scholarly journals Behavioural Adaptation for the Thermal Comfort and Energy Saving in Japanese Offices

2019 ◽  
Vol 15 (2) ◽  
pp. 14-25
Author(s):  
Hom B. Rijal ◽  
Michael A. Humphreys ◽  
J. Fergus Nicol
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Thermal Environment ◽  
Office Buildings ◽  
Behavioural Adaptation ◽  
Indoor Thermal Environment ◽  
Heating And Cooling ◽  
Adaptive Thermal Comfort ◽  
Window Opening ◽  
Behavioural Adaptations

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.

scholarly journals Study on Behavioural Adaptation for the Thermal Comfort and Energy Saving in Japanese Offices

2020 ◽  
Vol 15 (3) ◽  
pp. 292-299
Author(s):  
Hom B Rijal ◽  
Michael A Humphreys ◽  
J Fergus Nicol
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Thermal Environment ◽  
Office Buildings ◽  
Behavioural Adaptation ◽  
Indoor Thermal Environment ◽  
Adaptive Thermal Comfort ◽  
Window Opening ◽  
Open Window ◽  
Thermal Comfort Model

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.

scholarly journals Towards Sustainable Development: Building’s Retrofitting with PCMs to Enhance the Indoor Thermal Comfort in Tropical Climate, Malaysia

2021 ◽  
Vol 13 (7) ◽  
pp. 3614
Author(s):  
Zeyad Amin Al-Absi ◽  
Mohd Isa Mohd Hafizal ◽  
Mazran Ismail ◽  
Azhar Ghazali
Keyword(s):  
Climate Change ◽  
Sustainable Development ◽  
Thermal Comfort ◽  
Phase Change Materials ◽  
Thermal Environment ◽  
High Energy ◽  
Transition Temperatures ◽  
Indoor Thermal Environment ◽  
Adaptive Thermal Comfort ◽  
The Difference

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.

scholarly journals Importance of Behavioral Adjustments for Adaptive Thermal Comfort in a Condominium with HEMS System

2020 ◽  
Vol 15 (3) ◽  
pp. 163-170
Author(s):  
Rajan KC ◽  
Hom Bahadur Rijal ◽  
Masanori Shukuya ◽  
Kazui Yoshida
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Energy Use ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Outdoor Environment ◽  
Adaptive Behaviors ◽  
Outdoor Air ◽  
Indoor Thermal Environment ◽  
Indoor Thermal Comfort

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.

scholarly journals The effects of building layouts and envelope on indoor thermal environment of Hui style traditional buildings in Wuyuan

2020 ◽  
Vol 194 ◽  
pp. 05013
Author(s):  
Xiaowei Hong ◽  
Guangjin Zhang ◽  
Yufeng Zhang
Keyword(s):  
Quantitative Analysis ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Field Investigation ◽  
Indoor Thermal Environment ◽  
Adaptive Thermal Comfort ◽  
Thermal Comfort Model

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.

scholarly journals An Investigation of the Behavioral Characteristics of Higher- and Lower-Temperature Group Families in a Condominium Equipped with a HEMS System

Buildings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 4 ◽  
Author(s):  
Rajan KC ◽  
Hom Rijal ◽  
Masanori Shukuya ◽  
Kazui Yoshida
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Indoor Air ◽  
Energy Use ◽  
Thermal Environment ◽  
Indoor Thermal Environment ◽  
Home Energy Management ◽  
Temperature Group ◽  
Higher Temperature ◽  
Lower Temperature

A home energy management system (HEMS) shows the energy used indoors so that the energy waste can be easily identified and reduced. Thermal comfort is related to the trend of energy use in buildings. We conducted a survey in a condominium equipped with a HEMS to determine the indoor thermal environment and various behaviors of the occupants taken for thermal comfort adjustment. The results showed that there is a large variation of indoor air temperatures according to season, floor and flat. We categorized families into two groups, one with higher and the other with lower average indoor temperatures. The indoor air temperature of the higher temperature group in summer was found to be higher than the recommended indoor temperature during the summer season in Japan. The higher temperature group tended to adopt behaviors, such as window opening and using a fan more often, than the lower temperature group. Due to the moderately high insulating levels in the building surveyed, the indoor air temperature of both groups was not low in winter. Heating was used less and irregular. The overall results indicate that the groups of families behaved differently to adjust the indoor thermal environment even though they were equipped with the same HEMS system.

Comparative Evaluation of Indoor Thermal Comfort for Green and Conventional Office Buildings

Solar Energy ◽  
2004 ◽  
Author(s):  
Alex Nunez ◽  
Moncef Krarti
Keyword(s):  
Comparative Analysis ◽  
Thermal Comfort ◽  
Thermal Environment ◽  
Green Building ◽  
Mean Value ◽  
Building Construction ◽  
Office Buildings ◽  
Indoor Thermal Environment ◽  
Indoor Thermal Comfort ◽  
Construction Methods

A comparative analysis was conducted between two office buildings, one constructed using green design and the other erected using traditional building construction methods. As part of the analysis, thermal comfort indicators (using the Predicted Mean Value of Fanger model) were monitored by recording equivalent temperature, air temperature, and relative humidity at each site. The study tests whether office buildings constructed using different design approaches have significantly different indoor thermal environment. The results of the comparative analysis indicate that the green building provides better thermal comfort than the conventional building.

scholarly journals Comparative Analysis of Energy Use and Human Comfort by an Intelligent Control Model at the Change of Season

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6023
Author(s):  
Sung Hoon Yoon ◽  
Jonghoon Ahn
Keyword(s):  
Thermal Comfort ◽  
Intelligent Control ◽  
Energy Use ◽  
Thermal Environment ◽  
Operating Time ◽  
Adaptive Controller ◽  
Indoor Thermal Comfort ◽  
Heating And Cooling ◽  
Proposed Model ◽  
Deterministic Control

For improving control methods in the thermal environment, various algorithms have been studied to satisfy the specific conditions required by the characteristics of building spaces and to reduce the energy consumed in operation. In this research, a network-based learning control equipped with an adaptive controller is proposed to investigate the control performance for supply air conditions with maintaining the levels of indoor thermal comfort. In order to examine its performance, the proposed model is compared to two different models in terms of the patterns of heating and cooling energy use and the characteristics of operational signals and overshoots. As a result, the energy efficiency of the proposed control has been slightly decreased due to the energy consumption increased by precise controls, but the thermal comfort has improved by about 10.7% more than a conventional thermostat and by about 19.8% more than a deterministic control, respectively. This result can contribute to the reduction of actual installation and maintenance costs by reducing the operating time of dampers and the energy use of heating coils without compromising indoor thermal comfort.

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
Keyword(s):  
Secondary School ◽  
Thermal Comfort ◽  
Thermal Environment ◽  
Negative Impact ◽  
Residential Buildings ◽  
Temperate Climate ◽  
School Buildings ◽  
Preferred Temperature ◽  
Indoor Thermal Environment ◽  
Adaptive Thermal Comfort

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.

scholarly journals Energy-saving potential of intermittent heating system: Influence of composite phase change wall and optimization strategy

2020 ◽  
pp. 014459872096921
Author(s):  
Yanru Li ◽  
Enshen Long ◽  
Lili Zhang ◽  
Xiangyu Dong ◽  
Suo Wang
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Phase Change ◽  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Optimization Strategy ◽  
Indoor Thermal Environment ◽  
Indoor Thermal Comfort ◽  
Intermittent Heating

In the Yangtze River zone of China, the heating operation in buildings is mainly part-time and part-space, which could affect the indoor thermal comfort while making the thermal process of building envelope different. This paper proposed to integrate phase change material (PCM) to building walls to increase the indoor thermal comfort and attenuate the temperature fluctuations during intermittent heating. The aim of this study is to investigate the influence of this kind of composite phase change wall (composite-PCW) on the indoor thermal environment and energy consumption of intermittent heating, and further develop an optimization strategy of intermittent heating operation by using EnergyPlus simulation. Results show that the indoor air temperature of the building with the composite-PCW was 2–3°C higher than the building with the reference wall (normal foamed concrete wall) during the heating-off process. Moreover, the indoor air temperature was higher than 18°C and the mean radiation temperature was above 20°C in the first 1 h after stopping heating. Under the optimized operation condition of turning off the heating device 1 h in advance, the heat release process of the composite-PCW to the indoor environment could maintain the indoor thermal environment within the comfortable range effectively. The composite-PCW could decrease 4.74% of the yearly heating energy consumption compared with the reference wall. The optimization described can provide useful information and guidance for the energy saving of intermittently heated buildings.

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