scholarly journals Efecto de la temperatura de bulbo seco y humedad relativa en la sensación térmica percibida en espacios exteriores en clima cálido seco

Author(s):  
Gonzalo Bojórquez-Morales ◽  
Aníbal Luna-León ◽  
Ramona Romero-Moreno ◽  
Verónica Jiménez-López

Conditions of the thermal environment in outdoor spaces determine not only its quality, but also the risk of morbidity from remaining in it. The objective of this research was to estimate the effect of dry bulb temperature and relative humidity on the perceived thermal sensation in outdoor spaces in hot dry climate. The thermal comfort adaptation approach was used with the thermal sensation interval means method, the analysis considered three activity levels for the warm period (with 823 observations) and cold period (with 863 observations), and the adaptation level of subjects based on their thermal sensation. The results indicate that even when the critical effect is due to the dry bulb temperature, the relative humidity has an important effect on the perceived sensation.

Author(s):  
Golnoosh Manteghi

Season plays a key role in the development of outdoor spaces for pedestrians in hot humid cities. This research studies the influence of seasonal variations on pedestrian thermal comfort on the pedestrian level by means of meteorology and field observations of selected footpaths in the major tourist area of Malacca. This experiment was carried out on selected clear calm days indicative of each season during the development of a research project, and hourly meteorological transects from 10:00 am to 6:00 pm and questioned 200 respondents on their thermal awareness, comfort, and preferences were conducted. Adaptation, thermal comfort vote, thermal preference, age, season and hour of the day were significant non-meteorological factors, apart from meteorological information. The findings of analyzes showed that the thermal experience and expectation existed and in different seasons people changed perceptions for the outside thermal environment. Almost 80% local tourist and 55 % international tourist was accepted Physiologically Equivalent Temperature (PET) range affected by the local climate and thermal adaptation. The subjective thermal sensation on physiological equivalent temperature generated an acceptable physiological equivalent temperature of 32.6°C to 36.8°C based on the seasonal variations for Malacca tourist zone in Malaysia. These findings shed light on the optimal design of outdoor spaces for increasing the utilization rate. The seasonal variation must be taken into account so that the outdoor landscape design provides more opportunities for different seasons to communicate with the atmosphere and so enhance thermal comfort and utilization.


2020 ◽  
Vol 11 (2) ◽  
pp. 326-341
Author(s):  
Golnoosh Manteghi ◽  
Tasneem Mostofa ◽  
Hasanuddin Bin Lamit

The present study aims to establish a correlation between the physiological equivalent temperature (PET) and subjective thermal sensation in the Tropics, assessing their impact on local as well as international pedestrians. The pilot test was conducted in six scenarios in the Malacca region of Malaysia. The RayMan model calculated the PET, which is further used to synthetically evaluate the thermal environment for six scenarios, each with a different river width and pavement material. The independent t-test and regression analysis determined the correlation between human thermal comfort acceptability and the thermal environment indices of outdoor spaces. Most of the outdoor thermal comfort assessments have been carried out focusing on local urban residents, while the same assessments on tourists are limited. This research provides necessary insight into the perception of outdoor microclimatic conditions in the Malacca heritage area and also identifies the perception on a few important psychological factors of these two demographic groups. An awareness of such issues would be fruitful for architects, planners and urban designers engaged in the process of designing and planning tourist destinations.


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.


2021 ◽  
Vol 896 (1) ◽  
pp. 012074
Author(s):  
W Budiawan ◽  
K Tsuzuki ◽  
H Sakakibara

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.


Author(s):  
Zheming Liu ◽  
Yumeng Jin ◽  
Hong Jin

In the context of global climate change and accelerated urbanization, the deterioration of the urban living environment has had a serious negative impact on the life of residents. However, studies on the effects of forms and configurations of outdoor spaces in residential areas on the outdoor thermal environment based on the particularity of climate in severe cold regions are very limited. Through field measurements of the thermal environment at the pedestrian level in the outdoor space of residential areas in three seasons (summer, the transition season and winter) in Harbin, China, this study explored the effects of forms and configurations of three typical outdoor spaces (the linear block, the enclosed block, and the square) on the thermal environment and thermal comfort using the Physiologically Equivalent Temperature (PET). The results show that the thermal environment of all outdoor space forms was relatively comfortable in the transition season but was uncomfortable in summer and winter. The full-enclosed block with a lower sky view factor (SVF) had a higher thermal comfort condition in summer and winter. The linear block with higher buildings and wider south–north spacing had a higher thermal comfort condition in summer and winter. When the buildings on the south side were lower and the south–north spacing was wider, the thermal environment of the square was more comfortable in winter.


Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 769 ◽  
Author(s):  
Fabio Fantozzi ◽  
Giulia Lamberti

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.


2020 ◽  
Vol 12 (21) ◽  
pp. 9284
Author(s):  
Jiao Xue ◽  
Xiao Hu ◽  
Shu Nuke Sani ◽  
Yuanyuan Wu ◽  
Xinyu Li ◽  
...  

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.


2018 ◽  
Vol 878 ◽  
pp. 173-178
Author(s):  
Chorpech Panraluk ◽  
Atch Sreshthaputra

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.


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.


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.


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