Design Optimization of Energy Efficient Office Buildings in Tunisia

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Pyeongchan Ihm ◽  
Moncef Krarti
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
High Performance ◽  
Energy Use ◽  
Cost Effective ◽  
Energy Performance ◽  
High Energy ◽  
Office Buildings ◽  
Optimization Approach ◽  
Heating And Cooling

Optimal and cost-effective energy efficiency design and operation options are evaluated for office buildings in Tunisia. In the analysis, several design and operation features are considered including orientation, window location and size, high performance glazing types, wall and roof insulation levels, energy efficient lighting systems, daylighting controls, temperature settings, and energy efficient heating and cooling systems. First, the results of the optimization results from a sequential search technique are compared against those obtained by a more time consuming brute-force optimization approach. Then, the optimal design features for a prototypical office building are determined for selected locations in Tunisia. The optimization results indicate that utilizing daylighting controls, energy efficient lighting fixtures, and low-e double glazing, and roof insulation are required energy efficiency measures to design high energy performance office buildings throughout climatic zones in Tunisia. In particular, it is found that implementing these measures can cost-effectively reduce the annual energy use by 50% compared to the current design practices of office buildings in Tunisia.

scholarly journals ENERGY EFFICIENCY IN RESIDENTIAL BUILDINGS, LESS STRAIGHT FORWARD THEN PRESUMED

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Hugo Hens
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Energy Use ◽  
Low Voltage ◽  
Residential Buildings ◽  
Primary Energy ◽  
Heating And Cooling ◽  
Net Zero ◽  
Energy Conserving ◽  
New Construction

Since the 1990s, the successive EU directives and related national or regional legislations require new construction and retrofits to be as much as possible energy-efficient. Several measures that should stepwise minimize the primary energy use for heating and cooling have become mandated as requirement. However, in reality, related predicted savings are not seen in practice. Two effects are responsible for that. The first one refers to dweller habits, which are more energy-conserving than the calculation tools presume. In fact, while in non-energy-efficient ones, habits on average result in up to a 50% lower end energy use for heating than predicted. That percentage drops to zero or it even turns negative in extremely energy-efficient residences. The second effect refers to problems with low-voltage distribution grids not designed to transport the peaks in electricity whensunny in summer. Through that, a part of converters has to be uncoupled now and then, which means less renewable electricity. This is illustrated by examples that in theory should be net-zero buildings due to the measures applied and the presence of enough photovoltaic cells (PV) on each roof. We can conclude that mandating extreme energy efficiency far beyond the present total optimum value for residential buildings looks questionable as a policy. However, despite that, governments and administrations still seem to require even more extreme measurements regarding energy efficiency.

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.

Evaluation of Cooling, Heating, and Power (CHP) Systems Based on Building Energy-Rating

2007 ◽  
Author(s):  
N. Fumo ◽  
P. J. Mago ◽  
L. M. Chamra
Keyword(s):  
Energy Efficiency ◽  
Economic Analysis ◽  
Energy Efficient ◽  
Energy Use ◽  
Management Practices ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Star ◽  
Star Rating ◽  
Energy Efficient Buildings

Cooling, Heating and Power (CHP) systems are a form of distributed generation that uses internal combustion prime-power engines to generate electricity while recovering heat for other uses. CHP is a promising technology for increasing energy efficiency through the use of distributed electric and thermal energy recovery-delivery systems at or near end-user sites. Although this technology seems to be economically feasible, the evaluation and comparison of CHP systems cannot be restricted to economical considerations only. Standard economic analysis, such as life cycle economic analysis, does not take in consideration all the benefits that can be obtained from this technology. For this reason, several aspects to perform a non-conventional evaluation of CHP systems have to be considered. Among the aspects to be included in a non-conventional evaluation are: power reliability, power quality, environmental quality, energy-efficient buildings, fuel source flexibility, brand and marketing benefits, protection from electric rate hikes, and benefits from promoting energy management practices. Some benefits of these non-economical evaluations can be transferred into an economic evaluation but others give intangible potential to the technology. This paper focus on a non-conventional evaluation based on energy-efficient buildings, which is associated to energy conservation and improvement of the building energy performance rating for government energy programs like Energy Star and Leadership in Energy and Environmental Design (LEED). Results show that the use of CHP systems could improve the Energy Star Rating in more than 50 points. The Energy Star Rating is significant on the LEED Rating as a building can score up to 10 points of the 23 available in the Energy & Atmosphere category on energy efficiency alone. As much as 8 points can be obtained in this category due to the Energy Star rating increment from the use of CHP systems. Clearly the use of CHP systems will help building owners to reach the benefits from these energy programs while improving the overall energy use and energy cost.

scholarly journals Toward efficient energy consumption in middle income housing buildings in Egypt

2020 ◽  
Vol 15 (2) ◽  
pp. 180-189
Author(s):  
Ibrahim Rizk Hegazy
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Energy Use ◽  
Energy Analysis ◽  
Weather Conditions ◽  
Energy Performance ◽  
Middle Income ◽  
Efficient Energy ◽  
Hot Weather ◽  
The Impact

Abstract Current research pays special attention to the application of approaches that promote sustainable design in a built environment and ensure energy efficiency. In this context, the form of housing buildings is an important parameter that has a meaningful impact on the use of energy in housing buildings. Hence, this research attempts to study the impact of the form of housing buildings on energy efficiency taking into account the mid-hot weather conditions in one of the middle-income housing buildings in new communities in Egypt. To achieve the research aim, a comparative analysis is carried out using parametric numerical analysis—DesignBuilder energy analysis—to compare the various hypothetical proposals for different building configurations. The study determines that the efficiency of energy use in buildings depends to a large extent on their forms that will help urban designers and planners to propose the best energy performance in the form of housing buildings in the stage of conceptual design suitable for other environmental, social and economic urban planning issues. These results should be incorporated into the building codes adopted in Egypt’s new cities in order to reach more energy-efficient housing buildings in Egypt.

RE-STORM: REAL-TIME ENERGY EFFICIENT DATA ANALYSIS ADAPTING STORM PLATFORM

2016 ◽  
Vol 78 (10) ◽  
Author(s):  
Rizwan Patan ◽  
Rajasekhara Babu M.
Keyword(s):  
Energy Efficiency ◽  
Big Data ◽  
Response Time ◽  
Energy Efficient ◽  
Data Stream ◽  
High Performance ◽  
High Energy ◽  
Streaming Data ◽  
Stream Computing ◽  
High Energy Efficiency

It is necessary to model an energy efficient and stream optimization towards achieve high energy efficiency for Streaming data without degrading response time in big data stream computing. This paper proposes an Energy Efficient Traffic aware resource scheduling and Re-Streaming Stream Structure to replace a default scheduling strategy of storm is entitled as re-storm. The model described in three parts; First, a mathematical relation among energy consumption, low response time and high traffic streams. Second, various approaches provided for reducing an energy without affecting response time and which provides high performance in overall stream computing in big data. Third, re-storm deployed energy efficient traffic aware scheduling on the storm platform. It allocates worker nodes online by using hot-swapping technique with task utilizing by energy consolidation through graph partitioning. Moreover, re-storm is achieved high energy efficiency, low response time in all types of data arriving speeds.it is suitable for allocation of worker nodes in a storm topology. Experiment results have been demonstrated the comparing existing strategies which are dealing with energy issues without affecting or reducing response time for a different data stream speed levels. Finally, it shows that the re-storm platform achieved high energy efficiency and low response time when compared to all existing approaches.

Office of the Future: Advanced Lighting Control Strategies

2012 ◽  
Author(s):  
Brian James ◽  
Paul Delaney ◽  
Doug Avery
Keyword(s):  
Energy Efficiency ◽  
Energy Use ◽  
Energy Performance ◽  
Lighting Design ◽  
Office Buildings ◽  
Open Area ◽  
Pilot Projects ◽  
Office Space ◽  
The Future ◽  
Lighting Systems

The Office of the Future (OTF) program is a new energy efficiency approach supported by a consortium of some of the nation’s largest and most progressive energy utilities. OTF targets existing multi-tenant commercial office buildings with packages of advanced energy efficiency strategies that can be applied at the tenant level for building owners. The overall goal is to assemble technical guidelines to office renovation projects that specify performance requirements for different attributes of the office (lighting, plug loads, etc.) and whole building that result in 25% and 50% savings better than code. Three pilot projects were conducted: 1. Executive office space 2. Open area office space 3. Office space with five private offices, a conference room, lobby, kitchen, and corridor The executive offices provided an opportunity to measure energy use in a 1,360 square-meters (m2) office and to undertake a relighting project that met the architectural, aesthetic, and functional demands of the space while employing current energy-efficient products and design techniques. The open area office space consisted of 745 m2 of primarily cubicle office space — half of the 12th floor of a federal building in Santa Monica, CA. The project was highly representative of the challenges and complications faced in retrofit projects in everyday office buildings. The office space with private offices involved renovating the lighting and lighting controls in a 147 m2 office space in the 41,156 m2 building, and summarized the performance of the lighting design in accordance with the OTF Technical Guidelines. In addition, this project included details regarding the pre- and post-lighting systems and controls, compares the actual metered power and energy performance of the 2008 Title 24 code baseline, presents the code calculation basis, and reveals some of the complexities associated with this approach. These pilot projects had three primary goals: 1) examine the performance characteristics of highly-controlled lighting systems in a real office environment compared to existing lighting and applicable codes, 2) monitor plug load energy use, and 3) provide measured and technical data back to OTF consortium members to inform the OTF process. The measured results of the open area office space project revealed that a high-performance lighting design with controls delivers savings considerably beyond code-calculated estimates. In fact, results show that during daytime occupied hours, the average site usage is 43% less power than code calculations. The new system reduced the connected load by 56%. Similar results were found for the other two pilot projects.

Design and Performance of the Van Geet Off-Grid Home

2004 ◽  
Vol 126 (2) ◽  
pp. 738-743 ◽  
Author(s):  
C. Dennis Barley ◽  
Paul Torcellini ◽  
Otto Van Geet
Keyword(s):  
Computer Simulation ◽  
Energy Efficient ◽  
Performance Monitoring ◽  
Energy Use ◽  
Energy Savings ◽  
Energy Performance ◽  
Hot Water ◽  
Domestic Water ◽  
Heating And Cooling ◽  
And Performance

The Van Geet home near Denver, Colorado, demonstrates the successful integration of energy conservation measures and renewable energy supply in a beautiful, comfortable, energy-efficient, 295-m23,176-ft2 off-grid home in a cold, sunny climate. Features include a tight envelope, energy-efficient appliances, passive solar heating (direct gain and Trombe wall), natural cooling, solar hot water, and photovoltaics. In addition to describing this house and its performance, this paper describes the recommended design process of (1) setting a goal for energy efficiency at the outset, (2) applying rules of thumb, and (3) using computer simulation to fine-tune the design. Performance monitoring and computer simulation are combined for the best possible analysis of energy performance. In this case, energy savings are estimated as 89% heating and cooling (compared to 95 MEC), 83% electrical, and nearly 100% domestic water heating. The heating and cooling energy use is 8.96kJ/°Cs˙days˙m20.44Btu/°Fs˙days˙ft2.

scholarly journals A STUDY OF THE ENERGY EFFICIENCY RENOVATION ON PUBLIC HOUSING PROJECTS

2012 ◽  
Vol 7 (1) ◽  
pp. 192-212 ◽  
Author(s):  
Qian Chen ◽  
Qian Ma
Keyword(s):  
Energy Efficiency ◽  
Public Housing ◽  
Cost Effective ◽  
Building Energy ◽  
Energy Performance ◽  
High Energy ◽  
Efficiency Measures ◽  
The Government ◽  
Financial Burdens ◽  
Whole Building Energy Simulation

While the energy efficiency of commercial buildings, schools, and private homes has received increasing attention, the energy performance of public housing has long been neglected. The high energy usage and resulting utility costs associated with such subsidized houses have added great financial burdens to the government and tenants. Therefore, improving public housing's energy performance becomes an important task. This paper presents a comparative study that mainly investigates the effectiveness of energy efficiency measures (EEMs) recently implemented in the Columbus Metropolitan Housing Authority's green renovation projects. Whole building energy simulation results show that due to budget constraints, the limited EEMs put into place would only result in a marginal (7.6%) improvement to the renovated building's energy performance prior to renovation. Another 38.5% reduction would be needed, using the performance requirement of the current building energy code as a reference. Based on these findings, this research offers some insights into more cost-effective energy efficiency upgrades that can help reduce public housing's energy consumption and green renovation costs.

scholarly journals Free-Form, High Energy Performance, Transparent Envelope

2010 ◽  
Vol 168-170 ◽  
pp. 1486-1490
Author(s):  
Luis Alonso ◽  
Benito Lauret ◽  
Fernando Alonso
Keyword(s):  
Silica Gel ◽  
Thermal Insulation ◽  
Energy Efficient ◽  
High Performance ◽  
Vacuum Chamber ◽  
Energy Performance ◽  
High Energy ◽  
Free Form ◽  
Form Design ◽  
Envelope Model

This article examines, from the energy viewpoint, a new lightweight, slim, high energy efficient, light-transmitting envelope system, providing for seamless, free-form designs for use in architectural projects. The research was based on envelope components already existing on the market, especially components implemented with granular silica gel insulation, as this is the most effective translucent thermal insulation there is today. The tests run on these materials revealed that there is not one that has all the features required of the new envelope model, although some do have properties that could be exploited to generate this envelope, namely, the vacuum chamber of vacuum insulated panels (VIP), the monolithic aerogel used as insulation in some prototypes, reinforced polyester barriers. By combining these three design components — the high-performance thermal insulation of the vacuum chamber combined with monolithic silica gel insulation, the free-form design potential provided by materials like reinforced polyester and epoxy resins—, we have been able to define and test a new, variable geometry, energy-saving envelope system.

scholarly journals Are LEED-Certified Buildings Energy-Efficient in Practice?

2019 ◽  
Vol 11 (6) ◽  
pp. 1672 ◽  
Author(s):  
Ali Amiri ◽  
Juudit Ottelin ◽  
Jaana Sorvari
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Critical Analysis ◽  
Energy Use ◽  
Green Building ◽  
Energy Performance ◽  
Energy Resources ◽  
Search Result ◽  
Energy Performance Of Buildings ◽  
Energy Aspects

Depletion of natural resources and climate change are undoubtedly the biggest challenges that humankind faces today. Here, buildings have a crucial role since they consume the majority, i.e., 30% to 40% of the total energy resources. Green building certification is one of the solutions to limit the energy use in buildings. In addition, it is seen to indicate a consideration for sustainability aspects in construction. LEED is the most widely used certificate worldwide. However, recently some critics have raised doubts about LEED and whether it actually implies sustainability. Most of the criticism has been targeted to the energy aspects of LEED. Nevertheless, there is no consensus on the usefulness of LEED: is it really beneficial for the environment, and is it worth of the money and time invested on the certification process? In this study a critical analysis of the literature to find an answer to this question is presented. Altogether 44 peer reviewed articles dealing with the abovementioned issue were selected out of 164 search result. Based on the studied material, the different aspects of LEED from the viewpoint of energy-efficiency are discussed. From the 44 reviewed articles, ten articles state that LEED certificate indicates energy efficiency while eight papers end up with an opposite conclusion. The rest of the papers do not take any stand on this matter. The study showed that energy efficiency of LEED-certified buildings is questionable especially at lower levels, i.e., certified. Therefore, it is recommended to modify the Energy and Atmosphere category of LEED in order to improve the actual energy performance of buildings.

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