Effective control strategy for building temperature regulation plays an important role in meeting peoples’ comfort demand. In this paper, the problem of temperature control is studied for two neighbouring rooms of a building using backstepping technique. The mathematical model of the considered building has strong coupled variables, which makes room temperature control more challenging. Firstly, in order to be convenient for controller design, the model is represented in state space form. Then, an appropriate controller is constructed using backstepping technique. Design parameters are introduced in controller design procedure. By choosing suitable design parameters, indoor temperature of the considered rooms can be regulated to desired value. Finally, simulation analysis and comparison are given including both cases in summer and winter, and simulation results show the effectiveness of the proposed controller.

Urban microclimate directly affects building energy demand, particularly for the cooling and heating energy requirements. In this study, taking Harbin as an example, the local climate zone (LCZ) scheme, fixed-point weather station monitoring and EnergyPlus-based building energy simulation were employed to investigate the influence of LCZ type on building cooling and heating loads. Correction factors for Typical Meteorological Year (TMY)-based predictions were evaluated. The results show that urban microclimates could exert a more pronounced impact on cooling loads. Compared with the TMY-based prediction results, the annual cumulative heating load intensity (ACHLI) of a building under different LCZs was decreased by 5.0%–17.9%, the annual cumulative cooling load intensity (ACCLI) was increased by 12.3%–27.8%, and the total load was decreased by 0.1%–11.6%. The ACHLI and annual peak heating load intensity (APHLI) of the built types were generally lower than those of the land cover types, with an average reduction of 6.0% and 3.0%, respectively. Compared with TMY-based prediction, the correction factors of the ACHLI, ACCLI, APHLI and APCLI ranged from 0.82–0.97, 1.09–1.35, 0.97–1.14 and 1.02–1.16, respectively. These results have provided a theoretical framework for accurate load prediction, enhancing building energy standards and climate-responsive planning in severe cold regions.

This study has developed a sensor selection procedure for quickly confirming hazardous chemical exposure levels for electronics industry workers. We reviewed several papers and documents to determine the chemical substances used in semiconductor manufacturing. To source information about high-use and high-risk substances and the amounts of chemicals used in semiconductor manufacturing, we utilized chemical data from the Korea Ministry of the Environment and the Korea Occupational Safety and Health Agency. The method used to select chemicals involved assigning weights to hazardous substances and selecting those with high scores ultimately for the development of sensors. During the manufacturing of semiconductors, sensors are needed for hydrogen fluoride, chlorine, phosphine, carbon monoxide, hydrogen chloride, hydrogen peroxide and ammonia. Overall, the proposed procedure provides a practical and systematic framework for prioritizing hazardous chemicals and supporting sensor selection based on actual industrial usage and risk, thereby enhancing the applicability of real-time chemical monitoring in semiconductor manufacturing.

A multi-mode air-supply fume hood was designed to effectively remove contaminants of varying densities within the cabinet by altering the position and angle of the air supply. Numerical simulation methods were employed to analyse the performance of heavy-density and light-density modes in handling contaminants of different densities and to evaluate the impact of the airflow distribution on contaminant removal efficiency. The study demonstrates that optimised designs can reduce the leakage rate of the fume hood, enhancing its performance and efficiency. In heavy-density mode, increasing air supply effectively reduces room air conditioning load and building energy consumption, with a downward vertical air supply angle and a 70% air supply-exhaust ratio providing higher safety. In light-density mode, a vertically downward air supply angle offers better safety, and a downward air curtain at the lower end of the operating door is more effective in controlling contaminant leakage compared to a bottom slit air supply. The average concentration of contaminants in the fume hood was reduced by 35.98% at a 60% supply-to-exhaust ratio.

Thermal comfort in classrooms is mostly assessed in summer/hot and humid seasons; however, thermal perceptions across different climatic conditions have to be studied to undertake effective mitigation. In this study, thermal perception and occupant adaptive characteristics in classrooms of naturally ventilated school buildings were assessed during two different climatic conditions (i.e., hot-humid and monsoon seasons) in Sri Lanka. The assessments included: (1) measurements of weather parameters and (2) thermal sensation levels of students occupying those classrooms. About 879 and 852 responses were collected and assessed according to the ISO 7730 thermal sensation scale during hot-humid and monsoon seasons, respectively. Mean indoor temperatures were 30.5°C during the hot-humid season and 27.8°C during the monsoon season, while the corresponding mean relative humidity values were 75.8% and 79.8%, respectively. Findings revealed neutral temperatures of 28.5°C and 26.1°C, with comfort ranges of 25.9°C–31.0°C and 22.6°C–29.7°C, with 80% acceptability, were desired during hot-humid and monsoon seasons, respectively. The mean comfort temperatures forecasted for hot-humid and monsoon seasons using the Griffiths’ method were 28.9°C and 26.8°C, respectively. This study helps to align the design of classrooms in similar tropical climate conditions, considering the thermal comfort of occupants.

Student dormitories often face indoor environmental challenges due to high occupant density, functional demands and spatial constraints. This study explored trade-offs between indoor comfort and energy consumption through a holistic envelope design. A university dormitory with enclosed balconies in China was used as a case study, and a multidimensional optimisation framework for windows, shading devices and balconies was developed by integrating field measurements, simulation and algorithmic analysis. Indoor environmental conditions and energy performance were simulated using Ladybug, Honeybee and Butterfly. The extreme gradient boosting (XGBoost) model was combined with an improved decomposition-based multi-objective evolutionary algorithm (IMOEA/D) to predict and optimise thermal comfort, natural ventilation and energy use, whilst analysing the influence of envelope parameters on indoor environmental quality. Pareto front solutions were screened using the entropy weight-technique for order preference by similarity to ideal solution (EW-TOPSIS) method, yielding optimal ranges: an external window-to-wall ratio (EWWR) of 0.44–0.55, an internal window-to-wall ratio (IWWR) of 0.31–0.36, shading height (SH) of 2.8–3.18 m, shading width (SW) of 0.60–0.71 m, enclosed balcony depth (EBD) of 1.61–1.79 m, and floor height (FH) of 8.06–16.29 m. The study also examined building orientation effects. This research provides an efficient, systematic method for integrated envelope design and retrofit in student dormitories, targeting enhanced indoor health, comfort and energy efficiency.

This study focused on developing and optimizing a novel smart phase-change material integrated with thermochromic glazing (PCM-TCG) system specifically designed for buildings operated in the hot-summer-cold winter climate zone in China. The optimal integration of these materials for buildings has not been evaluated previously. The thermal and daylighting performance were evaluated with EnergyPlus and Radiance, respectively. The optimization model was established with MATLAB. The optimal solutions identified by NSGA II were further analyzed with Fluent and Radiance. The results indicated that the best solution for each orientation (south, west and east) shared similar features. The phase-change temperature of the phase-change material layer was 25 °C, which is close to the indoor air temperature in summer. The transition temperature of thermochromic glazing (TCG) was around 20 °C. The solar transmittance of TCG was low (around 50% in clear state and 30% in tinted state). The highest visible transmittance of TCG was measured within the feasible range (70%). The optimal thickness of the PCM layer was 11–13 mm to provide adequate thermal mass. The optimal PCM-TCG can reduce annual energy demand by at least 11.3% and improve spatial daylight autonomy by at least 32.7%, compared to low-E glazing.

Plastic greenhouses, widely adopted due to low cost and flexibility, often rely on natural ventilation, which can cause heat accumulation and the buildup of airborne pathogens and harmful gases. This study evaluated the influence of installation height of air purifiers and circulation fans on indoor air quality (IAQ) in a plastic greenhouse using CFD simulations. Device heights and operating conditions were varied, and IAQ was assessed through age of air. The CFD model was validated against measured indoor temperature data, yielding a mean absolute percentage error of 3.9%. A sensitivity analysis confirmed robustness, as variations in outdoor air temperature (±1°C), ground temperature (±1°C) and solar radiation (±10%) caused prediction variations of about ±1.6%, ±1.5% and ±1.0%, respectively. During daytime, placing air purifiers at 2.6 m and circulation fans at 4.0 m minimized the age of air and suppressed thermal stratification, while at nighttime favourable IAQ was maintained even without fan operation. Compared with less effective setups, the recommended configuration reduced the age of air by approximately 21%. These results suggest an energy-efficient strategy in which both devices are operated during the day and only the purifiers at night, providing practical guidance for low-cost IAQ management in plastic greenhouses.

The spatial distribution regulations and reconstruction methods of rural settlements in provincial border areas are significant for sustainable development in rural areas but have yet to receive much attention. Suitability evaluation, an essential method for rural settlement spatial reconstruction, has a particular subjectivity in indicator assignment and weight setting. Based on kernel density estimation, Geodetector and minimum cumulative resistance model, this study selected Wuqing District, a provincial border district of Tianjin, China, to address the above issues. The results revealed that rural settlements in Wuqing District face significant variations in spatial scale and density. Population size and arable land availability dominate as fundamental drivers, while boundary effects and transport conditions modulate the spatial clustering of settlements. The density of rural settlements varies in sub-regions with different distances to the provincial boundaries. The role of administrative boundaries may be a reconciling trade-off mechanism between two opposing effects. The suitability evaluation of rural settlements in Wuqing District indicates the practical necessity of rural settlement optimisation and reconstruction. This study brings new insights by explicitly focusing on provincial border areas and uncovering a boundary effect in rural settlement density, while achieving a data-driven weighting scheme.

As more complex tunnel projects are being constructed in the mountains of southwestern China, understanding the diffusion phenomenon of carbon monoxide (CO) in high-altitude tunnels is essential. This is particularly critical for tunnels with high ground temperatures during blasting. This study employed field monitoring and computer simulations, focusing on a specific plateau tunnel. A real-time monitoring system was established, using CO as the representative gas. A computational fluid dynamics model was developed and was validated against field data. Results show that forced ventilation could create four distinct flow regions. CO concentration in the tunnel declined during outward diffusion under ventilation. Specifically, the CO concentration was increased by a factor of 1.83 with the increase in the altitude from 0 to 5000 m. Furthermore, with ground temperature rising from 300 to 320 K, the propagation speed of the CO concentration peak accelerated, arriving at the tunnel exit section 53 s earlier, and its magnitude was decreased by 224 ppm. Finally, a functional relationship was established between CO concentration, ventilation time, distance, temperature and altitude. This study provides a valuable reference for safety assurance and informs ventilation design for tunnel construction in relation to CO diffusion in such tunnels.