scholarly journals Field Study on Adaptive Thermal Comfort in Naturally Ventilated Secondary School Buildings in Nepal

2020 ◽  
Vol 15 (3) ◽  
pp. 317-325
Author(s):  
Mishan Shrestha ◽  
Hom B Rijal ◽  
Masanori Shukuya

Most of the classroom in Nepalese school buildings are thermally less acceptable due to the poor thermal insulation. They are extreme cold in winter and extreme hot in summer season leading for the discomfort in classroom. Thermally uncomfortable classroom causes the negative impact in the academic performance of students. Therefore, there should be serious attention to improve the indoor thermal environment of classroom. There are limited indoor thermal environment studies conducted in Nepalese residential buildings but not at all in school buildings yet. This study investigated the students’ perceptions on thermal comfort inside the classroom of secondary school buildings during the autumn season of 2017 in a temperate climate (Dhading, Kathmandu and Nuwakot districts) of Nepal. 22 classrooms (33 students in average in each class) of 8 school buildings with a total of 818 students aged 12-18 years, 329 (40%) males and 489 (60%) females were participated in the survey. The two simultaneous surveys: questionnaire survey and thermal measurement survey were conducted during the regular lesson periods in each classroom. Students voted at the beginning, in the middle and at the end of the class in minutes’ lecture. About 76% responses were found to be in either of slightly cold, neutral or slightly hot. The results show that the comfort temperature of students was around 28 °C, 26°C and 24°C in Dhading, Kathmandu and Nuwakot districts, respectively. However, the mean comfort temperature and preferred temperature was found to be around 27 °C and 26 °C respectively. The findings of this study may hopefully invoke the awareness of the school building designers, teachers and students to maintain the thermally comfortable school buildings without using mechanical system.

2021 ◽  
Vol 13 (7) ◽  
pp. 3614
Author(s):  
Zeyad Amin Al-Absi ◽  
Mohd Isa Mohd Hafizal ◽  
Mazran Ismail ◽  
Azhar Ghazali

Building sector is associated with high energy consumption and greenhouse gas emissions, which contribute to climate change. Sustainable development emphasizes any actions to reduce climate change and its effect. In Malaysia, half of the energy utilized in buildings goes towards building cooling. Thermal comfort studies and adaptive thermal comfort models reflect the high comfort temperatures for Malaysians in naturally conditioned buildings, which make it possible to tackle the difference between buildings’ indoor temperature and the required comfort temperature by using proper passive measures. This study investigates the effectiveness of building’s retrofitting with phase change materials (PCMs) as a passive cooling technology to improve the indoor thermal environment for more comfortable conditions. PCM sheets were numerically investigated below the internal finishing of the walls. The investigation involved an optimization study for the PCMs transition temperatures and quantities. The results showed significant improvement in the indoor thermal environment, especially when using lower transition temperatures and higher quantities of PCMs. Therefore, the monthly thermal discomfort time has decreased completely, while the thermal comfort time has increased to as high as 98%. The PCM was effective year-round and the optimum performance for the investigated conditions was achieved when using 18mm layer of PCM27-26.


2020 ◽  
Vol 15 (3) ◽  
pp. 163-170
Author(s):  
Rajan KC ◽  
Hom Bahadur Rijal ◽  
Masanori Shukuya ◽  
Kazui Yoshida

The energy use in residential dwellings has been increasing due to increasing use of modern electric appliances to make the lifestyle easier, entertaining and better. One of the major purposes of indoor energy use is for improving indoor thermal environment for adjusting thermal comfort. Along with the use of passive means like the use of mechanical devices, the occupants in any dwellings use active means such as the use of natural ventilation, window opening, and clothing adjustment. In fact, the use of active means when the outdoor environment is good enough might be more suitable to improve indoor thermal environment than the use of mechanical air conditioning units, which necessarily require electricity. Therefore, the people in developing countries like Nepal need to understand to what extent the occupants can use active means to manage their own indoor thermal comfort. The use of active means during good outdoor environment might be an effective way to manage increasing energy demand in the future. We have made a field survey on the occupants’ adaptive behaviors for thermal comfort in a Japanese condominium equipped with Home Energy Management System (HEMS). Online questionnaire survey was conducted in a condominium with 356 families from November 2015 to October 2016 to understand the occupants’ behaviors. The number of 17036 votes from 39 families was collected. The indoor air temperature, relative humidity and illuminance were measured at the interval of 2-10 minutes to know indoor thermal environmental conditions. The occupants were found using different active behaviors for thermal comfort adjustments even in rather harsh summer and winter. Around 80% of the occupants surveyed opened windows when the outdoor air temperature was 30⁰C in free running (FR) mode and the clothing insulation was 0.93 clo when the outdoor air temperature was 0⁰C. The result showed that the use of mechanical heating and cooling was not necessarily the first priority to improve indoor thermal environment. Our result along with other results in residential buildings showed that the adaptive behaviors of the occupants are one of the primary ways to adjust indoor thermal comfort. This fact is important in enhancing the energy saving building design.


2020 ◽  
Vol 194 ◽  
pp. 05013
Author(s):  
Xiaowei Hong ◽  
Guangjin Zhang ◽  
Yufeng Zhang

Indoor thermal environment of Hui style traditional houses is depended on surrounding environments, building layouts and envelope. Quantitative analysis of the effects of building layouts and envelope on indoor thermal environment is of great significance for preventions of traditional houses and design of new archaized houses. A field investigation was conducted on thirty-six traditional houses from nine villages in Wuyuan, and the typical buildings’ layout and envelope were determined. Four traditional buildings in different location in Wuyuan were selected for continual recording. The four buildings with four types of building layouts and envelope were analyzed by using local adaptive thermal comfort model, and the effects of building layouts and envelope of traditional buildings were clearly revealed. The most crucial way to improve indoor thermal environment in Hui style traditional buildings was raising the indoor air temperature.


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.


2019 ◽  
Vol 15 (2) ◽  
pp. 14-25
Author(s):  
Hom B. Rijal ◽  
Michael A. Humphreys ◽  
J. Fergus Nicol

Office workers use a variety of adaptive opportunities to regulate their indoor thermal environment. The behavioural adaptations such as window opening, clothing adjustments, and use of heating/cooling are important factors for adaptive thermal comfort. It is well-known that they are the most important contributors in the adaptive thermal comfort model. Thus, if we understand the behavioural adaptation properly, we can explain the mechanism of the adaptive model. The indoor thermal environment is often adjusted using the air conditioning in Japanese office buildings to improve thermal comfort and productivity. Thus, it is necessary to conduct research on the behavioural adaptation in the offices because the occupant behavior is different from behaviour in dwellings. In order to record the seasonal differences in behavioural adaptation and to develop an adaptive algorithm for Japanese offices, we measured temperatures in 11 office buildings and conducted the thermal comfort and occupant behaviour survey for over a year. We collected 4,660 samples from about 1,350 people. The proportion of ‘open window’ in the free running mode (neither heating nor cooling being used) is significantly higher than that of the air conditioned mode. The behavioural adaptation is related to the outdoor air temperature. The behavioural adaptations such as window-opening, heating and cooling use predicted by regression analysis are in good agreement with the measured data. These findings can be applied to building thermal simulation to predict the behavioural adaptation and energy use in office buildings.


2012 ◽  
Vol 518-523 ◽  
pp. 4461-4465
Author(s):  
Li Li

The good and comfortable environment is beneficial to the health, and can improve working efficiency, make people imbued with more creativity. This means strengthening the competitiveness, increase economic efficiency. So, creating the good building environment not merely has a meaning on technology, and has social effect and economic meaning. In order to understand the situation of indoor thermal environment of the seaside residential building generally, a field measurement on the condition of summer was made in Xiamen from the last ten days of July to the first ten day of Aug, 2005, 2006 and 2008. Test the thermal environment and investigate the thermal comfort in residential buildings of natural ventilation condition, analyze the main influence factors of indoor thermal environment, and evaluate indoor thermal comfort with effective temperature (ET). The curves of indoor air temperature and relative humidity reflect the character of high temperature and high relative humidity in summer in Xiamen residential buildings. Discuss the methods of building energy saving. Suggest that, for seaside city in hot days, the natural ventilation and interval natural ventilation should be the main fundamental methods of improving the resident building thermal environment.


2020 ◽  
Vol 15 (3) ◽  
pp. 292-299
Author(s):  
Hom B Rijal ◽  
Michael A Humphreys ◽  
J Fergus Nicol

Office workers use a variety of adaptive opportunities to regulate their indoor thermal environment. The behavioural adaptations such as window opening, clothing adjustments, heating/cooling use are one of the important factors for the adaptive thermal comfort. It is well-known that they are the most important contributors in the adaptive thermal comfort model. Thus, if we understand the behavioural adaptation properly, we can explain the mechanism of the adaptive model. In addition, the indoor thermal environment is often adjusted using the air conditioning in Japanese office building to improve the thermal comfort and productivity. Thus, it is necessary to conduct research on the behavioural adaptation in the offices because the occupant behavior is different to the dwellings. In order to record the seasonal differences in behavioural adaptation and to develop an adaptive algorithm for Japanese offices, we measured temperatures in 11 office buildings and conducted the thermal comfort and occupant behaviour survey for over a year in Japanese offices. We collected 4,660 samples from about 1350 people. The proportion of ‘open window’ in the free running mode (neither heating or cooling being used) is significantly higher than that of the air-conditioned mode. The behavioural adaptation is related to the outdoor air temperature. The behavioural adaptation predicted by the regression analysis is in good agreement with the measured data. These findings can be applied to the building thermal simulation to predict the behavioural adaptation and energy use in office buildings.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4530
Author(s):  
Youcef Bouzidi ◽  
Zoubayre El Akili ◽  
Antoine Gademer ◽  
Nacef Tazi ◽  
Adil Chahboun

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.


2014 ◽  
Vol 10 (1) ◽  
pp. 172-183 ◽  
Author(s):  
Sushil B. Bajracharya

This paper seeks to investigate into the aspects of thermal performance of traditional residential buildings in traditional settlements of Kathmandu valley. This study proceeds to analyze the detailed field data collected, with a view to identify the indoor thermal environment with respect to outdoor thermal environment in different seasons. This paper also compares the thermal performance of traditional buildings with modern residential buildings of traditional settlements of the valley. There is a regression analysis to obtain information about the thermal environment of different traditional and modern residential buildings with different conditions. The paper concludes that, thermal performance of traditional residential building, adapted in various ways to the changing thermal regime for thermal comfort is better than that of contemporary buildings.DOI: http://dx.doi.org/10.3126/jie.v10i1.10898Journal of the Institute of Engineering, Vol. 10, No. 1, 2014,  pp. 172–183


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