Influence of Severe Cold Thermal Environment on Thermal Sensation and Physiological Responses

2019 ◽  
pp. 363-372
Author(s):  
Tomi Zlatar ◽  
J. Oliveira ◽  
J. Cardoso ◽  
D. Bustos ◽  
J. C. Guedes ◽  
...  
Keyword(s):  
Thermal Environment ◽  
Thermal Sensation ◽  
Physiological Responses

scholarly journals An Interactive Task Conditioning System Featuring Personal Comfort Models and Non-Intrusive Sensing Techniques: A Field Study in Shanghai

Technologies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 90
Author(s):  
Siliang Lu ◽  
Erica Cochran Hameen
Keyword(s):  
Thermal Comfort ◽  
Field Study ◽  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
New Paradigm ◽  
Dynamic Task ◽  
Current Task ◽  
Open Plan

Heating, ventilation and air-conditioning (HVAC) systems play a key role in shaping office environments. However, open-plan office buildings nowadays are also faced with problems like unnecessary energy waste and an unsatisfactory shared indoor thermal environment. Therefore, it is significant to develop a new paradigm of an HVAC system framework so that everyone could work under their preferred thermal environment and the system can achieve higher energy efficiency such as task ambient conditioning system (TAC). However, current task conditioning systems are not responsive to personal thermal comfort dynamically. Hence, this research aims to develop a dynamic task conditioning system featuring personal thermal comfort models with machine learning and the wireless non-intrusive sensing system. In order to evaluate the proposed task conditioning system performance, a field study was conducted in a shared office space in Shanghai from July to August. As a result, personal thermal comfort models with indoor air temperature, relative humidity and cheek (side face) skin temperature have better performances than baseline models with indoor air temperature only. Moreover, compared to personal thermal satisfaction predictions, 90% of subjects have better performances in thermal sensation predictions. Therefore, personal thermal comfort models could be further implemented into the task conditioning control of TAC systems.

scholarly journals Thermal Comfort-Based Personalized Models with Non-Intrusive Sensing Technique in Office Buildings

2019 ◽  
Vol 9 (9) ◽  
pp. 1768 ◽  
Author(s):  
Siliang Lu ◽  
Weilong Wang ◽  
Shihan Wang ◽  
Erica Cochran Hameen
Keyword(s):  
Surface Temperature ◽  
Skin Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Correlation Coefficients ◽  
Hvac Systems ◽  
Recall Score ◽  
Support Vector ◽  
Linear Kernel ◽  
Related Factors

Heating, ventilation and air-conditioning (HVAC) systems play a key role in shaping the built environment. However, centralized HVAC systems cannot guarantee the provision of a comfortable thermal environment for everyone. Therefore, a personalized HVAC system that aims to adapt thermal preferences has drawn much more attention. Meanwhile, occupant-related factors like skin temperature have not had standardized measurement methods. Therefore, this paper proposes to use infrared thermography to develop individual thermal models to predict thermal sensations using three different feature sets with the random forest (RF) and support vector machine (SVM). The results have shown the correlation coefficients between clothing surface temperature and thermal sensation are 11% and 3% higher than those between skin temperature and thermal sensation of two subjects, respectively. With cross-validation, SVM with a linear kernel and penalty number of 1, as well as RF with 50 trees and the maximum tree depth of 3 were selected as the model configurations. As a result, the model trained with the feature set, consisting of indoor air temperature, relative humidity, skin temperature and clothing surface temperature, and with linear kernel SVM has achieved 100% recall score on test data of female subjects and 95% recall score on that of male subjects.

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.

scholarly journals Determination of Thermal Comfort in Indoor Sport Facilities Located in Moderate Environments: An Overview

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 769 ◽  
Author(s):  
Fabio Fantozzi ◽  
Giulia Lamberti
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Future Research ◽  
Indoor Environmental Quality ◽  
Indoor Environments ◽  
Major Question ◽  
Sport Practice ◽  
Sport Facilities

In previous years, providing comfort in indoor environments has become a major question for researchers. Thus, indoor environmental quality (IEQ)—concerning the aspects of air quality, thermal comfort, visual and acoustical quality—assumed a crucial role. Considering sport facilities, the evaluation of the thermal environment is one of the main issues that should be faced, as it may interfere with athletes’ performance and health. Thus, the necessity of a review comprehending the existing knowledge regarding the evaluation of the thermal environment and its application to sport facilities becomes increasingly relevant. This paper has the purpose to consolidate the aspects related to thermal comfort and their application to sport practice, through a deep study concerning the engineering, physiological, and psychological approaches to thermal comfort, a review of the main standards on the topic and an analysis of the methodologies and the models used by researchers to determine the thermal sensation of sport facilities’ occupants. Therefore, this review provides the basis for future research on the determination of thermal comfort in indoor sport facilities located in moderate environments.

scholarly journals Outdoor Thermal Comfort at a University Campus: Studies from Personal and Long-Term Thermal History Perspectives

2020 ◽  
Vol 12 (21) ◽  
pp. 9284
Author(s):  
Jiao Xue ◽  
Xiao Hu ◽  
Shu Nuke Sani ◽  
Yuanyuan Wu ◽  
Xinyu Li ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Thermal History ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Cold Climate ◽  
Outdoor Thermal Comfort ◽  
Climate Index ◽  
University Campus ◽  
Winter Climate

Thermally comfortable outdoor spaces have contributed to high-quality urban living. In order to provide a further understanding of the influences of gender and long-term thermal history on outdoor thermal comfort, this study conducted field surveys at a university campus in Shanghai, China by carrying out microclimatic monitoring and subjective questionnaires from May to October, 2019. The analysis of collected data found that, during our survey, 57% of the occupants felt comfortable overall and 40–60% of them perceived the microclimate variables (air temperature, humidity, solar radiation, and wind speed) as “neutral”. The universal thermal climate index (UTCI) provided a better correlation with occupant thermal sensation than the physiologically equivalent temperature (PET). Females were more sensitive to the outdoor thermal environment than males. Older age led to lower thermal sensation, but the thermal sensitivities for age groups of <20, 20–50, and >50 were similar. Occupants who had resided in Shanghai for a longer period showed higher overall comfort rating and lower thermal sensation. Interviewees who came from hot summer and cold winter climate regions were less effected by the change of UTCI than those from severe cold or cold climate regions.

scholarly journals Decision Trees for Predicting the Physiological Responses of Rabbits

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 994
Author(s):  
Patrícia Ferreira Ponciano Ferraz ◽  
Yamid Fabián Hernández-Julio ◽  
Gabriel Araújo e Silva Ferraz ◽  
Raquel Silva de Moura ◽  
Giuseppe Rossi ◽  
...  
Keyword(s):  
Decision Making ◽  
Decision Trees ◽  
Environmental Variables ◽  
Thermal Environment ◽  
Physiological Responses ◽  
Rapid Evaluation ◽  
Production Environment ◽  
Experimental Database ◽  
Tree Models ◽  
Data Points

The thermal environment inside a rabbit house affects the physiological responses and consequently the production of the animals. Thus, models are needed to assist rabbit producers in decision-making to maintain the production environment within the zone of thermoneutrality for the animals. The aim of this paper is to develop decision trees to predict the physiological responses of rabbits based on environmental variables. The experiment was performed in a rabbit house with 26 rabbits at eight weeks of age. The experimental database is composed of 546 observed data points. Sixty decision tree models for the prediction of respiratory rate (RR, mov.min−1) and ear temperature (ET, °C) of rabbits exposed to different combinations of dry bulb temperature (tdb, °C) and relative humidity (RH, %) were developed. The ET model exhibited better statistical indices than the RR model. The developed decision trees can be used in practical situations to provide a rapid evaluation of rabbit welfare conditions based on environmental variables and physiological responses. This information can be obtained in real time and may help rabbit breeders in decision-making to provide satisfactory environmental conditions for rabbits.

Mathematical and experimental analysis of the thermal effectiveness of an oscillating jet with side-to-side swing louvers in a cassette split type air conditioner

2019 ◽  
Vol 29 (2) ◽  
pp. 240-254 ◽  
Author(s):  
Yunqing Fan
Keyword(s):  
Thermal Environment ◽  
Thermal Sensation ◽  
Control Strategies ◽  
Heating Time ◽  
Air Conditioner ◽  
Beta Distributions ◽  
Air Supply ◽  
The Face ◽  
Heating Mode ◽  
The Impact

The impact of air supply control strategies (louvers movement) on indoor thermal environment were evaluated in this study. The temperature uniformity was evaluated by: (i) the air distribution performance index (ADPI) to determine the air diffusion performance in heating mode; (ii) the air draught rate (DR%) on the face to determine the local discomfort due to cold draught; (iii) the mathematically determined vertical temperature stratification in a room with Beta distributions. A comparison of the conventional type with three different oscillating type airflows (louvers swing angle ±20°, ±40° and ±60°) were experimentally analysed to determine appropriate air supply control strategies. The results indicated that Beta distributions could capture the overall trend of the oscillating airflow, to establish the acceptable thermal uniformity and higher thermal effectiveness. The oscillating airflow as generated by the side-to-side swing type delivery louvers mounted inside a cassette split type air conditioner could shorten heating time by 20% to attain room temperature from 9°C. The data reveal that oscillating airflow can provide a better thermal sensation to feeling warm in the heating mode at both ankle and neck level. The ADPI is approximately 85% in the occupied zone. The actual draught rates on the face ranged 0–35%.

Thermal Comfort of the Elderly in Public Health Service Buildings of Thailand

2018 ◽  
Vol 878 ◽  
pp. 173-178
Author(s):  
Chorpech Panraluk ◽  
Atch Sreshthaputra
Keyword(s):  
Public Health ◽  
Metabolic Syndrome ◽  
Health Service ◽  
Thermal Comfort ◽  
Public Health Service ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
The Elderly ◽  
Environmental Data ◽  
The Metabolic Syndrome

The purpose of this study is to evaluate the Thermal comfort of the Thai elderly in air-conditioned space. The quantitative evaluation was conducted using 163 senior participants while recording their expressed satisfaction within the thermal environment in four public health service buildings in Phitsanulok Province, Thailand. It revealed that for the Thai elderly, the Predicted Mean Vote could not be used to identify the Thermal Sensation Vote. In addition, the results of this study indicated that personal factors, such as gender, age, and underlying disease correlating affect their Thermal Sensation Vote. Perhaps most significantly, a coincidental finding was that the thermal sensation of the Thai elderly was strongly dependent upon the condition of the occupant’s metabolic syndrome, which belonged to the Non-Communicable Disease group. This study assumed that in the elderly, the metabolic syndrome might have an effect on their metabolic rate (as one of the six factors of thermal comfort). In terms of the environmental factors, the on-site environmental data was collected via field works. It found that the air-conditioned spaces had mean radiant temperatures of 23.20-31.40 °C, this condition would make seniors feel comfortable if the thermal environment in the study areas were controlled: air temperature 23.00-27.80 °C, relative humidity 54.00-73.00% and air velocity 0.08-0.72 m/s. However, some elderly wanted to change this thermal environment to either cooler (10.68%) or warmer (4.85%). Therefore, it should be further study to find the proper thermal environment for covering the most of the seniors in Thailand.

Physiological temperature response and embryonic mortality in stressed swine

1975 ◽  
Vol 229 (6) ◽  
pp. 1471-1475 ◽  
Author(s):  
DE Wildt ◽  
GD Riegle ◽  
WR Dukelow
Keyword(s):  
Thermal Environment ◽  
Physiological Responses ◽  
Significant Proportion ◽  
Temperature Response ◽  
Reproductive Function ◽  
Embryonic Mortality ◽  
Delayed Effect ◽  
Short Term ◽  
Embryo Survival ◽  
Early Gestation

Physiological responses and some aspects of reproductive function were examined in mated female pigs subjected to a short-term heat stress during two intervals of early gestation. Trial 1 control and treated animals experienced temperatures of 24.0 and 40.2 degrees C, respectively, from days 2 through 13 of pregnancy. Trial 2 control and treated pigs were exposed to 23.3 and 40.4 degrees C, respectively, from days 14 through 25 of pregnancy. Both high thermal exposures caused significant increases (P less than 0.05) in rectal temperature. At body temperatures of 41.1 degrees C or above, animals became more active and behavioral patterns erratic. Stressed pigs in both trials exhibited adaptation to the short-term high thermal environment as treatment days progressed. Embryonic mortality in the stressed animals in trial 1 was greater than in controls, with the animals in the former group retaining a normal size litter or losing the entire litter by day of slaughter. A significant proportion (P less than 0.01) of litters from stressed animals contained degenerating fetuses at day 42 of gestation, suggesting a continuous or delayed effect of thermal stress on embryo survival.

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