scholarly journals Field Study on Energy-Saving Behaviour and Patterns of Air-Conditioning Use in a Condominium

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8572
Author(s):  
Kazui Yoshida ◽  
Hom B. Rijal ◽  
Kazuaki Bogaki ◽  
Ayako Mikami ◽  
Hiroto Abe
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Energy Use ◽  
Thermal Environment ◽  
Residential Energy ◽  
Indoor Thermal Environment ◽  
Energy Management Systems ◽  
Home Energy Management ◽  
Questionnaire Surveys ◽  
Floor Heating

In the international movement to combat the threat of climate change, the timely implementation of residential energy-saving practises is becoming an urgent issue. Because the number of apartments is increasing, we analysed data from home energy management systems (HEMSs) and data from questionnaire surveys of 309 households in a condominium. We focused on the seasonal variation in air-conditioning (AC) use in living-dining rooms to determine the tendency of energy use for heating/cooling related to the characteristics of flats, the profiles of residents, and energy-saving behaviours. In winter, 80% of residents mainly used gas floor heating rather than AC and 24% did not use AC in winter. In households where someone stays home for long hours, they prefer gas floor heating rather than AC in winter. These households also tend to engage in energy-saving behaviours to adjust the indoor thermal environment. There are several types of energy-saving lifestyles; therefore, effective energy-saving measures should be considered for both energy efficiency and the thermal comfort of residents.

Study on the Thermal Performance of the Vernacular Dwellings in Wei-He Plain of Shaanxi Province

2012 ◽  
Vol 476-478 ◽  
pp. 1589-1595
Author(s):  
Yi Ping Zhu ◽  
Xi Liao ◽  
Shu Yun Wu ◽  
Jing Luo ◽  
Yuan Jiang ◽  
...  
Keyword(s):  
Energy Saving ◽  
Thermal Insulation ◽  
Thermal Performance ◽  
Thermal Environment ◽  
Local Area ◽  
Shaanxi Province ◽  
Indoor Thermal Environment ◽  
Questionnaire Surveys

Based on indoor thermal environment test and questionnaire surveys, the paper studies on thermal insulation capacity and indoor thermal environment of the vernacular dwellings in Wei-he Plain of Shaanxi Province, China, and analyses their heating methods and application status. Besides, the popularity of sustainable techniques in local area has been evaluated and summarized. Moreover, the paper discusses the present problems in local indoor thermal environment and energy-saving status.

Evaluating Thermal Environments by Using an Air-Conditioning Energy-Saving Mechanism

2012 ◽  
Author(s):  
Nguyen Anh Tuan ◽  
K. D. Huang
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Energy Use ◽  
Thermal Environment ◽  
Minimum Energy ◽  
Outlet Port ◽  
Thermal Environments ◽  
Environment Control ◽  
Port Opening ◽  
Occupied Zone

In a highly developed living, people are always looking for a comfortable indoor environment with minimum energy use. Individual air-conditioning system (IACS) can create an individual thermal environment control in a workroom which can contribute to save air-conditioning energy. In this study, we analyze the airflow circulation cell of the IACS with varied outlet port opening and outlet port position dimensions using the computational fluid dynamics (CFD) technique. We created an IACS, two workstations, lightings, and a cabinet in a 3-dimensional room. The fluid was assumed to be Newtonian, unsteady, and incompressible. A Bossinesq approximation was determined in order to consider the buoyancy effect. We examined the effects of the outlet port opening and outlet port position on airflow circulation establishing process. Air temperatures along the various midline of the occupied zone were predicted and compared for a range of outlet port opening and outlet port position by using non-dimensional form. We also showed the occupied zone temperature at various planes in the workroom. Results will indicate the suitable outlet port opening and outlet port position for maintaining individual satisfied occupants’ requirements and improving energy saving potential.

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.

scholarly journals Improvements in Energy Saving and Thermal Environment after Retrofitting with Interior Insulation in Intermittently Cooled Residences in Hot-Summer/Cold-Winter Zone of China: A Case Study in Chengdu

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2776
Author(s):  
Xin Ye ◽  
Jun Lu ◽  
Tao Zhang ◽  
Yupeng Wang ◽  
Hiroatsu Fukuda
Keyword(s):  
Energy Saving ◽  
Thermal Environment ◽  
Real Life ◽  
Average Energy ◽  
Experimental Result ◽  
Cold Winter ◽  
The South ◽  
Indoor Thermal Environment ◽  
Space Cooling

Space cooling is currently the fastest-growing end-user in buildings. The global warming trend combined with increased population and economic development will lead to accelerated growth in space cooling in the future, especially in China. The hot summer and cold winter (HSCW) zone is the most densely populated and economically developed region in China, but with the worst indoor thermal environment. Relatively few studies have been conducted on the actual measurements in the optimization of insulation design under typical intermittent cooling modes in this region. This case study was conducted in Chengdu—the two residences selected were identical in design, but the south bedroom of the case study residence had interior insulation (inside insulation on all opaque interior surfaces of a space) retrofitted in the bedroom area in 2017. In August 2019, a comparative on-site measurement was done to investigate the effect of the retrofit work under three typical intermittent cooling patterns in the real-life scenario. The experimental result shows that interior insulation provides a significant improvement in energy-saving and the indoor thermal environment. The average energy savings in daily cooling energy consumption of the south bedroom is 42.09%, with the maximum reaching 48.91%. In the bedroom with interior insulation retrofit, the indoor temperature is closer to the set temperature and the vertical temperature difference is smaller during the cooling period; when the air conditioner is off, the room remains a comfortable temperature for a slightly longer time.

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.

Quantitative investigations on setting parameters of air conditioning (air-supply speed and temperature) in ventilated cooling rooms

2019 ◽  
Vol 30 (1) ◽  
pp. 99-113 ◽  
Author(s):  
Haofu Chen ◽  
Zhuangbo Feng ◽  
Shi-Jie Cao
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Inertial Force ◽  
Index Formula ◽  
Design Parameters ◽  
Dimensionless Number ◽  
Indoor Thermal Environment ◽  
Indoor Thermal Comfort ◽  
Air Supply

Rational and scientific design of indoor air conditioning is essential. In the design of Heating, Ventilating and Air Conditioning system, air-supply speed (ventilation rate) and air-supply temperature are the two most important parameters. In the current study, numerical simulations and experimental measurements were adopted to investigate the influences of ventilation mode, air-supply velocity and air-supply temperature on indoor thermal comfort as well as building energy consumption in summer. Different ventilation modes (up supply and down exit, ceiling supply and ceiling exit) were considered in modelling. Based on the simulation and experimental results, dimensionless index [Formula: see text] is proposed, which represents the ratio of buoyancy weighting force to inertial force. This index can be used as a pre-evaluation index of indoor thermal comfort in preliminary design of air conditioning. It is an indicator to judge the working conditions in cooling-ventilated rooms. When [Formula: see text], the settlement and diffusion effects of indoor airflow reach a good level, which means that the parameter setting could provide a comfortable indoor thermal environment. The dimensionless number [Formula: see text] is a theoretically based tool in the pre-evaluation of indoor thermal environment, providing guidance for setting of ventilation design parameters.

scholarly journals Evaluation of Thermal Behavior of the Skeleton in a Green Building with the Aid of TABS

2019 ◽  
Vol 111 ◽  
pp. 01085
Author(s):  
Hiroshi Muramatsu ◽  
Tatsuo Nobe
Keyword(s):  
Heat Flux ◽  
Thermal Behavior ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Concrete Slab ◽  
Ventilation System ◽  
Office Building ◽  
Air Conditioning System ◽  
Indoor Thermal Environment

In this study, an office building in Japan that incorporates energy-saving features and environmental technologies was investigated. This office building features a green façade, natural ventilation, a concrete slab with no suspended ceilings, and thermo-active building systems. Two airconditioning systems were installed in this building—a ceiling radiation air-conditioning system and a whole floor-blow off air conditioning system. In addition, a natural ventilation system was installed. We surveyed the heat flux of the ceiling surface and indoor thermal environment of this building from 2015 through 2016. The ceiling using the heat storage amount of concrete maintains a constant temperature in the workplace during as well as after office hours. We also performed detailed measurements of the heat flux of the ceiling surface and indoor thermal environment in the summer of 2017. The results showed that the ceiling radiation air-conditioning system provided a stable thermal environment. Furthermore, we report that making use of the thermal behavior of the skeleton improved the operation of the ceiling radiation airconditioning system.

scholarly journals User’s Perspective on Home Energy Management Systems

Environments ◽  
2018 ◽  
Vol 5 (12) ◽  
pp. 126 ◽  
Author(s):  
Ad Straub ◽  
Ellard Volmer
Keyword(s):  
Energy Saving ◽  
Energy Management ◽  
Energy Use ◽  
Electricity Consumption ◽  
Principal Component ◽  
Added Value ◽  
Q Method ◽  
Single Family ◽  
Home Energy Management ◽  
Saving Effect

A Home Energy Management System (HEMS) has no direct and immediate energy-saving effect. It gives insight into the resident’s behaviour regarding energy use. When this is linked to the appropriate feedback, the resident is in a position to change his or her behaviour. This should result in reduced gas and/or electricity consumption. The aim of our study is to contribute to the effective use of HEMSs by identifying types of homeowners in relation to the use of a HEMS. The research methods used were a literature review and the Q-method. A survey using the Q-method was conducted among 39 owners of single-family homes in various Rotterdam neighbourhoods. In order to find shared views among respondents, a principal component analysis (PCA) was performed. Five different types of homeowners could be distinguished: the optimists, the privacy-conscious, the technicians, the sceptics, and the indifferent. Their opinions vary as regards the added value of a HEMS, what characteristics a HEMS should have, how much confidence they have in the energy-saving effect of such systems, and their views on the privacy and safety associated with using a HEMS. The target group classification can be used as input for a way in which local stakeholders, e.g., a municipality, can offer HEMSs that are in line with the wishes of the homeowner.

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