scholarly journals Objective and subjective thermal comfort evaluation in Hungary

2017 ◽  
Vol 21 (3) ◽  
pp. 1409-1418 ◽  
Author(s):  
Laszlo Kajtar ◽  
Jozsef Nyers ◽  
Janos Szabo ◽  
Laszlo Ketskemety ◽  
Levente Herczeg ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Evaluation Method ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Climatic Conditions ◽  
Temperate Climate ◽  
Clothing Insulation ◽  
Winter Time ◽  
Radiant Temperature ◽  
S Model

Thermal comfort sensation can be predicted in the most exact way based on Fanger?s predicted mean vote (PMV) model. This evaluation method takes all the six influencing factors into consideration: air temperature and humidity, air velocity, mean radiant temperature of surrounding surfaces, clothing insulation, and occupants? activities. Fanger?s PMV method was developed for temperate climate and European people, with the participation of university students as subjects. Many researchers had investigated its validity in different geographic locations (i. e. climatic conditions, people) and under non-laboratory circumstances. The results were summarised by van Hoof which had been published in the scientific references. The articles gave us the idea to elaborate the former measurement results. During the last decades thermal comfort was evaluated by our research team using subjective scientific questionnaires and applying the objective Fanger?s model in several office buildings in Hungary. The relation between the PMV and actual mean vote values were analysed based on these results. Investigations were carried out under steady-state conditions in winter time. We performed objective thermal comfort evaluations based on instrumental measurements using the PMV theory. Parallel to this we assessed the subjective thermal sensation using scientific questionnaires. The mathematical relationship between the actual mean vote and PMV was defined according to the evaluated thermal environment: AMV = PMV + 0.275, (arg. ?1.7 ? PMV ? +0.5).

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 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 Thermal Comfort for Urban Parks in Subtropics: Understanding Visitor’s Perceptions, Behavior and Attendance

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Chuang-Hung Lin ◽  
Tzu-Ping Lin ◽  
Ruey-Lung Hwang
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Thermal Conditions ◽  
Urban Parks ◽  
Climatic Conditions ◽  
Urban Spaces ◽  
Thermal Perception ◽  
Behavioral Adaptations ◽  
Lower Limits

The paper is an effort toward thermal comfort assessment for urban parks under the climatic conditions of Taiwan to help architects achieve better climatic design. Field interviews, observations, and micrometeorological measurements were conducted in this study. The WBGT was used as the thermophysiological index to investigate the effects of thermal conditions on visitor’s thermal perception and adaptive behavior in outdoor urban spaces. In this study, behavioral adaptations used by visitors as a means of achieving comfort were evaluated. Observational results showed that the overall attendance was influenced by sun and thermal conditions. There was a robust relationship between thermal sensation votes, as well as thermal acceptability, and thermal environment, in terms of WBGT. The upper and lower limits of 80% acceptability are 26°C WBGT and 20°C WBGT, respectively.

scholarly journals How Can We Adapt Thermal Comfort for Disabled Patients? A Case Study of French Healthcare Buildings in Summer

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4530
Author(s):  
Youcef Bouzidi ◽  
Zoubayre El Akili ◽  
Antoine Gademer ◽  
Nacef Tazi ◽  
Adil Chahboun
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Linear Regression Analysis ◽  
Environmental Parameters ◽  
Physical Parameters ◽  
Mean Radiant Temperature ◽  
Operative Temperature ◽  
Neutral Temperature ◽  
Radiant Temperature

This paper investigates adaptive thermal comfort during summer in medical residences that are located in the French city of Troyes and managed by the Association of Parents of Disabled Children (APEI). Thermal comfort in these buildings is evaluated using subjective measurements and objective physical parameters. The thermal sensations of respondents were determined by questionnaires, while thermal comfort was estimated using the predicted mean vote (PMV) model. Indoor environmental parameters (relative humidity, mean radiant temperature, air temperature, and air velocity) were measured using a thermal environment sensor during the summer period in July and August 2018. A good correlation was found between operative temperature, mean radiant temperature, and PMV. The neutral temperature was determined by linear regression analysis of the operative temperature and Fanger’s PMV model. The obtained neutral temperature is 23.7 °C. Based on the datasets and questionnaires, the adaptive coefficient α representing patients’ capacity to adapt to heat was found to be 1.261. A strong correlation was also observed between the sequential thermal index n(t) and the adaptive temperature. Finally, a new empirical model of adaptive temperature was developed using the data collected from a longitudinal survey in four residential buildings of APEI in summer, and the obtained adaptive temperature is 25.0 °C with upper and lower limits of 24.7 °C and 25.4 °C.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

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 Comparative study on thermal comfort responses and sleep quality between Indonesian and Japanese students during summer in Japan

2021 ◽  
Vol 896 (1) ◽  
pp. 012074
Author(s):  
W Budiawan ◽  
K Tsuzuki ◽  
H Sakakibara
Keyword(s):  
Relative Humidity ◽  
Sleep Quality ◽  
Comparative Study ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Temperate Climate ◽  
Japanese Students ◽  
The Mean

Abstract The comfort temperature and sleep quality of Indonesian residing in Japan during summer might be different from Japanese. As an extended previous research, this study aimed to compare the thermal comfort and sleep quality between Japanese and Indonesian students. Male Indonesian and Japanese students aged 20-35 years participated in this study. The participants completed a survey regarding thermal sensation before sleep. During sleep, actigraphy was used to monitor sleep. Additionally, the temperature and relative humidity of the participants’ bedrooms were recorded. The findings of this study indicated that Indonesian students’ bedroom temperature and relative humidity were not significantly different from those of Japanese students during the summer. Most of Indonesian students preferred neutral, like the Japanese students. According to a thermal comfort survey, Indonesians had the same sensation as Japanese (slightly comfortable). However, the Griffiths method revealed that the mean comfort temperature of Indonesian was higher than those of Japanese students. We also discovered that Indonesian students had shorter duration on bed and sleep minute than Japanese students. Furthermore, the sleep rate of Indonesian students was comparable to that of Japanese students. In conclusion, Indonesian students as tropical native became capable of adjusting to the hot and humid conditions in temperate climate, Japan.

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.

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