Architecture / Mimarlık
Permanent URI for this collectionhttps://hdl.handle.net/11147/24
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Article Citation - WoS: 4Citation - Scopus: 4Estimation of Heat Production Rate Using Thermal Data During Exercise in Indoor Environments: a Study of Heat Storage Rate in Male Athletes(Springer, 2024) Balci, Gorkem Aybars; Avci, Ali Berkay; Colakoglu, Muzaffer; Basaran, Tahsin; Balcı, Görkem Aybars; Avcı, Ali Berkay; Çolakoğlu, Muzaffer; Başaran, TahsinThe increasing preference for indoor exercise spaces highlights the relationship between indoor thermal environments and physiological responses, particularly concerning thermal comfort during physical activity. Determining the metabolic heat production rate during exercise is essential for optimizing the thermal comfort, well-being, and performance of individuals engaged in physical activities. This value can be determined during the activity using several methods, including direct calorimetry measurement, indirect calorimetry that uses analysis of respiratory gases, or approximations using collected data such as speed, body mass, and heart rate. The study aimed to calculate the metabolic heat production rate by infrared thermal evaluation (ITE) based on the body's thermal balance approach and compare it with the values determined by indirect calorimetry (IC). Fourteen participants volunteered for the study, using a cycling ergometer in a controlled climatic chamber. After the familiarization sessions, maximal O-2 intake levels (VO2max) were determined through maximal graded exercise tests. Subsequently, constant work rate exercise tests were performed at 60% of VO2max for 20 min. The metabolic heat production rates were calculated by IC and ITE for each athlete individually. Respiratory gases were used to determine IC, while body skin and core temperatures, along with physical environmental data, were applied to calculate ITE using the human body thermal balance approximation of ASHRAE. According to the results, heat storage rates were misleading among the body's heat transfer modes, particularly during the first 8 min of the exercise. ITE showed a moderate level of correlation with IC (r: 0.03-0.86) with a higher level of dispersion relative to the mean (CV%: 12-84%). Therefore, a new equation (ITEnew) for the heat storage rates was proposed using the experimental data from this study. The results showed that ITEnew provided more precise estimations for the entire exercise period (p > 0.05). Correlations between ITEnew and IC values were consistently strong throughout the exercise period (r: 0.62-0.85). It can be suggested that ITEnew values can predict IC during the constant work rate steady-state exercise.Article Citation - WoS: 20Citation - Scopus: 17Optimizing Thermal Comfort in Physical Exercise Spaces: a Study of Spatial and Thermal Factors(Elsevier, 2024) Avcı, Ali Berkay; Balcı, Görkem Aybars; Başaran, TahsinFitness centers have become famous for maintaining a healthy lifestyle. They require different thermal comfort conditions and higher fresh air supply rates than other indoor spaces. However, even well-designed centers may cause discomfort due to factors such as design decisions, ventilation, overheating, and overcrowding. The standards for fitness centers do not consider these specific requirements sufficiently, so this study focuses on understanding the thermal comfort requirements during physical exercise and evaluating spatial and thermal factors affecting the thermal environment around the body. The study investigated the ceiling height, lateral and frontal distances between machines, and vent locations as spatial factors and inlet temperature and air velocity as thermal factors. A thirty-minute moderate-intensity constant work rate exercise test was conducted in a controlled climatic chamber using a cycle ergometer with six healthy male participants. The experiment conditions were simulated in CFD software using the collected data. Once a validated simulation model was provided, computational models for different environmental and spatial scenarios for the five-person cycling class were generated. Using Taguchi L9 (34) orthogonal arrays method, nine spatial scenarios were simulated with three different thermal operations each. Optimal factor levels were determined by using thermal comfort conditions (based on predicted mean vote) around the body's thermal plume. The results showed that a ceiling height of 5 m, lateral and frontal distances of 1 m and 0.5 m between machines, and Type 2 (two inlets mounted on the ceiling) ventilation strategy were optimal for achieving better thermal comfort values in a thermal condition of 18 °C and 0.2 m·s−1. The study found that increasing the ceiling height and using cross-positioned vents that project air vertically from the ceiling improved the comfort conditions significantly. It is expected that these criteria, which were determined, compared with the standards and detailed, will contribute to the production processes of comfortable exercise spaces.Article Citation - WoS: 2Cephe Yönlenmesinin Tarihi Konutların Enerji Kullanımına Etkileri: Güneybatı Anadolu’da Dış Sofalı Konutlar(Yıldız Teknik Üniversitesi, 2022) Timur, Barış Ali; Başaran, Tahsin; İpekoğlu, BaşakCephe yönlenme durumu, yapıların enerji kullanım miktarlarını etkileyen önemli bir tasarım parametresi olarak kabul edilmektedir. Bu parametre özellikle yeni yapı tasarımı alanında, yönlenme optimizasyon kararları geliştirmek üzere birçok araştırmada incelenmiştir. Buna karşılık, tarihi yapıların yönlenmesi ve enerji kullanım miktarları arasındaki ilişkiyi irdeleyen çalışmalar sınırlıdır. Bu çalışmanın amacı, Anadolu coğrafyasında yaygın bir tarihi yapı türü olan dış sofalı konutların Muğla kenti örnek yerleşmesindeki hâkim yönlenme durumları ile enerji kullanım düzeyleri arasında belirgin bir ilişki olup olmadığının araştırılmasıdır. Araştırma yöntemi, DesignBuilder v.5.4.0.21 yazılımında gerçekleştirilmiş olan yapı ısıl modellemesi ve simülasyonudur. Çalışmada, örnek bir tarihi konutun mimari özellikleri kullanılarak oluşturulmuş sanal bir yapı modelinin sofa yönlenme durumu, ana ve ara yönlere göre değiştirilerek ısıl simülasyonları gerçekleştirilmiş ve simülasyonlar sonucu hesaplanan ısıtma ve soğutma enerji ihtiyaçları karşılaştırılmıştır. Simülasyonlar, karşılaştırmalı olarak önce yapı çevresindeki kütle ve peyzaj elemanlarıyla sonra bu elemanlar olmadan iki sonuç seti için gerçekleştirilmiştir. Simülasyonlar sonucunda, örnek yapı türü için en iyi ve en verimsiz yönlenme durumları arasında enerji kullanımı açısından hesaplanan oransal farkın %1,3 ile %2,2 arasında olduğu saptanmıştır. Bu sonuca göre, örnek yapı türü enerji kullanım durumunun çok yüksek oranda yönlenmeden bağımsız olduğu, bu nedenle de örnek yerleşmedeki dış sofalı konutlar için hâkim yönlenme tercihi ile yapı enerji kullanım düzeyleri arasında dikkate değer bir ilişki olmadığı belirlenmiştir.Article Citation - WoS: 30Citation - Scopus: 30Thermal Retrofitting for Sustainable Use of Traditional Dwellings in Mediterranean Climate of Southwestern Anatolia(Elsevier, 2022) Timur, Barış Ali; Başaran, Tahsin; İpekoğlu, BaşakThermal retrofitting implementations are crucial for safeguarding the functional sustainability of historical buildings as they can improve the thermal performance of these buildings while maintaining thermal comfort for their occupants. This study aims to examine the thermal behavior of a common historical building type in Anatolia / Turkey, the traditional houses with exterior hall (sofa), and to determine enhancement potentials of possible thermal interventions. Research method consists of on-site thermal measurements, laboratory analyses on traditional construction materials and transient thermal analyses utilizing simulations on DesignBuilder software. Study cases were selected from both urban and rural sub-settlements. The results demonstrated that the thermal insulation works within floor assemblies, airtightness measures, adding secondary glazing to windows and suggesting transparent circulation corridors provide significant energy improvements. These interventions would save 26.5% of building energy consumption in the urban and 30.4% in the rural sub-settlements when applied together. Furthermore, when the integration of a modern HVAC system, ground-source heat pump is implemented, these improvement rates can be increased to more than 60%. Consequently, it was determined that the cases have significant potentials for thermal enhancements which renders the application of thermal interventions as a capable conservation tool.Article Citation - WoS: 23Citation - Scopus: 30Experimental Investigation of a Decentralized Heat Recovery Ventilation System(Elsevier Ltd., 2020) Pekdoğan, Tuğçe; Tokuç, Ayça; Ezan, Mehmet Akif; Başaran, TahsinIndoor air quality is an important issue for improving and maintaining the indoor environment because it is directly related to people's health and work performance. These days, in many settlements, the applicability of natural ventilation is limited in the face of the decreasing infiltration loads, increased atmospheric pollution, and the climatic conditions. Therefore, the use of mechanical systems that are designed to ensure proper ventilation is becoming widespread. This paper presents full-scale experimental research of a wall-integrated decentralized ventilation system with heat recovery in the laboratory conditions. The heat recovery unit includes a ceramic block for sensible thermal energy storage. Parametric experimental studies were carried out to obtain the temperature distributions and the thermal capacity of the ceramic block during the supply and exhaust modes of working. In order to simulate the winter and summer conditions, two large scale temperature-controlled rooms are built up. The duration of the ventilation period is varied to be 1, 2, 5, 7.5 and 10-min. Experimental measurements indicate that 2 min of operation time shows the best thermal performance in terms of maintaining a comfortable indoor temperature with the least energy consumption. And some shortcomings were observed about the fan and thermal storage limitations. © 2020 Elsevier LtdArticle Citation - WoS: 15Citation - Scopus: 19Associations Between Thermal and Physiological Responses of Human Body During Exercise(MDPI, 2017) Başaran, Tahsin; Zora, Süleyman; Balcı, Görkem Aybars; Çolakoğlu, MuzafferIn this study, thermal behaviours of the athletes were investigated with respect to thermal comfort and exercise intensity. The relationship between an index for analysing thermal comfort (Predicted Mean Vote: PMV) and Rating of Perceived Exertion (RPE) which shows exercise intensity and exhaustion level was evaluated. Eleven moderately trained male athletes (V) over dotO(2max) 54 +/- 9.9 mL.min(-1).kg(-1)) had volunteered for the study (age: 22.2 +/- 3.7 years; body mass: 73.8 +/- 6.9 kg; height: 181 +/- 6.3 cm; Body surface area (BSA): 1.93 +/- 0.1 m(2); body fat: 12.6% +/- 4.2%; (V) over dotO(2max): 54 +/- 9.9 mL.min(-1).kg(-1)). Experiments were carried out by using a cycle ergometer in an air-conditioned test chamber which provided fresh air and had the ability to control the temperature and relative humidity. The study cohort was divided into two groups according to maximal oxygen consumption levels of the participants. Statistical analyses were conducted with the whole study cohort as well as the two separated groups. There was a moderate correlation between PMV and RPE for whole cohort (r: -0.51). When the whole cohort divided as low and high aerobic power groups, an average correlation coefficient at high oxygen consumption cohort decreased to r: -0.21, while the average correlation coefficient at low oxygen consumption cohort increased to r: -0.77. In conclusion, PMV and RPE have a high correlation in less trained participants, but not in the more trained ones. The case may bring to mind that thermal distribution may be better in high aerobic power group in spite of high RPE and thus the relation between PMV and RPE is affected by exercise performance status.Article Citation - WoS: 40Citation - Scopus: 44Experimental and Numerical Investigation of Forced Convection in a Double Skin Façade by Using Nodal Network Approach for Istanbul(Elsevier Ltd., 2019) İnan, Tuğba; Başaran, TahsinIn this study, temperature distribution and heat transfer through the cavity of a double skin façade (DSF) was investigated in the laboratory environment and analyzed numerically by using nodal network approach. The verification of the nodal network method was conducted by using data from the steady-state experiments and the same method was applied for the climate of Istanbul, Turkey under unsteady outside boundary conditions. Furthermore, heat gain and loss values in DSF for January and July were calculated and compared with single skin façade (SSF) application for different directions of the façades. The results were given for a day and a working time period of the office buildings by using monthly average daily climate data. Distinction working hours were more convenient to investigate the energy performance of DSF because of solar radiation effect. Using DSF in all directions, the cooling loads decreased up to 26% comparing to the SSF. DSF system was disadvantageous comparing to the SSF for January. However, it was shown that the heated air in the cavity could be used for preheating process of air in a HVAC system for winter period.Article Citation - WoS: 12Citation - Scopus: 12An Evaluation Methodology Proposal for Building Envelopes Containing Phase Change Materials: the Case of a Flat Roof in Turkey’s Climate Zones(Taylor and Francis Ltd., 2017) Tokuç, Ayça; Yesügey, Sadık Cengiz; Başaran, TahsinPhase change materials (PCMs) can be used to enhance the thermal energy storage capacity of a building element to improve indoor thermal comfort conditions and decrease energy usage, yet these effects need to be carefully analysed to achieve the desired benefits. This paper proposes an evaluation methodology for building envelopes: first, a numerical computational fluid dynamics model is validated by experimental work; then, time-dependent simulations are used to analyse monthly energy requirements and heat flux. A sample flat roof is evaluated in terms of required cooling load with and without PCM in Turkey’s climate zones. Graphical phase change representations and heat flux results were used to evaluate the cooling load reduction in addition to the effects of PCM type and PCM amount and the necessity for night cooling. In conclusion, the methodology is flexible and can be utilized to evaluate the building element for various parameters.Article Citation - WoS: 18Citation - Scopus: 21Experimental and Numerical Investigation of Forced Convection in a Double Skin Façade(MDPI Multidisciplinary Digital Publishing Institute, 2017) İnan, Tuğba; Başaran, Tahsin; Erek, AytunçFlow and heat transfer of the air cavity between two glass façades designed in the box window type of double skin façade (DSF) was evaluated in a test room which was set up for measurements in the laboratory environment and analyzed under different working conditions by using a computational fluid dynamics tool. Using data from the experimental studies, the verification of the numerical studies was conducted and the air flow and heat transfer in the cavity between the two glass façades were examined numerically in detail. The depth to height of the cavity, the aspect ratio, was changed between 0.10 and 0.16, and was studied for three different flow velocities. Reynolds and average Nusselt numbers ranging from 28,000 to 56,500 and 134 to 272, respectively, were calculated and a non-dimensional correlation between Reynolds and Nusselt numbers was constructed to evaluate the heat transfer from the cavity (except inlet and outlet sections) air to the inside environment and it could be used the box window type of DSF applications having relatively short cavities.Article Citation - WoS: 30Citation - Scopus: 34Thermal Performance of Different Exterior Wall Structures Based on Wall Orientation(Elsevier Ltd., 2017) Pekdoğan, Tuğçe; Başaran, TahsinHeat transfer from opaque walls of buildings is very important for energy saving and providing thermal comfort in different climates. In this study, insulation models of opaque walls with different orientations and external, internal and sandwich materials were numerically analyzed in terms of their time-dependent thermal behaviors. The one-dimensional transient heat conduction equation was solved via the implicit finite difference method for summer and winter conditions and northern, southern, eastern and western orientations. Meteorological data for cities in Turkey with different climates, i.e., Ankara, Erzurum, İstanbul and İzmir, were used in these calculations. When the outside boundary conditions were defined by using January and July monthly averages of the daily data; the inside air temperature was assumed to be 20 °C and 24 °C in winter and summer. The results indicated that sandwich wall insulation produced more convenient heat loss and heat gain for each climate and direction. The standard deviations of the heat transfer values for the different directions were larger in summer than in winter because of the solar radiation effect. The numerical calculations for the sandwich wall applications were carried out for different insulation thicknesses namely 0.15 m and 0.25 m, and for an uninsulated wall; the results were also compared with Turkish directive on the thermal insulation of buildings, TS825 taken as a reference condition. Compared with the insulation thickness calculated based on the TS825, the heat loss and gain values could be decreased by up to 65% and 80% for the worst winter and summer conditions.