban carbon emissions and their influencing factors is essential for formulating effective carbon reduction policies and enhancing urban environmental quality. This study utilized nighttime light data to analyse the spatiotemporal distribution of carbon emissions in Hefei City. We employed a Random Forest regression model to explore the impact of urban spatial morphology on carbon emissions. The findings indicated that carbon emissions in Hefei have shown a consistent annual increase without a clear spatial pattern. Regression analysis revealed a nonlinear positive correlation between carbon emissions and factors such as floor area ratio, building density, architectural volume and staggered degree. Conversely, the body mass index and enclosure factor demonstrated a nonlinear negative correlation with carbon emissions. Amongst them, the body mass index was shown to have the highest impact weight on urban carbon emission, which was 0.195, followed by architectural volume and floor area ratio, which were 0.155 and 0.145, respectively. This research highlights the complex influence of urban spatial morphology on carbon emissions and provides valuable insights for the development of urban carbon reduction strategies.

This study evaluates the effects of heat waves on habitability conditions, energy consumption and cooling expenses through on-site measurements in two houses in Buenos Aires Province: an urban house located in La Plata, with low thermal quality of the envelope and two air conditioners; and a rural one in Brandsen, with an intermediate thermal quality of the envelope and one fan. Energy strategies were simulated on both houses that, simultaneously, allow the adaptation to heat waves and reduce, or generate the least possible, impact on electricity grids: a photovoltaic (PV) system and a ground source heat pump (GSHP) system. Both locations experienced similar average outdoor temperatures (∼28°C), but La Plata had fewer fluctuations due to heat accumulation in built surroundings. Indoor temperatures were comparable (∼29°C living spaces/∼27°C bedrooms), but the house in La Plata experienced lower thermal fluctuations due to its air-conditioning (ACs) and outdoor temperatures. Average heat index values were alike (∼30°C living spaces/∼29°C bedrooms). Although La Plata’s dwelling had ACs, results show the influence of envelope performance and nighttime ventilation in the Brandsen’s rural setting. Adaptation assessment revealed that PV and GSHP systems are adequate measures to face heat waves; however, they require important incentives to achieve massiveness.

The performance of rural residential buildings has a great energy-saving potential due to the great spontaneity and ignorance of the rural residential construction. To solve this problem, this paper provides a multi-objective optimization model based on Chebyshev inequality. The model takes energy consumption, indoor thermal comfort, project cost as optimization objectives and considers operating conditions in winter and summer. This study taking a rural residential house as an example and analysed the influence of its envelope parameters on building performance using EnergyPlus. The parameters of the building envelope were optimized, which verified the superiority of the method. Optimization results showed that the heating energy consumption was reduced by 29%, and the air conditioning energy consumption was reduced by 6%. This study analysed the relationship between the building energy consumption, indoor thermal comfort and the cost by multi-objective optimization method, to provide a new research idea for rural residential research. Optimal design solutions were generated under various weighting coefficients. The model aimed to meet the climatic and economic conditions of northern China and similar regions. Therefore, based on these optimization results, decision-makers can choose optimal design and construction solutions according to their own will.

The utilization of photocatalytic technology for the degradation of indoor volatile organic compounds (VOCs) offers the advantages of environmental friendliness, harmlessness and absence of secondary pollution. Integrating photocatalytic technology with the Trombe walls represents an effective form of building-based photocatalysis. However, there is an urgent need to improve the purification performance of photocatalytic Trombe walls. To address this issue, the impacts of co-catalysts and airflow organization on the degradation efficiency of indoor formaldehyde were investigated. TiO₂ with different co-catalysts and ratios were employed. The TiO₂-3% tourmaline achieved a 28.7% degradation rate within 1 h, exhibiting a 24.7% improvement compared to pure TiO₂. Furthermore, the impact of air layer structure on the airflow organization and photocatalytic performance was analysed using experiment and numerical model. By symmetrically arranging two vertical ribs (5 cm wide and spaced 12 cm apart) on the collector plate surface, the formaldehyde degradation rate reached 36.7%. Moreover, a quantitative analysis was conducted to optimize the air layer structure by examining the correlation between airflow distribution and indoor VOC degradation. The formaldehyde degradation rate reached 42.0% within one hour when the air layer was arranged with three spoiler plates at the upper middle of the collector plate surface.

Indoor plants can effectively improve indoor air quality, relieve depression and other negative emotions for indoor occupants, and improve their work efficiency. However, the effects of plants on indoor occupants were attributed to the aesthetic effects only in previous studies, without considering the effect of air-purification performance. In this study, the purification and aesthetic coupling effects of Epipremnum aureum were studied using various combinations of number and placement of artificial and real E. aureum. Indoor environment parameters like the formaldehyde concentration were monitored. The effects of plants on subjects’ work efficiency and psycho-physiological benefits were investigated. Quantitative analysis was conducted on the air-purification and aesthetic coupling effects of E. aureum on subjects’ psycho-physiological responses using Isight software. The results revealed that the CADR of E. aureum could reach 10.254 m³/h, and the air-purification performance of the plants contributed to the physiological and psychological benefits of subjects. The interaction term of number and ‘real or artificial’ of plants contributed the most to the work efficiency, physiological response and psychological response of the subjects, accounting for 39.78%, 43.09% and 25.50%, respectively. The interaction term was a positive stimulus to work efficiency and physiological response and had a negative effect on psychological response.