Comfortable Indoor Environment Research Articles

Improving Acoustic Comfort in Indoor Environments Using Eco-Sustainable Furnishings Based on Sheep's Wool

Eco-sustainable materials reduce environmental impact by limiting the use of non-renewable natural resources and the generation of toxic waste, thus contributing to the conservation of ecosystems and the mitigation of climate change. Furthermore, eco-sustainable materials demonstrate a concrete commitment to sustainability, increasing the appeal of a brand towards consumers that are sensitive to environmental issues Companies that adopt such materials often enjoy a better reputation and greater customer loyalty Natural fibers are emerging as a viable choice for sound-absorbing panels in construction because they exhibit favorable thermal and acoustic absorption characteristics, non-toxic nature, and abundant availability. In this study, the use of sheep's wool fibers as a sound absorption material is specifically explored through measurement and discussion of the absorption coefficient of samples with varying depth. Furthermore, the opportunity of utilizing commercial woven with various types of wool for sound absorption structures, to achieve this, modelled application of wool tapestries are placed at varying distances from a fixed back barrier. This study demonstrates significant sound absorption in specific frequency ranges, conditional on the strength of the rear cavity, affirming the suitability of wool tapestries for tailor-made acoustic interventions. The research highlights the returns of using sheep wool in environmental acoustic applications, demonstrating how the acoustic correction of an environment with the use of material based of sheep's wool provides results comparable to those of artificial materials traditionally used.

Environmental and Energy Performances of the Nearly Net-Zero Energy Solar Decathlon House with Dynamic Facades: A Comparison of Four Climate Regions

Dynamic facades allow for effective climate adaptability, representing a new trend in future building envelope design. Present research on dynamic facades often focuses solely on certain aspects of the built environment or relies entirely on simulation outcomes. Meanwhile, the real-time changing nature of dynamic facades poses challenges in accurately simulating these schemes. Therefore, it remains essential to quantify the energy consumption performances of different types of dynamic facades and their influence on the indoor environment comfort in response to ventilation, light, and thermal environment to improve energy savings. This study uses an energy management system to simulate the ability of five dynamic facades—an intelligent ventilated facade, a dynamic exterior shading, a dynamic interior shading, a buffer layer, and phase-change material (PCM) facades—to provide adequate comfort and reduce energy consumption in four climate zones in China. The simulation model of a nearly net-zero energy Solar Decathlon house “Nature Between” was validated with experimental data. Among the five dynamic facades, the energy-saving efficiency of intelligent ventilation was highest, followed by exterior shading. Compared with houses without dynamic facades, the use of the dynamic facades reduced energy consumption (and annual glare time) by 19.87% (90.65%), 22.37% (74.84%), 15.19% (72.09%), and 9.23% (75.53%) in Xiamen, Shanghai, Beijing, and Harbin, respectively. Findings regarding the dynamic facade-driven energy savings and favorable indoor environment comfort provide new and actionable insights into the design and application of dynamic facades in four climate regions in China.

Assessment of indoor environmental comfort for individuals wearing face masks of different thickness

The present paper experimentally analyses the subjective assessment of indoor environment comfort based on a questionnaire survey conducted in a climate chamber located at Kielce University of Technology (Poland), if two types of face masks are worn by the respondents: thin (medical) and thick (cotton-made) masks. Air temperature and relative humidity in the chamber ranged from around 19 to 28oC and 20 – 70%, respectively. Precise measurement of the microclimate parameters was obtained with a microclimate meter, which recorded air temperature and relative humidity at the moment of completing the questionnaires. The respondents were of similar age (22 – 31 years old) and wore two types of clothing during the experiments: summer and winter, which differed by thermal resistance. This value amounted to 0.5 clo for the summer outfit and 0.8 clo for the winter one.In total 960 questionnaires were analysed in the study. The results indicate that the increase in air temperature led to poorer overall comfort, while the largest comfort sensation was recorded for the most favourable thermal sensation range. In general, thicker masks provided lower overall comfort than thinner masks for all relative humidity values.

Optimizing Cooling System Design: A Case Study for Innovation Building

This paper presents the design and optimization of a cooling system tailored for innovation building, focusing on maximizing energy efficiency while ensuring optimal thermal comfort for occupants. The proposed cooling system integrates several key components, including chillers, air handling units, distribution systems, and control mechanisms. The system utilizes a combination of centralized and decentralized cooling strategies to efficiently manage thermal loads across different zones within the building. Additionally, advanced control algorithms are employed to dynamically adjust cooling operations based on real-time data, occupant preferences, and external environmental conditions. The optimization process involves comprehensive simulation studies and performance evaluations using building energy modeling software and an Hourly Analysis Program (HAP). Various design parameters such as equipment sizing, layout configurations, air distribution patterns, and control strategies are iteratively refined to achieve the desired balance between energy efficiency, cost-effectiveness, and occupant comfort. The design and optimization of a cooling system for an Innovation building represents a critical step toward achieving sustainable and energy-efficient building operations. By leveraging advanced technologies and innovative design approaches, this cooling system offers a viable solution for addressing the cooling needs of Innovation buildings while mitigating the environmental impact associated with traditional HVAC systems. The proposed design was applied in a case study of an innovation building during the cooling seasons and the results of the optimization demonstrate significant improvements in energy consumption, with substantial reductions in both electricity demand and greenhouse gas emissions compared to conventional cooling systems. Furthermore, the proposed cooling system maintains consistent thermal conditions throughout the building, ensuring a comfortable indoor environment for occupants while minimizing the risk of thermal discomfort and overheating.

Effects of thermal histories on human thermal adaptation to district heating environments: A cross-sectional investigation in the severe cold zone, China

Understanding personalized thermal comfort is critical for creating comfortable indoor environments and achieving energy efficiency. Thermal history has a significant impact on human thermal adaptation, but it has received insufficient attention. Combining field investigation and statistical analysis, this study introduces the thermal neutral rate (TNR) and thermal comfort and acceptability rate (TCAR) to analyze the differences in thermal and humidity responses and adaptability among groups with different thermal histories in northern China. Results show that as subjects acclimatize to indoor environments, their thermal neutral temperature rises, and humid sensation votes approach 'neutral' conditions. Participants with no prior northern thermal history require up to 1 year to adapt to district heating environments, while adaptation to humid environments may take 2–3 years. The thermal neutral temperature of the un-adapted subjects was 18.0 °C, and post-adaptation, it varied within the range of 20.2–21.4 °C. For engineers designing indoor environments, maintaining temperatures within the range of 19.1–22.3 °C meets the comfort and acceptability requirements of participants with different thermal histories in the office. These findings provide evidence for understanding human thermal adaptation mechanisms and give recommended heating temperature ranges for comfortable indoor environments in office buildings in the severe cold zone.

Optimal control strategy for a cutting-edge hybrid ventilation system in classrooms: Comparative analysis based on air pollution levels across cities

Natural ventilation has the potential to enhance indoor air quality in classrooms with elevated CO2 levels, although it may introduce outdoor pollutants. This study introduces a novel controller for automatic windows that simultaneously monitors outdoor air pollution and temperature, synchronizing window openings with mechanical ventilation system to create a comfortable, healthy, and energy-efficient indoor environment. The practicality of the proposed controller is assessed for a classroom in Delhi, Warsaw, and Stockholm, each with contrasting climates and outdoor pollution levels, specifically PM2.5 and NO2. The controller parameters are optimized for each city using a non-dominated sorting genetic algorithm (NSGA-II) to find the best trade-off between thermal comfort, CO2 levels, and energy consumption. The results show that the controller successfully met the indoor air quality standards in all cities; however, its operation was significantly influenced by the climate and pollution levels. While natural ventilation was utilized for 44% and 31% of the year in Warsaw and Stockholm, respectively, it was used for only 11% of the year in Delhi, the most polluted city. The optimization process significantly reduced energy use across all cities while also successfully reducing indoor CO2 concentrations. Although thermal comfort decreased slightly, it remained within acceptable thermal comfort conditions.

Summer Energy Use and Comfort Analysis in Rural Chinese Dwellings: A Case Study of Low-Income Older Populations in Shandong

This paper aims to investigate the indoor environmental conditions and energy use behaviours of older individuals in rural cold climates of China, with a specific focus on cooling practices during the summer months in the Shandong region. This study employs a mixed-method approach, combining quantitative indoor environmental monitoring with qualitative interviews and observations, to explore the relationship between environmental factors, household living conditions, and energy use patterns across five types of elderly households: three generations living together, older people living with grandchildren, older people living with children, older couples living together, and older people living alone. Data collection was conducted over five weeks during the summer of 2023 using HOBO UX100-003 data loggers, while external weather conditions were monitored by the China Meteorological Administration. Face-to-face interviews were conducted to gain deeper insights into daily cooling behaviours and energy use. The results reveal that cooling practices and indoor environmental conditions vary significantly among the different household types. Multigenerational households showed more complex energy use dynamics, with younger family members frequently operating high-energy appliances like air conditioners, while older individuals tended to rely on natural ventilation and electric fans to reduce energy costs. In contrast, older couples and solitary older individuals demonstrated more conservative cooling behaviours, often enduring higher indoor temperatures due to limited financial resources and a desire to minimize energy expenditures. Despite the high energy use intensity in some households, many homes failed to achieve comfortable indoor environments, particularly in dwellings with minimal insulation and older building materials. This study concludes that economic status, household structure, and building characteristics play crucial roles in shaping cooling behaviours and indoor comfort during the summer.

Dynamic thermal comfort skin temperatures of young adults during sleep and the effects of gender and sleep stage

This study aims to investigate the local skin temperatures of young adults during sleep in a thermally comfortable indoor environment (thermal sensation vote of −1 to +1). Differences in the thermal comfort skin temperatures (Tsk,tc) caused by changes in gender and sleep stage (i.e., wake, REM, light, deep) are discussed. 8-Hour sleep tests were conducted involving 40 subjects (20/20 males/females). Their local skin temperatures at nine sites were recorded every minute, forming a physiological database of thermal comfort. Analysis on the collected data demonstrated significant (p < 0.05) variations in local Tsk,tc both between genders and between distinct stages of sleep. Throughout the 8-h sleep, females had higher Tsk,tc than males. Notably, this difference is most pronounced at the abdomen region, where the Tsk,tc was 0.43 °C higher for females. Additionally, females had a wide range of mean Tsk,tc from 34.08 °C to 34.75 °C, while males had a narrow range from 33.80 °C to 34.25 °C. Furthermore, the Tsk,tc during the wake stage is significantly lower compared to that in the other three stages, implying skin temperature could be used as an indicator to distinguish sleep stages. Also, the variation in Tsk,tc across sleep stages is more pronounced among females than males. This research reveals gender-specific and sleep stage-related disparities in local Tsk,tc. These findings provide a scientific basis for set-point skin temperatures in thermal regulation models for sleeping. Besides, the development of personalized sleep comfort systems and indoor environment would benefit from current findings, which improves human sleep thermal comfort and quality.

An efficient thermal comfort prediction method for indoor airflow environment using a CFD-based deep learning model

Thermal comfort in indoor environments significantly affects human health and productivity, while there remains room for improvement in enhancing thermal comfort around individuals. This study proposed an efficient thermal comfort prediction method based on the Convolutional Neural Networks-Long Short-Term Memory (CNN-LSTM) model to rapidly and accurately assess indoor thermal comfort. As demonstrated with a high-speed train, the computational fluid dynamics (CFD) technology is combined to establish the dataset. Five design parameters (the ratio and angle of the upper inlets, supply air temperature and humidity, and external temperature) and four evaluation indices (air velocity, air temperature, Predicted Mean Vote, and Draft Rate) are considered in assessing the accuracy of the method on the test dataset. The results indicate that CNN-LSTM achieves consistent and accurate predictive performance, with average mean absolute error (MAE) close to 0.01 m/s, 0.2 °C, 0.1, and 1.0. On the generalization test set, the predictive performance of CNN-LSTM decreases slightly, but the average of the determination coefficients (R2) still approaches 0.89. The thermal comfort prediction method developed in this study demonstrates significant advantages in predictive performance, showing great potential for application in the construction of healthy and comfortable indoor environments in buildings, aircraft, subways, etc.

Impact of future climate scenarios on thermal performance and resilience of building façades: Canadian climate case study

Buildings in urban areas are responsible for a significant share of GHG emissions that directly contribute to climate change. Nevertheless, the built environment is vulnerable to the changing climate. Particularly, the unpredictable weather threatens the performance of building components, durability of building materials, and indoor environmental comfort. In this study, the impact of future climate on thermal performance of building façades in the Canadian climate is investigated using simulation analysis. To account for different climate conditions, three future weather scenarios pertaining to global temperature rise of 0.5 °C, 1.5 °C, and 2.5 °C were compared with historical weather data. Both hourly and Typical Meteorological Year (TMY) weather data were studied. The results, including thermal transmittance, heat flux, moisture content, and façade temperature were compared. This comparison could show the applicability of using averaged TMY data compared to the large hourly dataset. The results show a pattern of change in the façade's thermal and hygrothermal performance as temperature, relative humidity and solar radiation norms change in both seasons. The comparison between the TMY and the Yearly data showed an underestimation of heat transfer within the façade when the TMY data is used. The historical TMY data results showed the inadequacy of this weather file for climate impact assessments of facades in both summer and winter. The approach used in this study can be repeated for different climate conditions, acting as a tool to design façades and predict their performance in face of a changing climate.

3DP for sustainable built environment – Synthesis and thermomechanical characterization of composite materials based on local soil and date palm fiber waste

There is an increasing demand for sustainable construction materials to address the challenges posed by the environmental impact of the built environment (BE), which is driven by climate change, population growth, and urbanization. Conventional construction materials like cement contribute significantly to carbon emissions during production, transport, use, and disposal phases, and their poor thermal conductivity hinders efforts to maintain comfortable indoor environments. To address these challenges, there is an urgent need for innovative, locally sourced thermal insulation materials specifically designed for regions with extreme climates and high energy demands to maintain building comfort. This research explores synthesizing novel, environmentally friendly building materials using locally sourced date palm fiber waste and clay. The study also investigates the developed material's 3D printing (3DP) capabilities and optimizes its printing parameters with lab-scale prototypes. Additionally, thermo-mechanical characterization is conducted to assess its suitability for built environment applications. Different concentrations, from 1 to 5 wt% of date palm fiber to clay ratio (Dpf/C), were studied regarding microstructural, thermal, and mechanical properties, dimensional accuracy, and feasibility for 3DP of BE structures. Results demonstrated a significant reduction in thermal conductivity by 73%, achieving 0.244 W/mK, and an increase in compressive strength by 106%, reaching 10.9 MPa at 5 wt% Dpf/C. The promising thermomechanical properties of these composites and their suitability for 3DP support their use in real-world applications in the future's sustainable built environment. This scalable methodology can be adapted to regions with similar sustainable local and waste resources, advancing the circular economy.

Development and performance evaluation of an indoor thermal environment control algorithm incorporating MET estimation model with object detection

As people increasingly spend time indoors, the significance of the indoor environment in influencing occupant quality of life is becoming more pronounced. Traditionally, indoor environment control primarily relied on fixed temperature settings, which failed to accommodate the diverse circumstances of occupants. This approach limited the creation of a comfortable indoor environment and the enhancement of energy efficiency. Consequently, there is growing interest in occupant-centric control (OCC), which integrates metabolic rate (MET) information, which is a critical factor in determining the thermal sensation of occupants. Previously, a method was developed to estimate MET by classifying occupant poses and detecting the objects they interact with from indoor images. This study aims to develop and experimentally validate an indoor thermal environment control algorithm (ITEC-algorithm) using the MET estimation model and assess its effectiveness and applicability in real building environments.The performance evaluation revealed that the ITEC-algorithm significantly enhanced the comfort ratios, achieving improvements of up to 59% compared to the fixed temperature control and 28% compared to the control methods that only used the pose classification model for MET estimation. The energy consumption varied depending on the activity and control method, with a reduction of up to 88% compared to fixed temperature control. These results indicate that thermal comfort can be enhanced while minimizing unnecessary energy consumption by incorporating the MET of the occupants. Consequently, it has been confirmed that the ITEC-algorithm effectively improves thermal comfort by managing the MET of various occupants.

Indoor Environment in Kindergartens Located in the North of Portugal: Evaluation of Thermal Comfort and Carbon Dioxide Concentration

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

Advancing energy recovery ventilators with phase change materials for cooling load reduction and heat exchange efficiency improvement

Efforts to reduce building energy emissions and achieve net-zero carbon scenarios globally have increasingly focused the building sector on improving energy efficiency. Heating, ventilation, and air conditioning (HVAC) systems play a vital role in providing comfortable indoor environments but significantly contribute to energy consumption and greenhouse gas emissions. Energy recovery ventilators are efficient active systems that prevent unnecessary indoor heat loss and gain, regardless of outdoor climate, making them excellent technologies for achieving zero energy. In a hot and humid summer climate, such as in Korea, it is crucial to enhance the efficiency of energy recovery ventilators and reduce cooling energy consumption. A Green HVAC design aimed at reducing the energy consumption of active systems to near zero was proposed by applying phase change material-based modules with high heat storage performance to energy recovery ventilators. The phase change material module is stabilized with high thermal conductivity aluminum packing and is configured as a mesh-type structure to amplify heat exchange efficiency with air. Compared to the energy recovery ventilator, the application of the module demonstrated a reduction in supply air temperature by an average of 2.6 °C in high-temperature outdoor. During the effective operating period, a continuous indoor intake temperature reduction effect was observed, and the sensible heat exchange efficiency showed a 21.32 % improvement with the module using n-octadecane. Phase change material modules that can enhance ventilation and improve energy efficiency in high-temperature environments can be proposed as a technology to achieve Green HVAC.

Experimental and numerical investigation of the cooling performance of a solar chimney integrated with a humidification system

Solar chimneys are efficient systems for natural ventilation based on thermal principles. However, in regions with high temperatures it may not serve to ensure a comfortable indoor environment. To overcome this challenge, integrating air humidification into the ventilation process becomes necessary. The present study investigates the feasibility of integrating a solar chimney with a humidification setup for evaporative cooling in the climate of Kirkuk, Iraq. This investigation utilizes both experimental and numerical techniques. Numerical simulations carried out using a finite volume approach and validated against the experimental data. The experimental outcomes highlight the effectiveness of evaporative cooling in lowering outdoor air temperatures entering the room from months May to August in the range 5°C–10°C. A parametric analysis of the system indicates that increasing water supply can enhance the rate of evaporative cooling and lower the room temperature while elevating relative humidity. Additionally, higher humidity diminishes air buoyancy, leading to a significant decrease in air changes per hour (ACH) rate. The findings also show that both air changes per hour and water consumption reach their peak at a chimney height of 0.5 m. Moreover, a direct correlation is observed between chimney width and both ACH and water consumption. Expanding the chimney width results in higher ACH and increased water consumption for evaporative cooling. Artificial neural network (ANN) model demonstrates robust predictive accuracy, evidenced by high regression coefficients of 0.9566 for ACH and 0.9505 for room temperature correlated from computational fluid dynamics (CFD) results. This underscores ANN model effectiveness in forecasting system performance under varying input conditions, providing valuable insights for different scenarios and configurations of the system.

DESIGN AND FABRICATION OF SMART ENVIRO GUARDIAN

This project tackles the challenge of maintaining a comfortable and healthy indoor environment in the face of unpredictable weather conditions. The primary objective is to develop an automated weather monitoring system integrated with a humidifier, leveraging Internet of Things (IoT) technology and a suite of sensors including the DHT11 for temperature and humidity, a rain sensor, an LDR sensor, and a BMP180 barometric pressure sensor. The system aims to monitor real-time weather data and adjust indoor conditions accordingly, enhancing comfort and reducing health risks such as respiratory issues, allergies, and mold growth. Additionally, it provides remote monitoring and real-time alerts through IoT connectivity, improving user convenience and energy efficiency. The methodology includes detailed requirement analysis, hardware and software development, testing, and deployment. This project promises to significantly improve indoor environmental quality, especially in regions with erratic weather patterns, by providing a robust, adaptable solution. Keywords: Automated Weather Monitoring, Climate Control, IoT Technology, Humidifier, DHT11 Sensor, Rain Sensor, LDR Sensor, Energy Efficiency

Construction of a Model for Assessing the Comfort of Residential Indoor Environment Based on Multisensory Design

Economic development and technological progress have made people’s demand for indoor environments higher and higher, and designing safe, comfortable, and healthy indoor environments through multisensory design is worthy of serious consideration. In order to realize the assessment of indoor environment comfort under multi-sensory design, this paper carries out data assessment from three dimensions of thermal environment, light environment and air environment. Relying on the PMV model of thermal environment comfort, we analyze the trends of indoor temperature and humidity, average radiant temperature, and PMV values. Combine Weber-Fechler and lighting coefficient to study the visual comfort change of indoor light environment, and analyze the lighting illuminance of indoor light environment under different working conditions by illuminance uniformity. From the basic principle of indoor wind environment, the changes of effective temperature difference and blowing sense caused by air temperature and wind speed are investigated. The temperature difference of the south-facing room decreased between 12.14% and 15.65% before and after the heating was stopped, which is a small change. The average indoor ambient radiant temperature values at different measurement points were up to 27.59 °C, and the fluctuations of the average indoor thermal ambient PMV values were within the range of [-1.2,1.6]. When the indoor light ambient illuminance value increased from 200 lux to 600 lux, the visual comfort improvement was more significant than from 600 lux to 1000 lux. The indoor air distribution characteristic ADPI value was 100% when the air velocity was 0.15m/s and 0.25m/s. Based on the results of indoor environment comfort assessment, multisensory optimization of indoor environment comfort from heat, light and air environments is proposed to provide guidance for improving people’s satisfaction with indoor environment.

Effects of the Acoustic-Visual Indoor Environment on Relieving Mental Stress Based on Facial Electromyography and Micro-Expression Recognition

People working and studying indoors for a long time can easily experience mental fatigue and stress. Virtual natural elements introduced into indoor environments can stimulate the human visual and auditory senses, thus relieving psychological stress. In this study, stress induction was achieved through noise playback, and the recovery effects on psychological stress of three set indoor environments, visual, auditory, and audio-visual, were investigated through changes in subjects’ facial expressions, electromyographic (EMG) signals, and subjective questionnaires. The experiment found that after stress induction through noise, the participants’ stress levels changed significantly. At this time, the subject scored low on the questionnaire, with electromyography readings higher than usual, and micro-expression recognition indicated negative emotions. After the restoration effects under the three working conditions of visual, auditory, and audio-visual combination, the average EMG values during the recovery period decreased from the baseline period (10 min after the subject acclimated to the environment), respectively. The results indicate that all three restoration conditions have the effect of relieving psychological stress, with the stress recovery effects of auditory and audio-visual conditions being superior to visual conditions. This study is of great significance for creating comfortable indoor environments and minimizing psychological pressure on indoor office workers.

Real‐Time Model Predictive Control of Air‐Conditioners Through IoT—Results From an Experimental Setup in a Tropical Climate

ABSTRACTThere is an increasing demand for air‐conditioners (ACs) to maintain a comfortable indoor environment for all types and sizes of buildings including commercial, industrial, and office spaces. Such ACs are mostly operated by traditional ON–OFF controllers to maintain a temperature setpoint. Extensive control engineering knowledge resulting from experiments on actual buildings is needed before the wide application of an advanced control methods, such as model predictive control (MPC), which are more effective and energy‐efficient than the traditional controllers. Simulation studies on the application of control may provide promising results, but the corresponding experimental validations may prove otherwise. User‐friendly experimental setups to investigate the performance of real‐time advanced control on an actual building and its HVAC system is scarce. This paper details the design, implementation and testing of a user‐friendly, remote and autonomous test bed to acquire measured data through an IoT platform, and to control ACs in real time through MATLAB Thingspeak. Measurement and data acquisition equipment are installed in a two‐zone concrete building in Mauritius. MPC of the indoor air temperature achieved an AC temperature setpoint tracking RMSE which was 0.7°C lower than that achieved by the built‐in ON/OFF AC control. The test bed also revealed that portable air‐conditioners are not very efficient, given that the maximum cooling efficiency achieved in this work was only 60%. It also provided valuable insights based on the experiments carried out, in terms of improvements to sensing and data acquisition. Control engineers can implement such a test bed for the development and application of advanced controllers as per their needs and applications.

Real-scale experiments of resistive heating laminate composite panels for radiant heating in railway vehicles

Railways, as one of the representative mass transit systems, are vulnerable to highly contagious respiratory diseases due to their operation in densely populated environments. Notably, the current convective heating system creates an environment susceptible to virus transmission within railway vehicles. To improve this situation, there have been attempts to introduce radiant heating systems to reduce the risk of virus transmission and create a comfortable indoor environment. Previous studies focused on developing radiant heating composite material for railway vehicles by incorporating a carbon fiber heating element within a glass fiber composite to enable heat generation through joule heating. However, this development was limited to the specimen level. In contrast, this study aims to demonstrate their applicability and performance for actual railway vehicle parts at the component level. Specifically, resin flow and manufacturability were analyzed to assess applicability to railway vehicles. Additionally, heating performance and heat flow characteristics were evaluated to determine heating effects. Based on these results, it is anticipated that the application of multifunctional composite materials in the railway industry will improve the vulnerability to winter viruses and indoor environments and expand the utilization of multifunctional composite materials in various fields.