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

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.

2008 ◽  
Author(s):  
Mohamad Al-Othmani ◽  
Nesreen Ghaddar ◽  
Kamel Ghali

In this work, human transient thermal responses and comfort are studied in non-uniform radiant heating and convective heating environments. The focus was on a change from walking activity of human in outdoor cold environment at high clothing insulation to warm indoor environment at sedentary activity level associated with lower clothing insulation. A transient multi-segmented bioheat model sensitive to radiant asymmetry is used to compare how fast the human body approaches steady state thermal conditions in both radiative and convective warm environments. A space thermal model is integrated with the bioheat model to predict the transient changes in skin and core temperature of a person subject to change in metabolic rate and clothing insulation when entering conditioned indoor space. It was found that overall thermal comfort and neutrality were reached in 6.2 minutes in the radiative environment compared to 9.24 minutes in convective environment. The local thermal comfort of various body segments differed in their response to the convective system where it took more than 19 minutes for extremities to reach local comfort unlike the radiative system where thermal comfort was attained within 7 minutes.


Author(s):  
Nurshahrily Idura Ramli ◽  
Mohd Izani Mohamed Rawi ◽  
Ahmad Zahid Hijazi ◽  
Abdullah Hayyan Kunji Mohammed

<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>


Volume 1 ◽  
2004 ◽  
Author(s):  
Nawaf Al-Mutawa ◽  
Walid Chakroun ◽  
Mohammad H. Hosni

It has been known that the human thermal comfort is not exclusively a function of air temperature but also a function of six additional parameters, namely, mean radiant temperature, air velocity, turbulence intensity, humidity, activity level, and clothing insulation. The combined physical and psychological impact of these parameters on thermal comfort is mathematically described in various comfort models. The current comfort models, while use extensive human comfort data, may not be applicable in all world regions due to environmental conditions and people’s expectations. The State of Kuwait has a population of 2.5 million inhabitants with majority of people living in a few populated cities with heavy vehicle traffic, office buildings, factories, petroleum operations, and shopping centers. During the summer months (especially in July and August) the temperature reaches 48 °C in the afternoon, and can sometimes exceed 55 °C requiring extensive use of air conditioning. The traditional clothing (Disdasha) is made of lightweight, white, fabric material to provide some level of comfort. To better understand the regional preferences and assess the applicability of the standard comfort models in Kuwait, important parameters influencing human thermal comfort were measured in ten different government offices and the corresponding PMV indices were calculated. The results were compared with other comfort indices to obtain the most viable comfort index and the appropriate temperature range for local comfort for Kuwait offices. This study is not only important for comfort evaluations but also for evaluation of energy consumption in office buildings.


1997 ◽  
Vol 273 (2) ◽  
pp. E321-E327 ◽  
Author(s):  
B. Morio ◽  
B. Beaufrere ◽  
C. Montaurier ◽  
E. Verdier ◽  
P. Ritz ◽  
...  

Gender effects on energy expended during light seated activities, walking, cycling, and sleep and their consequences on daily energy expenditure (EE) were examined in 11 men and 15 women aged 66.4 +/- 7.1 yr. Two open-circuit whole body calorimeters were used for EE measurements, except for cycling, during which EE was measured separately with the use of a face mask. Lean body mass (determined using H218O dilution method), fat mass, usual physical activity level, and activity intensity (e.g., walking speed and cycling power output) were taken as covariates in the analysis of EE variations before studying gender effects. Sleeping metabolic rate (SMR) and daily EE, adjusted for differences in all covariates, were 11.2 (P = 0.005) and 8.7% (P = 0.071) lower in women than in men, respectively. No gender-related differences were found in the various physical activity EEs above SMR (e.g., gross EE-SMR) [light seated activities (P = 0.790), walking (P = 0.263), and cycling (P = 0.287)] and daily physical activity EE above SMR (P = 0.587) after adjustment for differences in all covariates. Therefore, the lower adjusted daily EE of women could be related to their lower SMR, the most reliable criterion of whole body metabolic rate.


Author(s):  
Yang Liu ◽  
Xiaoling Li ◽  
Jiarui Lai ◽  
Aibin Zhu ◽  
Xiaodong Zhang ◽  
...  

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.


2019 ◽  
Vol 111 ◽  
pp. 04056
Author(s):  
Loes Visser ◽  
Boris Kingma ◽  
Eric Willems ◽  
Wendy Broers ◽  
Marcel Loomans ◽  
...  

Studies indicate that the energy performance gap between real and calculated energy use can be explained for 80% by occupant behaviour. This human factor may be composed of routine and thermoregulatory behaviour. When occupants do not feel comfortable due to high or low operative temperatures and resulting high or low skin temperatures, they are likely to exhibit thermoregulatory behaviour. The aim of this study is to monitor and understand this thermoregulatory behaviour of the occupant. This is a detailed study of two females living in a rowhouse in the city of Heerlen (Netherlands). During a monitoring period of three weeks over a time span of three months the following parameters were monitored: activity level, clothing, micro climate, skin temperatures and thermal comfort and sensation. Their micro climate was measured at five positions on the body to assess exposed near body conditions and skin temperature. Every two hours they filled in a questionnaire regarding their thermal comfort and sensation level (7-point scale), clothing, activities and thermoregulatory behaviour. The most comfortable (optimal) temperature was calculated for each person by adopting a biophysical model, a thermoneutral zone model. This study shows unique indivual comfort patterns in relation to ambient conditions. An example is given how this information can be used to calculate the buildings energy comsumption.


2003 ◽  
Vol 62 (3) ◽  
pp. 645-650 ◽  
Author(s):  
Klaas R. Westerterp

Activity intensity is a potential determinant of activity-induced energy expenditure. Tri-axial accelerometery is the most objective measurement technique for the assessment of activity intensity, in combination with doubly-labelled water for the measurement of energy expenditure under free-living conditions. Data on the effects of subject characteristics, including body size and age, and exercise training on the relationship between activity intensity and daily energy expenditure are reviewed. Average daily metabolic rate and non-basal energy expenditure are positively related to body size. The duration and intensity of physical activities do not need to be equivalent to the energy spent on activity. Obese subjects spend more energy on physical activity but can perform fewer activities, especially high-intensity (weight-bearing) activities, because of their higher body weight. Physical activity generally declines gradually from about 60 years of age onwards. Most subjects >80 years have an activity level well below the level defined for sedentary middle-aged adults. Spending relatively more time on low-intensity activities has a negative effect on the mean physical activity level. To obtain a higher physical activity level does not necessarily imply high-intensity activities. In an average subject 25% of the activity-induced energy expenditure may be attributed to high-intensity activities. Exercise training, as a form of high-intensity activity, affects the physical activity level more in younger subjects than in elderly subjects.


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