Energy Systems Engineering / Enerji Sistemleri Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4752
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Article Citation - WoS: 12Citation - Scopus: 13Assessment of Thermal Comfort Preferences in Mediterranean Climate a University Office Building Case(Vinca Inst Nuclear Sci, 2018) Turhan, Cihan; Gökçen Akkurt, Gülden; Gökçen Akkurt, Gülden; Turhan, Cihan; 03.10. Department of Mechanical Engineering; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThis study aims at evaluating the perceived thermal sensation of occupants with respect to thermal comfort standards, ASHRAE 55 and ISO 7730, for office buildings located in Mediterranean climate. A small office building in Izmir Institute of Technology Campus Area, Izmir, Turkey, was chosen as a case building and equipped with measurement devices to assess thermal comfort of occupants with respect to predicted mean vote and actual mean vote. Both objective and subjective measurements were conducted. The former included indoor and outdoor air temperature, mean radiant temperature, relative humidity and air velocity that were used for evaluating the thermal comfort of occupants. Oxygen concentration which can play an additional role in thermal comfort/discomfort, health and productivity of the office occupants, was also measured. Furthermore, occupants were subjected to a survey via a mobile application to obtain subjective measurements to calculate actual mean vote values. Based on objective and subjective measurements, the relationships among the parameters were derived by using simple regression analysis technique while a new combined mean vote correlation was also derived but this time by using multiple linear regression model. Neutral and comfort temperatures were obtained using indoor air temperature and actual mean vote values which were calculated from subjective measurements. The results showed that neutral temperature in the university office building was 20.9 degrees C whilst the comfort temperature range was between 19.4 and 22.4 degrees C for the heating season. By applying new comfort temperatures, energy consumption of the case building located in Mediterranean climate, can be reduced.Conference Object Citation - WoS: 1Citation - Scopus: 3Green Smart Cities: Living Healthily With Every Breath(Institute of Electrical and Electronics Engineers Inc., 2019) Turhan, Cihan; Turhan, Cihan; Atalay, Ali Serdar; Gökçen Akkurt, Gülden; Gökçen Akkurt, Gülden; 03.10. Department of Mechanical Engineering; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyFifty-four percent of the world's population lives in big cities and it is projected to increase to nearly 70% by 2050s. Rapid and dense urbanization leads to smart cities which improve the quality of lives of the citizens. Therefore, development of smart cities is becoming vital. The quality of the citizens is affected by many factors including poor air quality, increased pollutants and microclimates called urban heat islands. The URBAN GreenUP project, initiated in June 2017, is a project funded under the European Union's Horizon 2020 programme. The main objective of the project is the development, application and replication of re-naturing Urban Plans in a number of European cities. In this study, measurement of nature-based solutions for mitigation of urban heat island effect and improvement of air quality for Urban GreenUP project in Izmir, will be introduced.Article Citation - WoS: 15Citation - Scopus: 11The Relation Between Thermal Comfort and Human-Body Exergy Consumption in a Temperate Climate Zone(Elsevier, 2019) Turhan, Cihan; Gökçen Akkurt, Gülden; Gökçen Akkurt, Gülden; Turhan, Cihan; 03.10. Department of Mechanical Engineering; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyHuman body exergy balance calculation method gives minimum human body exergy consumption rates at thermal neutrality (TSV = 0) providing more information on human thermal responses than other methods. The literature is lacking the verification of this method in various climatic zones. The aim of this study is to investigate the relationship between thermal comfort and human body exergy consumption in a temperate climate zone. A small office building in Izmir Institute of Technology campus, Izmir/Turkey, was chosen as a case building and equipped with measurement devices. The occupant was subjected to a survey via a mobile application to obtain his Thermal Sensation Votes. Objective data were collected via sensors and used for predicting occupant thermal comfort and for exergy balance calculations. Under given conditions, the results show that Thermal Sensation Votes are generally zero at a T-i range of 21-23 degrees C and, are mostly lower than Predicted Mean Votes in summer while the opposite is observed in winter. Predicted Mean Votes at minimum Human Body Exergy Consumption rates were on slightly warm side while Thermal Sensation Votes are zero. It means that for given case, the HBexC rate calculation gave a better prediction of the environmental parameters for the best thermal comfort. (C) 2019 Elsevier B.V. All rights reserved.Book Part Citation - Scopus: 2Ventilation Strategies for the Preventive Conservation of Manuscripts in the Necip Paşa Library, Izmir, Turkey(Elsevier, 2018) Coşkun, Turgay; Gökçen Akkurt, Gülden; Şahin, Cem Doğan; Coşkun, Turgay; Gülhan, Özcan; Durmuş Arsan, Zeynep; Durmuş Arsan, Zeynep; Şahin, Cem Doğan; Gökçen Akkurt, Gülden; 02.02. Department of Architecture; 03.10. Department of Mechanical Engineering; 01. Izmir Institute of Technology; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 02. Faculty of ArchitectureLibraries are specific spaces in which the indoor microclimate should meet rigorous requirements such as the thermal comfort of humans and the conservation of books, manuscripts, and cultural property. An inadequate indoor microclimate (mainly temperature, relative humidity, and their fluctuations) in libraries may cause chemical, biological, and mechanical degradations in paper-based collections. In this chapter, the indoor microclimate of the Necip Paşa Library, the historic library located in Tire-Izmir, Turkey, is discussed from the perspective of the preventive conservation of manuscripts. The library, which has no active heating, cooling, and ventilation system, was modeled with the help of a building energy simulation tool, DesignBuilder. The indoor temperature and relative humidity were monitored throughout 1 year and the model was calibrated with respect to these measurements. To reduce the risks of the manuscripts degrading, ventilation strategies were proposed including natural and mechanical control. The results showed that risks of chemical degradation can be diminished to some extent. © 2018 Elsevier Inc. All rights reserved.Conference Object Citation - WoS: 14Citation - Scopus: 16Drying of Olive Leaves in a Geothermal Dryer and Determination of Quality Parameters of Dried Product(Elsevier, 2019) Helvacı, Hüseyin Utku; Menon, Abhay; Helvacı, Hüseyin Utku; Korel, Figen; Gökçen Akkurt, Gülden; Gökçen Akkurt, Gülden; Korel, Figen; 01. Izmir Institute of Technology; 03.08. Department of Food Engineering; 03.06. Department of Energy Systems Engineering; 03. Faculty of EngineeringIn this study, a cabinet type geothermal dryer was designed, operated and tested for drying olive leaves with minimum losses of phenolic content and antioxidant capacity by optimization of drying conditions. Two factors; face centered central composite design was applied and response surface methodology was used to optimize the drying conditions of olive leaves. The results indicate that phenolic content stability were mainly affected by air temperature, whereas antioxidant capacity is affected by both air temperature and velocity (p<0.05). The optimal drying conditions were found to be at 50°C of air temperature and 1 m/s of air velocity for the minimum losses of determined quality parameters, where 88.8% of phenolic content and 95.3% of antioxidant capacity were recovered.Book Part Citation - Scopus: 11Thermodynamic Performance Evaluation of a Geothermal Drying System(Springer Verlag, 2014) Helvacı, Hüseyin Utku; Gökçen Akkurt, Gülden; Helvacı, Hüseyin Utku; Gökçen Akkurt, Gülden; 01. Izmir Institute of Technology; 03.06. Department of Energy Systems Engineering; 03. Faculty of EngineeringRenewable energy sources such as geothermal energy can be used in drying processes as a heat source due to the high energy costs of fossil fuels. In this study, geothermal cabinet type dryer was constructed and situated in Balcova-Narlidere Geothermal Field, Turkey where the clean city water of district heating system is used as an energy source for the dryer. The dryer was tested on site for drying of olive leaves and energy and exergy analyses of the drying process conducted under two cases: Case 1. Exhaust air was rejected to the environment. Case 2. A portion of exhaust air was re-circulated. Energy Utilization Ratio (EUR) was determined as 7.96 for Case 1 and 50.36 for Case 2. The highest rate of exergy destruction occurred in the fan, followed by heat exchanger and the dryer, accounting for 0.2913, 0.05663 and 0.0115 kW, respectively. Exergetic efficiency of the drying chamber was calculated as 89.66 %. Re-circulating the exhaust air decreased the exergy value at the outlet of the dryer from 0.1013 to 0.08104 kW, indicating that re-using the air increases the performance of the dyer.Article Citation - WoS: 7Citation - Scopus: 8Performance Indices of Soft Computing Models To Predict the Heat Load of Buildings in Terms of Architectural Indicators(Yıldız Teknik Üniversitesi, 2017) Turhan, Cihan; Kazanasmaz, Zehra Tuğçe; Gökçen Akkurt, Gülden; Kazanasmaz, Zehra Tuğçe; Turhan, Cihan; 02.02. Department of Architecture; 03.10. Department of Mechanical Engineering; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology; 02. Faculty of ArchitectureThis study estimates the heat load of buildings in Izmir/Turkey by three soft computing (SC) methods; Artificial Neural Networks (ANNs), Fuzzy Logic (FL) and Adaptive Neuro-based Fuzzy Inference System (ANFIS) and compares their prediction indices. Obtaining knowledge about what the heat load of buildings would be in architectural design stage is necessary to forecast the building performance and take precautions against any possible failure. The best accuracy and prediction power of novel soft computing techniques would assist the practical way of this process. For this purpose, four inputs, namely, wall overall heat transfer coefficient, building area/ volume ratio, total external surface area and total window area/total external surface area ratio were employed in each model of this study. The predicted heat load is evaluated comparatively using simulation outputs. The ANN model estimated the heat load of the case apartments with a rate of 97.7% and the MAPE of 5.06%; while these ratios are 98.6% and 3.56% in Mamdani fuzzy inference systems (FL); 99.0% and 2.43% in ANFIS. When these values were compared, it was found that the ANFIS model has become the best learning technique among the others and can be applicable in building energy performance studies.Conference Object Citation - WoS: 6Citation - Scopus: 8The Effect of Spatial Interventions on Historic Buildings' Indoor Climate (case Study: Tire Necip Paşa Library, Izmir-Turkey)(Elsevier Ltd., 2017) Coşkun, Turgay; Gülhan, Özcan; Coşkun, Turgay; Durmuş Arsan, Zeynep; Gökçen Akkurt, Gülden; Gökçen Akkurt, Gülden; Durmuş Arsan, Zeynep; Şahin, Cem Doğan; 02.02. Department of Architecture; 03.10. Department of Mechanical Engineering; 01. Izmir Institute of Technology; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 02. Faculty of ArchitectureThe indoor climate of historic libraries should meet rigorous requirements related to human thermal comfort and conservation of books, manuscripts and cultural proper-ties. Paper based collections in historic libraries can be deteriorated chemically, mechanically and biologically because of inadequate indoor climate conditions. In this paper, Necip Paşa Library, the historic library located in Tire-Izmir, Turkey, was selected as a case study. The chemical, mechanical and biological degradation risks on the manuscripts were evaluated based on the indoor climate parameters measured for one year period. The Library, consisting of a main hall, a manuscript zone and an entrance hall, was modelled via the dynamic simulation software, Design Builder. Calibration of the model was conducted with respect to the measured indoor temperature and relative humidity values. The portico/Revak at the south facade of Library was converted into the entrance hall by wooden framed windows in 1930. To be able to see the effect of that intervention on the indoor climate (correspondingly on degradation risk of the manuscripts), a new model, namely semi-open model, was created and simulated. A remarkable change has not been observed on chemical degradation risk when the results of semi-open and existing library models were compared, while mechanical and biological degradation risks were less in semi-open model.Article Citation - WoS: 7Citation - Scopus: 7The Importance of Internal Heat Gains for Building Cooling Design(Yıldız Teknik Üniversitesi, 2017) Durmuş Arsan, Zeynep; Turhan, Cihan; Durmuş Arsan, Zeynep; Coşkun, Turgay; Turhan, Cihan; Gökçen Akkurt, Gülden; 02.02. Department of Architecture; 03.10. Department of Mechanical Engineering; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology; 02. Faculty of ArchitectureThis paper aims to investigate the effect of internal heat gains on the cooling load of a building. The house occupied by three adult men is selected as the case study for paper. The house is in the third floor of the apartment. The apartment has four flats and it has no insulation around the external walls. The heat dissipation from lighting devices, electrical equipment and the occupants are calculated by using the DesignBuilder v4 Beta release simulation program. The temperature of the house is observed during three weeks by using hobo data loggers and calibration of the measurements is made with respect to weather data file of the flat. Detailed schedule based on time of operation and occupancy is prepared to get more accurate results. Annual energy consumption and cooling load of the house is determined by using the dynamic simulation program.Conference Object Citation - WoS: 21Citation - Scopus: 27Applying Underfloor Heating System for Improvement of Thermal Comfort in Historic Mosques: the Case Study of Salepçioglu Mosque, Izmir, Turkey(Elsevier Ltd., 2017) Bughrara, Khaled S. M.; Durmuş Arsan, Zeynep; Gökçen Akkurt, Gülden; Durmuş Arsan, Zeynep; 02.02. Department of Architecture; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology; 02. Faculty of ArchitectureMosques differ from other types of buildings by having an intermittent operation schedule. Due to five prayer times per day throughout the year, mosques are fully or partially, yet periodically, occupied. This paper examines the potential of using an underfloor heating system for improvement of indoor thermal comfort in a historic mosque, which is naturally ventilated, heated and cooled, based on adaptive thermal comfort method. The selected Salepçioǧlu Mosque, housing valuable wall paintings, was built in 1905 in KemeraltI, Izmir, Turkey. It requires specific attention with its cultural heritage value. Firstly, indoor microclimate of the Mosque was monitored for one-year period of 2014-15. Then, dynamic simulation modelling tool, DesignBuilder v.4.2 was used to create the physical model of the Mosque. The ASHRAE Guideline 14 indices were utilized to calibrate the model, by comparing simulated and measured indoor air temperature to achieve hourly errors within defined ranges. The results of calibrated baseline model indicate that the Mosque does not satisfy acceptable thermal comfort levels for winter months that provided by the adaptive method. Then, the effect of underfloor heating was examined in the second model by the.