Thermal Comfort Perception Research Articles

Experimental evaluation of subjective thermal perceptions for different local window screenings

In tropical climate, restricting convective gain while allowing cross ventilation creates paradoxical difficulty regarding indoor thermal comfort. Changing global climate gives new dimensions to the scenario results in subsequent pressure on increasing energy demand towards thermal comfort. Passive techniques can be a good way to dealt with the problem. However, occupants’ thermal perception may vary from person to person for a definite indoor environmental setup. Perception of subjective thermal comfort is crucial for human health and wellbeing which in turns effects performance. In the current study evaluation of subjective thermal performance regarding improved indoor thermal comfort has been studied for three different local window screening: i) plastic bottle with its wider face towards wind direction, ii) plastic bottle with its narrower face towards wind direction and iii) perforated bamboo screen. Six subjects: four female and two male (ages between 22-24), have been investigated for 30mins. in an experimental simulation chamber for three consecutive days. Questionnaire regarding thermal sensation and perception has been prepared to collect subjective response at 10mins. interval. From the experiment it is seen that subjective responses varies for different window screenings as well as for a specific indoor thermal condition created with definite screening. Subjects find the indoor environment comfortable for screening with plastic bottle with its wider face towards wind direction compared to other two. Bamboo screening has comparatively better performance than the screening plastic bottle with its narrower face towards wind direction. The current analysis only considers the thermal sensation of the subject and further extension of study considering factors like the subject's site-specific thermal sensation and other psychological effects can contribute towards improving indoor thermal comfort in tropics towards human health and wellbeing.

Sleep quality and thermal comfort assessment in the hot and humid climate of Malaysia

ABSTRACT This study examines the relationship between thermal comfort and sleep quality among 417 Malaysian adults via an online survey conducted from November 2019 to April 2020. Participants provided demographic information, thermal comfort, and sleep quality data. The research explores how factors such as air conditioning and pre-sleep behaviours influence individuals’ perceptions of thermal comfort and sleep quality. Findings reveal that thermal sensations change during sleep, with respondents reporting a 50% decrease in warmer sensations upon waking compared to before sleep, and a nearly threefold increase in preference for warmer conditions. Sleep quality responses indicate high levels of calmness and satisfaction, with minimal awakenings at an average of 0.9. Air conditioning, available to 60% of respondents, showed limited improvement in perceived sleep quality, with more air-conditioned individuals reporting night awakenings (68%) compared to those without (53%). Pre-sleep behaviours, such as consuming drinks, were associated with lower thermal sensation upon waking, suggesting a potential cooling effect, while taking a shower before sleep correlated with increased overall comfort, potentially enhancing the sleep experience.

Perceived Thermal Comfort Of Collegiate Marching Band Artists Completing A Heat Acclimatization Protocol

Perceived Thermal Comfort Of Collegiate Marching Band Artists Completing A Heat Acclimatization Protocol

Appliance utility in low-income housing: On the relation between socio-economic characteristics, thermal comfort and appliance usage pattern

This study examines the effect of behavioural aspects, dwelling characteristics, and socio-economic drivers, particularly cooling appliance usage patterns, on perceived thermal comfort and further estimates the utility of using different household appliances within low-income archetypes of Mumbai, India. Field-survey-derived 625 samples were drawn from slums and rehab housing and empirically examined using the Ordinal Logistic Regression and Fractional Multinomial Logit models. The results reveal a significant influence of household income and occupant behaviour on thermal satisfaction. Income is a significant barrier to the adoption and usage of thermal appliances. Residents in social housing drive higher utility from operating refrigerators and TVs than washing machines. Low-income quartiles, however, reveal a higher utility from using iron. A positive correlation exists between the proportion of working individuals and appliance usage like washing machine, refrigerator and iron. Surprisingly, larger households are less likely to use exhaust. Considerable heterogeneity thus exists in thermal comfort and appliance usage behaviour and derived energy services in the studied area. This research sheds light on the critical role of income and socio-cultural factors in shaping thermal comfort perceptions and appliance usage patterns. The findings have implications for policy interventions aimed at improving energy efficiency, indoor comfort, and access to essential appliances in low-income communities of developing nations.

Emotional Perceptions of Thermal Comfort for People Exposed to Green Spaces Characterized Using Streetscapes in Urban Parks

Thermal comfort is a key determinant ruling the quality of urban park visits that is mainly evaluated by equivalent meteorological factors and lacks evidence about its relationship with emotional perception. Exposure to green space was believed to be an available approach to increase thermal comfort, but this argument still needs verification to confirm its reliability. In this study, about ~15,000 streetscapes were photographed at stops along sidewalks and evaluated for green view index (GVI) and plant diversity index in five urban parks of Changchun, Northeast China. The faces of visitors were captured to analyze happy, sad, and neutral scores as well as two net positive emotion estimates. Meteorological factors of temperature, relative humidity, and wind velocity were measured at the same time for evaluating thermal comfort using equivalent variables of discomfort index (DI), temperature and humidity index (THI), and cooling power index (CP). At stops with higher GVI, lower temperature (slope: from −0.1058 to −0.0871) and wind velocity (slope: from −0.1273 to −0.0524) were found, as well as higher relative humidity (slope: from 0.0871 to 0.8812), which resulted in positive relationships between GVI and thermal comfort evaluated as DI (R2 = 0.3598, p < 0.0001) or CP (R2 = 0.3179, p < 0.0001). Sad score was positively correlated with THI (R2 = 0.0908, p = 0.0332) and negatively correlated with CP (R2 = 0.0929, p = 0.0294). At stops with high GVI, more positive emotions were shown on visitors’ faces (happy minus sad scores, 0.31 ± 0.10). Plant diversity had varied relationships with GVI in parks depending on age. Overall, our study demonstrated that using imagery data extracted from streetscapes can be useful for evaluating thermal comfort. It is recommended to plan a large amount of touchable nature provided by vegetation in urban parks so as to mitigate micro-climates towards a trend with more thermal comfort that evokes more positive emotions.

Thermal comfort in open spaces in the arid climate of Kuwait: a study of construction training institute students

This article assesses the students’ sensation of thermal comfort in the open areas of the construction training institute in Kuwait, a hyper arid desert. This is carried out using field measurements from the site, and then handing out in-depth questionnaires to 100 students. The questionnaire provides great insight into the students’ perception of thermal comfort, as well as the constituents that impact it. Moreover, the students’ recommendations to improve thermal comfort in open spaces sheds light on the various methods that should be further researched and quantified. These solutions include adding substantial vegetation and trees for shading and redesigning the inadequate existing shading devices on campus. Overall, the findings indicate that the air temperature and humidity are well below the comfort level. These field measurements are sufficiently validated with the questionnaire results that indicate a substantially negative experience. While outdoor thermal comfort is heavily under researched in Kuwait, there are endless opportunitiesfor improvement and development. Consequently, this paper acts as a catalyst for future endeavors, quantitative analysis, and raised awareness

Exercise and resting periods: Thermal comfort dynamics in gym environments

Physical exercise spaces emerged as popular facilities due to recognizing the significance of physical well-being. This study investigates the relationship among physiological responses, human body energy transfer modes, and indoor environmental conditions in influencing thermal comfort perception within indoor physical exercise space. Seven male participants engaged in a 30 min constant-work-rate cycling exercise and a 20 min resting period in a climatic chamber. The physiological and environmental responses were recorded during the experiments, and the body’s energy transfer modes were calculated using the collected data. The dataset was prepared using the 2 min averages of the collected data and calculated parameters across the experiment phases, including the features of skin temperature, core temperature, skin relative humidity, heart rate, oxygen consumption, body’s heat transfer rates through convection, radiation, evaporation, and respiration, net metabolic heat production rate (metabolic rate minus external work rate), indoor air temperature, indoor relative humidity, air velocity, and radiant temperature. Gradient boosting regressor (GBR) was selected as the analyzing method to estimate predicted mean vote (PMV) and thermal sensation vote (TSV) indices during exercise and resting periods using features determined in the study. Thus, the four GBR models were defined as PMV-Exercise, PMV-Resting, TSV-Exercise, and TSV-Resting. In order to optimize the models’ performances, the hyperparameter tuning process was executed using the GridSearchCV method. A permutation feature importance analysis was performed, emphasizing the significance of net metabolic heat production rate (24.2%), radiant temperature (17.0%), and evaporative heat transfer rate (13.1%). According to the results, PMV-Exercise, PMV-Resting, and TSV-Resting GBR models performed better, while TSV-Exercise faced challenges in predicting exercise thermal sensations. Critically, this study addresses the need to understanding the interrelationship among physiological responses, environmental conditions, and human body energy transfer modes during both exercise and resting periods to optimize thermal comfort within indoor exercise spaces. The results of this study contribute to the operation of indoor gym environments to refine their indoor environmental parameters to optimize users’ thermal comfort and well-being. The study is limited to a small sample size consisting solely of male participants, which may restrict the generalizability of the findings. Future research could explore personalized thermal comfort control systems and synergies between comfort optimization and energy efficiency in indoor exercise spaces.

Designing Climate-Adaptive Buildings: Impact of Courtyard Geometry on Microclimates in Hot, Dry Environments

Designing climate-adaptive buildings is crucial for mitigating the adverse effects of climate change by enhancing energy efficiency and reducing greenhouse gas emissions. Additionally, such designs improve thermal comfort and resilience in urban environments, particularly in regions with extreme climates, thereby promoting sustainable living conditions. This study aims to mitigate climate change through strategic urban and building design, focusing on the impact of building geometry and courtyard configurations on enhancing microclimates and thermal comfort in the UAE's hot arid climate. Utilizing ENVI-met software for qualitative analysis, the research examines design modifications in a school building's layout and courtyards. The analysis and findings reveal that strategic alterations can reduce outdoor air temperatures by up to 1.45°C and average building temperatures by approximately 1.89°C. Additionally, these modifications significantly improve thermal comfort perceptions on the PMV scale. The findings underscore the potential of architectural design to contribute to climate change mitigation efforts, highlighting the importance of thoughtful building and courtyard designs in promoting sustainable architecture and urban planning. This study offers novel insights into the role of design in enhancing thermal environments, providing a practical approach for developing climate-adaptive buildings in hot, dry environments. Doi: 10.28991/CEJ-2024-010-08-017 Full Text: PDF

KENYAMANAN TERMAL DI KAWASAN TENGAH KOTA JAKARTA

This research is to determine the level of thermal comfort based on occupant perception, microclimate and is associated with architectural engineering in human adaptation to urban heat island (UHI). One of the problems in cities is the increase in earth temperature caused by climate change and vertical obstruction. The impact of climate change and vertical obstruction will affect the level of human comfort in their environment. Thermal comfort is an absolute need for the human body, and with its ability, humans also create a built environment to fulfill their comfort both outside and inside a building. This research takes a case study at The Lavande Residence Apartment, which is a residence in the central area of ​​Jakarta. This research uses a descriptive analysis method from data obtained primarily through direct observation and interviews and several other secondary data. The research results show that the suitability of the comfort level based on climate simulations and the comfort calculator is at a neutral level and compared with the perception of residents who still feel comfortable. This perception of thermal comfort after being analyzed is due to architectural engineering efforts carried out by humans in the context of adaptation to climate change.

Predictive Heating Control and Perceived Thermal Comfort in a Norwegian Office Building

Predictive Heating Control and Perceived Thermal Comfort in a Norwegian Office Building

Analysis of the Thermal Comfort Perception in Residential Buildings in Loja City based on Ecuadorian Energy Efficiency Standard

Analysis of the Thermal Comfort Perception in Residential Buildings in Loja City based on Ecuadorian Energy Efficiency Standard

Advancing personal thermal comfort prediction: A data-driven framework integrating environmental and occupant dynamics using machine learning

Various individual thermal preferences do not always lead to optimal thermal comfort, despite the high energy consumption of Heating, Ventilation, and Air Conditioning (HVAC) systems. Thermal comfort models often struggle to accurately predict occupants’ thermal sensations due to their inability to adapt to diverse scenarios. This research employs machine learning techniques to develop personalized data-driven thermal comfort models using a global database of 17,814 samples from the ASHRAE Global Thermal Comfort Database II. Specifically, the study implements random forest and k-nearest neighbor algorithms to analyze the influence of environmental factors (such as air temperature, outdoor temperature, relative humidity, and air velocity) and personal factors (including clothing insulation, activity level, and individual differences) on thermal comfort perception. The study systematically compares the predictive performance of different output types (thermal sensation vs. preference vote), input parameters (6 vs. 12), and machine learning methods. The optimized random forest model with 12 inputs demonstrated an accuracy of over 70% in predicting thermal preference votes, which was significantly higher than the 34% accuracy of the PMV model. The results present new optimized data-driven models and offer insights into the relative influence of parameters such as climate, building cooling strategies, and occupant age and gender. This research aims to enable personalized thermal comfort predictions to improve satisfaction and energy efficiency in various buildings.

Energy consumption and thermal comfort of rock-cut and modern buildings

Energy consumption in the building sector justifies the necessity of knowing the thermal comfort perception of vernacular and modern architectural types, based on which a correct recognition was reached for the design of buildings suitable for the climatic conditions of each region. It should be determined that the different types of modern and traditional architecture are in the comfort level in harsh hot climate conditions and how much energy they consume to reach the comfort level. Despite consideration of energy consumption and thermal comfort in different buildings in Iran, there is no clear framework for evaluating these two parameters in different buildings and comparing them. This research aims to compare the indoor thermal comfort levels of vernacular architectural buildings and modern buildings in Iran's semi-hot and dry climate at the peak of summer heat and determine their energy consumption to reach the comfort level. This study has been accomplished by collecting field data, examining the indoor predicted mean vote (PMV) index of the buildings, and comparing them. It was found that rock-cut architecture buildings are in better thermal comfort conditions without energy consumption due to the use of groundmass temperature and low heat exchanges between the indoors and outdoors because of the thermal phase of the materials and the thickness of its layers. The indoor PMV average of rock-cut buildings in summer is −0.61; in modern buildings, it is 0.77, while these two building complexes are in the same climate and close. Also, the energy consumption to reach the comfort level in rock-cut buildings is zero, while modern buildings consume an average of 7.7 kW of electricity daily. The research results will lead to recognizing and modeling the climate design of vernacular architecture, which can be used in today's architecture to reduce energy consumption.

Investigating the Role of Thermal Comfort Perception on Negotiating Heritage Conservation and Energy Efficiency Decisions through System Dynamics

Investigating the Role of Thermal Comfort Perception on Negotiating Heritage Conservation and Energy Efficiency Decisions through System Dynamics

Thermophysiological responses and thermal comfort of occupants in indoor spaces under different speaking and non-speaking conditions

As speaking is one of the fundamental behaviours in human activities, understanding the thermal comfort of occupants during speaking is crucial to providing a satisfactory environment. To further strengthen this understanding and identify how occupant thermal responses change during speaking activities, this study performs an experiment to examine the thermophysiological parameters and thermal comfort of occupants across three different speaking and non-speaking conditions: (1) silent (i.e., non-speaking); (2) speech (i.e., continuous speaking); and (3) conversation (i.e., intermittent speaking). During the experiment, thermophysiological parameters, including skin temperature, electrodermal activity, and heart rate, were collected using smart wristbands from 30 subjects at three different temperature settings to represent three distinct thermal environmental conditions: (1) Cold: 20 °C; (2) Neutral: 24 °C; and (3) Hot: 28 °C. Subjects were also required to report their thermal comfort perceptions in terms of thermal sensation votes, thermal preference votes, and thermal satisfaction votes. Repeated measures ANOVA test and Friedman test were used to analyse the thermophysiological parameters and thermal comfort perceptions. The null hypothesis, which suggests no significant differences in thermal responses and comfort across the three speaking conditions, will be rejected at a significance level of 0.05 (two-tail). The results revealed significant differences in all three thermophysiological parameters between speaking conditions at all temperature settings, while the thermal comfort perception did not consistently show statistically significant differences between speaking conditions. The findings contribute to our understanding of the relationship between communication and thermal responses, highlighting the importance of contextual factors in designing comfortable environments for speaking-related activities.

Occupant’s Thermal Perception in Mixed-mode Office Buildings of the Tropical Climate

Thermal comfort and energy consumption in office buildings is a global critical concern. This study investigated this challenge in the Faculty of Environmental Technology, Abubakar Tafawa Balewa University, Bauchi-Nigeria. Through a field survey and physical environment measurements. The study explored occupant perceptions of thermal comfort and satisfaction. It evaluated the thermal comfort and satisfaction of occupants in a mixed-mode office building, focusing on potential discrepancies between perceived comfort and internationally recommended standards. Despite air temperatures falling outside the PMV model's comfort range, high thermal comfort, and satisfaction levels were reported by the respondents. These findings align with other studies in Nigeria, suggesting adaptation and acclimatization to local conditions. The study further examined the relationship between thermal comfort and occupant satisfaction. The result revealed a moderate positive association, suggesting increased thermal comfort leads to higher satisfaction among occupants. While thermal comfort explained 25% of the variance in satisfaction scores. Finally, the study suggests the localization of comfort standards, improved mixed-mode system performance, and encouraging evidence-based design interventions that will ultimately benefit both occupants and the environment.

Thermoregulation of Feet in Cold Environments: A Study on Alpinism

Thermal comfort plays a crucial role in the performance and well-being of mountaineers, especially in extreme environments. The aim of this study was to develop a reliable protocol to assess the thermal comfort of mountaineering boots, with a specific focus on temperature variations in different regions of the foot and their correlation with physiological factors. Two different models of mountaineering boots were tested at two different environmental temperature (-15°C and -30°C). The mean skin temperature, measured according to International Standards BS EN ISO 9886:2004, was used as an indicator of overall thermal comfort. Physiological factors such as heart rate (HR), body mass index (BMI) and body surface area (BSA) were also measured to understand their relationship to thermoregulation. Kruskal-Wallis and Pearson's ProductMoment correlation tests were performed to investigate whether there was a statistically significant relationship.The results showed significant differences in foot temperature among the Testers, indicating variations in the perception of thermal comfort. The correlation analysis showed a strong positive relationship between mean skin temperature and HR, highlighting the influence of physiological factors on thermal comfort.In addition, the analysis showed that the dorsum and hallux areas had the largest temperature variations, suggesting the occurrence of vasoconstriction and potential discomfort.This study represents a preliminary approach to establishing a reliable protocol for assessing the thermal performance of cold protective footwear.

Occupants’ mood states in evaluating indoor environmental quality (IEQ) acceptance

Previous studies have developed many models for indoor environmental quality (IEQ) assessment. However, almost none of them included mood states that could impact occupants’ IEQ perceptions significantly. This study developed an IEQ acceptance model that considers occupants’ perception of thermal comfort, visual quality, and acoustic quality, as well as their mood as an additional IEQ parameter. The model constants are evaluated by a Bayesian approach with the prior estimates determined from seven existing IEQ models including 4 parameters (without mood). Two hundred fifty-nine students’ perceptions against the five parameters collected in a university library were used as the observed data to update the prior beliefs. The results indicated that involving mood in the IEQ acceptance model could improve the model's accuracy more significantly. Additionally, the updated IEQ acceptance model estimated that students with positive moods are more likely to accept the overall IEQ than those with negative or neutral moods.

Association of Perceived Thermal Comfort and Air Quality with Building- and Occupant-Related Characteristics and Environmental Parameters in Sweden

The aim of the article is to analyze the perceived thermal comfort and indoor air quality of occupants and establish associations between these responses and the building-related, occupant-related characteristics, and environmental parameters of residential buildings (a total of 38 variables). The analysis is focused on the Swedish building stock as investigated during the latest national survey in 2008. The analysis covers 1035 residential buildings (multifamily and single-family dwellings). Analytical statistical analysis has been conducted, and logistic regression models have also been developed for the identification of statistically significant covariates. The analysis showed that users in this study demonstrated a significantly positive response to perceived thermal comfort and indoor air quality conditions. Perceived ratings were also highly correlated with each other. As the regression models indicated, the majority of the significant variables were related to the buildings. Nevertheless, this study also underscores the significance of contextual occupant attributes and behaviors as a crucial element influencing the subjective perception of indoor environments. Policymakers, guided by these insights, are encouraged to integrate considerations of occupant attributes into design and urban planning.

Assessment of sheltered walkways in tropics: understanding contextual influence and user perception of outdoor thermal comfort

Assessment of sheltered walkways in tropics: understanding contextual influence and user perception of outdoor thermal comfort