scholarly journals Systematic Method for the Energy-Saving Potential Calculation of Air Conditioning Systems via Data Mining. Part II: A Detailed Case Study

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 86
Author(s):  
Rongjiang Ma ◽  
Shen Yang ◽  
Xianlin Wang ◽  
Xi-Cheng Wang ◽  
Ming Shan ◽  
...  
Keyword(s):  
Data Mining ◽  
Energy Saving ◽  
Air Conditioning ◽  
Cost Savings ◽  
Systematic Method ◽  
Efficient Operation ◽  
Energy Saving Potential ◽  
Detailed Case ◽  
Air Conditioning Systems

Increased data monitoring enables the energy-efficient operation of air-conditioning systems via data-mining. The latter is projected to have lesser consumption but more comprehensive diagnosis than traditional methods. Following the companion paper that proposed a systematic method for energy-saving potential calculations via data-mining, this article presents a detailed case study in an ice-storage air-conditioning system by employing the proposed method. Raw data were preprocessed prior to recognizing the constant- and variable-speed devices in the system. Classification and regression tree algorithms were utilized to identify the operating modes of the system. The regression models between the energy-consumption and operating-state parameters of the nine pumps and two chillers were fitted. Furthermore, the constraints pertaining to system operation were summarized. From the results, the particle swarm optimization method was applied to elucidate the benchmark energy cost and the consequent cost savings potential. The cost savings potential for the chiller plant room during the investigation duration of 59 d reached as high as 24.03%. The case study demonstrates the feasibility, effectiveness, and stability of the systematic approach. Further studies can facilitate the development of corresponding control strategies based on the potential analysis results, to investigate better optimization algorithm, and visualize the analysis process.

scholarly journals Systematic Method for the Energy-Saving Potential Calculation of Air-Conditioning Systems via Data Mining. Part I: Methodology

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 81
Author(s):  
Rongjiang Ma ◽  
Shen Yang ◽  
Xianlin Wang ◽  
Xi-Cheng Wang ◽  
Ming Shan ◽  
...  
Keyword(s):  
Data Mining ◽  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Storage System ◽  
Operation Mode ◽  
Systematic Method ◽  
Potential Analysis ◽  
Energy Saving Potential ◽  
Air Conditioning Systems

Air-conditioning systems contribute the most to energy consumption among building equipment. Hence, energy saving for air-conditioning systems would be the essence of reducing building energy consumption. The conventional energy-saving diagnosis method through observation, test, and identification (OTI) has several drawbacks such as time consumption and narrow focus. To overcome these problems, this study proposed a systematic method for energy-saving diagnosis in air-conditioning systems based on data mining. The method mainly includes seven steps: (1) data collection, (2) data preprocessing, (3) recognition of variable-speed equipment, (4) recognition of system operation mode, (5) regression analysis of energy consumption data, (6) constraints analysis of system running, and (7) energy-saving potential analysis. A case study with a complicated air-conditioning system coupled with an ice storage system demonstrated the effectiveness of the proposed method. Compared with the traditional OTI method, the data-mining-based method can provide a more comprehensive analysis of energy-saving potential with less time cost, although it strongly relies on data quality in all steps and lacks flexibility for diagnosing specific equipment for energy-saving potential analysis. The results can deepen the understanding of the operating data characteristics of air-conditioning systems.

Are Apprenticeships Still Relevant in the 21st Century? A Case Study of Changing Youth Training Arrangements in German Banks

ILR Review ◽  
2002 ◽  
Vol 55 (4) ◽  
pp. 667-685 ◽  
Author(s):  
David Finegold ◽  
Karin Wagner
Keyword(s):  
21St Century ◽  
Cost Savings ◽  
New Firms ◽  
Workplace Flexibility ◽  
Transferable Skills ◽  
The Past ◽  
Detailed Case ◽  
The Cost ◽  
Youth Training

The authors present a detailed case study of the evolution of apprenticeships in German banking over the past two decades to analyze why employers continue to be willing to invest in these programs that provide workers with transferable skills. They explain employers' motivation in terms of two “logics.” Some considerations stemming from the logic of consequences, such as recruitment cost savings and enhanced workplace flexibility, encourage retention of the apprenticeship system. On balance, however, the cost calculus that is at the heart of the logic of consequences would, if unopposed, encourage head-hunting for apprentices trained by other firms, eventually undermining the system. The countervailing logic of appropriateness, however, discourages defections from the system by fostering trust among employers, encouraging new firms to participate in the system, supporting the strong reputational effect associated with training, and creating mechanisms with which banks can have a hand in keeping the system efficient.

scholarly journals Energy saving potential of occupancy sensors in intermittent-use space types.

2021 ◽  
Author(s):  
◽  
Georgia Alexander
Keyword(s):  
Time Delay ◽  
Energy Saving ◽  
Energy Use ◽  
Energy Savings ◽  
Cost Savings ◽  
Sensor Technology ◽  
Building Industry ◽  
User Survey ◽  
User Perceptions ◽  
Energy Saving Potential

<p>For decades, studies have been suggesting the idea of occupancy sensors in intermittent use spaces for energy savings. This work investigates the potential energy savings of occupancy sensors in hallways, stairwells, seminar rooms and lavatories of an education building. Lighting is one of the largest consumers of energy in the building industry and these space types are often fully illuminated for long periods of vacancy. Lighting is for the user, not the building. Discussions centre around light use habits, energy saving behaviours and sensor technology such as time delay and daylight sensors. The experiment uses wireless light sensors and PIR sensors to measure light energy use and occupant use of 20 intermittent use spaces. A user survey was planned to run alongside the experiment to investigate user perceptions of changes in lighting but was discontinued due to unresolved software issues. Results of the experiment encouraged the use of occupancy sensors in intermittent use spaces. Lavatories attained highest energy saving potential 54%, seminar rooms highest annual cost savings per fitting $15.47 and highest annual energy savings 482kWh and hallways calculated the quickest payback of 8.6 years. Hallways, stairwells, seminar rooms and lavatories all offer potential for energy savings, supporting the theoretical ideas and success of occupancy sensors in intermittent use spaces.</p>

scholarly journals CASE STUDY OF ENERGY CONSERVATION IN INDUSTRY BY APPLICATION OF LEAN TOOLS

2021 ◽  
Vol 5 (12) ◽  
Author(s):  
N.Sujith Prasanna ◽  
Dr.J.Nagesh Kumar
Keyword(s):  
Energy Conservation ◽  
Energy Saving ◽  
Energy Cost ◽  
Energy Use ◽  
Energy Savings ◽  
Sustainable Manufacturing ◽  
Integrated Approach ◽  
Energy Saving Potential ◽  
Lean Tools

Energy cost is significant in many of the manufacturing activities. The efficiency of energy use is quiet low as there are substantial visible and hidden losses. Visible losses can be easily identified and corrective action can be taken. However hidden and indirect losses form a sizeable portion of the losses. Identifying these losses is not easy and requires an integrated approach which includes thorough study of process, operations and their interactions with energy use. Industries across sectors have implemented lean management principles which target various wastes occurring in the plant. This paper discusses case studies which highlight the exploitation of lean tools as a means for unearthing hidden energy saving potential that often go unnoticed. In addition to the energy savings which results in improved profits and competitiveness, the approach also aids the industry to pursue a path of sustainable manufacturing.

Air Conditioning System Water Quality and Equipment Condition Investigation and Analysis of Energy Saving Measures

2012 ◽  
Vol 516-517 ◽  
pp. 1224-1228
Author(s):  
Na Liang ◽  
Rui Li
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Water System ◽  
Building Energy ◽  
Development Trend ◽  
Air Conditioning System ◽  
Effective Utilization ◽  
Energy Saving Potential ◽  
Central Air Conditioning ◽  
Points Of View

Due to energy reserves reduces gradually and uneven distribution, all countries pay more and more attention to energy saving and improve the effective utilization of energy, China also attaches great important to this. Energy saving of buildings is a necessary development trend. Air conditioning system as a large important part of building energy consumption has a huge energy-saving potential. This article mainly introduced the related strategies of energy saving in central air conditioning water system from the following three points of view: the water treatment, the cooling tower, and the variable frequency pump.

STANDARD ASSESSMENT FOR ENERGY SAVING STRATEGIES OF INDUSTRIAL AIR-CONDITIONING SYSTEMS

2021 ◽  
Author(s):  
Jéssica Duarte ◽  
Lara Werncke Vieira ◽  
Rafael Zanardo ◽  
Augusto Delavald Marques ◽  
Paulo Smith Schneider
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Standard Assessment ◽  
Air Conditioning Systems
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