scholarly journals Development of guidelines for enhancement of thermal comfort and energy efficiency during winter for Thailand’s senior centers using surveys and computer simulation

2020 ◽  
Vol 19 ◽  
pp. 79-96
Author(s):  
Chorpech Panraluk ◽  
Atch Sreshthaputra

The objective of this study is to develop guidelines for thermal comfort and energy efficiency for senior centers during winter. The study was conducted in Phitsanulok, Thailand and it applied 3 study’s methods; field survey, laboratory study, and simulation in scSTREAM–a CFD program and DOE-2 program; to develop the guidelines. With a temperature set-point at 25.0°C in the existing air-conditioned senior centers, the study shows that occupants feel "Slightly cool". These feeling can be adjusted to "Neutral" by applying natural ventilation and fans to generate air speed of 0.57–0.60 m/s during 8:00 AM–1:00 PM, and by setting the temperature set-point at 26.0°C with air speed of 0.10–0.26 m/s during 1:00 AM–4:00 PM. The guidelines can help reduce energy consumption by 23.0 % and can apply for senior centers.  

Author(s):  
Elise Belleil ◽  
Long Phan ◽  
Cheng-Xian Lin ◽  
Mirko Schäfer ◽  
Johannes Wagner

The solar powered house at the Engineering Center of Florida International University is out of the U.S. Solar Decathlon 2005 competition. A computational simulation using EnergyPlus is conducted to study different ventilation strategies in this solar house model, with consideration of the hot and humid climate in Miami, Florida. Several modes of ventilation including mechanical cooling systems, natural ventilation utilization, and hybrid systems were considered to seek the best possible option for ventilation in such extreme climate. While the need for a mechanical ventilation system is always present, a resort to natural ventilation could significantly reduce energy consumption. As for natural ventilation utilization, a few methods including earth tubes (ET), thermal chimneys (TC), cooling towers (CT), and openings have been simulated and compared with the mechanical cooling system of the original house. However, as the simulation results suggested, relying on only natural ventilation could cause a dramatic impact to the human thermal comfort. Therefore, a coupling strategy between mechanical systems and natural ventilation was extensively investigated in hope for a better solution in terms of both energy consumption and thermal comfort. In fact, the hybrid system has proved to tremendously reduce energy consumption while complying with the minimum requirements for thermal comfort recommended by ASHRAE standards.


2015 ◽  
Vol 8 (1) ◽  
pp. 206-210 ◽  
Author(s):  
Yu Junyang ◽  
Hu Zhigang ◽  
Han Yuanyuan

Current consumption of cloud computing has attracted more and more attention of scholars. The research on Hadoop as a cloud platform and its energy consumption has also received considerable attention from scholars. This paper presents a method to measure the energy consumption of jobs that run on Hadoop, and this method is used to measure the effectiveness of the implementation of periodic tasks on the platform of Hadoop. Combining with the current mainstream of energy estimate formula to conduct further analysis, this paper has reached a conclusion as how to reduce energy consumption of Hadoop by adjusting the split size or using appropriate size of workers (servers). Finally, experiments show the effectiveness of these methods as being energy-saving strategies and verify the feasibility of the methods for the measurement of periodic tasks at the same time.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.


2013 ◽  
Vol 689 ◽  
pp. 250-253 ◽  
Author(s):  
Mohamed M. Mahdy ◽  
Marialena Nikolopoulou

The objective of this research is to study the effect of using different material specifications for the external walls on the cost of the energy consumption for achieving internal thermal comfort. We refer to this as operation running cost, which in turn is compared to initial construction cost for each type of the used external walls. In order to achieve this objective, dynamic thermal simulation were carried out for four different types of external walls – commonly used in Egypt – in two different sets of cooling: natural ventilation and mechanical means. Experiments recommend that using the Egyptian Residential Energy Code (EREC) to achieve inner thermal comfort with the minimum energy consumption (consequently the minimum CO2 emissions) and the minimum running cost as well.


Author(s):  
Mauro Cepeda ◽  
Santiago Morales F. ◽  
Viviana Cabrera

When high thermal comfort and energy efficiency are provided in an academic environment many beneficial effects on student’s comfort, performance, productivity, and health are shown. The research provides a parametric airflow evaluation of a skylight in a ground floor of new educational building assuming a variation of 4 stages with eight scenarios for the admissions office. By means of the bioclimatic analysis, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) indices, the best internal airflow performance for the study area applying natural ventilation is achieved with the air flow optimization. A minimum area of 1.79 m has been established for extraction and movement of the internal flow, both with the natural extraction louvers system measuring 12 inches by 60 inches and the 18 inches by 60 inches, they work properly. However, the 18 inches by 60 inches system has better effectiveness as it has fewer louver units to be placed, is more homogeneous, avoids turbulence and provides better air extraction. In addition, by having fewer louver units distributed along the length of the skylight, it will allow the operation to be more controlled during the operation of the building. The use of 8 louvers of those proportions, with an individual effective area of 0.23 m and a total of 1.84 m was recommended in accordance with the results obtained.


Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1531 ◽  
Author(s):  
Roberto Robledo-Fava ◽  
Mónica C. Hernández-Luna ◽  
Pedro Fernández-de-Córdoba ◽  
Humberto Michinel ◽  
Sonia Zaragoza ◽  
...  

In the present work, we analyze the influence of the designer’s choice of values for the human metabolic index (met) and insulation by clothing (clo) that can be selected within the ISO 7730 for the calculation of the energy demand of buildings. To this aim, we first numerically modeled, using TRNSYS, two buildings in different countries and climatologies. Then, we consistently validated our simulations by predicting indoor temperatures and comparing them with measured data. After that, the energy demand of both buildings was obtained. Subsequently, the variability of the set-point temperature concerning the choice of clo and met, within limits prescribed in ISO 7730, was analyzed using a Monte Carlo method. This variability of the interior comfort conditions has been finally used in the numerical model previously validated, to calculate the changes in the energy demand of the two buildings. Therefore, this work demonstrated that the diversity of possibilities offered by ISO 7730 for the choice of clo and met results, depending on the values chosen by the designer, in significant differences in indoor comfort conditions, leading to non-negligible changes in the calculations of energy consumption, especially in the case of big buildings.


2012 ◽  
Vol 178-181 ◽  
pp. 92-97 ◽  
Author(s):  
Jin Feng Mao ◽  
Yu Liang Huang ◽  
Jun Zhou ◽  
Zhe Li Xing

City highway tunnel ventilation design is one of the key processes in whole tunnel design. The ventilation design has important influence in ventilation sanitation effect, equipment investment, operations energy consumption and operations cost. On the premise of safety and sanitation, if city tunnel adopts natural ventilation, this can reduce energy consumption, construction cost and operations cost. Combining practical conditions of a project, this paper evaluated three kinds of mechanical ventilation, and analyzed contrastively economic efficiency of the natural ventilation and the jet longitudinal ventilation. At last drew the conclusion that the natural ventilation can reduce the total investment by 30% and has obvious energy-saving efficiency, then put forward the pertinent suggestions to the ventilation construction of highway tunnel.


2011 ◽  
Vol 20 (1) ◽  
pp. 101-111 ◽  
Author(s):  
Baizhan Li ◽  
Wei Yu ◽  
Meng Liu ◽  
Nan Li

Yangtze River Valley is situated within the Hot Summer and Cold Winter zone, and residents in this region of China would require HVAC system to alleviate thermal comfort conditions, although this is tempered by the Design Code (DBJ50-071-2007) for energy efficiency. A 1-year survey of about 200 residential homes was carried out in eight cities covering the breadth of the region. The acceptable temperature range for the residents in this area was 16.3—28.1°C and the thermal neutral temperature was found to be 27.6°C in summers and 17.5°C in winters. People in different area can vary in their adaptability and comfortableness. Therefore, there is a need to investigate the national comfort parameter introduced in the Code for Design of Heating and Ventilation and Air Conditioning (GB50019-2003). The results found that if air-conditioning system was set to 27.5°C instead of 26°C as required by GBJ19-87: Design Standard of Heating and Ventilation and Air Conditioning, a 16.5% saving of energy consumption could be achieved. The findings demonstrated the role of natural ventilation in the expansion of the thermal comfort zone for the residents, especially during the summer seasons. A climatic adaptability model has been established by this study to contribute to the passive climatic design strategies for a better economic and energy efficiency of buildings.


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