scholarly journals The Effects of a Passive Exoskeleton on Human Thermal Responses in Temperate and Cold Environments

2021 ◽  
Vol 18 (8) ◽  
pp. 3889
Author(s):  
Yang Liu ◽  
Xiaoling Li ◽  
Jiarui Lai ◽  
Aibin Zhu ◽  
Xiaodong Zhang ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Thermal Response ◽  
Clothing Insulation ◽  
Ambient Temperatures ◽  
Cold Environments ◽  
Significant Difference ◽  
Passive Exoskeleton ◽  
Package Handlers

The exoskeleton as functional wearable equipment has been increasingly used in working environments. However, the effects of wearing an exoskeleton on human thermal responses are still unknown. In this study, 10 male package handlers were exposed to 10 °C (COLD) and 25 °C (TEMP) ambient temperatures while performing a 10 kg lifting task (LIFTING) and sedentary (REST) both with (EXO) and without the exoskeleton (WEXO). Thermal responses, including the metabolic rate and mean skin temperature (MST), were continuously measured. Thermal comfort, thermal sensation and sweat feeling were also recorded. For LIFTING, metabolic heat production is significant decrease with the exoskeleton support. The MST and thermal sensation significantly increase when wearing the exoskeleton, but thermal discomfort and sweating are only aggravated in TEMP. For REST, MST and thermal sensation are also increased by the exoskeleton, and there is no significant difference in the metabolic rate between EXO and WEXO. The thermal comfort is significantly improved by wearing the exoskeleton only in COLD. The results suggest that the passive exoskeleton increases the local clothing insulation, and the way of wearing reduces the “pumping effect”, which makes a difference in the thermal response between COLD and TEMP. Designers need to develop appropriate usage strategies according to the operative temperature.

scholarly journals Investigating Thermal Comfort for the Classroom Environment using IoT

2018 ◽  
Vol 9 (1) ◽  
pp. 157 ◽  
Author(s):  
Nurshahrily Idura Ramli ◽  
Mohd Izani Mohamed Rawi ◽  
Ahmad Zahid Hijazi ◽  
Abdullah Hayyan Kunji Mohammed
Keyword(s):  
Environmental Factors ◽  
Metabolic Rate ◽  
Thermal Comfort ◽  
Classroom Environment ◽  
Thermal Sensation ◽  
Influencing Factor ◽  
Physiological Factors ◽  
Clothing Insulation ◽  
Air Movement ◽  
Radiant Temperature

<p>In this modern century where fine comfort is a necessity especially in buildings and occupied space, the study to satisfy one aspect of human comfort is a must. This study encompasses of exploring the physiological and environmental factors in achieving thermal comfort which specifically considering the clothing insulation and metabolic rate of students as well as the deployment of dry-bulb temperature, mean radiant temperature, humidity, and air movement in order to obtain the level of comfort students are experiencing in class. The level of comfort are detected by using ASHRAE 55 to determine the average thermal sensation response through the Predicted Mean Vote (PMV) value. An android application were developed to read input of recognizing clothing level (thickness of clothing) and capturing metabolic rate to cater the inputs for physiological factors, while radiant temperature, humidity and air movement are captured through static sensors set up in the classroom space. This paper analyses both the physiological and environmental factors in affecting students in class and further determine their comfort levels that is a major influencing factor of focus in learning. Through cross referencing collected data from IoT enabled nodes, it is found that both physiological and environmental factors, and the combination of them greatly influence in getting the most comfortable state with PMV value of 0.</p>

scholarly journals Clothing Insulation Rate and Metabolic Rate Estimation for Individual Thermal Comfort Assessment in Real Life

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 619
Author(s):  
Jinsong Liu ◽  
Isak Worre Foged ◽  
Thomas B. Moeslund
Keyword(s):  
Metabolic Rate ◽  
Thermal Comfort ◽  
Real Life ◽  
Activity Level ◽  
Tracking Accuracy ◽  
Classification Rate ◽  
Clothing Insulation ◽  
Activity Intensity ◽  
Bounding Box ◽  
Tracking By Detection

Satisfactory indoor thermal environments can improve working efficiencies of office staff. To build such satisfactory indoor microclimates, individual thermal comfort assessment is important, for which personal clothing insulation rate (Icl) and metabolic rate (M) need to be estimated dynamically. Therefore, this paper proposes a vision-based method. Specifically, a human tracking-by-detection framework is implemented to acquire each person’s clothing status (short-sleeved, long-sleeved), key posture (sitting, standing), and bounding box information simultaneously. The clothing status together with a key body points detector locate the person’s skin region and clothes region, allowing the measurement of skin temperature (Ts) and clothes temperature (Tc), and realizing the calculation of Icl from Ts and Tc. The key posture and the bounding box change across time can category the person’s activity intensity into a corresponding level, from which the M value is estimated. Moreover, we have collected a multi-person thermal dataset to evaluate the method. The tracking-by-detection framework achieves a mAP50 (Mean Average Precision) rate of 89.1% and a MOTA (Multiple Object Tracking Accuracy) rate of 99.5%. The Icl estimation module gets an accuracy of 96.2% in locating skin and clothes. The M estimation module obtains a classification rate of 95.6% in categorizing activity level. All of these prove the usefulness of the proposed method in a multi-person scenario of real-life applications.

Required temperature distribution based on clothing insulation and metabolic rate survey in Japan

2019 ◽  
Vol 29 (6) ◽  
pp. 775-782
Author(s):  
Masanari Ukai ◽  
Tatsuo Nobe
Keyword(s):  
Physical Activity ◽  
Temperature Distribution ◽  
Metabolic Rate ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Metabolic Rates ◽  
Clothing Insulation ◽  
Office Environment ◽  
Temporal And Spatial ◽  
Temperature Side

In this study, the authors evaluated clothing insulation and changes in the metabolic rate of individuals in an office environment to determine thermal comfort. Clothing was evaluated using a questionnaire completed by 1306 workers in nine offices. The metabolic rates of 86 workers in three offices were measured using a physical activity meter. The distribution of the temperature at which a person in the room perceived a neutral thermal sensation was then calculated from the determined metabolic rates and clothing insulation values. The results demonstrate a noticeable difference between the average and most frequent values during the summer. Moreover, the required temperature distribution is not normal; rather, it is broad and skewed to the low-temperature side. Therefore, even if a thermally uniform environment is provided at the average required temperature by preventing temporal and spatial variations in the thermal environment, complaints of an unacceptably hot thermal environment are more likely to occur than complaints of an excessively cold thermal environment.

Influence of sinusoidal airflow and airflow distance on human thermal response to a personalized ventilation system

2016 ◽  
Vol 27 (3) ◽  
pp. 317-330 ◽  
Author(s):  
Yongxin Xie ◽  
Sauchung Fu ◽  
Chili Wu ◽  
Christopher Y.H. Chao
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Human Subjects ◽  
Ventilation System ◽  
Thermal Response ◽  
Joint Effect ◽  
Experimental Conditions ◽  
Movement Perception ◽  
Air Movement ◽  
Personalized Ventilation

Since the concept of personalized ventilation was introduced in the late 1990s, many studies on thermal comfort have been conducted and a number of parameters identified. In this research, the influence of three parameters, the airflow speed, airflow fluctuating period and a parameter which has drawn less attention in previous studies – the airflow distance between the human subject and the nozzle of the personalized ventilation device on air movement perception, thermal sensation and thermal comfort – are studied. The combinations of fluctuating period and airflow amplitude were selected based on the Power Spectrum Density method. Then 25 human subjects participated in the thermal comfort experiment, each of them underwent 54 tests of different experimental conditions and expressed their thermal feelings by completing the survey questionnaire. Our findings showed that a longer airflow distance could lead to cooler thermal sensation, but not cause any difference in thermal comfort. Changing the fluctuating period of the sinusoidal airflow from 10 s to 60 s did not cause an influence on thermal sensation, but a shorter fluctuating period could result in a higher air movement perception. When dealing with thermal comfort issues, a joint effect with airflow speed and fluctuating period occurs and this should also be considered.

scholarly journals Significance of variation in basal metabolic rate in laboratory mice for translational experiments

2021 ◽  
Author(s):  
Paweł Brzęk ◽  
Andrzej Gębczyński ◽  
Piotr Selewestruk ◽  
Aneta Książek ◽  
Julita Sadowska ◽  
...  
Keyword(s):  
Physical Activity ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Activity Level ◽  
Laboratory Mice ◽  
Ambient Temperatures ◽  
Thermoneutral Zone ◽  
Significant Difference ◽  
The Mean ◽  
Spontaneous Physical Activity

AbstractThe basal metabolic rate (BMR) accounts for 60–70% of the daily energy expenditure (DEE) in sedentary humans and at least 50% of the DEE in laboratory mice in the thermoneutral zone. Surprisingly, however, the significance of the variation in the BMR is largely overlooked in translational research using such indices as physical activity level (PAL), i.e., the ratio of DEE/BMR. In particular, it is unclear whether emulation of human PAL in mouse models should be carried out within or below the thermoneutral zone. It is also unclear whether physical activity within the thermoneutral zone is limited by the capacity to dissipate heat generated by exercise and obligatory metabolic processes contributing to BMR. We measured PAL and spontaneous physical activity (SPA) in laboratory mice from two lines, divergently selected towards either high or low level of BMR, and acclimated to 30 °C (i.e., the thermoneutral zone), 23 or 4 °C. The mean PAL did not differ between both lines in the mice acclimated to 30 °C but became significantly higher in the low BMR mouse line at the lower ambient temperatures. Acclimation to 30 °C reduced the mean locomotor activity but did not affect the significant difference observed between the selected lines. We conclude that carrying out experiments within the thermoneutral zone can increase the consistency of translational studies aimed at the emulation of human energetics, without affecting the variation in physical activity correlated with BMR.

A Fan in Winter

1983 ◽  
Vol 27 (8) ◽  
pp. 742-745 ◽  
Author(s):  
Frederick H. Rohles ◽  
Byron W. Jones
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Test Chamber ◽  
Air Velocity ◽  
Subjective Responses ◽  
Human Thermal Comfort ◽  
Significant Difference ◽  
Maximum Period ◽  
Air Space ◽  
Indoor Conditions

In order to determine the effect of ceiling fans on human thermal comfort under winter indoor conditions, 72 subjects (36 men and 36 women) were exposed to 21°C/40% rh for 3 hours while experiencing still air conditions (0.08 m/s) and air velocities where a ceiling fan was operating in a upward-thrust mode at 2 velocities (0.18 and 0.28 m/s). Two subjective responses, thermal sensation and thermal comfort, were recorded each half hour. The results showed that after 2 hours, which may be assumed to be the maximum period of time that an individual would sit without getting up, the subjects recorded (1) the same neutral thermal sensation when the fan was at the still air condition (0.0 8 m/s) as when it was producing an air velocity of 0.18 m/s, (2) a slightly cool thermal sensation at a velocity of 0.28 m/s and (3) no significant difference in thermal comfort between still air (0.08 m/s) and velocities up to 0.28 m/s. It was concluded that the air movement created by operating the ceiling fan under winter conditions does not contribute to nor detract from human comfort nor did it produce any response resembling wind chill. These results were considered conservative since no temperature stratification existed in the test chamber air space which would be expected in exist in a conventionally heated room space.

scholarly journals Investigation on Wintry Thermal Comfort in Traditional Houses of Nepalese Three Climatic Regions

2020 ◽  
Vol 15 (3) ◽  
pp. 133-140
Author(s):  
Basudev Gautam ◽  
Hom Bahadur Rijal ◽  
Masanori Shukuya
Keyword(s):  
Thermal Comfort ◽  
Thermal Condition ◽  
Building Materials ◽  
Thermal Sensation ◽  
New Technology ◽  
Cold Climate ◽  
Clothing Insulation ◽  
Climatic Regions ◽  
The Mean ◽  
Temperate Climates

The traditional houses are well adapted to the climate and socio-culture using local building materials and techniques. However, traditional practices are being replaced by the artificial materials, modern design and new technology. It requires strong policies to sustain the traditional architecture. The objectives of this study are to evaluate the thermal condition of traditional houses and to estimate the comfort temperature of residents. The thermal comfort survey was conducted during winter in the traditional houses. The thermal sensation votes were collected from 275 people in cold, temperate and sub-tropical climatic regions. This study was revealed that the mean indoor air temperature in cold climatic region is 12.3°C, which was 9.5K and 4.4K lower than sub-tropical and temperate climates. The comfort temperature of the residents in the cold climate was 13.9°C, which was 8.8K and 3.8K lower than sub-tropical and temperate climates. The mean clothing insulation in cold climate was 1.63 clo which was 0.48 clo and 0.31 clo higher than sub-tropical and temperate climates. It concludes that the people were well adapted to each climate with clothing adjustments and made themselves satisfied with the thermal condition of their houses.

scholarly journals A Field Investigation on Adaptive Thermal Comfort in an Urban Environment Considering Individuals’ Psychological and Physiological Behaviors in a Cold-Winter of Wuhan

2021 ◽  
Vol 13 (2) ◽  
pp. 678
Author(s):  
Mehdi Makvandi ◽  
Xilin Zhou ◽  
Chuancheng Li ◽  
Qinli Deng
Keyword(s):  
Thermal Comfort ◽  
Large Scale ◽  
Thermal Sensation ◽  
Field Investigation ◽  
Outdoor Thermal Comfort ◽  
Sustainable Urban Development ◽  
Physical Factors ◽  
Cold Winter ◽  
Physiological Equivalent Temperature ◽  
Clothing Insulation

To date, studies of outdoor thermal comfort (OTC) have focused primarily on physical factors, tending to overlook the relevance of individual adaptation to microclimate parameters through psychological and physiological behaviors. These adaptations can significantly affect the use of urban and outdoor spaces. The study presented here investigated these issues, with a view to aiding sustainable urban development. Measurements of OTC were taken at a university campus and in urban spaces. Simultaneously, a large-scale survey of thermal adaptability was conducted. Two groups were selected for investigation in a cold-winter-and-hot-summer (CWHS) region; respondents came from humid subtropical (Cfa) and hot desert (BWh) climates, according to the Köppen Climate Classification (KCC). Results showed that: (1) neutral physiological equivalent temperature (NPET) and preferred PET for people from the Cfa (PCfa) and BWh (PBWh) groups could be obtained with KCC; (2) PCfa adaptability behaviors were, subjectively, more adjustable than PBWh; (3) Clothing affected neutral temperature (NT), where NT reduced by approximately 0.5 °C when clothing insulation rose 0.1 Clo; and (4) Gender barely affected thermal acceptance vote (TAV) or thermal comfort vote (TCV) and there was a substantial relationship between thermal sensation, NT, and PET. These findings suggest ‘feels like’ temperature and comfort may be adjusted via relationships between microclimate parameters.

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