The Thermal Comfort of Sedentary Workers

1987 ◽  
Vol 1 (2) ◽  
pp. 74-77 ◽  
Author(s):  
S C Foo ◽  
WO Phoon

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.

Technologies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 90
Author(s):  
Siliang Lu ◽  
Erica Cochran Hameen

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.


Author(s):  
Pardeep Kumar ◽  
Amit Sharma

Outdoor thermal comfort (OTC) promotes the usage frequency of public places, recreational activities, and people's wellbeing. Despite the increased interest in OTC research in the past decade, less attention has been paid to OTC research in cold weather, especially in arid regions. The present study investigates the OTC conditions in open spaces at the campus area in the arid region. The study was conducted by using subjective surveys(questionnaire) and onsite monitoring (microclimate parameters). The study was conducted at the Deenbandhu Chhotu Ram University of Science and Technology, Murthal, Haryana-India campus during the cold season of 2019. The timings of surveys were between 9:00 and 17:00 hours. The authors processed the 185 valid questionnaire responses of the respondents to analyze OTC conditions. Only 8.6% of the respondents marked their perceived sensation "Neutral." Regression analysis was applied between respondents' thermal sensations and microclimate parameters to develop the empirical thermal sensation model. The air temperature was the most dominant parameter affecting the sensations of the respondents. The empirical model indicated that by increasing air temperature, relative humidity, and solar radiation, the thermal sensations also increased while wind speed had an opposite effect. Physiological equivalent temperature (PET) was applied for assessing the OTC conditions; the neutral PET range was found to be 18.42-25.37°C with a neutral temperature of 21.89°C. The preferred temperature was 21.99 °C by applying Probit analysis. The study's findings could provide valuable information in designing and planning outdoor spaces for educational institutions in India's arid regions


2016 ◽  
Vol 34 (4/5) ◽  
pp. 427-445 ◽  
Author(s):  
Baharuddin Hamzah ◽  
Muhammad Taufik Ishak ◽  
Syarif Beddu ◽  
Mohammad Yoenus Osman

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.


2013 ◽  
Vol 805-806 ◽  
pp. 1620-1624 ◽  
Author(s):  
Wan Ying Qu

A thermal comfort field study was investigated in residential buildings of cold regions in transition season during which the indoor thermal environment conditions are measured, the thermal sensation value of the occupants is questioned and recorded. A seven-point thermal sensation scale was used to evaluate the thermal sensation. The statistical method was used to analyze the data and the conclusions are as follows in transition season: clothing increase in 0.1clo when the indoor air temperature is lowered by 1°C; and clothing will be a corresponding increase in 0.06clo when the outdoor air temperature is lowered by 1°C; clothing also varies with gender, age, weight and thermal history and other related; the measured thermal neutral temperature is 21.3°C; and the minimum accepted temperature is 11.4 °C in transition season in cold regions. Most people choose to change clothes, switch and other passive measures, and occasionally take active measures of heater, electric fans and others.


2021 ◽  
pp. 277-277
Author(s):  
Xiaozhou Wu ◽  
Genglin Liu ◽  
Jie Gao ◽  
Shuang Wu

A ceiling cooling (CC) system integrated with a mechanical ventilation system is an advanced HVAC system for the modern office building with glass curtain wall. In this paper, considering the influence of heat transfer of external envelope, the indoor thermal environment and human thermal comfort were objectively measured and subjectively evaluated in a ceiling cooling room with mixing ventilation (MV) or underfloor air distribution (UFAD). Indoor physical parameters and human skin temperatures were measured as the chilled ceiling surface temperature and supply air temperature were 17.1?C-17.6?C and 22.2?C - 22.6?C. Simultaneously, 16 subjects (8 males and 8 females) were selected to subjectively evaluate the thermal environment. The results showed that the difference between mean radiant temperature and air temperature in the occupied zone was 0.8?C with CC+MV and 1.2?C with CC+UFAD, and the indoor air velocity was 0.17m/s with CC+MV and 0.13m/s with CC+UFAD. In addition, the calculated and measured thermal sensation votes with CC+MV were all slightly less than those with CC+UFAD. Therefore, ventilation system type had a slight impact on the indoor thermal environment and human thermal comfort in the ceiling cooling room.


2021 ◽  
Vol 2 (1) ◽  
pp. 20-27
Author(s):  
Azka Millatina ◽  
Nedyomukti Imam Syafii

Thermal comfort is a basic human demand in interacting with space/architectural design. Determination of thermal comfort criteria can help the designer/architect in improving quality, function, and user thermal experience in an artificial environment. ISO 7730: 1994 standard states that the thermal sensation experienced by humans is the result of climate parameters (such as air temperature, radiation temperature, humidity, and wind speed) and human parameters (such as activity and clothing). These parameters were the focus of this study. The work program of this research collaboration was basically divided into 2 phases of activity, namely measuring and monitoring the conditions of thermal comfort in the Gallery 1 environment, Affandi Museum and providing recommendations for improvement of Gallery 1 thermal environment conditions. Primary data was taken from the indoor and outdoor measurement of air temperature, relative humidity and air velocity for 6 months. Physical architectural measurement of this study building and questionnaire methods followed the ASHRAE scale which was simplified to determine the level of thermal comfort, the scale of which was 2 (hot) to -2 (cold). The result of the measurement and analysis using a calculator based upon the ASHARE standard indicated that Gallery 1 of the Affandi Museum was in uncomfortable conditions. While the results of the questionnaire of 20 analyzes showed that at least 87,5% of respondents felt discomfort in Gallery 1, however, 60% of the respondent were still able to enjoy the collection and the atmosphere in gallery 1. The effective temperature index which provide 27,5-27,6 C and 66,7% RH as acceptable indoor environment in warm humid climate at Affandi museum case.


2021 ◽  
Vol 39 (1) ◽  
pp. 275-291
Author(s):  
Md Sarfaraz Alam ◽  
Urmi Ravindra Salve

There are ample literature studies available, focusing on hot-humid built environment, which have achieved an increase in thermal comfort conditions by proper installation of ventilation-systems. The present thermal comfort study has been carried out in the kitchen environment of a non-air-conditioned railway pantry car in Indian Railways. The purpose is to enhance thermal comfort level under the currently applied ventilation system inside the kitchen of pantry car by determining the standard effective temperature (SET) index. During the summer and winter seasons, a field study was carried out to obtain the value of air temperature, globe temperature, relative humidity, and air velocity inside the pantry car for estimation of the SET index. A computational fluid dynamics (CFD) analysis was used to obtain a better-modified case model of the pantry car kitchen for the improvement of thermal comfort. The design interventions for the pantry car kitchen were created, with emphasis on increasing energy efficiency based on low-power consumption air ventilation system. The study results indicated that, modified case-I model has a better ventilation design concept as compare to the existing and other models, which increased the air velocity and significantly decreased the air temperature inside the kitchen of pantry car at all cooking periods. A value of SET (28.6–30℃) was found with a comfortable thermal sensation within all cooking periods, which is better for the pantry car workers. This finding suggests a sustainable improvement in the thermal environment of the "non-air-conditioned" pantry car kitchen in the Indian Railways, which can be applied immediately.


2018 ◽  
Vol 225 ◽  
pp. 01003 ◽  
Author(s):  
Kelly Koh ◽  
Hussain H. Al-Kayiem ◽  
Jundika C. Kurnia

As a lot of people spend their time indoor, indoor thermal comfort will affect the performance of the occupants in terms of health, comfort and productivity. This paper aims to investigate the thermal comfort of an office building constructed using low cost materials in tropical climate condition. That has been achieved by investigating the PMV using the CBE thermal comfort tool in the post-graduate office building in the solar research site in UTP. The experimental measurements have been conducted at two different cases; without ventilation and with air-conditioned in the office building. The thermal comfort of the office building is assessed by using the ASHRAE thermal sensation scale. Results have demonstrated that the office room without ventilation is hot and not suitable for occupants to work at such thermal environment. Thermal comfort of the room with air-conditioning is warm and is slightly better than the room without ventilation as the PMV has been improved by around 60%. However, the acceptable thermal comfort level in the low-cost material office building is yet to be achieved.


2021 ◽  
Vol 881 (1) ◽  
pp. 012029
Author(s):  
H Handri ◽  
L H Sari ◽  
A Munir ◽  
A Ariatsyah

Abstract Pesisir Selatan is one of the districts in West Sumatra with a humid tropical climate with temperatures reaching 32°C during the day. The majority of coastal communities work as fishermen and build houses on the beach, such as in fishermen’s housing in South Painan. In this area there are two models of fisherman housing, namely government-assisted fisherman housing and fisherman’s original housing. Housing on the beachfront will be faced with quite extreme climatic conditions such as air velocity, air temperature, and air humidity which are relatively high on average. Therefore, it is necessary to evaluate the level of thermal comfort in the space in both models of fisherman housing to determine the performance of each fisherman’s housing in dealing with the climate. This study uses a quantitative approach by measuring the parameters of thermal comfort, namely air temperature, humidity and air velocity using a thermohygrometer and anemometer. The data collection method uses descriptive quantitative. Comfort level is evaluated based on the Indonesian national standard (SNI 03-6572-2001) and adaptive thermal comfort. Based on the results of the study, the level of thermal comfort in both models of fisherman housing is classified as uncomfortable according to SNI 03-6572-2001 and adaptive thermal comfort.


2014 ◽  
Vol 672-674 ◽  
pp. 1665-1669 ◽  
Author(s):  
Iman Asadi ◽  
Ibrahim Hussein ◽  
Kumaran Palanisamy

Field study was carried out on the thermal conditions and thermal comfort of occupants in air conditioned buildings in Malaysia. The study was carried out in 10 staff offices and 6 student study areas of Universiti Tenaga Nasional (UNITEN) during October and November 2013, collecting a full set of objective physical measurements and subjective assessments through questionnaires. The measured environmental parameters were air temperature, relative humidity and air velocity. The subjective responses concern the judgment of the occupants about the thermal environment at the moment of measurements. The obtained results showed that most places are in acceptable and comfort zone according to Fanger’s predicted mean vote (PMV) model. The neutral air temperature obtained through linear regression analysis of thermal sensation vote (TSV) is 23.9°C for UNITEN. The result of this study demonstrates that the acceptability of thermal comfort among UNITEN occupant is about 78 %.


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