Evaluation Of Thermal Comfort Research Articles

Characteristics and Trends of Urban Waterfront Human Settlements Based on CiteSpace

Urban waterfront human settlements have gradually become a hot topic for research in recent years. Using CiteSpace, 597 publications from 2017 to 2023 that were retrieved from the Web of Science were analyzed and sorted out, and the following characteristics were found: (1) The research hotspots transitioned from thermal comfort evaluation to the functional mechanism of water bodies, and then to the impact on the environment and residents’ behavior. (2) The integration of disciplines has promoted the diversification of perspectives on urban waterfront human settlements, and the content has become more concentrated in interdisciplinary fields. Research on corresponding technology and methods of urban waterfront human settlement has improved, and so has the extensiveness of the experiments. (3) The research on urban waterfront human settlement from the perspective of ecology has been improving. The research focuses more on the harmonious coexistence of ecological and cultural values and human beings.

Evaluation of Air Quality and Thermal Comfort in University Dormitories in China

Evaluation of Air Quality and Thermal Comfort in University Dormitories in China

Evaluation and application research on thermal comfort of mining face in hot and humid mines

The hot and humid environment in the coal mines negatively affects miners' health and mental health. This paper analyzes the factors that affect the human body heat dissipation, puts forward the concept of dressing rate, and uses the dressing rate to correct the human skin heat dissipation loss and sweat evaporation heat dissipation loss in the underground environment. A human-body thermal comfort model suitable for the hot and humid mine environment is constructed. Then the evaluation index UPMV of thermal comfort in hot and humid mines is proposed, and the mathematical model of human thermal comfort evaluation is constructed which improves the accuracy of human thermal comfort evaluation in hot and humid mines. Lastly, a software system of thermal comfort evaluation for hot and humid mines is developed, which is used to evaluate the thermal comfort of the human body at different working points of horizontal mining roadway in Shoushan mine, and the accuracy of the evaluation model is validated. The research results provide a theoretical basis for the evaluation system of human thermal comfort in hot and humid environments, and provide a reference for a scientific and reasonable arrangement of underground production.

Multi-fanning and its improvement of thermal and wind comfort: An auxiliary means to air conditioning

Space cooling has led to an increase in building energy consumption and the incidence of issues related to indoor air quality. Faced with these challenges, the use of dynamic airflow has become a major area of interest in order to create a comfortable, healthy, and sustainable environment. However, it is revealed that previous studies mostly used single air sources to supply airflow uni-directionally, studying their thermal comfort performance mainly at background temperatures below 30 °C. Considering the dynamic velocity and direction characteristics of outdoor natural wind, in this study, we designed twelve wind conditions and analyzed their airflow characteristics and comfort evaluation. The analysis results revealed that multi-fanning airflows had more dynamic velocity and direction characteristics than directly-supplied constant mechanical wind. Besides, twenty subjects participated in this experiment, they were exposed to these twelve wind conditions at two background temperatures of 31 °C and 32 °C. It was indicated that, other than the air velocity, the diversity of incoming airflows’ direction was also of utmost importance in affecting wind comfort. According to the thermal and wind comfort evaluations, it was found that a diversified use of electrical fans can still maintain great wind comfort without sacrificing thermal comfort in hot environments (up to 32 °C). This study proposes the multi-fanning cooling scenario as an auxiliary means to air conditioning. It may not only help mitigate anthropogenic emissions to achieve carbon neutrality, but will also be greatly beneficial to the comfort, health, and well-being of occupants.

Adaptative comfort modeling for a typical non-centrifugal cane sugar processing facility

The production of non-centrifuged cane sugar in Colombia takes place in post-harvest facilities that generate significant heat and steam resulting from the evaporation of cane juices during the process. This study aimed to improve the comfort conditions of a facility of this type in the municipality of Pacho, Cundinamarca, Colombia, through bioclimatic simulation, where the enclosure on the walls and the lantern window were modified. The evaluation of adaptative thermal comfort revealed that configurations with open perimeter and lantern window demonstrated the best bioclimatic behavior. This is attributed to the increased ventilation area and chimney effect, which optimizes the transfer of heat and mass. Likewise, it was observed that there is a generalized behavior of thermal discomfort for workers in the thermal zone of the oven, due to the high emissions of heat and steam in this specific area.

Effects of indoor environment on EEG and thermal comfort under the ceiling-fan-integrated air conditioning system

This study investigated the correlations between the relative EEG power at different frequency bands under ceiling-fan-integrated air conditioning (CFIAC) systems. Twenty subjects participated in the experiments with the combinations of five air temperature levels (24, 25, 26, 27, and 28 °C) and six ceiling fan gears (Levels 1, 2, 3, 4, 5, and closed). The EEG signals and indoor environmental parameters (relative humidity, air velocity, and temperature) were recorded synchronously, and the thermal comfort online survey for each subject was obtained as well. The most comfortable combination was found when the air temperature was 27 °C and the fan speed was 0.3 m/s. When the air temperature was 25 °C, the relative EEG power in the different bands was least distinguishable, but when the temperature rose to 27 °C, it occurred an obvious change in different lobes. The δ, θ, β, and γ-bands significantly correlated with indoor setting temperature for the whole brain, but only the θ-band located at the occipital lobe significantly correlated with ceiling fan speed. The significance for the α-band with setting temperature and the β-band signal with air velocity varies with the subjects. Compared to the common air conditioning (CAC) system, CFIAC had a different effect on the relationship between relative EEG power and exposure environment. The airflow due to the ceiling fan may reverse this relationship between α-band, β-band, and IAT from positive (CFIAC system) to negative (CAC system). This study can contribute to developing wearable sensing data-driven thermal comfort evaluation models.

Prediction of occupant thermal state via infrared thermography and explainable AI

Accurate and real-time assessment of occupant thermal comfort can provide a solid foundation for efficient air conditioning operations. Existing studies already show the feasibility of using contactless technologies for thermal comfort prediction assisted by machine learning algorithms. However, the lack of transparency in machine learning often weakens user trust. This study performs explainable AI analysis to explore the potential of infrared imaging in thermal comfort evaluation. Specifically, an investigation was carried out in a climatic chamber, and infrared cameras were used to collect facial temperature data. Five popular ensemble tree models were employed to construct prediction models, and explainable AI analysis was performed using SHAP (SHapley Additive exPlanations) theory. Results show that combining additional facial information can significantly improve the overall model performance, and certain facial attributes present high contributions based on SHAP values. Combining facial features with explainable AI provides a convincing basis for thermal comfort assessment. The high SHAP values of facial features can also contribute to finding selective occupants with low neutral voting rates, providing evidence for customized cooling or heating from building systems.

Evaluasi Kenyamanan Termal dan Estetika Berbasis Analisis Tapak dan Persepsi User Taman Kota Depok

The condition of Parks in Depok City has become unmaintained since the covid-19 pandemic due to restrictions on the number of visitors. On the other hand, a comfortable park can improve health. This study identifies existing conditions and analyzes thermal comfort and aesthetics in Taman Lembah Gurame, Taman Lembah Mawar, and Taman Merdeka based on site analysis and users’ perceptions. Evaluation of thermal comfort using Thermal Humidity Index (THI) analysis, while evaluation of landscape aesthetic using the Scenic Beauty Estimation (SBE) method. The perception and preference of respondents using descriptive statistical analysis methods. The THI analysis result showed that the thermal comfort of three city parks was classified as uncomfortable to very uncomfortable. However, the aesthetic assessment in Taman Lembah Gurame and Taman Lembah Mawar was highly aesthetic, while Taman Merdeka was lowly aesthetic. It could be caused by planting design, layout, and activities on-site, which makes users more tolerant of the thermal comfort of parks. Improving facilities and adding flowering plants and shady trees are needed to make city parks more comfortable, beautiful, also adaptive in the new normal era.

Evaluation of thermal comfort during showering with system-related temperature fluctuations

With the decarbonization of heating sector with temperature-sensitive heat pump, comfort must be considered. For users, comfort is a decisive criterion that can hinder the decision for a supply system using renewable energies. Instantaneous domestic hot water heater pose a particular challenge here, as load changes can easily lead to temperature fluctuations. Therefore, the following study aims to determine the perception of temperature fluctuations during showering and to classify them for an assessment procedure. For this purpose, we carried out tests with 120 persons in a controlled environment. The test subjects showered at their desired temperature and gave direct feedback on imposed temperature fluctuations. Positive and negative changes with different rates of change were examined. We reported clear individual differences in the set desired temperatures as well as in the noticed and tolerated temperature fluctuations. The average desired temperature was 38.5 °C, with a quite large variation of ±5.5 K. While 2 % of the test subjects already noticed fluctuations <0.5 K and found them uncomfortable, for others (≈40 %) deviations of 4 K were still comfortable. Therefore, the resulting evaluation was based on a proportion of dissatisfied subjects according to the procedure described by the ISO 7730. This study represents a first step towards the introduction of standardized assessment of instantaneous water heaters and the comfort criteria would allow a comparison of control quality for different applications.

A preliminary study of multidimensional semantic evaluation of outdoor thermal comfort in Chinese

Traditional method to evaluate outdoor thermal comfort which used indicators (UTCI, PET, SET, etc.) has its limitations. Firstly, emotional factors are not included in the assessment, and secondly, the results lead to less accessibility, and it is difficult for non-experts to understand.Due to the above reasons, some scholars have investigated how to evaluate outdoor thermal comfort by ‘English vocabulary’, and there is still a gap in exploring the multidimensional semantic assessment of outdoor thermal comfort by using ‘Chinese vocabulary’. This paper established a ‘Chinese vocabulary’ thesaurus for outdoor thermal comfort evaluation through online and on-site questionnaire survey including 63 words, and an outdoor experiment was carried out to validate the effectiveness of the thesaurus. The results showed a significant correlation between the 2-phases results, revealing the effectiveness of the multidimensional semantic Chinese thesaurus. PET value has a wide range when Thermal Comfort Vote (TCV) are the same, and the words people used to describe the thermal environment in 5 dimensions are very different. The results showed that it is necessary to evaluate the thermal environment by the way of multidimensional semantic, which could make up the short comings of the traditional way (thermal comfort indicators).The field validation experiment of this study was only carried out for 3 days in spring in Shenyang city, thus the result was highly influenced by the experiment conditions and has its limitations. This study could be a fundamental exploration of thermal comfort evaluation by semantic way in Chinese words.

Ventilation performance index fully considering effects of ventilation air parameters on thermal comfort: Effective Draft – Moisture Temperature

Ventilation methods are widely used for creating livable indoor environments. The ventilation performance index of thermal comfort is indispensable for the provision of thermal comfort in indoor environments with ventilation methods. While the air temperature, air velocity, and relative humidity are three predominant environmental air parameters of ventilation methods affecting thermal comfort, existing ventilation performance indices, i.e., Effective Draft Temperature (EDT) and Effective Moisture Temperature (EMT), cannot account for these three parameters simultaneously for thermal comfort evaluation. This study proposes a novel ventilation performance index, i.e., Effective Draft – Moisture Temperature (EDMT) to simultaneously consider the abovementioned three environmental air parameters for the thermal comfort evaluation. The EDMT is proposed based on equivalent thermal comfort effect transfers of the air velocity and relative humidity to the air temperature. Two algorithms of cascaded equivalent thermal comfort transfers are developed, based on which the EDMT is quantified and tabulated for the practical convenience of different demands of thermal comfort under cooling and heating. The results based on Monte Carlo simulations and ASHRAE Thermal Comfort Database II show that the accuracies of thermal comfort evaluation by the EDT and EMT are 88.7% − 95.5% and 70.9% – 89.0% respectively, and those of the proposed EDMTs of Algorithms 1 and 2 are 97.3% − 99.3% and 97.7% − 99.3% respectively. The proposed EDMTs of Algorithms 1 and 2 are credible and convenient for practical applications and contribute to updating ventilation performance evaluation-related standards for developing thermally comfortable buildings.

A Systematic Review on the Studies of Thermal Comfort in Urban Residential Buildings in China

There have been fruitful publications on thermal comfort of urban residential buildings in China. However, there is a lack of reviews on this topic to perform a comprehensive analysis and find opportunities to meet occupants’ thermal comfort needs while improving building energy efficiencies. This paper addresses this issue by presenting a systematic review on the advancements in research on thermal comfort in urban residential buildings in China. Firstly, two common thermal comfort research approaches, i.e., field studies and laboratory studies, are discussed. Secondly, eleven main thermal comfort evaluation indicators are summarized. Finally, this paper analyzes the thermal comfort survey data from different researchers, discusses the impacts of adaptive behaviors on human thermal comfort, and provides recommendations for future research on urban residential thermal comfort. It was found that people have higher and higher requirements for their indoor thermal environment as time goes by, especially in the winter; the thermoneutral temperature is higher in warmer climate regions in the summer but lower in the winter than in colder climate regions; the thermoneutral temperature tends to increase with the indoor air temperature due to an adaptation to the indoor thermal environment. The outcomes of this paper provide valuable information on thermal comfort behaviors of urban residents in different climate zones in China, which can serve as a resource for the academic community conducting future research on thermal comfort and assist policymakers in enhancing building energy efficiencies without compromising the occupants’ comfort.

Thermal comfort evaluation of natural convective-radiant evaporator for air conditioning

The radiant systems come to the fore due to energy saving potential and good integration. The effect of different forms of cold surfaces on human thermal comfort is focused on its application. A novel natural convection-radiant evaporator for heat pumps was developed and its influence on thermal comfort was investigated. A numerical model of the chamber with the evaporator was established and verified with experimental results. Thermal comfort experiments were conducted in a climate chamber and the influence of its asymmetric and uneven cold radiation on the thermal comfort was investigated. Due to the limitation of PMV in uneven radiation situations, the revised predicted mean vote (RPMV) was proposed to assess the thermal comfort in asymmetric and uneven radiation environments based on experimental results. Based on RPMV, the influence of the surface area and temperature of the evaporator on thermal comfort was numerically analyzed. The results indicate that indoor air temperature and relative humidity, RPMV increase with the increase of plate temperature, but decrease with an increase in plate area. The most favourable indoor thermal comfort environment was obtained at an indoor air temperature of 28°C and relative humidity of 50%, which is 2°C higher than traditional air conditioning system.

Research on Automotive Seat Heating Strategy Based on Objective Thermal Comfort Evaluation

Abstract Seat heating is an essential means to improve cabin occupant thermal comfort. How to set a reasonable seat heating strategy is very important to improve occupant thermal comfort and reduce vehicle energy consumption. Based on objective thermal comfort evaluation criteria, this paper analyzes three strategies: fixed heating power, fixed seat surface temperature, and intermittent seat heating. It explores the occupant thermal comfort characteristics under different strategies. It is found that the optimum heating power or optimum seat surface temperature to maintain occupant thermal comfort varies with the initial seat temperature. Compared with the two strategies of fixed heating power and fixed seat surface temperature, the intermittent seat heating proposed in this paper can make the human body reach the optimal state of comfort in a shorter period, and the power consumption is less as the seat heating is opened for a longer time. This intermittent seat heating strategy not only adapts to different low-temperature environments outside but also provides sufficient safety guarantees while improving human thermal comfort. It can provide some references for the design of car seat heating and research on passenger cabin thermal comfort.

Research on indoor thermal environment evaluation and thermal adaptation in winter of Japanese wood-framed detached houses

Indoor space is the place where human beings live, and how to meet people's indoor thermal comfort needs in the context of energy scarcity is one of the important issues for sustainable development of buildings, and the evaluation of the indoor thermal environment has become the key to it. In the case of Japanese wood-framed detached houses, which contain different types of space forms, it is difficult to accurately apply the existing thermal environment evaluation results. In this study, detached houses in Kitakyushu City, Japan, were selected as the research object, and continuous measurements and subjective questionnaires of the indoor thermal environments were conducted based on three modes of no heating, continuous heating, and intermittent heating, in order to grasp the current information of the thermal comfort in detached houses. The results showed that: 1. The average indoor temperatures in both Washitsu and Yoshitsu were lower than the human thermal comfort range; 2. The thermally neutral temperature of 15.9 °C in Washitsu was lower than that of 17.7 °C in Yoshitsu, and the acceptable temperature zones were (14.3–17.5 °C) and (15.6–18.9 °C), respectively; 3. Develop modified models (PMVe) and adaptive predicted mean vote (aPMV) model suitable for thermal comfort evaluation of detached houses in Japan. The results of this study will help to improve the indoor thermal environment and thermal comfort evaluation system of Japanese detached houses, and provide a useful reference for the study of the renewal and renovation of houses in this area.

Study on preparation and application comfort of composite personal protective nanofiber filter material for mining

Miner's pneumoconios is a serious global public health problem. To further improve the application performance of individual protective materials, this paper prepared three-layered composite filter material composed of a hydrophobic external layer, a dust filter intermediate layer, and a moisture permeable internal layer, and explored the influence of composite ratio on the comprehensive performance of the filter material. The thermal comfort evaluation index system under complex working conditions environment was established. The results show that the optimal composite ratio of composite filter material is 2/6/2. This optimal composite filter material has dual-structure with high filtration efficiency of 99.9 %, low resistance of 98.7Pa, high quality factor of 0.07 and high air permeability of 364 mm/s. The construction of the wetting gradient realizes the efficient moisture permeability of 11.1 kg·m−1·d−1of the filter media. In addition, it shows the antibacterial activity of over 90 % against S.aureus and E.coli. The ergonomics experiments shows the heart rate and oxygen uptake are the key influencing factors reflecting the thermal comfort of the filter material. The composite filter material developed with excellent air and moisture permeability can provide a comfortable and safe breathing environment under the working environment of high temperature, high humidity and high labor intensity.

Preliminary Research on Outdoor Thermal Comfort Evaluation in Severe Cold Regions by Machine Learning

The thermal comfort evaluation of the urban environment arouses widespread concern among scholars, and research in this field is mostly based on thermal comfort evaluation indexes such as PMV, PET, SET, UTCI, etc. These thermal comfort index evaluation models are complex in the calculation process and poor in operability, which makes it difficult for people who lack a relevant knowledge background to understand, calculate, and apply them. The purpose of this study is to provide a simple, efficient, and easy-to-operate outdoor thermal comfort evaluation model for severe cold areas in China using a machine learning method. In this study, the physical environment parameters are obtained by field measurement, and individual information is obtained by a field questionnaire survey. The applicability of four machine learning models in outdoor thermal comfort evaluation is studied. A total of 320 questionnaires are collected. The results show that the correlation coefficients between predicted values and voting values of the extreme gradient lifting model, gradient lifting model, random forest model, and neural network model are 0.9313, 0.7148, 0.9115, and 0.5325, respectively. Further analysis of the extreme gradient model with the highest correlation coefficient shows that individual factors (such as residence time, distance between hometown and residence, clothing, age, height, and weight) and environmental factors (such as air humidity (RH), wind speed (v), air temperature (Ta), and black bulb temperature (Tg)) have different influences on thermal comfort evaluation. In summary, using a machine learning method to evaluate outdoor thermal comfort is simpler, more direct, and more efficient, and it can make up for the lack of consideration of complex individual factors in the evaluation method of thermal comfort index. The results have reference value and application value for the research of outdoor thermal comfort evaluation in severe cold areas of China.

The airflow characteristics and thermal comfort evaluation in high-speed train cabin with mixing ventilation: An experimental and numerical study

The airflow characteristics and distribution in high-speed train (HST) cabins have been of great significance for the travel comfort of passengers, while the indoor dynamic airflow characteristics and overall thermal comfort are still unclear. This study first conducted a transient experiment in a real train cabin with the mixing ventilation mode. Measurements showed that the turbulence intensity of the whole airflow is between 20% and 60%. The center zone airflow has a higher turbulence kinetic energy, while the spectral characteristics are closer to the natural wind with the β value between 1.2 and 1.8. Moreover, considering the limitations of the experiment, a corresponding numerical study was carried out. To be closer to the actual situation, the numerical simulation adopted a partitioned heat transfer wall setting, the average deviation of the airflow velocity and temperature from the experimental comparison was 0.057 m/s and 0.25 °C, respectively. Numerical results revealed two vortices in the seating area, a significant longitudinal airflow and an increasing temperature near the carriage ends. Then, to further analyze the compartment's thermal environment and the acceptance of airflow, thermal comfort indicators based on the airflow parameters were used. The predicted mean vote (PMV) showed the thermal comfort of the cabin is slightly cold. Predicted percentage dissatisfaction (PPD) and draught rate (DR) in the center area are barely satisfactory, more than 25% and 20%, respectively. The results of this study can provide an essential reference for the optimization design of ventilation systems in public transport.

Assessing and enhancing the applicability of standard effective temperature in outdoor thermal sensation prediction for continental climates

Accurate thermal sensation prediction is crucial for assessing outdoor thermal environments. This study aims to enhance the applicability of the standard effective temperature (SET*) in continental climates for a more comprehensive evaluation of outdoor thermal comfort. Taking Zhengzhou, China as an exemplar, a comprehensive 12-day survey involving questionnaire surveys and microclimatic measurements was conducted in residential communities during the summer, autumn, and winter seasons. Based on this, the relationship between the SET* and thermal sensation was explored. Furthermore, the SET*-original thermal sensation scale was modified using linear and probit regression, and the accuracy of modified scale was assessed using predicted accuracy percentage (PAP) and mean absolute error (MAE). The results indicated that the SET*-original scale performs poorly in predicting thermal sensation in continental climates (P = 27.3 %, MAE = 1.24). The modified scale using probit regression model was better suited for continental climates (P = 39.5 %, MAE = 0.87). It outperformed the modified scale obtained through a linear regression model, with PAP increasing by 5.9 % and MAE decreasing by 0.04. The SET*-modified scale extended thresholds at the colder end and significantly enhanced predictive accuracy for colder conditions, making it more suitable for predicting thermal perception in continental climates.

An Evaluation of Different Landscape Design Scenarios to Improve Outdoor Thermal Comfort in Shenzhen

The pivotal role of urban greening in landscape design for mitigating climate change and enhancing the thermal environment is widely known. However, numerous evaluations of outdoor thermal comfort are seldom applied within the realm of landscape design scenarios. This study explores the relationship between street design and urban microclimate, aiming to propose a range of design strategies that can significantly improve thermal comfort within the street environment in Shenzhen, China. These design strategies hold immense potential for urban greening implementation and provide valuable insights to enhance the overall thermal quality of streetscapes in subtropical cities. The study employs landscape design and environmental simulation methods to evaluate the different design scenarios for the streetscape. The landscape design encompasses three scenarios with revised interventions: 1. the incorporation of building greening and enhanced pavement material albedo; 2. the introduction of trees and grass at the ground level; and 3. a combination of scenarios 1 and 2. Environmental simulations are utilized to assess the effectiveness of each design scenario. The findings reveal that increasing urban vegetation leads to a reduction in urban heat and significantly improves outdoor thermal comfort. Moreover, the incorporation of shade-providing trees proves to be more efficacious than employing vertical greening in alleviating outdoor thermal discomfort.