Field Study on Human Thermal Adaptation in Summer of Tibetan Dwellings in Kangding, China

2015 ◽  
Vol 737 ◽  
pp. 169-172
Author(s):  
Xiao Ji Song ◽  
Wu Xing Zheng ◽  
Quan He ◽  
Yi Mei Ren
Keyword(s):  
Thermal Environment ◽  
Thermal Sensation ◽  
Thermal Adaptation ◽  
Outdoor Temperature ◽  
Indoor Temperature ◽  
Clothing Insulation ◽  
Preferred Temperature ◽  
Change Rate ◽  
Neutral Temperature ◽  
Environment Parameters

In order to study the human thermal adaptation in Tibetan dwellings of Kangding Tibetan Autonomous Prefecture, Sichuan Province, selected 4 dwellings in Tagong and Zhonggu village as the research objects and used the method of objective thermal environment parameters test combined with the subjective questionnaire, and got a total of 119 valid samples, the data analysis results show that indoor air temperature in this area was low, average clothing insulation was 0.75clo and it correlated with outdoor temperature was stronger than that with indoor temperature. The change rate of human thermal sensation changing along with outdoor temperature was 0.113 per temperature and it was 0.147 per temperature changing along with indoor temperature. Thermal neutral temperature was 18.5°C and preferred temperature was 20.65°C, neutral temperature was lower than preferred temperature but closer to average indoor temperature (17.36°C).

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.

The Thermal Comfort of Sedentary Workers

1987 ◽  
Vol 1 (2) ◽  
pp. 74-77 ◽  
Author(s):  
S C Foo ◽  
WO Phoon
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Tropical Climate ◽  
Climatic Conditions ◽  
The Body ◽  
Office Workers ◽  
Preferred Temperature

Two hundred and eighty-five Office workers were surveyed and the micro-climatic conditions in which they worked were measured to evaluate their preferred temperature. About 78% of workers considered the natural tropical climate uncomfortable. However, 76% to 87% of workers in airconditioned Offices approved of their thermal environment if its temperature ranged from 21°C to 27°C. Many workers who felt that the temperature produced a neutral thermal sensation in the body as a whole, tended to complain that their heads were too warm and at the same time their limbs too cool. About 60% of workers in airconditioned Offices were exposed to an air temperature of less than 24°C. Present data suggest that an air temperature of 27°C would be comfortable for more than 80% of workers.

Thermal comfort analyses of naturally ventilated university classrooms

2016 ◽  
Vol 34 (4/5) ◽  
pp. 427-445 ◽  
Author(s):  
Baharuddin Hamzah ◽  
Muhammad Taufik Ishak ◽  
Syarif Beddu ◽  
Mohammad Yoenus Osman
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
National Standard ◽  
Content Type ◽  
Thermal Environments ◽  
Neutral Temperature ◽  
Radiant Temperature ◽  
University Classrooms

Purpose The purpose of this paper is to analyse thermal comfort and the thermal environment in naturally ventilated classrooms. Specifically, the aims of the study were to identify the thermal environment and thermal comfort of respondents in naturally ventilated university classrooms and compare them with the ASHRAE and Indonesian National Standard (SNI); to check on whether the predicted mean vote (PMV) model is applicable or not for predicting the thermal comfort of occupants in naturally ventilated university classrooms; and to analyse the neutral temperature of occupants in the naturally ventilated university classrooms. Design/methodology/approach The study was carried out at the new campus of Faculty of Engineering, Hasanuddin University, Gowa campus. A number of field surveys, which measured thermal environments, namely, air temperature, mean radiant temperature (MRT), relative humidity, and air velocity, were carried out. The personal activity and clothing properties were also recorded. At the same time, respondents were asked to fill a questionnaire to obtain their thermal sensation votes (TSV) and thermal comfort votes (TCV), thermal preference, and thermal acceptance. A total of 118 respondents participated in the study. Before the survey was conducted, a brief explanation was provided to the participants to ensure that they understood the study objectives and also how to fill in the questionnaires. Findings The results indicated that the surveyed classrooms had higher thermal environments than those specified in the well-known ASHRAE standard and Indonesian National Standard (SNI). However, this condition did not make respondents feel uncomfortable because a large proportion of respondents voted within the comfort zone (+1, 0, and −1). The predictive mean vote using the PMV model was higher than the respondents’ votes either by TSV or by TCV. There was a huge difference between neutral temperature using operative temperature (To) and air temperature (Ta). This difference may have been because of the small value of MRT recorded in the measured classrooms. Originality/value The research shows that the use of the PMV model in predicting thermal comfort in the tropic region might be misleading. This is because PMV mostly overestimates the TSV and TCV of the respondents. People in the tropic region are more tolerant to a higher temperature. On the basis of this finding, there is a need to develop a new thermal comfort model for university classrooms that is particularly optimal for this tropical area.

scholarly journals Human-Oriented Design of an Indoor Thermal Environment

2019 ◽  
Vol 111 ◽  
pp. 02001
Author(s):  
Masanari Ukai ◽  
Tatsuo Nobe
Keyword(s):  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Hot Spot ◽  
Clothing Insulation ◽  
Air Conditioning System ◽  
Indoor Thermal Environment ◽  
Initial Survey ◽  
Air Conditioning Systems ◽  
Temperature Side

In this study, an initial survey of clothing insulation and changes in the metabolic rate of individuals in office spaces was performed to establish the distribution of room temperatures at which individuals perceived a neutral thermal sensation. Subsequently, the indoor thermal environment in four offices was surveyed during the summer with different air-conditioning systems to determine the thermal environment stability in each case. The results revealed that for the required temperature, there was a noticeable difference between the average and most frequent values. Moreover, it was determined that the required temperature distribution is not normal, but rather, it is skewed to the low-temperature side. In addition, the radiant air-conditioning system was found to generate a narrow distribution of the equivalent temperature and hence, facilitated a more uniform thermal environment compared to a convective (multi-unit) air-conditioning system. Therefore, in buildings with convective air-conditioning systems, even if the planar average thermal environment is categorized as comfortable, it may be possible that workers who are sensitive to the cold or heat will complain of discomfort more frequently than those in buildings with radiant air-conditioning systems because the probability of workers sitting in cold- or hot-spot areas is higher in the former case.

scholarly journals Perceived Thermal Environment of NaturallyVentilated Classrooms in India

2016 ◽  
Vol 3 (2) ◽  
pp. 149-165
Author(s):  
Ramprasad Vittal ◽  
Subbaiyan Gnanasambandam
Keyword(s):  
Regression Analysis ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Thermal Preference ◽  
Comfort Zone ◽  
Neutral Temperature ◽  
Adaptive Comfort ◽  
Cross Tabulation ◽  
Institute Of Technology ◽  
Lower Temperature

A ield study of thermal environment in naturally ventilated classrooms was conducted in the Department of Architecture at the National Institute of Technology, Tiruchirappalli, India. The study included 176 architecture students and was conducted over ive days during the comparatively cool months of December and January. The results show that 82% of participants voted for ‘comfortable’ on the thermal sensation scale. Cross tabulation of thermal sensation and thermal preference shows that 50% of those who voted within the ‘neutral’ thermal sensation range preferred cooler temperatures and 43% wanted no change. Classroom temperature was acceptable to 85% of students and unacceptable to 15% of students. Perceived thermal sensation tends toward the cool side (mean -0.26). Regression analysis yielded a comfort zone (voting within -1 and +1) of 26.9–30.8 °C, with neutral temperature of 29.0 °C. Standard adaptive comfort models yielded lower temperature than ield indings.

scholarly journals Thermal Environment Perceptions from a Longitudinal Study of Indoor Temperature Profiles in Inpatient Wards

Buildings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 136
Author(s):  
Badr S. Alotaibi ◽  
Stephen Lo
Keyword(s):  
Indoor Environment ◽  
Thermal Environment ◽  
Extended Period ◽  
Temperature Profiles ◽  
Thermal Indices ◽  
Indoor Temperature ◽  
Preferred Temperature ◽  
Patient Dissatisfaction ◽  
Hot Climate ◽  
Fixed Set

Inpatient wards in general have cooling systems with a “one-size-fits-all” approach, driven by a fixed set-point temperature (21–24 °C) that is flexible to lower limits down to 18 °C or less. This approach does not consider patients’ temperature demands, which vary due to thermo-physiology caused by medical conditions, and mixed demographics. It also causes additional cooling demands in hot climates that are infrequently utilized by patients, who tend to adopt warmer internal set temperatures. Thus, this research examined the indoor temperature profiles (distribution of shape) in patient rooms in fully air-conditioned inpatient wards over an extended period of time. During four months of summer, longitudinal monitoring of internal temperature and relative humidity was carried out in 18 patient rooms in the surgical, medical, cardiology, and oncology wards of two hospitals in Saudi Arabia. In parallel, 522 patients were surveyed to capture common subjective thermal indices. The findings revealed that the most frequently preferred temperature (peaks) varied significantly between wards; peaks (modes) were 20.1–21.8 °C in cardiology; 22.2–23.9 °C in the surgical ward; warmer 24.8–25.3 °C in medical ward; and 25.3–26.8 °C in oncology. Surveys also showed that patients were not satisfied with the indoor environment in both hospitals. Given the significant variance in temperature profiles between wards and patient dissatisfaction with the indoor environment, these results suggest that more appropriately designed zoned cooling strategies are needed in hospitals as per the nature of each ward. Besides its implications for benchmarking the HVAC system, this approach will substantially reduce energy loads and operational costs in hot-climate hospitals if patients desire warmer conditions than the set conditions provided by system.

scholarly journals Investigations on the Winter Thermal Environment of Bedrooms in Zhongxiang: A Case Study in Rural Areas in Hot Summer and Cold Winter Region of China

2019 ◽  
Vol 11 (17) ◽  
pp. 4720 ◽  
Author(s):  
Liu ◽  
Ren ◽  
Wei ◽  
Song ◽  
Li ◽  
...  
Keyword(s):  
Rural Areas ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Residential Buildings ◽  
Environmental Parameters ◽  
Thermal Conditions ◽  
Cold Winter ◽  
Clothing Insulation ◽  
Local Residents ◽  
Lower Temperature

In this paper, onsite measurements and a subjective questionnaire were conducted to study the thermal environment and heating condition of bedrooms during the winter in rural areas in China’s hot summer and cold winter (HSCW) region. Indoor and outdoor thermal environmental parameters were measured to evaluate the thermal conditions of bedrooms. Thermal sensation/tendency/acceptance, heating, and health condition were investigated to complete the analysis of attitudes of local residents on the thermal environment of bedrooms, heating and health issues, as well as the analysis of buildings. The observed results demonstrate that occupants in this region have a strong tolerance to low-temperature environments with the 80% acceptable lower temperature of 4.7 °C and a neutral temperature of 10.7 °C, with an average clothing insulation over 2.2 clo. Oversized volume and acreage of buildings and windows induce a lower temperature in the bedroom. Infants have a significant effect on heating requirements, including heating duration and temperature setpoint. Local residents are highly concerned about the costs, safety, and health related to heating and thermal environments. All evidence obtained through this investigation shows that it is beneficial to formulate regulations for the shape, envelope, and centralized heating policy for rural residential buildings in the HSCW region.

The indoor thermal environment of rural school classrooms in Northwestern China

2016 ◽  
Vol 26 (5) ◽  
pp. 662-679 ◽  
Author(s):  
Yanfeng Liu ◽  
Jing Jiang ◽  
Dengjia Wang ◽  
Jiaping Liu
Keyword(s):  
Thermal Comfort ◽  
Rural Schools ◽  
Fatigue Testing ◽  
Thermal Environment ◽  
Learning Performance ◽  
Northwestern China ◽  
Clothing Insulation ◽  
Indoor Thermal Environment ◽  
Neutral Temperature ◽  
The Impact

School classroom thermal environments could impact on thermal comfort and learning performance. Currently, the majority of research on the school indoor thermal environment has been focusing on urban areas, but notably little research has been conducted on rural schools. A field study was undertaken during the winter in Northwestern China, in order to investigate the indoor thermal environment and the impact on students’ thermal comfort and learning performance in rural primary and secondary schools. Through subjective surveys and objective measurements, we gathered 763 sets of data and questionnaires. Together with the measured air temperature, relative humidity, air velocity, globe temperature, teenagers’ activity levels and clothing insulation levels, the sensations of the indoor air conditions and the learning performance were evaluated. The current thermal environment situation in rural schools was identified. The neutral temperature was found to be approximately 15.0℃ with an average clothing insulation of 1.6 clo. Overall, the environment is satisfactory and comfortable. Moreover, the results from the students’ fatigue testing demonstrated the temperature corresponding to the highest learning performance is lower than the actual neutral temperature by about 1.0℃. The basic parameters of our findings have provided a future reference for improvement of the thermal environment in rural schools.

scholarly journals Thermal comfort environment for migrants: a long-term follow-up climate chamber experiment

2021 ◽  
Vol 2069 (1) ◽  
pp. 012237
Author(s):  
Yu Dong ◽  
Yuan Shi ◽  
Yanfeng Liu ◽  
Jørn Toftum
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Thermal Sensitivity ◽  
Thermal Adaptation ◽  
Indoor Climate ◽  
Climate Chamber ◽  
Chamber Experiment ◽  
Long Term Follow Up

Abstract Migration between different climate regions may change people’s thermal experience and their thermal adaptation. However, few studies have explored the thermal adaptation process and the suitable indoor thermal environment of migrants. In this study, we conducted a long-term tracking comparative experiment on thermal adaptation of migrants moving from severe cold (SC) regions, hot summer and cold winter (HSCW) regions, and hot summer and warm winter (HSWW) regions to cold region of China. A two-year climate chamber experiment was conducted to follow migrants’ progressive thermal adaptation, such as different weeks, months and seasons after they migrated. The results show that the thermal sensation of migrants was significantly associated with their origin, the time after migration and air temperature. In addition, with the increase time after migration, the thermal sensitivity of HSCW and SC migrants showed a significant upward and downward trend, respectively. Two years after migration, the thermal comfort limits of migrants from SC, HSWW and HSCW were almost identical at 23.5-27.8°C, 23.8-27.8°C, and 23.5-27.6°C. The results provides insight to the progression of thermal adaptation and helpful to guide the design of indoor climate for immigrants with different thermal experiences.

scholarly journals Verification of the Fanger Model in Real Conditions

2020 ◽  
Vol 328 ◽  
pp. 01001
Author(s):  
Natalia Krawczyk ◽  
Andrej Kapjor ◽  
Łukasz J. Orman
Keyword(s):  
Light Intensity ◽  
Thermal Comfort ◽  
Temperature Sensor ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Winter Period ◽  
Air Humidity ◽  
Relative Air Humidity ◽  
Globe Temperature ◽  
Environment Parameters

This study presents the issue of thermal comfort based on the Fanger model. The research was conducted in 5 rooms in the autumn-winter period. The research consisted of measurement of thermal environment parameters, air temperature and flow rate, relative air humidity, globe temperature sensor and light intensity. During the research, the students filled in questionnaires concerning thermal sensation. This allowed them to express their assessment of thermal comfort (predicted mean vote PMV and predicted percentage of dissatisfied PPD), as well as their preferences concerning the prevailing room conditions. Differences between the actual average predicted rating index and the Fanger model were shown. It can be noted that Fanger’s model does not reflect the results of the respondents.

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