scholarly journals Understanding the Reasons behind the Energy Performance Gap of an Energy-Efficient Building, through a Probabilistic Approach and On-Site Measurements

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6178
Author(s):  
Pierryves Padey ◽  
Kyriaki Goulouti ◽  
Guy Wagner ◽  
Blaise Périsset ◽  
Sébastien Lasvaux
Keyword(s):  
Energy Efficient ◽  
Probabilistic Approach ◽  
Energy Performance ◽  
High Energy ◽  
Performance Gap ◽  
Post Evaluation ◽  
Energy Efficient Buildings ◽  
Ex Post ◽  
The Difference ◽  
Energy Efficient Building

The performance gap, defined as the difference between the measured and the calculated performance of energy-efficient buildings, has long been identified as a major issue in the building domain. The present study aims to better understand the performance gap in high-energy performance buildings in Switzerland, in an ex-post evaluation. For an energy-efficient building, the measured heating demand, collected through a four-year measurement campaign was compared to the calculated one and the results showed that the latter underestimates the real heating demand by a factor of two. As a way to reduce the performance gap, a probabilistic framework was proposed so that the different uncertainties of the model could be considered. By comparing the mean of the probabilistic heating demand to the measured one, it was shown that the performance gap was between 20–30% for the examined period. Through a sensitivity analysis, the active air flow and the shading factor were identified as the most influential parameters on the uncertainty of the heating demand, meaning that their wrong adjustment, in reality, or in the simulations, would increase the performance gap.

scholarly journals The Performance Gap in Energy-Efficient Office Buildings: How the Occupants Can Help?

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1480 ◽  
Author(s):  
Qadeer Ali ◽  
Muhammad Jamaluddin Thaheem ◽  
Fahim Ullah ◽  
Samad M. E. Sepasgozar
Keyword(s):  
Energy Efficient ◽  
Behavioral Interventions ◽  
Energy Use ◽  
Energy Savings ◽  
Energy Performance ◽  
Office Buildings ◽  
Occupant Behavior ◽  
Energy Usage ◽  
Performance Gap ◽  
Energy Efficient Buildings

Rising demand and limited production of electricity are instrumental in spreading the awareness of cautious energy use, leading to the global demand for energy-efficient buildings. This compels the construction industry to smartly design and effectively construct these buildings to ensure energy performance as per design expectations. However, the research tells a different tale: energy-efficient buildings have performance issues. Among several reasons behind the energy performance gap, occupant behavior is critical. The occupant behavior is dynamic and changes over time under formal and informal influences, but the traditional energy simulation programs assume it as static throughout the occupancy. Effective behavioral interventions can lead to optimized energy use. To find out the energy-saving potential based on simulated modified behavior, this study gathers primary building and occupant data from three energy-efficient office buildings in major cities of Pakistan and categorizes the occupants into high, medium, and low energy consumers. Additionally, agent-based modeling simulates the change in occupant behavior under the direct and indirect interventions over a three-year period. Finally, energy savings are quantified to highlight a 25.4% potential over the simulation period. This is a unique attempt at quantifying the potential impact on energy usage due to behavior modification which will help facility managers to plan and execute necessary interventions and software experts to develop effective tools to model the dynamic usage behavior. This will also help policymakers in devising subtle but effective behavior training strategies to reduce energy usage. Such behavioral retrofitting comes at a much lower cost than the physical or technological retrofit options to achieve the same purpose and this study establishes the foundation for it.

scholarly journals The Discrepancy between As-Built and As-Designed in Energy Efficient Buildings: A Rapid Review

2020 ◽  
Vol 12 (16) ◽  
pp. 6372
Author(s):  
Christine Eon ◽  
Jessica K. Breadsell ◽  
Joshua Byrne ◽  
Gregory M. Morrison
Keyword(s):  
Life Cycle ◽  
Energy Efficient ◽  
Building Energy ◽  
Energy Performance ◽  
Rapid Review ◽  
Building Performance ◽  
Performance Gap ◽  
Energy Efficient Buildings ◽  
Building Life Cycle ◽  
Building Standards

Energy efficient buildings are viewed as one of the solutions to reduce carbon emissions from the built environment. However, studies worldwide indicate that there is a significant gap between building energy targets (as-designed) and the actual measured building energy consumption (as-built). Several underlying causes for the energy performance gap have been identified at all stages of the building life cycle. Focus is generally on the post-occupancy stage of the building life cycle. However, issues relating to the construction and commissioning stages of the building are a major concern, though not usually researched. There is uncertainty on how to address the as-designed versus as-built gap. The objective of this review article is to identify causes for the energy performance gap in buildings in relation to the post-design and pre-occupancy stages and review proposed solutions. The methodology applied in this research is the rapid review, which is a variant of the systematic literature review method. Findings suggest that causes for discrepancies between as-designed and as-built energy performance during the construction and commissioning stages relate to a lack of knowledge and skills, lack of communication between stakeholders and a lack of accountability for building performance post-occupancy. Recommendations to close this gap during this period include better training, improved communication standards, collaboration, energy evaluations based on post-occupancy performance, transparency of building performance, improved testing and verification and reviewed building standards.

Recommended angle of a modular dynamic façade in hot-arid climate: daylighting and energy simulation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Seyedeh Samaneh Golzan ◽  
Mina Pouyanmehr ◽  
Hassan Sadeghi Naeini
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Energy Performance ◽  
Arid Climate ◽  
Visual Comfort ◽  
Building Envelopes ◽  
Content Type ◽  
Optimum Angle ◽  
Energy Efficient Buildings ◽  
Hot Arid Climate

PurposeThe modular dynamic façade (MDF) concept could be an approach in a comfort-centric design through proper integration with energy-efficient buildings. This study focuses on obtaining and/or calculating an efficient angle of the MDF, which would lead to the optimum performance in daylight availability and energy consumption in a single south-faced official space located in the hot-arid climate of Yazd, Iran.Design/methodology/approachThe methodology consists of three fundamental parts: (1) based on previous related studies, a diamond-based dynamic skin façade was applied to a south-faced office building in a hot-arid climate; (2) the daylighting and energy performance of the model were simulated annually; and (3) the data obtained from the simulation were compared to reach the optimum angle of the MDF.FindingsThe results showed that when the angle of the MDF openings was set at 30°, it could decrease energy consumption by 41.32% annually, while daylight simulation pointed that the space experienced the minimum possible glare at this angle. Therefore, the angle of 30° was established as the optimum angle, which could be the basis for future investment in responsive building envelopes.Originality/valueThis angular study simultaneously assesses the daylight availability, visual comfort and energy consumption on a MDF in a hot-arid climate.

scholarly journals BIM and BEM Methodologies Integration in Energy-Efficient Buildings Using Experimental Design

Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 491
Author(s):  
Jorge González ◽  
Carlos Alberto Pereira Soares ◽  
Mohammad Najjar ◽  
Assed N. Haddad
Keyword(s):  
Experimental Design ◽  
Energy Efficient ◽  
Thermal Characteristics ◽  
Energy Performance ◽  
Building Envelope ◽  
Climatic Zones ◽  
Energy Efficient Buildings ◽  
Energy Modelling ◽  
Building Information ◽  
Energetic Performance

Linking Building Information Modelling and Building Energy Modelling methodologies appear as a tool for the energy performance analysis of a dwelling, being able to build the physical model via Autodesk Revit and simulating the energy modeling with its complement Autodesk Insight. A residential two-story house was evaluated in five different locations within distinct climatic zones to reduce its electricity demand. Experimental Design is used as a methodological tool to define the possible arrangement of results emitted via Autodesk Insight that exhibits the minor electric demand, considering three variables: Lighting efficiency, Plug-Load Efficiency, and HVAC systems. The analysis concluded that while the higher the efficiency of lighting and applications, the lower the electric demand. In addition, the type of climate and thermal characteristics of the materials that conform to the building envelope have significant effects on the energetic performance. The adjustment of different energetic measures and its comparison with other climatic zones enable decision-makers to choose the best combination of variables for developing strategies to lower the electric demand towards energy-efficient buildings.

scholarly journals Office Interior: The Influence of Office Environmental Factors towards Task Performance

2018 ◽  
Vol 7 (3.32) ◽  
pp. 116
Author(s):  
Arita Hanim Awang ◽  
Zuraini Denan ◽  
Noor Hanita Abdul Majid
Keyword(s):  
Task Performance ◽  
Energy Efficient ◽  
High Energy ◽  
Office Workers ◽  
Related Field ◽  
Second Home ◽  
Environmental Setting ◽  
Environmental Air ◽  
Energy Efficient Building ◽  
High Energy Consumption

Office environment has become crucial in providing comfort for the workers and in maintaining the sustainability of an office.  Office environmental comfort is significant to office workers life as the office has become their second home. Almost half of the five working days were spend in the office.  Air conditioning and lighting are among the most significant contributors to high energy consumption in office building in Malaysia. In promoting an energy efficient building, consumption of electrical lighting and air condition in office from morning till evening requires an investigation. The aim of the research is to explore the environmental condition of office which occupied by design related field employees. The environmental air condition and lighting preference are among the significant variables tested.  A controlled experiment of a mock-up office with combination of those variables was conducted. The findings indicate that the office workers can still perform their task in extreme conditions which are low level of lighting below 200 lux with highest or lowest temperature between 16 to 32 Degree Celsius, however, the percentage of completion (POC) of the AutoCAD drafting task relatively decreasing. This scenarios show that the designers’ office environmental conditions have significant impact towards task performance. The optimum office environmental setting is needed in order to increase employee’s task performance.  

scholarly journals Power-Efficient Computing: Experiences from the COSA Project

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Daniele Cesini ◽  
Elena Corni ◽  
Antonio Falabella ◽  
Andrea Ferraro ◽  
Lucia Morganti ◽  
...  
Keyword(s):  
Power Systems ◽  
Energy Efficient ◽  
Nuclear Physics ◽  
Energy Performance ◽  
High Energy ◽  
High Ratio ◽  
Scientific Applications ◽  
Computing Systems ◽  
Power Efficient ◽  
Energy Efficient Computing

Energy consumption is today one of the most relevant issues in operating HPC systems for scientific applications. The use of unconventional computing systems is therefore of great interest for several scientific communities looking for a better tradeoff between time-to-solution and energy-to-solution. In this context, the performance assessment of processors with a high ratio of performance per watt is necessary to understand how to realize energy-efficient computing systems for scientific applications, using this class of processors. Computing On SOC Architecture (COSA) is a three-year project (2015–2017) funded by the Scientific Commission V of the Italian Institute for Nuclear Physics (INFN), which aims to investigate the performance and the total cost of ownership offered by computing systems based on commodity low-power Systems on Chip (SoCs) and high energy-efficient systems based on GP-GPUs. In this work, we present the results of the project analyzing the performance of several scientific applications on several GPU- and SoC-based systems. We also describe the methodology we have used to measure energy performance and the tools we have implemented to monitor the power drained by applications while running.

scholarly journals Managing the risk of the energy performance gap in non-domestic buildings

2021 ◽  
pp. 014362442110083
Author(s):  
David Thompson ◽  
Esfand Burman ◽  
Dejan Mumovic ◽  
Mike Davies
Keyword(s):  
Energy Use ◽  
Energy Performance ◽  
Contributing Factors ◽  
Performance Gap ◽  
New Developments ◽  
Energy Efficient Buildings ◽  
The United Kingdom ◽  
Formidable Challenge ◽  
Research Programmes ◽  
Construction Operation

Energy use in buildings accounts for one-third of the overall global energy consumption and total building floor area continues to increase each year as new developments are constructed and delivered. If stringent climate goals are to be met, these buildings will need to consume less energy and emit less carbon. However, design intentions for energy efficient buildings are not always met in practice. This performance gap between calculated and measured energy use in buildings threatens the progress necessary to meet these energy targets. The aim of this paper is to identify the factors that contribute to the performance gap and propose solutions for reducing the gap in practice. A quantitative and qualitative analysis of two research programmes completed in the past few years was utilized for an in-depth look at the performance of around 50 non-domestic buildings in the United Kingdom. While no direct links were found between any one variable and the performance gap, several correlations exist between contributing factors indicating a complex, entangled web of interrelated problems. The multitude of the variables involved presents a formidable challenge in finding practical solutions. However, the results indicate that the combination of the ventilation strategy of a building and the building services control strategy during partial occupancy is a key determinant of the performance gap. A more straightforward procurement approach with clearly delineated targets and responsibilities, along with advanced and seasonal commissioning instituted at the beginning of a project and implemented after building completion can also be very effective in reducing the gap. Finally, mandatory requirements or an appropriate system of incentives for monitoring and disclosure of performance data can help identify many of the underlying issues affecting performance in-use and untangle some of the web of complex issues across the building sector. Awareness of the performance gap and knowledge of the factors contributing to its impact on the building industry is important for all stakeholders involved in the design, construction, operation and occupation of non-domestic buildings. Understanding potential solutions to mitigate these risks may help to reduce the prevalence and magnitude of the performance gap.

Study of EV Composite Power Supply for Energy Saving

2012 ◽  
Vol 578 ◽  
pp. 3-6
Author(s):  
Jin Yu Qu ◽  
Ru Wang ◽  
Ying Chao Zhou
Keyword(s):  
Power Supply ◽  
Energy Efficient ◽  
Energy Performance ◽  
High Energy ◽  
High Energy Density ◽  
Work Efficiency ◽  
Super Capacitor ◽  
Large Current ◽  
Performance Problem ◽  
Efficient Recovery

Composite power supply technology is an efficient way to solve the energy performance problem of EV, it makes battery with high energy density and super capacitor which has the advantage of high power combined with together. Using the super capacitor characteristics of instantaneous large current charge and discharge, when EV in starting, accelerating or climbing, provide the actuating motor for peak current; and when in braking, absorb the generator feedback current, so as to avoid the battery are damaged, prolong its service life, and realizes the braking energy efficient recovery. In this paper according to the characteristics of battery, super capacitor, and bidirectional DC/DC converter, use backward simulation model of electric vehicle to perform drive cycle. The results show that, the work efficiency of battery is enhanced by using the super capacitor, and to make the composite power supply obtain a higher braking energy recycling efficiency.

Research on New Technology of Energy Efficient Buildings and Utilization of Renewable Energy Sources

2011 ◽  
Vol 224 ◽  
pp. 104-108
Author(s):  
Ya Guang Sun
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Energy Efficient ◽  
New Technology ◽  
Renewable Energy Sources ◽  
Building Design ◽  
Energy Sources ◽  
Building Technology ◽  
Energy Efficient Buildings ◽  
Energy Efficient Building

Current social development is pressing for energy efficient buildings. The trend of consistent updating of energy-efficient building technology reflects the importance and urgency of energy efficiency in buildings. Through analysis on the current situation of building development, it can be obtained that the energy efficient buildings as well as utilization of renewable energy sources in buildings will be bound to be one of main topics for discussion in future building design.

Design of A GUI Tool for the Prediction of Building Energy Performance

2010 ◽  
Vol 29-32 ◽  
pp. 2789-2793
Author(s):  
Cheng Wen Yan ◽  
Jian Yao ◽  
Jin Xu
Keyword(s):  
Bp Neural Network ◽  
Energy Efficient ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Building Energy Efficiency ◽  
Building Energy Performance ◽  
Mathematical Equations ◽  
Building Physics ◽  
Energy Efficient Building

In the present study a GUI tool for the prediction of building energy performance based on a three-layered BP neural network and MATLAB was developed. The inputs for this tool are the 18 building envelope parameters. The outputs are building heating, cooling and total energy consumptions and the energy saving rate. Compared with the complicated mathematical equations, this tool provides a very easy and effective method for students to learn the effects of building envelope performance parameters on the building energy performance. Thus, this tool can be used in building physics and building energy efficiency courses for the design of energy efficient building.

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