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Desk fans allow individual thermal adjustment in shared spaces which increases occupants' thermal satisfaction. When associated with the increase of room conditioning system setpoint temperature, they can also reduce energy use. In comparison to other Personal Comfort Systems (PCS), low-power desk fans can be very efficient for cooling. Nevertheless, previous studies identify some barriers to their implementation and show no clear guidelines on how to overcome them. Therefore, this study presents the results of a field implementation of desk fans in an open office in Brazil. The intervention consisted of providing one desk fan for each occupant and progressively increasing the setpoint temperature. Indoor thermal conditions were recorded simultaneously with occupants' thermal perception using sensors and surveys. Results show fans increased thermal satisfaction by 20 %. And, when fans were available, the preferred indoor air temperature increased by 1 °C. However, many constraints affect the results. Based on this experience, we propose guidelines for future implementation. We emphasize the need to understand the HVAC system, engage building operators, and apply gradual temperature modification. As occupants’ expectations had a great impact on the potential temperature extension, we suggest a way to limit temperature extension in future implementations.

To improve occupant comfort and save energy in buildings, we have developed a closed-loop air conditioning (AC) sensor-controller that predicts occupant thermal sensation from the thermographic measurement of skin temperature distribution, then uses this information to reduce overcooling (cooling-energy overuse that discomforts occupants) by regulating AC output. Taking measures to protect privacy, it combines thermal-infrared (TIR) and color (visible spectrum) cameras with machine vision to measure the skin-surface temperature profile. Since the human thermoregulation system uses skin blood flow to maintain thermoneutrality, the distribution of skin temperature can be used to predict warm, neutral, and cool thermal states. We conducted a series of human-subject thermal-sensation trials in cold-to-hot environments, measuring skin temperatures and recording thermal sensation votes. We then trained random-forest classification machine-learning models (classifiers) to estimate thermal sensation from skin temperatures or skin-temperature differences. The estimated thermal sensation was input to a proportional integral (PI) control algorithm for the AC, targeting a sensation level between neutral and warm. Our sensor-controller includes a sensor assembly, server software, and client software. The server software orients the cameras and transmits images to the client software, which in turn assesses occupant skin temperature distribution, estimates occupant thermal sensation, and controls AC operation. A demonstration conducted in a conference room in an office building near Houston, TX showed that our system reduced overcooling, decreasing AC load by 42% when the room was occupied while improving occupant comfort (fraction of “comfortable” votes) by 15 percentage points.

Achieving thermal comfort in buildings while maintaining energy efficiency is a critical challenge in architecture and engineering design and operation. Traditional thermal comfort metrics used in the early stages of design tend to neglect two key aspects: spatial variability of thermal conditions within buildings and the promotion of passive design strategies over active conditioning systems. This oversight leads to localized discomfort, excessive energy use, and increased vulnerability to overheating. To address these issues, we propose a novel metric called spatial Thermal Autonomy (sTA). The primary advantage of sTA is its ability to capture spatial variability in thermal conditions, offering a more comprehensive view of comfort across different building zones. Additionally, sTA supports passive design by quantifying a building's capacity to maintain comfort without active energy use. We performed a simulation case study evaluating sTA for different thermal zone sizes, passive design levels, and climate scenarios. Our findings suggest that buildings with high spatial thermal autonomy tend to use less energy, demonstrate greater thermal resilience during extreme weather or power outages, and experience fewer local discomfort problems. Optimizing building designs for spatial Thermal Autonomy encourages passive design solutions in key decisions related to building form, envelope, conditioning strategies, and HVAC system design. In buildings with reduced heating and cooling loads, this approach supports the increased adoption of local low-energy personal comfort systems, such as fans or local heating solutions, and can lead to more adaptive, resilient, and comfortable indoor environments in a changing climate.

This study assessed the energy-saving and climate-adaptive potential of cool skin and ventilated cavity skin facade technologies in Seoul's high-rise apartment buildings. We created weather scenarios for historical, mid-term future, and long-term future conditions using Coordinated Regional Downscaling EXperiment (CORDEX) method. Building energy simulations were conducted on a South Korean high-rise apartment model to evaluate their performance under different weather conditions. The results indicate that cool skin and ventilated cavity skin technologies can save cooling energy during summers but lead to heating energy penalties in winters. Ventilated cavity skin outperforms cool skin, offering better cooling energy savings and reduced heating penalties. Combining both technologies yields the highest overall energy savings, with 7 %, 9 %, and 10 % cooling energy savings for cool skin, ventilated cavity skin, and the combined package, respectively. However, cool skin increases heating energy consumption by 5 %, while ventilated cavity skin has minimal impact on heating energy. These envelope technologies also reduce peak electricity demand by at least 5 %, 8 %, and 9 %, respectively. They contribute to heat stress reduction, enhance resilience, and decrease extreme heat risks for occupants during power outages by at least 18 % under various weather conditions. Considering the prevalence of aging high-rise apartments in South Korea, adopting these envelope renovation strategies can effectively reduce cooling loads, enhance thermal comfort, and boost resilience under future climates, while avoiding costly reconstruction.

The indoor comfort of occupied buildings has become essential, as it significantly affects the productivity and health of occupants. This review provides a comprehensive overview of air and thermal comfort studies in residential buildings using alternative materials. This study aims to provide the trends and the state of the research in this field, to summarize the optimization methods, and to offer a perspective on future studies. The results demonstrate that in comparison to traditional air conditioning systems, natural ventilation systems, and air purifying plants have the potential to reduce energy consumption and carbon emissions in buildings by up to 60%. Also, cross-laminated timber (CLT) buildings can achieve energy savings of up to 30% compared to conventional buildings due to their superior insulation properties and reduced thermal bridging. This review has provided highlights to help the building owners to promote a healthier environment, reduce energy consumption and achieve more comfortable indoor air quality. The study promotes incorporating innovative materials and use of natural ventilation systems, smart air conditioning systems and air purifying plants. [ABSTRACT FROM AUTHOR]

Global higher education aims to develop students' intellectual capacities, foster personal growth, and mold behaviors, thoughts, and creativity for a fulfilling life. Within this framework, university residential spaces play a vital role in advancing these objectives. A well-designed hostel, tailored to students' needs and comfort, promotes shared interests and positive educational outcomes. Therefore, the importance of satisfactory residential facilities in improving students' performance should not be underestimated. This research examined the satisfaction levels of current residents of the College of Agriculture and Environmental Science hostel at Kaduna State University (KASU) regarding their accommodation. It also explored variations in satisfaction among groups with different socio-demographic characteristics. The study focused on two performance requirements for the evaluation of students' satisfaction, namely, the technical performance requirement (thermal comfort, acoustical comfort, visual comfort, indoor air quality, and fire safety) and the functional performance requirement (interior and exterior finish systems, room layout, support services, efficiency of circulation, and proximity to other facilities on campus). A total of forty-eight (48) performance indicators from the two performance requirement were evaluated through a survey questionnaire. The findings indicated that students generally expressed dissatisfaction across all performance elements, except thermal comfort and indoor air quality, room layout and size, efficiency of circulation, and proximity to facilities. The significance of this study lies in its potential to inform targeted improvements and interventions that enhance student satisfaction, comfort, and overall experience within university hostel accommodations. Findings from this study will contribute to creating a more supportive, enjoyable and conducive living environment for students, ultimately promoting their well-being and academic success. [ABSTRACT FROM AUTHOR]

Experimental work is carried out to study the performance of nanoparticle enhanced phase change materials (NEPCMs) when applied to the Egyptian weather for indoor thermal comfort. Nanoparticle alumina and copper-oxide are used as the additive material into the PCMs 7, 11, 24, 26 and 29. The enhanced PCMs are characterized and tested for thermal performance during solidification and melting cycles. Observations are then made to conclude that, compared to the base fluid, PCM11 has the optimum performance for the Egyptian winter weather and PCM26 is the best for the summer conditions. PCM11 with a favorable phase change range ∼11–13∘C for Egyptian winter conditions, shows a reduction of melting time by over 10% when 5wt.% CuO nanoparticles (NPs) are added. Similarly, further to thermal stability and reduced corrosive action, PCM26 enhanced with 5wt.% CuO NPs has over 14% faster melting compared to the base fluid and does not undergo supercooling when tested for summer application. [ABSTRACT FROM AUTHOR]

In recent years, our time spent indoors has risen to around 90% and to maintain an occupant's comfort and well-being, Indoor Environmental Quality (IEQ) is monitored. Concerned with inhabitant's satisfaction and health, the adoption of smart solutions for IEQ monitoring and improvement has expanded. The solution this study explores is an occupant-centric approach involving the implementation of an Internet of Things (IoT) IEQ sensing network in a prominent office skyscraper in Hong Kong. Over the course of 15 months, real-time IEQ data were collected from 12 locations within the building. The data were collected at 1-min time intervals and consisted of readings of indoor air temperature, radiant temperature, relative humidity, air velocity, carbon dioxide (CO2), particulate matter (PM10 and PM2.5), horizontal illuminance levels, and sound pressure levels, which served as the basis of the assessment made about the qualities of thermal comfort, indoor air quality (IAQ), aural comfort, and visual comfort. Compared to traditional periodic surveys, this IoT-based sensing network captured instantaneous environmental variations, providing valuable insights into the indoor environment's spatial characterization and temporal dynamics. This smart solution also assisted facility management in terms of identifying sources of discomfort and developing effective mitigation strategies accordingly. This study presents an occupant-centric approach to improve occupant comfort and energy efficiency within office buildings. By customizing the built environment to enhance occupants' well-being, comfort, and productivity, an emphasis is placed on a more personalized and occupant-focused design strategy. This approach integrates technical design with human experience, highlighting the importance of real-time physical and subjective surveys for achieving optimal results. [ABSTRACT FROM AUTHOR]

Adaptive thermal comfort models are increasingly utilized to condition thermal environments by considering occupants' adaptability. The most widely recognized models internationally are the ASHRAE 55-2020 and UNE-EN 16798-1:2020 standards, primarily applied in residential and office buildings. However, their use in heritage buildings such as museums has been very limited. These environments present unique challenges that complicate the implementation of conventional energy-saving methodologies due to restrictions on interventions in the buildings to safeguard their historical value. Therefore, it is essential to develop research that evaluates the applicability of these standards as an alternative strategy to the specific conditions of museums in heritage buildings in Spain. This study aims to explore the application of the international adaptive thermal comfort models of the ASHRAE 55-2020 and UNE-EN 16798-1:2020 standards in parallel with the preventive conservation conditions of the collections established by the UNE-EN 15757:2011 standard. The aim is to evaluate new strategies for environmental reconditioning to improve visitor comfort while ensuring the conservation of the collections in the exhibition spaces of the Museum of Popular Arts and Customs, housed in a 1914 building known as the Mudejar Pavilion in Seville. Field monitoring was conducted to assess the thermal environment and visitor comfort. The results revealed that the monitored environmental conditions of the exhibition spaces of the Mudejar Pavilion, in accordance with ASHRAE 55-2020 standards, showed high effectiveness in ensuring thermal comfort for visitors, achieving comfort 99% of the time annually, with an acceptability of 80%. High suitability for the conservation of collections was also observed, with optimal conditions achieved 87% of the time. However, under the standards of UNE-EN 15757:2011 for a Category III expectation level, comfort was only achieved 70% of the year, while stability of conservation conditions was achieved 88% of the time. Finally, the implementation of specific correction guidelines is proposed to achieve the acceptability limits of greater energy efficiency. [ABSTRACT FROM AUTHOR]

In this paper, a morphologically stable composite phase change material (CPCM) suitable for use in the field of building energy conservation was developed using Na2HPO4∙12H2O (DHPD) as the phase change material, Na2SiO3∙9H2O (SSNH) as the nucleating agent, and silica aerogel (SA) as the carrier. The results showed that the incorporation of 25 wt% SA resulted in the as-prepared DHPD-SSNH/SA CPCM with a phase change temperature of 30.4 °C, an enthalpy of 163.4 J/g, and a low supercooling degree of 1.3 °C, which also solved the corrosion problem of reinforcing bars caused by the hydrated salt PCM. Meanwhile, DHPD-SSNH/SA CPCM had good shape stability and low thermal conductivity (0.1507 W/(m·K)). The phase change temperature was basically unchanged, and the enthalpy only decreased by 4.8% after 200 cold-heat cycles. In addition, the thermal performance evaluation of CPCM showed that the indoor thermal comfort time of the testing system loaded with PCM board accounted for 50.75%, which was 43.38% higher than that of the one without PCM board (7.37%). The results suggest that the obtained CPCM had a good energy saving effect and great potential in the field of building energy conservation. [ABSTRACT FROM AUTHOR]

Longwave radiation is a crucial factor affecting human thermal comfort and thermal stress, especially in outdoor spaces in summer, owing to the vast effect of longwave radiation emitted from high-heated asphalt roads, building walls, and automobiles. Although controlling the longwave radiation environment to improve thermal comfort in summer is crucial, the prediction of the longwave radiation environment is frequently conducted only at the assessment stage of the final proposal because of the high computational cost of radiation calculations and unsteady heat balance analysis considering multiple reflections. This is a significant constraint for the design of urban and architectural environments. A previous study proposed a method to rapidly estimate the longwave radiation environment based on a point-by-point method with longwave radiation intensity distributions of the heat sources. To use this method, 3D models of the geographical objects in urban areas, such as buildings and trees, must be accurately generated, and these models should have information on the longwave radiation emitted in each direction from each object. However, no specific examples of a 3D model and longwave radiation intensity distribution have been presented. In this study, a 3D modeling method for geographical objects in urban areas with longwave radiation information based on drones and photogrammetric techniques was utilized. Moreover, a 3D model of a small-scale building was generated. A longwave radiation intensity distribution was produced for the building. Based on the distribution data, the directional characteristics of longwave radiation were discussed, and the availability of the proposed method was assessed. [ABSTRACT FROM AUTHOR]

Personal cooling garment can effectively prevent human from heat injury and realize global energy saving. However, it is hard to optimize the system with simultaneously realize thermal comfort and high coefficient of performance. To overcome this challenge, a thermoelectric‐water hybrid cooling garment is designed. The key performance indicators of personal cooling garments and experimentally demonstrate the necessity of hybridizing thermoelectric cooler with the employed water cooling garment is first analyzed. Correspondingly, the influence of inlet temperature and volume flow rate are studied and optimized step by step. Finally, under the optimized inlet temperature of 24 °C and the volume flow rate of 5 L h−1, employing water as the cooling media, a coefficient of performance of 1.31 can be approached at the working time ranging from 10 to 60 min. This study demonstrates that the thermoelectric‐water hybrid cooling garment technology can realize an effective cooling with simultaneously high coefficient of performance and maintain thermal comfort. [ABSTRACT FROM AUTHOR]

The 13th Nordic Symposium on Building Physics (NSB 2023) was held at Aalborg University in Denmark, attracting participants from around the world to discuss topics such as heat, air, and moisture transport in buildings, energy performance, and indoor environmental quality. The conference featured keynotes, paper presentations, and workshops, with selected papers published in the Journal of Building Physics. Notable research topics included using Nuclear Magnetic Resonance to measure moisture distribution in building materials and investigating air entrapment effects on water transfer in porous materials. [Extracted from the article]

Ventilation significantly impacts energy consumption in ultra-low-energy buildings (ULEBs). However, in Chinese residential kitchens, the influence of mechanical ventilation formed by range hoods and make-up air systems on energy consumption has received limited attention. This study assesses the heating and cooling demands in ULEBs resulting from kitchen make-up air across different climate zones in China. The results reveal that in natural make-up air mode, there is a substantial rise in annual heating demand in cold and severe cold zones and a notable increase in annual cooling demand in hot summer and warm winter as well as hot summer and cold winter zones. Additionally, the natural make-up air mode often poses challenges in maintaining a satisfactory thermal environment in kitchens during both heating and cooling seasons. Conversely, the mechanical make-up air mode, especially with pretreatment of outdoor air to ensure thermal comfort in kitchens, significantly elevates both annual heating and cooling demands, making it hard for the building to meet the ULEB specifications, particularly in cold and severe cold zones. Furthermore, despite a generally small increase in annual cooling demand, the percentage rise in heating demand often exceeds the ULEB limits, ranging from 12.0% to 36.0%, depending on the climate zone. [ABSTRACT FROM AUTHOR]

Horizontal and vertical viewing perspectives exert varying influences on the environmental perceptions and emotional states of college students. Despite this, scant research addresses the impact on this demographic. We selected typical campus open spaces for comprehensive physical parameter assessments, encompassing meteorological and spatial characteristics. A cohort of 36 healthy college students participated in a questionnaire survey designed to ascertain shifts in visual comfort, thermal comfort, and emotional responses when viewing landscapes in look-forward and look-up orientations. Key findings following both viewing modalities included: 1) a notable rise in mean visual comfort vote (MVCV), by 1.22 for look-forward and 1.01 for look-up, with a pronouncedly higher sunlight sensation vote (SSV) for the latter orientation; 2) a significant increase in thermal comfort vote (TCV), although the difference in increments between the two viewing angles was minimal; 3) Positive affect (PA) exhibited considerable improvement in both viewing conditions, while negative affect (NA) was markedly reduced in the look-up condition relative to look-forward viewing; 4) The SSV was predominantly influenced by the trunk ratio and canopy-to-trunk ratio, with substantial weights of 31.47% and 32.15%, respectively. Landscape element diversity emerged as the most critical factor affecting visual comfort vote (VCV) and aesthetic assessment score (AAS), with overwhelming weights of 70.67% and 63.15%, respectively. Moreover, the leaf ratio was identified as the chief determinant of emotional responses. Our results provide insights into the design of campus spaces for enhanced student well-being. [ABSTRACT FROM AUTHOR]

This study focuses on assessing tourists' perception of bioclimatic comfort in the urban context of Porto, Portugal, specifically in the areas of Avenida dos Aliados and Praça da Liberdade. The study examines the relationship between meteorological conditions, tourists' clothing choices, and their physical activity levels. The study integrates microclimatic measurements and questionnaire surveys carried out during the summers of 2019 and 2020, and the winter of 2019-2020. A comprehensive questionnaire following international standards was administered to a representative sample of 563 tourists. The results show significant variations in mean air temperature (AT), wind speed (Wχ), relative humidity (RH), global radiation (GRAD), and total mean radiant temperature (TMRT) over the study periods. The assessment of Outdoor Thermal Comfort (OTC) is based on ASHRAE 55 standards, using the Thermal Sensation Vote (TSV) scale and the tourists' opinions on their thermal preferences. Clothing choices are found to be influenced by AT, with tourists choosing lighter clothing in warmer conditions. Gender and age differences in clothing insulation (Icl) are identified, suggesting potential differences in OTC perception. AT varied significantly, with an inflection point in clothing choices at 21.7°C and a correlation between AT and reduction in clothing layers (r2 = 0.846; p < 0.05). The study also observes seasonal variations in physical activity levels of tourists, with higher activity levels in summer due to milder weather (110.0 W·m⁻2). More thermally comfortable environments tend to promote a sense of well-being among visitors, which directly affects their satisfaction during their stay in the city. When tourists feel comfortable with the thermal conditions of the urban environment, they are more likely to explore and enjoy local attractions for longer periods of time, thereby enhancing their cultural and leisure experiences. Women tend to wear fewer layers of clothing than men in summer, reflecting potential differences in OTC perception. Results align with previous studies, indicating the impact of clothing insulation of individual subject (Icl) on OTC varies across locations and cultures. Cultural factors influence clothing preferences and thermal tolerance, emphasizing the need for nuanced considerations in understanding OTC perceptions. The study provides to the understanding of the OTC of tourists in the city of Porto, but also offers relevant contributions for improving the visitor experience and sustainable development, namely in other geographical contexts. The major contribution of this research lies in the comparative analysis of Icl and OTC between tourists, based on physical measurements and questionnaire surveys conducted in summer and winter, providing valuable insights for tourist spot design. [ABSTRACT FROM AUTHOR]

Algerian Mzab traditional houses, using passive techniques since the eleventh century (from 1012 to 1882), have seen recent modifications. Analysis of 612 questionnaires and interviews with Mzab residents reveals 81.2% of these houses have been modified. Modifications include adding floors, thinning walls, and replacing lime with cement, driven by the need for space, ventilation, and modernisation. However, such modifications often increase energy consumption, with residents requiring more heating in winter and air conditioning in summer. This reliance on fossil fuels exacerbates regional climate insecurity. Planting roof terraces and using high-insulation building materials can reduce energy consumption in modified Mzab houses. [ABSTRACT FROM AUTHOR]

Thermal energy harvesting and its applications significantly rely on thermal energy storage (TES) materials. Critical factors include the material's ability to store and release heat with minimal temperature differences, the range of temperatures covered, and repetitive sensitivity. The short duration of heat storage limits the effectiveness of TES. Phase change materials (PCMs) are a current global research focus due to their desirable thermal properties, which improve energy performance and thermal comfort. PCMs require relatively less synthesis effort while maintaining high efficiency and enhancing cost-effectiveness. However, limited temperature range and storage capacity restrict the application of conventional PCMs. Consequently, the demand for high-energy PCM storage with enhanced thermo-physical properties is high. It is essential to explore the potential of new PCMs to improve thermal storage performance and capacity while reducing energy consumption. This review article explores the classifications and applications of PCMs, addresses the challenges in enhancing their thermo-physical properties, and outlines the selection criteria for high-heat storage applications. Additionally, it provides an in-depth analysis of recent research and developments related to PCMs. [ABSTRACT FROM AUTHOR]

We characterized the mechanical and thermophysical properties of the compressed earth bricks (CEB) incorporating cotton waste ash. The obtained values of compressive strength are acceptable, as they are well above the limits set by the standards for CEB in Cameroon. Regarding the thermophysical properties, the measured heat capacity decreases by 17% compared to cement stabilization, which is an improvement in the material's ability to store heat. Thermal conductivity is reduced by 28% compared to the cement formulation. Therefore, the incorporated material improves the natural thermal comfort of buildings. Water absorption tests have shown that these materials absorb less water. [ABSTRACT FROM AUTHOR]

From 2012 to 2019, there were approximately 3455 large-scale National Football League injuries reported. There is widespread commercial acceptance of compression garments as tools for reducing injury, promoting recovery, and improving performance in athletic activity. While studies have been conducted to assess the exercise physiology benefits of compression garments, there remains a gap in the scientific literature regarding the clothing comfort and resultant thermoregulation effects of compression girdles for performance athletes. This study aimed to assess the effects of tighter fitting, multi-layer compression systems when worn by American football athletes. A negative impact on thermoregulation may negate or outweigh any realized local benefit such as increased skin blood flow or reduced muscle oscillatory properties. Therefore, the purpose of this research was to determine the predicted hypothalamus temperature, skin blood flow, skin temperature, sweat rate, temperature sensation, and comfort perceptions of the male human body when wearing a compression girdle. A sweating thermal manikin was utilized to predict the physiological responses of a 50th percentile male when wearing football girdles in both practice and play settings. The results indicate significant differences in skin blood flow, skin temperature, core temperature, sweat rate, and comfort and sensation perceptions when wearing compression girdles compared to boxer briefs in replicated practice and play settings. Findings also demonstrate the use of real-time manikin simulation modeling for predicting physiological response outcomes of wearing compression garments to a realized extent. [ABSTRACT FROM AUTHOR]

The stricter requirements for the energy performance of buildings are creating a market for several building‐integrated photovoltaic (BIPV) technologies, including photovoltaic (PV) windows. Herein, an innovative multifunctional PV window concept designed to enhance energy generation while providing overheating protection for better indoor thermal and visual comfort is presented. This concept utilizes bifacial c‐Si solar cell strips combined with venetian blinds, all embedded in a unique insulating glazing unit. The bifacial technology increases the energy yield by using the blinds as reflectors, directing more irradiance to the cells' rear side. The goal of this study is to analyze the outdoor performance of this concept under real operating conditions. Twelve demonstrators are installed and monitored. Various measurement campaigns are conducted, examining the impact of different blind types, tilt angles, sun positions and sky conditions. The highest energy boosts occur when the blinds are fully closed at a 75° angle with their convex side facing outward. Blinds with the highest specular reflectance achieve a maximum performance increase of 25% on sunny days and a daily average increase of 12% compared to the case of no blinds. [ABSTRACT FROM AUTHOR]

Featured Application: Developing occupant presence monitor and sensor station incorporated into heating and cooling system controllers in residential buildings. This study proposes an occupant-centric control strategy for residential heating systems, aiming to enhance thermal comfort and reduce energy consumption. A sensor station utilizing a frequency-modulated continuous wave radar sensor was developed to detect occupancy and infer activities within residential spaces. By analyzing field measurement data, schedules for occupancy and activities were established. These schedules were then used to implement a variable control strategy for the hydronic radiant heating system, adjusting its operating characteristics based on the identified activities. The proposed control strategy, which includes resetting the indoor set temperature during unoccupied periods and adjusting it during sleep to account for changes in metabolic rate and clothing insulation, resulted in significant energy savings. Compared to continuous operation, the hydronic radiant heating system's energy consumption was reduced by approximately 21% on peak load days and up to 34% over three winter months. This study demonstrates the potential of occupant-centric control for achieving substantial energy savings in residential buildings while maintaining occupant thermal comfort. [ABSTRACT FROM AUTHOR]

Recently, the dairy sector has been ever more affected by global warming. This study aimed to test a novel conductive cooling system for cattle that was successfully implemented and evaluated under summer thermally challenging weather conditions in Poland. The system consists mainly of the chiller, tank, and chilled water-driven mattress, designed to prioritize animal well-being. The experimental evaluation was carried out on three Friesian dry cows, housed on different types of bedding—commercial water mattress, straw, and cooling water mattress—and supplied with water at 10 °C (day) and 16 °C (night). The cooling water mattress' surface temperature was twice as low as that of the commercial water mattress. The animal's thermal comfort was assessed with physiological and behavioral reactions. The cooling effect on animals' bodies was demonstrated with a lower reticulorumen temperature of the cooled cow (p < 0.05) than the reference ones. The local effect of cooling was proved with an 8 °C-lower skin temperature after the cow's resting period. The presented study opens a new research direction toward dairy cattle's welfare, sustainability, and the food–energy–water nexus, based on potential energy and water savings. [ABSTRACT FROM AUTHOR]

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Textiles, serving as a second skin for the human body, play a significant role in regulating the microenvironment temperature, and enhancing thermal comfort of the human body during cold weather. However, the most current methods for enhancing the warmth of fabrics involve complex chemical treatment or the application of advanced materials, thus suffering from potential chemical toxicity (especially for infants), complex processing and high cost. Herein, we report a simple strategy for directly processing cotton roving into environmentally friendly and structurally stable thermal-retention cotton textiles by means of hierarchically self-locking structures. The textile not only shows excellent heat-retention properties and mechanical firmness compared with conventional thermal insulation wadding and certain commercial blankets, but is also environmentally friendly and cost effective. This method may provide a new generation of thermal insulation materials with enhanced health and environmental benefits based on hierarchical structure design and natural textile materials. [ABSTRACT FROM AUTHOR]

We evaluate the thermal performance of PUF-insulation boards embedded in the roof of an office-sized room. Two rooms were constructed: one with and the other without insulation. The thermal comfort was evaluated by performing an experimental study according to ANSI/ASHRAE Standard 55-2017. The inside air temperature, humidity, wall and ceiling temperatures, air velocities and thermal flux were measured for the summer April–June 2023. Using these measurements, the PMV and PPD values were computed. The effectiveness of the insulation material with regard to thermal comfort is judged by the reduction in values of these indices. During a typical day, a reduction of around 30% is achieved just by adding the insulation. Nusselt number correlations are proposed to predict the convective heat transfer from the walls. Detailed CFD simulations were performed and a parametric study to understand the effect of insulation thickness, wall insulation, roof thickness and room dimensions on thermal comfort was undertaken. [ABSTRACT FROM AUTHOR]

Due to the popularization of high-speed rail (HSR), there have been increasing concerns of passengers about the thermal comfort of HSR air conditioning. The corrected predicted mean vote (CPMV) model considering the impact of solar radiation on indoor thermal comfort has been previously proposed and validated for accuracy in office buildings. To verify the accuracy of the CPMV model in evaluating the thermal comfort of passengers inside HSR carriages, the field study on HSR in the Yangtze River Delta region of China was conducted in winter and summer. The results indicate thermal sensation vote values obtained from passengers fit well with CPMV values. When the temperature is high in summer and low in winter, the CPMV model ignores people's ability to adapt and tolerate harsh environments. In addition, the thermal preference temperature of passengers in summer is 0.57°C higher than the neutral temperature, indicating that there is an overcooling situation in summer. The study recommends to lower the set temperature of summer air conditioning in HSR. This study contributes to the promotion of the CPMV model on HSR and provides technical support for the design of air-conditioning systems for HSR carriages from the perspective of thermal comfort of passengers. [ABSTRACT FROM AUTHOR]

The salivary immunoglobulin E (IgE) level that usually acts as an indicator of human immunity could change significantly with the air temperature. Electroencephalography (EEG) is a commonly used technique to assess the thermal responses of the human body to the environment. However, the relations between them under step-change temperatures would still need more evidence. Experiments were conducted in this study to explore the EEG–IgE relation. Three step-changed temperature conditions in the controlled environment by a climate chamber were selected in this study, under which the air temperature was suddenly transitioned from a low temperature of 15°C to higher temperatures of 18°C, 24°C and 30°C, respectively, before returning to the initial low-temperature condition. The subjective questionnaires, the EEG signals and the salivary samples from 14 subjects in these three step-changed temperature conditions were collected. Results showed that the thermal comfort voting was significantly correlated with the EEG spectral power and the IgE concentration. In addition, a significant negative correlation between the frontal lobe spectral power and the salivary IgE changes was observed. The spectral power of the frontal lobe could be used as an objective indicator to evaluate the salivary IgE levels under step-change temperature environments. This study has provided some guidance for future studies of the human immunity responses to the indoor environment in different seasons. [ABSTRACT FROM AUTHOR]

This study investigated the impact of design parameters on indoor thermal comfort in hotel buildings, using both PMV-PPD and adaptive models. The aim is to provide guidance for improvement in the energy performance and thermal comfort of the accommodation structures, providing analysis extended to the eight Algerian climate zones. The adopted methodology was applied to a reference building hotel in Ghardaïa, Algeria. The energy model was validated through in-situ measurements and then the analysis was extended through EnergyPlus dynamic simulations to assess the influence of 13 design parameters using sensitivity analysis. Results reveal that design temperatures on the hottest days ranged from 34.4°C to 39.3°C, despite external temperatures reaching 45°C. The PMV-PPD model was most affected by space density, ventilation rate, infiltration, ventilation schedules, roof design and azimuth. Conversely, the adaptive model was influenced primarily by ventilation rate, window-to-wall ratio, lighting, space density, ventilation schedules, glazing and azimuth. This study underscores the potential for optimising hotels' design to enhance thermal comfort and has broader relevance for regions with similar climates to Algeria. The findings offer insights for creating more comfortable indoor environments and fostering sustainable building practices in challenging climates. [ABSTRACT FROM AUTHOR]

The indoor environment in most of the tropical coastal regions is associated with the residents' health and well-being. However, limited studies reported on quantifying the interrelation between indoor environmental quality, thermal comfort and residents' health risks in such climatic regions. Here, we evaluate indoor thermal comfort in coastal eastern India that falls under the ' Tropical Savanna ' climatic region. The perception survey was conducted to collect primary data in summer, monsoon, post-monsoon and winter across the year and the perception of warmth appeared to have a similar trend to direct and rational human thermal indices derived from a composite body heat exchange. Results indicate that indoor thermal stress significantly differed (p <.05) between seasons and across study locations. The maximum summer and monsoon days lay in a warm to very hot zone. Additionally, most of the heat-related stress or disorders significantly differed (p <.01) amongst different age groups of people. Finally, a principal component analysis using the human thermal indices yielded three groups of heat-related symptoms (a) physical fatigue and responses, (b) neural stressors and (c) hyperhidrosis disorder. Overall, results suggested that physical fatigue and responses arose predominantly from climate-induced thermal stress. The study recommends an effective bioclimatic design strategy following human-environment friendliness that can improve indoor thermal comfort in coastal eastern India. [ABSTRACT FROM AUTHOR]

Heating, ventilation and air conditioning (HVAC) systems could significantly impact indoor environmental quality, particularly in terms of thermal comfort and indoor air quality. Achieving a high-quality indoor environment poses challenges to the energy consumption of HVAC systems. Thus, balancing thermal comfort, indoor air quality (IAQ) and energy consumption becomes a challenging task. Currently, indoor environment prediction methods are considered effective solutions to address this issue. However, the published literature usually concentrates on single aspects like thermal comfort, air quality or energy consumption, with multi-aspect prediction methods being rare. The present work reviews research spanning the last decade that employs machine learning methods for predicting indoor environments and HVAC energy consumption through separate and multi-output predictive models. Separate predictive models focus on HVAC systems' impact on the indoor environment, while multi-output models consider the interplay of various outputs. This article gives a thorough insight into machine learning prediction models' workflow, detailing data collection, feature selection and model optimization for each research goal. A systematic assessment of methods for data collection of diverse prediction targets, machine learning algorithms and validation approaches for different prediction models is presented. This review highlights the complexities of data management, model development and validation, enriching the knowledge base in indoor environmental quality optimization. [ABSTRACT FROM AUTHOR]

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]

Sustainable school design is becoming increasingly important worldwide, particularly in the UAE, where schools are significant energy consumers. This study explores the impact of courtyard orientation on microclimate and energy consumption in UAE schools, utilizing a standardized template applied across 70 existing schools. By employing advanced simulation tools, ENVI-met and IES-ve software, the research provides a comprehensive analysis of air temperature and energy use related to different courtyard orientations, specifically on key dates of September 21st and March 21st, representing seasonal variations. The results indicate that North-facing courtyards consistently provide cooler microclimates compared to other orientations. Specifically, North-facing courtyards showed temperature reductions of 1.31°C in September and 1.9°C in March compared to the least favorable orientations. This orientation recorded the lowest average mass temperatures of 29.36°C in September and 25.13°C in March, surpassing the West-facing orientation by 0.39°C and 0.45°C, respectively. The primary factor for this improvement is the reduced solar radiation exposure on East-West aligned courtyards, which significantly lowers the heat gain. Additionally, the study assessed Physiologically Equivalent Temperature (PET) readings and cooling demands, both of which were found to be lower in North-facing courtyards. Cooling load reductions varied between 1% and 4%, depending on the day, further emphasizing the efficiency of this orientation. These findings suggest that strategic courtyard orientation is a critical design consideration for enhancing thermal comfort and energy efficiency in school buildings. The implications of this research are significant for sustainable design and construction practices. By highlighting the benefits of optimal courtyard orientation, this study offers practical solutions for reducing energy consumption and improving the indoor and outdoor thermal environments of schools. These insights contribute to the broader goal of developing greener, more sustainable educational facilities, particularly in hot climates like the UAE. This research not only informs architects and urban planners but also supports policymakers in implementing effective sustainability strategies in the educational sector. [ABSTRACT FROM AUTHOR]

The model for predicting thermal comfort conditions established by Fanger remains widely used in scientific work, as a default means of in situ measurements. However, the use of Fanger data leads to dissatisfaction among users of air-conditioned buildings in humid tropical areas. This conclusion emerges from the work of Kemajou and al. (Cameroon) and Olissan and al. (Benin) in 2012, after survey studies on the judgments of thermal sensations of people occupying various air-conditioned spaces. This article develops a correction model for the Fanger model, by coupling the latter to models for predicting skin temperature and heat loss by evaporation of sweat through the skin, as well as to the skin thermal sensitivity of people active in a humid tropical climate. The model thus determined shows that the predicted optimal comfort temperatures are located in the range of 26.1 °C to 27.5 °C and better meets the expectations of the populations in this region. The respective differences with the investigations of Kemajou and al. and those of Olissan and al. are 0.40 °C and 0.55 °C. It also appears that the comfort humidity range is 30% to 80%, apart from any other safety measures. [ABSTRACT FROM AUTHOR]

Civil construction and buildings account for a significant 36% of worldwide energy consumption, contributing to 37% of global CO2 emissions. In Brazil, buildings consume a substantial 51.2% of the nation's electricity production. Remarkably, approximately one-third of this energy is allocated specifically for maintaining thermal comfort within these structures. The thermal performance of a building has a significant impact on its energy efficiency; in this way, technologies developed to contribute to the energy efficiency of envelopes can directly contribute to the reduction in the building's overall energy consumption. PCMs are technologies capable of absorbing heat without increasing temperature and can contribute to the better energy performance of envelopes. PCMs are used as a thermal performance solution in cold climate regions, and studies show that they are likely to work in buildings in tropical climates. The objective of this work is to analyze the performance of PCMs in tropical regions of the southern hemisphere, specifically in Brazil, and their behavior according to the constructive system used. Computer simulation contributes to an analysis closer to the reality of the implementation of this technology in these regions. This work is carried out with simulations in the software EnergyPlusTM version 24.1. The results demonstrate that PCMs can effectively contribute to a reduction in energy consumption for the thermal comfort of buildings in tropical climates, demonstrating the possible feasibility of the development of this technology for tropical climates. [ABSTRACT FROM AUTHOR]

Rural areas in Northeast China present a large demand for heating energy in winter, but there are problems in such areas with poor thermal performance of building envelopes and poor indoor thermal comfort. In addition, coal-fired boilers are still widely used. China's "Dual-Carbon Goals" and "Clean Heating" policy call for the creation of a green and comfortable living environment for rural residential buildings. This paper considers the impact of the improvement of the thermal performance of envelope structures on the initial investment of the transformation program and the rated power of the ASHP and proposes an energy-saving transformation method to replace traditional coal-fired boilers with the ASHP on the basis of the improvement of the thermal performance of envelope structures. By establishing a typical rural residential building model in Northeast China, this energy-saving method is simulated based on TRNSYS. The results show that the payback period of investment of the transformation method of "envelope structure + heating system" is not superior to that of the transformation method of only improving the thermal performance of the envelope structure, but it has advantages in the comprehensive life-cycle benefits and it has great advantages in improving the satisfaction of rural residents in the use of heating systems. [ABSTRACT FROM AUTHOR]

In recent years, advanced controllers, including Model Predictive Control (MPC), have emerged as promising solutions to improve the efficiency of building energy systems. This paper explores the capabilities of MPC in handling multiple control objectives and constraints. A first MPC controller focuses on the task of ensuring thermal comfort in a residential house served by a heat pump while minimizing the operating costs when subject to different pricing schedules. A second MPC controller working on the same system tests the ability of MPC to deal with demand response events by enforcing a time-varying maximum power usage limitation signal from the electric grid. Furthermore, multiple combinations of the control parameters are tested in order to assess their influence on the controller performance. The controllers are tested on the BOPTEST framework, which offers standardized test cases in high-fidelity emulation models, and pre-defined baseline control strategies to allow fair comparisons also across different studies. Results show that MPC is able to handle multi-objective optimal control problems, reducing thermal comfort violations by between 66.9% and 82% and operational costs between 15.8% up to 20.1%, depending on the specific scenario analyzed. Moreover, MPC proves its capability to exploit the building thermal mass to shift heating power consumption, allowing the latter to adapt its time profile to time-varying constraints. The proposed methodology is based on technologically feasible steps that are intended to be easily transferred to large scale, in-field applications. [ABSTRACT FROM AUTHOR]

The Energy Performance of Buildings Directive (EPBD) has set a target to achieve carbon-neutral building stock and generate 80% of its electricity from renewable sources by 2050. While Model Predictive Control (MPC) can contribute significantly to energy flexibility in buildings, its remote implementation remains relatively unexplored, especially in the residential sector. The purpose of this research is to demonstrate the reliability, robustness, and computational efficiency of a cloud-based application of an MPC called Smart Energy Management (SEM) on a multi-family residential building. The SEM was tested on a virtual building model in TRNSYS using an open-source distributed event streaming platform for data exchange and synchronization. Simplified models for thermal behavior prediction, including an R3C3 model of the building, were developed in C++. The SEM was evaluated in eight scenarios with varying weather conditions, optimization criteria, and runtime periods. The results demonstrate that the SEM maintains stability and robustness over a 2-week period with a 15-minute planning resolution while ensuring thermal comfort. The C++ implementation of the optimization algorithm enables SEM deployment on low-spec servers, supporting cost-effective applications in real buildings with minimal intervention. [ABSTRACT FROM AUTHOR]

This study investigates the impact of vertical greenery systems (VGSs) applied to several typical wall configurations on indoor thermal conditions in a building module situated in the Mediterranean climate of Catania, Italy. By means of dynamic simulations in TRNSYS vers.18, the research compares the thermal behavior of walls made of either hollow clay blocks (Poroton) or lava stone blocks against a lightweight wall setup already in place at the University of Catania. The primary focus is on evaluating the VGSs' capability of reducing peak inner surface temperatures and moderating heat flux fluctuations entering the building. The findings indicate that adding an outer vertical greenery layer to heavyweight walls can decrease the peak inner surface temperature by up to 1.0 °C compared to the same bare wall. However, the greenery's positive impact is less pronounced than in the case of the lightweight wall. This research underscores the potential of green facades in enhancing the indoor thermal environment in buildings in regions with climates like the Mediterranean one, providing valuable insights for sustainable building design and urban planning. [ABSTRACT FROM AUTHOR]

While aspects of indoor environmental quality, such as thermal comfort, indoor air quality (IAQ), acoustic, and visual comfort, are usually studied separately, their interactions are crucial yet often overlooked. Understanding how these factors influence each other is essential for a comprehensive perception of the indoor environment. This paper investigates the relationship between indoor air quality (IAQ) and thermal comfort using an extensive field investigation conducted in university classrooms during the heating season, collecting 712 samples of subjective responses correlated with environmental measurements. Key findings reveal significant correlations between subjective responses related to the thermal environment and those related to air quality. Perceived control over the thermal environment shows stronger correlations with IAQ responses than with thermal responses, particularly with perceived ventilation (r = 0.41), COVID-19 risk (r = 0.28), and air quality (r = 0.28). Additionally, environmental parameters demonstrate stronger correlations with thermal responses than with IAQ responses. Higher CO2 concentration is associated with increased thermal sensation and decreased thermal preference and perceived control. Conversely, IAQ responses remain relatively stable with changes in indoor operative temperature. The difference between the operative temperature to which the occupants are exposed and their expressed neutral temperature widens as CO2 concentration rises, indicating a reduced adaptive capacity of occupants which is associated with increasing CO2 levels. These insights are crucial for providing HVAC system management strategies that consider the interaction between different aspects of IEQ, aiming to improve occupants' well-being and reduce energy consumption. [ABSTRACT FROM AUTHOR]