Halil Zafer Alibaba

Prof. Dr. Halil Zafer Alibaba

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Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 February 2016 in Sustainability
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HAHalil Zafer Alibaba
Halil Zafer Alibaba
Heat loss and gain through windows has a very high impact on the thermal comfort of offices. This paper analyzes a standard low energy consumption university office that has a standard envelope. Dynamic thermal simulations with EDSL Tas software, a predicted mean vote (PMV), and a predicted percentage of dissatisfied (PPD) with all local discomfort as stated in ASHRAE, ISO 7730: 2005, EN 15251: 2007 were used for thermal sensation, in order to optimize the best window to external wall proportion in a hot and humid climate that exists in the Famagusta case study. A simulated office building is oriented east to west in order to take advantage of the wind direction. In May 45% (PPD < 6%–0.7% open window), 93% (PPD < 10–0.2 open window), and 97% (PPD < 15%–0.1% open window) thermal comfort scores are obtained when the window to external wall ratio (WWR) is 10%. In October 43% (PPD < 6%–0.7% open window), 86% (PPD < 10–0.2 open window), and 92% (PPD < 15%–0.1% open window) thermal comfort scores are obtained when the WWR is 10%. In September 49% (PPD < 10% full open window) and 51% (PPD < 15%–0.1% open window) thermal comfort scores are obtained when the WWR is 10%.

1 May 2016 in Renewable and Sustainable Energy Reviews
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Journal Article
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Pooya LotfabadiPooya Lotfabadi
Pooya Lotfabadi
HAHalil Zafer Alibaba
Halil Zafer Alibaba
AAAref Arfaei
Aref Arfaei

15 November 2017 in Sustainability
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HAHardi K. Abdullah
Hardi K. Abdullah
HAHalil Zafer Alibaba
Halil Zafer Alibaba
This study presents a retrofit strategy: integrating optimized photovoltaics (PV) in the form of responsive shading devices using a dual-axis solar tracking system. A prototype-based model was fabricated to compare the efficiency of PV in this implementation with the conventional fixed installation. The office building, T1 Empire World in Erbil, was selected as a retrofit case study and for the application of the proposed integration system. In order to assess the effectiveness of the proposed retrofit method, the energy performance of the base case is simulated to be compared later with the energy performance simulations after the integration technique. The amount of generated electricity from the PV surfaces of the integrated shading elements is calculated. The energy simulations were performed using OpenStudio® (NREL, Washington, DC, USA), EnergyPlusTM (NREL, Washington, DC, USA), and Grasshopper/ Ladybug tools in which the essential results were recorded for the baseline reference, as well as the energy performance of the retrofitted building. The results emphasize that the PV-integrated responsive shading devices can maximize the efficiency of PV cells by 36.8% in comparison to the fixed installation. The integrated system can provide approximately 15.39% of the electricity demand for operating the building. This retrofit method has reduced the total site energy consumption by 33.2% compared to the existing building performance. Total electricity end-use of the various utilities was lowered by 33.5%, and the total natural gas end-use of heating demand was reduced by 30.9%. Therefore, the percentage reduction in electricity cooling demand in July and August is 42.7% due to minimizing the heat gain in summer through blocking the sun’s harsh rays from penetrating into interior spaces of the building. In general, this system has multiple benefits, starting with being extremely efficient and viable in generating sustainable alternative energy—which is the global growing concern of today’s sustainable development—providing thermal comfort for occupants, and granting a dynamic appearance to the building when the PV-integrated elements rotate according to the sun’s position in the sky.

8 January 2020 in Sustainability
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HAHardi K. Abdullah
Hardi K. Abdullah
HAHalil Zafer Alibaba
Halil Zafer Alibaba
Natural ventilation through window openings is an inexpensive and effective solution to bring fresh air into internal spaces and improve indoor environmental conditions. This study attempts to address the “indoor air quality–thermal comfort” dilemma of naturally ventilated office buildings in the Mediterranean climate through the effective use of early window design. An experimental method of computational modelling and simulation was applied. The assessments of indoor carbon dioxide (CO2) concentration and adaptive thermal comfort were performed using the British/European standard BS EN 15251:2007. The results indicate that when windows were opened, the first-floor zones were subjected to the highest CO2 levels, especially the north-facing window in the winter and the south-facing window in the summer. For a fully glazed wall, a 10% window opening could provide all the office hours inside category I of CO2 concentration. Such an achievement requires full and quarter window openings in the cases of 10% and 25% window-to-floor ratios (WFR), respectively. The findings of the European adaptive comfort showed that less than 50% of office hours appeared in category III with cross-ventilation. The concluding remarks and recommendations are presented.

8 March 2017 in Sustainability
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MAMohammad Abugrain
Mohammad Abugrain
HAHalil Zafer Alibaba
Halil Zafer Alibaba
Recent global developments in awareness and concerns about environmental problems have led to reconsidering built environment approaches and construction techniques. One of the alternatives is the principle of low/zero-energy buildings. This study investigates the potentials of energy savings in an existing multi-story building in the Mediterranean region in order to achieve net-zero energy as a solution to increasing fossil fuel prices. The Colored building at the Faculty of Architecture, Eastern Mediterranean University, Cyprus was chosen as a target of this study to be investigated and analyzed in order to know how energy efficiency strategies could be applied to the building to reduce annual energy consumption. Since this research objective is to develop a strategy to achieve net-zero energy in existing buildings, case study and problem solving methodologies were applied in this research in order to evaluate the building design in a qualitative manner through observations, in addition to a quantitative method through an energy modeling simulation to achieve desirable results which address the problems. After optimizing the building energy performance, an alternative energy simulation was made of the building in order to make an energy comparison analysis, which leads to reliable conclusions. These methodologies and the strategies used in this research can be applied to similar buildings in order to achieve net-zero energy goals.

13 March 2020 in Sustainability
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RSRefaa Sokkar
Refaa Sokkar
HAHalil Zafer Alibaba
Halil Zafer Alibaba
Atria are added to buildings for their aesthetical, environmental, and economic benefits; the appropriate atrium design can enhance an atrium’s thermal performance and the adjacent spaces’ temperatures. However, inappropriate design decisions cause thermal discomfort and consequently, higher energy consumption. Since the Mediterranean climate has diverse climatic conditions around the year, a central atrium with a top-lit skylight is recommended, but during the summer period it can cause overheating, and the insertion of shading elements shrinks the lighting performance: thus, the atrium skylight design is supposed to improve thermal comfort without affecting the lighting level. This study investigated the improvement of thermal performance in the atrium building by the implementation of a double-skin skylight (DSS) to enhance the atrium thermal performance without shading. The research conducted computer simulations with Environmental Design Solutions (EDSL) Tas software sequentially. The study prepared various design strategies, and different proposals were tested and compared in terms of indoor temperatures, with reference to American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE-55). The implementation of DSS achieved an average of 77% comfort in working hours around the year with different opening percentages according to the outdoor conditions. Moreover, results show that changing the DSS glazing materials did not affect the thermal performance of the atrium.