Architecture / Mimarlık
Permanent URI for this collectionhttps://hdl.handle.net/11147/24
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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: 1On-Site Measurements of Temperature and Humidity Conditions for the Comparison of Urban and Rural Sub-Spaces of Traditional Settlements: Historical City of Mugla, Turkey(Taylor & Francis, 2023) Timur, Barış Ali; Başaran, Tahsin; İpekoğlu, BaşakOne of the significant processes that ensures realistic determination of the energy needs of historical buildings is case-specific definition of their local microclimatic conditions. Accordingly, the aim of this study is to determine differences for the parameters of temperature and humidity in urban and rural sub-settlements of the historical city, Mugla/Turkey. Study method consists of on-site measurements of these variables in sub-settlements for comparisons. As a result, it was identified urban zone shows heat island characteristics with warmer, drier, and more stable conditions; while rural sub-settlement remains cooler, more humid, and more erratic. In parallel, calculated extents of these differences demonstrate the significance and necessity of on-site measurements and consequential microclimatic zoning of historical cities as conservation/planning tools for responding to the thermal needs of architectural heritage. A key application of these processes would be the establishment of local databases of case-specific weather data to be used in thermal simulation assessments.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: 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: 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.Article Citation - WoS: 30Citation - Scopus: 32Experimental and Numerical Investigation of Natural Convection in a Double Skin Facade(Elsevier Ltd., 2016) İnan, Tuğba; Başaran, Tahsin; Ezan, Mehmet AkifIn this study, airflow and heat transfer in a rectangular cavity that simulates a double skin facade and includes natural convection were examined numerically and experimentally. This cavity separates the exterior space and the thermally controlled interior space. The temperatures of the surfaces that interact with these spaces were determined experimentally, while the other surfaces were regarded as adiabatic. With these temperature values, the parameters of the numerical study were defined. After the validation of the numerical model was completed based on experimental studies in the literature, the results related to flow and heat transfer in the cavity were analyzed. The numerical model provided results that agree with the air temperature values found experimentally in the cavity. Accordingly, in natural convection, with Rayleigh numbers ranging from 8.59 ∗ 109 to 1.41 ∗ 1010 and the effect of buoyancy on the regions close to the surface, the increasing tendency of the average Nusselt number from 142.6 to 168.8 was shown. In addition, a correlation between the Rayleigh and Nusselt numbers for a cavity aspect ratio of 8.64 was constructed to evaluate the heat flux; this correlation was also shown graphically.Article Citation - WoS: 54Citation - Scopus: 63An Experimental and Numerical Investigation on the Use of Phase Change Materials in Building Elements: the Case of a Flat Roof in Istanbul(Elsevier Ltd., 2015) Tokuç, Ayça; Başaran, Tahsin; Yesügey, Sadık CengizThis paper reports on the experimental and numerical analysis of a building element-a flat roof-that incorporates phase change material (PCM) as a layer. First, a planar model of the building element of 50 cm by 50 cm surface area was constructed in laboratory conditions to be used in the experimental work. During the experiment, changes in the thermal balance were investigated by temperature and volumetric flow rate measurements, as well as observation of the phase change interface. Next, the experimental measurements were used to validate a numerical computer fluid dynamics (CFD) model for simulation purposes. The model is one-dimensional and is based on the first law of thermodynamics. Finally, a time-dependent simulation for summer conditions was performed using the climatic data of Istanbul. The thickness of the PCM inside the roof element was investigated accordingly. The simulation data showed the solid/liquid phase of PCM over time. Monthly graphs were drawn for ease of comparison of the use of PCM with thicknesses varying between 1 and 5 cm. Consequently, a PCM thickness of 2 cm was found to be suitable for use in flat roofs in Istanbul.Article Citation - WoS: 17Citation - Scopus: 19Experimental Investigation of the Pressure Loss Through a Double Skin Facade by Using Perforated Plates(Elsevier Ltd., 2016) Başaran, Tahsin; İnan, TuğbaThe aim of this study is to analyze the effect of perforated elements on pressure drop in a double skin facade cavity. This cavity separates the exterior and interior space as thermally controllable. The temperatures of the surfaces facing cavity with exterior and interior spaces have been determined experimentally under different airflow conditions. Two distinct perforated plates having different circular hole dimensions are positioned in the double skin facade cavity in order to create a pressure drop in the cavity. Pressure drops and temperature distributions in the cavity have been examined based on experimental measurements. The results show the surface and air temperature distributions in the cavity, the pressure drops under three different air flow rates and two different perforated plates. The dependence of the dimensionless pressure drop coefficient, Euler versus Reynolds numbers is investigated experimentally for different geometric characteristic of the perforated plates. So, Eu numbers independency after 30,000 of the Re numbers approximately is shown graphically. Evaluating the pressure loss in the DSF's cavity under usage of different type of pressure drop elements is essential for ventilating the cavity and choosing the fan capacity in the DSF applications.Article Citation - WoS: 23Citation - Scopus: 28Thermal Analysis of the Domed Vernacular Houses of Harran, Turkey(SAGE Publications Inc., 2011) Başaran, TahsinMinimum energy consumption and economic efficiency using local and recyclable materials is essential for achieving sustainability, considering the depletion of global energy sources. The Anatolian Peninsula presents a diverse range of local building construction techniques accumulated over centuries, which meet the criteria mentioned above. Due to richness of climatic variety and the influence of many civilisations throughout history, Anatolian regions reflect this richness in their respective solutions to building construction. Built mainly out of brick and stone, mortared and plastered by mud, the domed vernacular houses of Harran, a small town in the province of Urfa in the hot arid climate of southeastern Anatolia, are one of the best examples that deserve attention with respect to minimum energy consumption. In this study, the thermal performance of the "Harran house" as a vernacular type was analysed. For this purpose, temperatures inside and outside a Harran house complex with relative humidity variations were measured. In addition, for investigating the domed houses' thermal behaviour, temperature measurements at different surfaces and media were recorded. The solar chimney effect obtained from the dome and the importance of the thermal mass of the square base of the house were also evaluated. The study yielded results, which showed that the indoor conditions were within the limits for thermal comfort even under extreme summer conditions.