Thermal Comfort Vote Research Articles

Thermal perception and dressing behaviors of pregnant women during different stages of pregnancy: A field study at a hospital in Xi'an, China

Pregnant women have different thermal preferences during pregnancy. This paper aims to investigate the thermal characteristics of pregnant women in hospitals, addressing a research gap in the field of thermal comfort for this population. This study assessed the thermal environments of the pregnancy examination spaces (i.e., B-ultrasound room and waiting area) in a hospital located in Xi'an during the winter season. Data were collected from 1055 pregnant women at different stages of pregnancy, including demographic characteristics, thermal sensation votes (TSVs), thermal comfort votes (TCVs), and clothing insulation. The results show that the thermal sensation was significantly more influenced by the pregnancy stage than the current weight. Pregnant women in the third trimester reported a higher mean thermal sensation vote (MTSV) than in other pregnancy stages. Furthermore, the clothing insulation of pregnant women exhibited a non-normal distribution, resembling a bimodal structure. Based on this structure, typical clothing insulation values were determined to be 0.9 clo in the B-ultrasound room and 1.3 clo in the waiting area. Given these characteristics in both thermal perception and dressing behaviors of pregnant women via a subjective questionnaire, we advise lowering the temperature to ensure their comfort and save heating energy. Some personalized seats are also provided to compensate for differences in thermal preference at various stages of pregnancy. These findings contribute to the creation of comfortable and healthy pregnancy examination environments.

Physiological and perceptual responses of firefighters wearing protective clothing under various training environment and activity conditions

To enhance operational capabilities of firefighters in live-fire scenarios, daily training is absolutely important which involves various types of training tasks in diverse thermal environments. Fire training in heat may impose severe heat stress on firefighters. Yet, the thermal burden associating with different training has rarely been studied. In this study, twelve healthy male firefighters performed 50 min of treadmill exercise while wearing firefighting protective clothing (FPC) in two environmental conditions (34°C and 37°C) with three training intensities (3 km/h, 4.5 km/h and 6 km/h). Results showed that in hot environments, training intensity exhibited a more pronounced effect on physiological responses than ambient temperature. Exposure to 37°C with heavy activity produced high level of core temperature (38.8±0.2°C), near maximal heart rate (164±18 bpm), increased energy expenditure (27.10±1.42 ml/min/kg) coupled with mild dehydration (2.08%±0.35%). The forehead, back and chest which showed the highest level of thermal sensation vote, wetness sensation vote and thermal comfort vote are suggested to be primarily considered when designing cooling strategies. Moreover, when providing recovery and cooling for firefighters working in extreme heat while wearing fully encapsulated FPC, the priority should be given to work intensity and duration, followed by environmental conditions.

Evaluating thermal comfort indices for outdoor spaces on a university campus

This study evaluates the applicability of three thermal comfort indices—Physiologically Equivalent Temperature (PET), Standard Effective Temperature (SET), and Universal Thermal Climate Index (UTCI)—in various outdoor environments on the campus of Xi’an University, China. Meteorological data were collected on sunny days using a portable weather station at a height of 1.5 m, and subjective questionnaires were administered to 25 healthy university students over three months to gather Thermal Sensation Votes (TSV) and Thermal Comfort Votes (TCV). The study was conducted at four distinct outdoor locations: a lakeside area (Location 1), a shaded path (Location 2), a sports field (Location 3), and a plaza (Location 4). PET, SET, and UTCI values were calculated from the collected data using Rayman software. The analysis revealed significant differences in thermal comfort across the four locations, with the highest proportion of subjects feeling hot at the sports field (54.4%) and the highest proportion feeling cold at the lakeside (39%). The shaded path had the highest proportion of subjects feeling comfortable (79.4%), while the lakeside had the lowest (60.1%). The results indicated that SET underestimated thermal sensation at Locations 1, 3, and 4, necessitating calibration. PET was suitable for Locations 2, 3, and 4 but failed to reflect the thermal sensation at Location 1 due to prolonged sun exposure. In contrast, UTCI demonstrated applicability across all locations. To enhance accuracy, revised indices SET’ and PET’ were formulated using the mean-median method, providing more precise thermal comfort assessments. These findings underscore the limitations of SET and PET under specific conditions and highlight the robustness of UTCI, offering valuable insights for urban planning and design aimed at improving outdoor thermal comfort and well-being.

Cooking-related thermal comfort and carbon emissions assessment: Comparison between electric and gas cooking in air-conditioned kitchens

The global shift to cleaner cooking methods is gaining momentum, with many countries considering electricity as a viable alternative to reduce carbon emissions. Cooking raises temperatures and humidity in residential kitchens, impacting comfort and increasing energy consumption. This study employed scenarios with and without kitchen air conditioning and focused on the comparative benchmark between electric cooking and gas cooking through an experiment on the unifying cooking heating effect (CHE), meaning that the heat gained by the substance in the pot was the same for both methods. Subsequent experiments explored thermal comfort under different conditions. The findings revealed that air conditioning notably enhances the thermal environment during electric cooking compared to gas cooking. At 21 °C with air conditioning for gas cooking, the overall thermal sensation vote (TSV) increases by 0.827 units (a 68.9 % rise), while the thermal comfort vote (TCV) decreases by 1.74 units (an 89.7 % reduction) compared with electric cooking at 25 °C. Furthermore, carbon emission analysis demonstrated the clear advantage of electric cooking over gas, which showed a 25 % reduction (0.50 kgCO2/h) in Shanghai. Considering cooking only, and assuming a 50 % shift to electric cooking in Shanghai's residential buildings, this could lead to a substantial reduction of 1.07 million tons of carbon emissions (a 9.98 % decrease) as well as 4.09 million tons of direct carbon emissions. These reductions account for 5.21 % and 19.99 % respectively of Shanghai's operational carbon emissions from residential buildings, respectively. A phased transition from gas to electric cooking is recommended to leverage these environmental benefits.

Comparative analysis of visual-thermal perceptions and emotional responses in outdoor open spaces: Impacts of look-up vs. look-forward viewing perspectives.

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.

Vests with Radiative Cooling Materials to Improve Thermal Comfort of Outdoor Workers: An Experimental Study.

This study focuses on improving human thermal comfort in a high-temperature outdoor environment using vests with a radiative cooling coating. The effects of coating thickness on the radiative cooling performance were first evaluated, and an optimal thickness of 160 μm was achieved. Then, six subjects were recruited to evaluate the thermal comfort in two scenarios: wearing the vest with radiative cooling coatings, and wearing the standard vest. Compared with the standard vest, the coated vest decreases the maximum temperature at the vest inner surface and the outer surface by 5.54 °C and 4.37 °C, respectively. The results show that thermal comfort is improved by wearing radiative cooling vests. With an increase of wet bulb globe temperature (WBGT), the improving effects tend to decline. A significant improvement in human thermal comfort is observed at a WBGT of 26 °C. Specifically, the percentage of thermal sensation vote (TSV) wearing the cooling vest in the range of 0 to 1 increases from 29.2% to 66.7% compared with that of the untreated vest. At the same time, the average value of thermal comfort vote (TCV) increases from -0.5 to 0.2.

Cooling collars incorporated with PCM packs and gels to improve indoor thermal comfort in healthy young females

The human neck is one of the most thermally sensitive body regions to nociceptive stimuli. Neck cooling has been extensively researched to improve athletic performance in the heat. However, there has been very little research into the use of conductive neck cooling for indoor thermal comfort. We thereby designed three ultralight cooling collars with cooling gels or phase change materials (GEL6, PCM15, and PCM18). Their cooling performance on thermal comfort enhancement of 14 healthy young female participants under two warm indoor temperatures (28 °C and 30 °C) was investigated. Thermophysiological and perceptual responses, including skin temperature, heart rate, sweating, thermal sensation vote (TSV), thermal comfort vote (TCV), and thermal preference vote (TPV), were extensively studied. Results showed that, in contrast to GEL6, PCM15 and PCM18 significantly decreased the neck skin temperature, with PCM15 exhibiting the greatest reduction of 4.37 °C at 28 °C. PCM15 and PCM18 significantly decreased overall and local TSVs while also increasing overall and local TCVs (all p < 0.05), thus they could maintain >80 % occupant satisfaction at 28 °C. At 30 °C indoor temperature, however, none of these three cooling collars were found to meet the 80 % occupant satisfaction criterion. When compared to GEL6, PCM15 and PCM18 were found to only significantly reduce local TSVs at the head and neck (all p < 0.05). In sum, PCM15 and PCM18 have the potential to increase acceptable HVAC summer cooling setpoint temperature by 2.5 °C, from 25.5 °C to 28.0 °C, leading to a 25 % reduction in building cooling energy consumption.

Exploring the Multi-Sensory Coupling Relationship of Open Space on a Winter Campus

Exploring the combined effects of multisensory interactions in open spaces can help improve the comfort of campus environments. Nine typical spaces on a university campus in Fuzhou were selected for this study. Subjects perceived the environment and then completed an on-site subjective questionnaire. At the same time, meteorological data (global radiation, air temperature, globe temperature, wind speed, relative humidity, and illumination intensity) were measured to determine the interactions between visual and acoustic and thermal perceptions. Differences in the meteorological parameters between the measuring points were described using a one-way ANOVA and Tukey’s post hoc test, and a chi-square test of independence was used to determine significant associations between thermal, acoustic, and visual comfort, which in turn led to the study of interactions between visual, acoustic, and thermal comfort using a two-way ANOVA. The following conclusions were drawn: (1) the Thermal Comfort Vote (TCV) increased with the increasing Acoustic Comfort Vote (ACV) at all levels of thermal stress. (2) The highest and lowest Acoustic Sensation Vote (ASV) values for each sound type were derived from either “slightly cold” or “warm” conditions. Both the Thermal Comfort Vote (TCV) and the Acoustic Comfort Vote (ACV) were positively correlated. (3) When “neutral”, the Thermal Sensation Vote (TSV) increased with increasing illumination intensity (LUX). (4) The Sunlight Sensation Vote (SSV) increased with the increasing Universal Thermal Climate Index (UTCI) when illumination intensity (LUX) was moderate and bright. (5) The highest and lowest Acoustic Sensation Vote (ASV) values for each sound type came from either “slightly cold” or “warm” conditions.

Study on personal comfort heating system and human thermal comfort in extremely low-temperature building environments

Exposure to extremely low-temperature building environments around −20 °C causes various hazards to human health. However, few studies have studied human thermal comfort and physiological response in such environments, nor the personal comfort heating system. Thus, this study investigated the heating characteristics of personal comfort heating system and their effects on thermal responses and thermophysiological parameters in extremely low-temperature building environments. We conducted experimental tests and questionnaires in a cryogenic enthalpy difference laboratory with air temperature ranging from −21.2 to −15.6 °C and a relative humidity of 55 %. Eight experimental conditions were designed with several heating measures (heating mat, heating gloves, heating cushion and airwarmer). The heating parameters of the personal comfort heating systems as well as the subjective evaluations and skin temperature of the subjects were recorded and analyzed. The results showed that the airwarmer confinement box condition had a corrective power of up to 38.3 K. The overall thermal sensation vote and overall thermal comfort vote were maintained at 0.25 and −0.25. Further, we found that the face, hands, calves and feet got cold easier with the largest skin temperature difference of −4.9, −8.1, −6.7 and −7.6 °C, respectively. Besides, the relationships between thermal responses and between thermal responses and skin temperature were examined, as well as a thermal comfort assessment methodology was established for extremely low-temperature environments.

An experimental study on differences in aesthetic experience according to thermal environments

Over an extended period, the art museum prioritized regulating its thermal environment solely for the preservation of artworks, without considering the visitors' aesthetic experience. However, it is no longer an exception, given the ongoing development of HVAC systems. This research aims to investigate how museums' thermal environment and the resulting thermal comfort impact visitors' aesthetic experience. The experiment was performed to examine the subjects' aesthetic experience under three temperature conditions: 18 °C, 26 °C, and 32 °C. Subjects experienced VR museum exhibition, and their physiological responses, heart rates and variability were measured. Psychological responses were gathered through thermal comfort votes, and Aesthetic Experience Questionnaire (AEQ). As a result, the thermal comfort votes were highest in the order of 26 °C, 18 °C, and 32 °C. Aesthetic experience responses, measured by AEQ, were highest at 26 °C and lowest at 32 °C. This suggests that subjects enhanced aesthetic experiences in a thermally comfortable environment, while high temperature hindered them. Beyond temperature, factors like thermal sensation and comfort were considered influential in aesthetic experiences. Thermal sensation was found to impact aesthetic experiences in a quadratic manner, and thermal comfort had a positive effect on them. Lastly, physiological responses previously associated with aesthetic experiences showed no significant impact in this study. Only thermal sensation demonstrated a significant influence, attributed to thermoregulation responding to thermal environment changes. In other words, when the thermal environment changes, the physiological response can't reliably indicate aesthetic experiences due to the thermoregulation. This study is significant in proposing unexplored aspects of thermal environments in enhancing aesthetic experiences.

How outdoor horticultural activities affect elderly adults' thermal, physiological and psychological responses: a field study.

We recruited 162 healthy elderly adults to determine the thermal, physiological, and psychological effects of horticultural activities (flower arranging, transplanting, and rubble masonry) in outdoor open spaces. We linked these to local climate conditions, physiology, and comfort through a questionnaire survey. The results showed that: (1) the neutral physiological equivalent temperature (NPET) before the horticultural activities were 22.18℃ for flower arranging, 23.67℃ for transplanting, and 20.78℃ for rubble masonry, while the NPET decreased to 18.53℃, 20.73℃ and 18.04℃ (respectively) after activities. (2) The heart rate and blood oxygen saturation changed significantly (p < 0.05) only after rubble masonry. (3) The average positive affect (PA) scores increased after flower arranging by 4.83, transplanting by 3.30, and rubble masonry by 4.00. (4) After activities, the thermal sensation vote was mainly influenced by globe temperature (41.36%), air temperature (33.47%), and wind speed (25.17%). Thermal comfort vote could be promoted because of 37.35% of an increasing positive and 21.20% of decreasing negative emotion.

Experimental study on thermo-physiological differences between children and adults during indoor sedentary conditions

Previous research has shown that children prefer cooler environments and have lower thermal sensitivity than adults. This disparity may be attributed to physiological differences between these age groups. However, studies are scarce that specifically measure children's physiological parameters. In this study, we measured the physiological parameters of children aged 6–9 years and their parents, concurrently collecting their thermal comfort votes. Measured physiological parameters include metabolic rate, blood flow, body composition, core temperature, blood oxygen, heart rate, skinfold thickness, and skin temperature.We found that the average metabolic rate of the measured children was 1.20 met, 39% higher than the measured adults who had their average metabolic rate as 0.86 met. Children consistently exhibited higher metabolic rates than their own parents. Children were observed to have less body fat and thinner skin folds compared to adults. Additionally, children exhibited higher skin temperatures in core areas, elevated heart rates, and quicker recovery of skin blood flow and local skin temperature after experiencing cold exposure on hand compared to adults. These characteristics reveal children's superior thermoregulatory abilities, explaining their preference for cooler environments and reduced thermal sensitivity. Besides, no gender difference was observed in the thermal physiology of the measured children.All of the distinctive thermal physiological traits of children underscore the necessity of specific criteria for evaluating the thermal comfort of children.

Experimental investigation on physiological and perceptual thermal responses through simulated hot-humid deep mine conditions

Miners in underground space often experience discomfort and heat strain due to combination of hot-humid environment and strenuous physical intensity. To investigate the impacts of manipulated variables, amounts of trials were conducted in a controlled climate chamber, with air temperatures of 29 °C and 32 °C, air velocities of 0.8 m/s and 1.8 m/s, and labor intensities of 3 km/h and 5 km/h, respectively. The physiological responses of mean skin temperature (Tmsk), oral temperature (Tor), sweat loss (SW), and heart rate (HR) were measured during these trials, along with the perceptual responses of thermal sensation vote, thermal comfort vote, thermal satisfaction vote, thermal acceptability vote, air movement expectation vote. The results indicate that Tmsk, Tor, SW and HR exhibit an upward trend in response to increasing air temperature and labor intensity, but decrease with rising air velocity. Tmsk and Tor are primarily affected by air temperature, while SW and HR are predominantly influenced by labor intensity. Notably, increased air temperature and labor intensity have negative effects on perceptual sensations, whereas augmentation in air velocity can marginally mitigate perceptual sensations. Tmsk and sweating rate exhibit the potential to serve as an indicator for evaluating and forecasting perceptual sensation. Tmsk values of 36 °C and 35 °C can be identified as the maximum thresholds for miners' thermally acceptable and comfortable skin temperatures. The findings can provide valuable references for understanding thermal responses of individuals in hot-humid deep mine conditions, and establish a robust basis for promoting working safety and comfort of miners.

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.

Unraveling the link between draught and upper respiratory mucosal immunity: Assessing lysozyme and S-lgA concentrations in nasal lavage fluid

The purpose of this study is to investigate the effect of draught on upper respiratory tract mucosal immunity, by assessing concentrations of lysozyme and secretory immunoglobulin A (S-IgA) in nasal lavage fluid. A total of 26 subjects were recruited and experienced 4 experiment conditions combined with two ambient temperatures (24 °C and 28 °C) and two air velocities towards the nape (0 m/s and 1 m/s). Physiological parameters, and subjective questionnaires (i.e., thermal sensation vote (TSV), thermal comfort vote (TCV), and air movement vote (AMV)) were also collected. Our findings revealed that physiological parameters fluctuated significantly under 24 °C, 1 m/s (p < 0.05). Significant decreases in lysozyme concentration occurred under both 24 °C, 1 m/s (p = 0.003) and 24 °C, 0 m/s (p = 0.017). S-IgA concentrations significantly decreased after one-day lag (p = 0.028) under 24 °C, 1 m/s. When TSV deviated from neutral, lysozyme concentrations decreased, especially when the TSV was [-3, −1.5) (p = 0.01). The S-IgA concentration increased when subjects felt slightly uncomfortable and decreased steadily for further discomfort. The proportion of subjects with decreased immune biomarker levels was minimized in the neutral TSV zone. The findings suggest that under the investigated scenarios, cold draught can suppress respiratory immunity by altering thermal sensations, with effects potentially persisting beyond exposure duration. Ensuring a neutral and comfortable thermal environment is pivotal for maintaining immunity stability. However, more experiments under a wider range of thermal parameters need to be performed to prove the robustness of current results.

Machine learning-based prediction of outdoor thermal comfort: Combining Bayesian optimization and the SHAP model

Rising global temperatures have resulted in urban heat waves in recent years, endangering residents' health and even their lives. As a result, accurate outdoor thermal comfort prediction is critical. The goal of this research is to develop highly accurate and interpretable machine learning models of outdoor thermal comfort. We created a summer outdoor thermal comfort dataset for cold regions using microclimate parameter measurements and questionnaires, and divided it into two datasets: without and with shading. The prediction performance of nine machine learning models was compared, as well as their prediction performance following Bayesian optimization. Finally, the SHAP model was used to explain the important features of the best machine learning models and their impact on thermal comfort. The results show that after partitioning the dataset by shading, the accuracy of the best machine learning prediction models for Thermal sensation vote (TSV), Thermal acceptable vote (TA), and Thermal comfort vote (TCV) in the unshaded space improves by 9.2%, 9.31%, and 6.16%, respectively, while the prediction accuracy in the shaded space remains basically unchanged. Extreme gradient boosting (XGBoost), Light Gradient Boosting Machine (LightGBM), and categorical boosting (CatBoost) outperform other methods. After Bayesian optimization (BO), the machine learning models' TSV, TA, and TCV prediction accuracies improved by 6.83%, 4.05%, and 2.55%, respectively. CatBoost model with Bayesian optimization (CatBoost + BO) was the best model in most cases. TSV, TA, and TCV predictions were heavily influenced by microclimate parameters, with mean radiant temperature being the most important in unshaded spaces and air temperature being critical in shaded spaces. Furthermore, age, body mass index, and emotional state all had a significant impact on TA and TCV. This research will contribute to improving the quality of life of urban residents by providing a scientific foundation for the design and planning of urban open space.

Investigation of drivers’ thermal comfort based on selective cooling seats with air conditioner in summer using biosignals and subjective survey

In this study, biosignals (skin temperature, heart rate variability (HRV), and electroencephalogram (EEG)) as objective indices and questionnaires as subjective indices of the subjects were investigated and compared to study the changes in the thermal comfort of drivers during driving by applying various cooling seats with air conditioner (AC) operation. The HRV analysis showed that the stress index (SI) was reduced by up to 8.2 % and 28.6 % for AC with a ventilation seat (AC-VS) and AC with a water cooling seat (AC-WCS), respectively, compared to the AC mode alone. In addition, EEG showed that the attention index (AI) was reduced by up to 4.2 % and 17.9 % for AC-VS and AC-WCS, respectively, compared with the AC mode only. In particular, owing to the direct contact cooling, the AC-WCS showed a greater improvement in thermal sensation vote (TSV) in the early driving state than the other cooling modes, but the driver felt cold, and the thermal comfort vote (TCV) increased. Therefore, using an AC-WCS in the early driving stages of a hot summer significantly contributes to improving thermal comfort. This confirms that reasonable thermal comfort can be maintained using the AC-VS. It was concluded that the appropriate use of the VS and WCS with AC will reduce vehicle cooling load. Proper use of VS and WCS with AC systems in the automobile is expected to lead to reduced vehicle fuel consumption, resulting in energy savings and reduced environmental pollution owing to the optimized operating control of HVAC.

Effects of green walls on thermal perception and cognitive performance: An indoor study

In this study, 144 university students were recruited to investigate the effects of greenery dosing on emotional and physiological properties by testing neurobehavioral responses, measuring a physiological index, monitoring electroencephalogram signals, and a questionnaire survey. Where there was a non-green wall (green view index (GVI) = 0 %), a small green wall (GVI = 5 %), and a large green wall (GVI = 15 %), the mean thermal comfort vote increased by 0.02, 0.25, and 0.44, respectively, compared to pre-trial conditions. Subjects’ cognitive performance was highly improved in the presence of a large green wall. Systolic blood pressure and heart rate were reduced (1.68 and 3.14, respectively) most significantly in the presence of a large green wall. Diastolic blood pressure decreased significantly by 1.92 in the presence of a small green wall. Oxyhemoglobin saturation and eardrum temperature were not affected by indoor green wall sizes. We found no significant change in the frontal asymmetrical activity of the brain among subjects where there was a non-green wall, but it increased significantly in the event of a small (+0.12) and a large green wall (+0.14). Finally, in a non-green and small green wall conditions, the relative power of δ brain wave activity was minimized and α brain wave activity was maximized 13 and 9 min after the subjects began looking at green walls. After 7 min of exposure to a large green wall, the relative power of δ reached its minimum and α and θ both reached their maximum.

The comprehensive impact of thermal-PM2.5 interaction on subjective evaluation of urban outdoor space: A pilot study in a cold region of China.

Urban outdoor space has a very important impact on the quality of people's outdoor activities, which has influenced people's health and moods. Its influence is the result of the combined action of various factors. Thermal and air quality environment are important factors affecting the overall comfort of the urban outdoor space. At present, there are few research on interaction with thermal and air quality environment. Therefore, a meteorological measurement and questionnaire survey have been conducted in a representative open space in a campus in Xi'an, China. The following are the research results:(1) Mean physiological equivalent temperature (MPET) is a significant factor affecting thermal sensation vote (TSV) and thermal comfort vote (TCV). PM2.5 has no significant effect on thermal comfort vote (TCV), but it is a considerable factor affecting thermal sensation vote (TSV) when 10.2°C ≤ MPET<21°C (P = 0.023 *). (2) PM2.5 is a significant factor affecting air quality vote (AQV) and breathing comfort vote (BCV).Mean physiological equivalent temperature (MPET) has no significant impact on air quality vote (AQV), but it is a considerable factor affecting breathing comfort vote (BCV) when 10.2°C ≤ MPET<21°C (P = 0.01 **). (3) Mean physiological equivalent temperature (MPET) is a significant factor affecting overall comfort vote (OCV), but PM2.5 is not. In general, When 10.2°C ≤ MPET<21°C (-0.5 < -0.37 ≤ TCV ≤ 0.12 <0.5), the interaction between thermal and PM2.5 environment is significant on thermal sensation vote (TSV) and breathing comfort vote (BCV). This study can provide experimental support for the field of multi-factor interaction, which has shown that improving the thermal environment can better breathing comfort, while reducing PM2.5 concentration can promote thermal comfort. And can also provide reference for the study of human subjective comfort in urban outdoor space in the same latitude of the world.

Experimental Study of the Effects of Siestas on the Nocturnal Sleep Quality and Thermal Comfort Levels under Thermoneutral Environment in Summer

It has been determined that siestas could potentially have both mental and physical influences on the human body. However, the effects of siestas on the nocturnal sleep quality and thermal comfort levels under thermoneutral environment had not yet been examined in detail. In order to explore the potential influences of siestas on nocturnal sleep, twenty subjects were recruited and divided into two groups based on whether they took siestas or not. During this study's experiment, the temperature was maintained at 25°C, and sleep duration was recorded throughout the night. In addition, thermal comfort votes (TCV) and thermal satisfaction votes (TSV) were obtained both before and after the nocturnal sleep. Furthermore, dopamine (DA) levels, which played important roles in emotional regulation, were measured after the nocturnal sleep. Results showed that the siesta group had a significant increase in self-reported nocturnal sleep quality (p < 0.05), although slight decreases in slow-wave sleep (SWS) duration and rapid eye movement (REM) duration were observed. Additionally, higher TCV and TSV values were reported in the siesta group (p < 0.05). Higher DA concentration was also detected in the siesta group after the nocturnal sleep. Furthermore, some correlations were illustrated between the thermal voting values and the sleep duration, as well as the DA concentration levels. Results implied that siestas could have an influence on the nocturnal sleep quality and thermal comfort levels under thermoneutral environment. Besides, DA concentration levels played an important role in the thermal comfort evaluations when exploring the influences of siestas on nocturnal sleep.