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Historic building restoration and renovation requires sensitivity to the cultural heritage, historic value, and sustainability (i.e., building physics, energy efficiency, and comfort) goals of the project. Energy-efficient ventilation such as demand-controlled ventilation and heat recovery ventilation can contribute to the aforementioned goals, if ventilation concepts and airflow distribution are planned and realized in a minimally invasive way. Compared to new buildings, the building physics of historic buildings are more complicated in terms of hygrothermal performance. In particular, if internal insulation is applied, dehumidification is needed for robust and risk-free future use, while maintaining the building’s cultural value. As each ventilation system has to be chosen and adapted individually to the specific building, the selection of the appropriate system type is not an easy task. For this reason, there is a need for a scientifically valid, systematic approach to pair appropriate ventilation system and airflow distribution solutions with historical buildings. This paper provides an overview of the interrelationships between heritage conservation and the need for ventilation in energy-efficient buildings, regarding building physics and indoor environmental quality. Furthermore, a systematic approach based on assessment criteria in terms of heritage significance of the building, building physics (hygrothermal performance), and building services (energy efficiency, indoor air quality, and comfort rating) according to the standard EN 16883:2017 are applied.

Isıl konfor, insanın yapısı, yaşı, cinsiyeti gibi kişisel parametrelerin yanı sıra çevresel parametrelere de bağlıdır. HVAC sistemlerinin çalışma şekli ve dış hava sıcaklıkları ısıl konfor için önemli parametrelerdir. Fanger deneysel çalışmalar sonucu “tahmini ortalama oy (PMV)” olarak adlandırılan bir gösterge oluşturmuş ve PMV=0’ı konfor için en iyi değer olarak belirlemiştir. Bu çalışmada, farklı iklim bölgelerinden dört il seçilerek, her bir il için ısıl konfor sıcaklıkları belirlenmiş ve bu ısıl konfor sıcaklıklarındaki enerji performansları değerlendirilmiştir. Isıtma ve soğutma sistemi için kişisel kontrole izin verilmeyen tam mekanik kontrollü sistem seçilmiş, kesikli ve sürekli rejim için hesaplamalar yapılmıştır. Çalışmada, konfor koşullarının PMV=0 olması durumunda enerji tüketimleri incelenerek iller arasındaki ısıl konfor memnuniyeti ve enerji tüketiminindeki farklılıklar saptanmaya çalışılmıştır. PMV değerlerinin istatistiksel analizinde, İzmir ili için kesikli rejimde çalışmanın sürekli rejime göre daha iyi olmasına rağmen İstanbul için sürekli rejimde konfor koşulları açısından daha iyi sonuçlar alınmıştır. Tüm illerde sürekli rejim uygulandığında birim enerji tüketiminde artış olduğu belirlenmiştir. Sürekli rejim, kesikli rejime göre ısıtma enerji tüketiminde % 4,5-6,2, soğutma enerji tüketiminde ise % 9,1-23,2 daha yüksektir.

Building dynamic simulation tools, traditionally used to study the hygrothermal performance of new buildings during the preliminary design steps, have been recently adopted also in historical buildings, as a tool to investigate possible strategies for their conservation and the suitability of energy retrofit scenarios, according to the boundary conditions. However, designers often face with the lack of reliable thermophysical input data for various envelope components as well as with some intrinsic limitations in the simulation models, especially to describe the geometric features and peculiarities of the heritage buildings. This paper attempts to bridge this knowledge gap, providing critical factors and possible solutions to support hygrothermal simulations of historical buildings. The information collected in the present work could be used by researchers, specialists and policy-makers involved in the conservation of building's heritage, who need to address a detailed study of the hygrothermal performance of historical buildings thorugh dynamic simulation tools.

Mosques are sanctuary places for Muslims where they can perform their religious activities and also can communicate with each other. On the other hand, historical mosques may contain artworks which have cultural heritage values. These mosques originally have not any Heating, Ventilating and Air-Conditioning systems. For this reason, obtaining thermal comfort becomes a significant issue. In this study, a systematic approach on monitoring and evaluating thermal comfort of historical mosques were developed. As a case study, The Ulu Mosque, Manisa/Turkey was monitored from 2015 to 2018, and thermal comfort evaluation of the mosque was conducted during prayer times based on the method provided by ISO 7730. A dynamic Building Energy Performance Software, DesignBuilder, was used to model the mosque, and the model was calibrated by using hourly indoor temperature data. The calibrated model was then used to evaluate existing conditions of the mosque and develop retrofitting scenarios in order to increase thermal comfort of prayers. Thirteen different scenarios were proposed to improve thermal comfort of prayers during worship periods. The results were evaluated according to EN 16883 for conservation of cultural heritage of the mosque. Electrical radiator heating with intermittent operating schedules was obtained as the best scenario to protect cultural heritage via artworks, while decreasing disssatisfaction level of the prayers from 45% to 10% in winter months. Additionally, intermittent operation saved 46.9% of energy compared to continuous operating schedule.

Increasing thermal comfort and reducing energy consumption are two main objectives of advanced HVAC control systems. In this study, a thermal comfort driven control (PTC-DC) algorithm was developed to improve HVAC control systems with no need of retrofitting HVAC system components. A case building located in Izmir Institute of Technology Campus-Izmir-Turkey was selected to test the developed system. First, wireless sensors were installed to the building and a mobile application was developed to monitor/collect temperature, relative humidity and thermal comfort data of an occupant. Then, the PTC-DC algorithm was developed to meet the highest occupant thermal comfort as well as saving energy. The prototypes of the controller were tested on the case building from July 3rd, 2017 to November 1st, 2018 and compared with a conventional PID controller. The results showed that the developed control algorithm and conventional controller satisfy neutral thermal comfort for 92 % and 6 % of total measurement days, respectively. From energy consumption point of view, the PTC-DC decreased energy consumption by 13.2 % compared to the conventional controller. Consequently, the PTC-DC differs from other works in the literature that the prototype of PTC-DC can be easily deployed in real environments. Moreover, the PTC-DC is low-cost and user-friendly.

The agricultural sector, which is highly dependent on water, is urged to build on improved water management practices and explore available options to match supply and demand because of the water scarcity risks and a sustainable and productive agri-food chain. Geothermal water is an energy source used to generate electricity and/or heat. After harnessing its energy, the remaining water can be used as a water source for irrigation following treatment because of its high ionic content. Geothermal fields are mostly located in rural areas where agricultural activities exist. This would be a good match to decrease the transportation cost of irrigation water. The energy demand of the desalination process for agriculture is higher, requiring additional post-treatment processes. Fossil fuels to fulfill the energy requirements are becoming expensive, and greenhouse gas emissions are harmful to the environment. Thus, efforts should be directed towards integrating renewable energy resources into desalination process. This work focuses on presenting a comprehensive review of geothermal water desalination which is powered by renewable energy and provides specific cases from Turkey and Poland. Furthermore, possible new generation renewable energy systems in desalination are introduced, considering their potential application in the desalination of geothermal water for agricultural irrigation., TUBITAK-NCBR [118Y490-POLTUR3/Geo4Food/4/2019]; Presidency of the Turkish Abroad and Associated Communities (YTB), This study was financed by an international research project funded by TUBITAK-NCBR (Project No: 118Y490-POLTUR3/Geo4Food/4/2019). We are very thankful to Izmir Geothermal Inc., Izmir, for enabling us to mount our mini-pilot system in their sector. Y.A. Jarma would like to thank the Presidency of the Turkish Abroad and Associated Communities (YTB) for a Ph.D. scholarship.

9th Mediterranean Conference of HVAC: Historical Buildings Retrofit in the Mediterranean Area, Climamed 2017; Matera; Italy; 12 May 2017 through 13 May 2017, Mosques 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.

Conservation of library collections requires an interdisciplinary approach. Dealing with the agents of deterioration via curative and preventive conservation methods has become a significant goal with new standards and norms in recent years. Preventive conservation aims indirect physical interventions such as climate control, good housekeeping and pest management. The aim of this study is to assess the degradation potential of indoor climate on valuable manuscripts that date back to 12th century, in a historic library in Tire-Izmir, Turkey. Through the study, first the library, namely Necip Pasa Library was continuously monitored by measurements of thermo-hygrometric parameters for one year. Then, the measured data were evaluated for the risk assessment based on the control classes of ASHRAE Chapter 21 to evaluate the mechanical, chemical and biological degradation risks. Finally, the conservation-oriented measures were proposed in order to keep the manuscripts under the better conditions. Results suggest that introducing a heating, ventilation and air-conditioning system to the building should be considered as the last option since natural hygrothermal behavior of the library gives reasonably sufficient evidences to prevent the manuscripts from degradations to some extent. Therefore, passive solutions should be given higher priorities not to disturb environmental past of the historic library.

Human beings have been benefiting from geothermal energy for different uses since the dawn of civilization in many parts of the world. One of the earliest uses of geothermal energy was for heating and it was used extensively by Romans in Turkey. The Aegean region is favored with a large number of thermal springs known since ancient times. However, it was in the twentieth century that geothermal energy was first used on a large scale for direct use applications and electricity generation. The country’s installed heat capacity is 3322.3 MWt for direct use and 1347 MWe for power production. Also, many drilled wells to extract oil or natural gas were abandoned for various reasons in the southeast of Turkey. Some of the oil fields have heat content that can be used for geothermal energy. Some even have hot fluid in the reservoir. This paper presents an investigation into how to use geothermal energy in abandoned oil and natural gas wells. Methods used to generate geothermal energy from abandoned oil fields other than conventional geothermal energy production are examined. Downhole heat exchangers can be used to extract heat without producing geothermal fluid which decrease gas emissions to the atmosphere and energy need for reinjection, from the abandoned oil wells to generate electricity or direct use applications. Using this method, it is possible to use abandoned wells in southeastern Turkey where this energy improves the economy of the region.

Downhole heat exchanger is a device to extract heat from geothermal fluid. While it is widely used for heating purposes, its use for power generation has not been reported. The aim of this study is to examine the feasibility of power generation from a 2500 m deep existing geothermal well with high temperature gradient and insufficient flowrate by using a downhole heat exchanger. For this purpose, a thermodynamic and an economic evaluation model are developed by the use of Engineering Equation Solver software. Additionally, the parametric studies have been carried out to identify the effects of insulation, geothermal well conditions, geometry of downhole heat exchanger, mass flowrate and type of working fluids on the performance of downhole heat exchanger system. Consequently, work output of the best alternative is computed as 2511 kWe with 64 kg/s mass flowrate of R-134a for 2500 m-deep downhole heat exchanger having inner pipe diameter of 0.127 m. Electricity generation cost and simple payback time are calculated as 46 $/MWh and 2.25 years, respectively. The obtained results showed that the downhole heat exchanger system can be a feasible alternative for wells with very low geothermal flowrate to generate power.

7th International Istanbul Smart Grids and Cities Congress and Fair (ICSG); APR 25-26, 2019; Istanbul, Turkey, Fifty-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.

In this paper, a new trigeneration system is proposed to decrease atmospheric carbon dioxide emission and produce methanol, hydrogen, and power. The system is composed of an organic Rankine cycle, a direct methanol fuel cell, a carbon capture unit, a proton exchange membrane electrolyzer, and a methanol synthesis unit. A flue gas stream with a defined composition, solar energy, and the atmospheric air are the system's inlets. In the design step, special attention is paid to heat and mass integration between different components so that its waste can be lowered as much as possible. Then, mass balance law, energy conservation principle, exergy relations, and auxiliary equations are applied for each subsystem to investigate the system's thermodynamic performance. Also, the effect of changing operating parameters on the performance of each subsystem is studied. The obtained results show that the proposed system has the energy and exergy efficiencies of 66.84% and 55.10%, respectively. Furthermore, 94% of the total exergy destruction rate belongs to the water electrolyzer, while the contribution of the organic Rankine cycle is negligible. The performance of the methanol synthesis reactor depends strongly on its inlet temperature. Maximum equilibrium methanol concentration and carbon dioxide conversion are achieved at the inlet temperature of 210 °C. The parametric studies reveal that there is an optimum fuel cell current density in which its produced power density is maximized.

Libraries 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 Pasa 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.

Buildings account for 40% of total energy consumption in the European Union, yet at the same time they have considerable energy saving potentials. Historic buildings should be treated different from contemporary ones when it comes to energy improvements. The specifications which underline historical, sociocultural and architectural values require certain care during realization of energy saving implementations to sustain these values. The purpose of this study is to demonstrate how the energy efficient retrofitting in historic buildings should be managed in a transdisciplinary approach with a case study conducted on the historic building in ̄zmir - Turkey. A detailed building energy simulation tool was used to determine the impacts of energy efficient retrofits. The actual energy consumption of case building was based on the utility bills regarding electricity and heating fuel consumption. Building energy simulation tool was calibrated by comparing the measured and simulated indoor air temperatures and total energy consumptions. The inappropriate retrofits, which contradict to the cultural heritage values, were eliminated with a transdisciplinary approach. Later appropriate retrofits were gathered into three packages to evaluate their effects on the energy consumption. The results show that energy saving of more than 34% can be obtained without damaging the heritage values., Swedish Energy Agency within the national R&D program for energy efficiency in historic buildings

This 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., Scientific and Technological Research Council of Turkey (TUBITAK -- 109M450)

9th Mediterranean Conference of HVAC: Historical Buildings Retrofit in the Mediterranean Area, Climamed 2017; Matera; Italy; 12 May 2017 through 13 May 2017, The 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.

The paper presents the design and the implementation of different advanced control strategies that are applied to a nonlinearmodel of a thermal unit. A data-driven grey-box identification approach provided the physically-meaningful nonlinear continuous-time model, which represents the benchmark exploited in this work. The control problem of this thermal unit is important, since it constitutes the key element of passive air conditioning systems. The advanced control schemes analysed in this paper are used to regulate the outflow air temperature of the thermal unit by exploiting the inflow air speed, whilst the inflow air temperature is considered as an external disturbance. The reliability and robustness issues of the suggested control methodologies are verified with a Monte Carlo (MC) analysis for simulating modelling uncertainty, disturbance and measurement errors. The achieved results serve to demonstrate the effectiveness and the viable application of the suggested control solutions to air conditioning systems. The benchmark model represents one of the key issues of this study, which is exploited for benchmarking different model-based and data-driven advanced control methodologies through extensive simulations. Moreover, this work highlights the main features of the proposed control schemes, while providing practitioners and heating, ventilating and air conditioning engineers with tools to design robust control strategies for air conditioning systems., University of Ferrara

Human 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 Ti range of 21–23 °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.

Most historic library buildings house valuable paper-based collections that are kept in unconditioned environments. This vulnerable cultural heritage is expected to be highly affected by climate change in the future. In this study, indoor microclimate of an unconditioned historic library, Necip Pasa Library (Izmir, Turkey) is analysed for existing conditions and future climate data. The measured and predicted indoor microclimate data from 'present' till 2080s are used to determine possible chemical degredation risk on library collection and human comfort. Comparison of periodic results of future climate data indicates an increase in temperature that could cause both an increase in chemical degredation risk on the library collection and a decline in thermal comfort conditions. Mitigation of climate change effects on library collection and human comfort requires taking some actions such as adding light and adaptive mechanical solutions.

The paper presents the design and the implementation of different advanced control strategies that are applied to a nonlinear model of a thermal unit. A data–driven grey–box identification approach provided the physically meaningful nonlinear continuous–time model, which represents the benchmark exploited in this work. The control problem of this thermal unit is important since it constitutes the key element of passive air conditioning systems. The advanced control schemes analysed in this paper are used to regulate the outflow air temperature of the thermal unit by exploiting the inflow air speed, whilst the inflow air temperature is considered as an external disturbance. The reliability and robustness issues of the suggested control methodologies are verified with a Monte–Carlo analysis for simulating modelling uncertainty, disturbance and measurement errors. The achieved results serve to demonstrate the effectiveness and the viable application the suggested control solutions to air conditioning systems. The benchmark model represents one of the key issues of this study, which is exploited for benchmarking different model–based and data–driven advanced control methodologies through extensive simulations. Moreover, this work highlights the main features of the proposed control schemes, while providing practitioners and heating, ventilating and air conditioning engineers with tools to design robust control strategies for air conditioning systems.

13th European Workshop on Advanced Control and Diagnosis, ACD 2016; Hautes Etrudes d'Ingenieur (HEI)Lille; France; 17 November 2016 through 18 November 2016, This paper presents the design of different control strategies applied to a heating element nonlinear model. The description of this heating element was obtained exploiting a data-driven and physically meaningful nonlinear continuous-time model, which represents a test-bed used in passive air conditioning for sustainable housing applications. This model has low complexity while achieving high simulation performance. The physical meaningfulness of the model provides an enhanced insight into the performance and functionality of the system. In return, this information can be used during the system simulation and improved model- based and data-driven control designs for tight temperature regulation. The main purpose of this study is thus to give several examples of viable and practical designs of control schemes with application to this heating element model. Moreover, extensive simulations and Monte- Carlo analysis are the tools for assessing experimentally the main features of the proposed control schemes, in the presence of modelling and measurement errors. These developed control methods are also compared in order to evaluate advantages and drawbacks of the considered solutions. Finally, the exploited simulation tools can serve to highlight the potential application of the proposed control strategies to real air conditioning systems.

The several parameters affect the heat load of a building; geometry, construction, layout, climate and the users. These parameters are complex and interrelated. Comprehensive models are needed to understand relationships among the parameters that can handle non-linearities. The aim of this study is to predict heat load of existing buildings benefiting from width/length ratio, wall overall heat transfer coefficient, area/volume ratio, total external surface area, total window area/total external surface area ratio by using artificial neural networks and compare the results with a building energy simulation tool called KEP-IYTE-ESS developed by Izmir Institute of Technology. A back propagation neural network algorithm has been preferred and both simulation tools were applied to 148 residential buildings selected from 3 municipalities of Izmir-Turkey. Under the given conditions, a good coherence was observed between artificial neural network and building energy simulation tool results with a mean absolute percentage error of 5.06% and successful prediction rate of 0.977. The advantages of ANN model over the energy simulation software are observed as the simplicity, the speed of calculation and learning from the limited data sets., Scientific and Technological Research Council of Turkey (TUBITAK-109M450)

By considering the energy efficiency legislations among the European Union, Turkey is responsible to provide regulations to comply for the latest European Energy Performance of Buildings Directive 2010/31/EC. New legislation in Turkey requires information about the evaluation of energy performance of existing buildings. This study aimed to determine energy performance of residential buildings in Izmir, regarding significant relationships between their performance and architectural configuration through statistical analysis. The focus was on the heating energy consumption due to Energy Efficiency Law (2007) and Building Energy Performance Regulation (2008), and Standard Assessment Method for Energy Performance of Dwellings (KEP-SDM). This energy performance assessment method was based on Turkish standard TS 825, and European standard EN ISO 13790. It is known that architectural configuration of buildings and design norms have impact on energy performance of buildings. However, emphasis was given on significant values of architectural considerations through certain area-based ratios. The levels of these ratios were matched with the levels of energy consumption. By this, the consideration was to take early-precautions against high energy consumptions in the early design stage and to enhance legislation by adding recommendations of concrete architectural values. These would assist to predict the level of energy performance in the early design phase. Findings would provide feedback information on the residential building stock in İzmir, Turkey., Scientific and Technological Research Council of Turkey (TUBITAK--109M450)

Renewable 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.