References of "Hamdy, Mohamed"
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See detailTwenty-year tracking of lighting savings and power density in the residential sector
Attia, Shady ULiege; Hamdy, Mohamed; Ezzeldin, Sherif

in Energy and Buildings (2017), 154

Lighting energy consumption represents a significant percentage of total energy consumption in residential building sector. During the last 20 years, advanced energy-efficient lighting fixtures have been ... [more ▼]

Lighting energy consumption represents a significant percentage of total energy consumption in residential building sector. During the last 20 years, advanced energy-efficient lighting fixtures have been introduced worldwide to conserve the energy consumption in residences. In the Middle East and North Africa (MENA) region, very few studies have been conducted to evaluate the association between the introduced lighting fixtures and the resulted energy savings using valid measurements and verification techniques. This study evaluates the techno-economic impact of replacing new energy efficient lighting in residences in Egypt (a representative MENA region country). A quantitative analysis is applied by tracking the utility bills of 150 residential apartments in Cairo. The average measured power consumption before (1993-1998) and after (2009-2014) installation energy efficient lighting fixtures is analyzed. A building performance simulation model is developed to back the findings. The findings indicate a significant disparity between the estimated savings based on simulation and the real measured savings due to penetration, rebound effect and low quality lamps. Moreover, the findings present an example of quantified benefits of energy efficient lighting, which is very important to inform the decision making of public policy makers, investors and building occupants. [less ▲]

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See detailImpact of Financial Assumptions on the Cost Optimality towards Nearly Zero Energy Buildings- A case study
Hamdy, Mohamed; Siren, Kai; Attia, Shady ULiege

in Energy and Buildings (2017), 153

The energy efficiency challenge in Europe is mainly concerned with existing buildings and the investment scenarios to implement deep renovations. The cost-optimal approach imposed on EU-Member states by ... [more ▼]

The energy efficiency challenge in Europe is mainly concerned with existing buildings and the investment scenarios to implement deep renovations. The cost-optimal approach imposed on EU-Member states by the European Energy Performance of Buildings Directive aims to identify the investment gap and challenges to transform existing buildings into nearly Zero Energy Buildings (nZEBs). The investment gap is function of several volatile financial parameters including discount rate (r), developing of energy price (e), decline rate of technology price (d), as well as nZEB’s incentives like feed-in-tariff (FiT) and investment grant (iG). In this context, the decision making process of individuals or investment institutions is hindered by complexity and uncertainty. In order to assist the decision making process and improve the visibility of financial energy benefits, a novel optimization-based parametric analysis scheme (OptnZEB-I) is developed. The scheme is designed to investigate a large number of economic scenarios (i.e., combinations of financial assumptions) in a short computational time while a holistic optimization approach is adopting for exploring all possible design options including energy conservation measures (ESMs); renewable energy sources (RETs) and mechanical systems (Sys). For demonstration, the scheme is applied to analyse the impact of several financial parameters on the cost-optimal energy performance level (CO-EPL) of a single family house in Finland. In line with the EU-directive, a large number of possible design options (∼3 × 109million) are optimized for 4608 cases of economic scenarios. The results of the address case study show that, in average, the CO-EPL ranges from 90 to 160 [kWh/m2]. The range has most frequent value of 145 kWh/m2. The CO-EPL is significantly sensitive to the e, f, then i, respectively. Less sensitivity is found to the other financial parameters. The robustness of the optimization results are verified by solving the addressed design problem by using four different optimization algorithms (i.e., pattern search, interior-point, simulated annealing and genetic algorithms). [less ▲]

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See detailModelling, Design, and Optimisation of Net-Zero Energy Buildings
Attia, Shady ULiege; Hamdy, Mohamed; Carlucci, Salvatore et al

in Athienitis, Andreas; O’Brien (Eds.) Building Performance Optimisation of Net Zero-Energy Buildings (2015)

Automated mathematical building performance optimisation (BPO) paired with building performance simulation (BPS) is a promising solution to use as a means to evaluating many different design options and ... [more ▼]

Automated mathematical building performance optimisation (BPO) paired with building performance simulation (BPS) is a promising solution to use as a means to evaluating many different design options and obtain the optimal or near optimal for a given objective or combination of objectives (e.g., lowest life-cycle cost, lowest capital cost, highest thermal comfort) while achieving fixed objectives (e.g., net zero-energy) (Wetter 2001; Charron and Athienitis 2006; Christensen and Anderson 2006; Brown, Glicksman et al. 2010; Bucking, Athienitis et al. 2010 ). Traditionally, buildings are designed based on heuristic rules separating the design process into early and late design stages with two different discipline specialisations mainly architecture and engineering. By employing optimisation techniques building designers can cross those barriers between disciplines and address the design process as one continuous stage. Optimisation can allow that by addressing all building design parameters, as shown in Figure 4.1, in a holistic approach allowing the optimisation of geometry, envelope, comfort, systems and renewable. The previously often ill defined design problem would under this perspective be defined as a problem with explicit multi-objective criteria. This will push fully integrated net zero-energy building (Net-ZEB) designs where the builder designers can act to influence the direction of the optimisation. Despite optimisation’s potential in Net-ZEB buildings, it remains largely a research tool and has yet to emerge in common industry practice. As this section reports, major obstacles to BPO in industry include lack of appropriate tools, lack of resources (time, expertise), and the requirement that the problem be very well defined (e.g., constraints, objective function, finite list of design options). The objective of this section is to document the current state-of-the-art and future research in terms of Net-ZEB optimisation tools in practice and its use for design and operation of buildings for energy, comfort and cost optimisation. [less ▲]

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See detailComputational Optimisation for Zero Energy Buildings Design Interviews results with twenty eight International expert
Attia, Shady ULiege; Hamdy, Mohamed; O’Brien, William et al

in Proceedings of the 13th Conference of International Building Performance Simulation Association (2013, August)

This paper summarizes a study that was undertaken to reveal potential challenges and opportunities for integrating optimisation tools in Net/Nearly Zero Energy Buildings (NZEB) Design. The paper reviews ... [more ▼]

This paper summarizes a study that was undertaken to reveal potential challenges and opportunities for integrating optimisation tools in Net/Nearly Zero Energy Buildings (NZEB) Design. The paper reviews current trends in simulation-based Building Performance Optimisation (BPO) and outlines major criteria for optimisation tools selection and evaluation. This is based on analyzing users’ needs for tools capabilities and requirement specifications. The review is carried out by means of interviews with 28 optimisation experts. The findings are based on an inter-group comparison between experts. The aim is to assess the gaps and needs for integrating BPO tools in NZEB Design. The findings indicate existing limitations including model uncertainty, computation time, difficulty of implementation and steep learning curve. Future directions anticipated or needed for improvement of current tools are presented. [less ▲]

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See detailAssessing gaps and needs for integrating building performance optimization tools in net zero energy buildings design
Attia, Shady ULiege; Hamdy, Mohamed; O’Brien, William et al

in Energy and Buildings (2013), 60

This paper summarizes a study undertaken to reveal potential challenges and opportunities for integrating optimization tools in net zero energy buildings (NZEB) design. The paper reviews current trends in ... [more ▼]

This paper summarizes a study undertaken to reveal potential challenges and opportunities for integrating optimization tools in net zero energy buildings (NZEB) design. The paper reviews current trends in simulation-based building performance optimization (BPO) and outlines major criteria for optimization tools selection and evaluation. This is based on analyzing user's needs for tools capabilities and requirement specifications. The review is carried out by means of a literature review of 165 publications and interviews with 28 optimization experts. The findings are based on an inter-group comparison between experts. The aim is to assess the gaps and needs for integrating BPO tools in NZEB design. The findings indicate a breakthrough in using evolutionary algorithms in solving highly constrained envelope, HVAC and renewable optimization problems. Simple genetic algorithm solved many design and operation problems and allowed measuring the improvement in the optimality of a solution against a base case. Evolutionary algorithms are also easily adapted to enable them to solve a particular optimization problem more effectively. However, existing limitations including model uncertainty, computation time, difficulty of use and steep learning curve. Some future directions anticipated or needed for improvement of current tools are presented. [less ▲]

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See detailTowards strategic use of BPS tools in Egypt
Attia, Shady ULiege; Hamdy, Mohamed; Samaan, Mina et al

in Proceedings of 12th International Building Performance Simulation Association - 2011 (2011, November 14)

This paper provides an overview of the use of building performance simulation (BPS) among the building design professionals in Egypt. To assess the situation and highlight the status and difficulties ... [more ▼]

This paper provides an overview of the use of building performance simulation (BPS) among the building design professionals in Egypt. To assess the situation and highlight the status and difficulties encounter in the usage and the needs for BPS tools, three workshops were held, in July and August 2010 in Cairo. The paper first presents a brief overview of the status of the use of BPS in practice then describes the methods used, including, surveys, interviews, tools testing, brainstorming sessions and discussions. Finally, the study presents recommendations for the process of developing and using performance simulation tools for building design support. [less ▲]

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