Thesis Defense - Ali Can Yelekci (MSME)

Ali Can Yelekci - M.Sc.

Prof. M. Pınar Mengüç – Advisor

Assit. Prof.  Altuğ Melik Başol – Co-Advisor

Date: 10.06.2021

Time: 17:00

Location: This meeting will be held ONLINE. Please send an e-mail to gizem.bakir@ozyegin.edu.tr in order to participate in this defense.

Effect of Solar Radiation in Office Spaces

Thesis Committee:

Prof. M. Pınar Mengüç, Özyeğin University

Asst. Prof. Altuğ Melik Başol, Özyeğin University

Asst. Prof. Özgür Ertunç, Özyeğin University

Asst. Prof. Hande Öztürk, Özyeğin University

Prof. Dr. Tuba Okutucu Özyurt, Istanbul Technical University

Abstract:

This thesis examines the design components of an office that influences the thermal comfort of the occupants due to solar radiation, such as external solar shades, various window glasses, partitions between desks and floor materials.

 The steps of solar shade design and design parameters specific to the building, along with the types of solar shades are explored. Solar shades can be integrated with photovoltaic (PV) panels to be mounted on the façade and windows to block the unnecessary solar radiation for energy efficiency and electricity generation purposes. Optical properties of window glasses are studied for a multi-band thermal radiation model and thermal radiative properties of low-iron, clear and grey soda lime silica glasses are supplied. PV panel system is examined along with various types of PV panels and losses in efficiency of PV panels due to misalignment, temperature and blockage by dust, clouds or solar shade are discussed. A detailed numerical study is conducted to couple natural convection in an office space with thermal radiation due to solar radiation. The study specifically investigates the combined effects of partitions located between desks of the office space, solar shades, window types and floor materials to develop a tool-box to determine the effect of windows on thermal and visual comfort of occupants. Two different geometries are used due to different partition cases (according to the aspect ratio of the partition to the ceiling height, which are taken as 0.3 and 0.5) were studied. Single inlet and outlet is modeled for ventilation purposes. All walls other than the façade of the enclosure are assumed adiabatic, and the enclosure has a single window, which acts as a thermal radiative heat source. All surfaces are assumed to be gray-diffuse surfaces for the calculation of thermal radiation. The solar radiation is analyzed as a two-band model (visible and IR spectra) with both diffuse and direct sunlight for a summer day and a winter day. Finally, an extreme winter day with only diffuse sunlight, colder temperature, and higher wind speed is studied.

Based on the choice of window glass type, solar shade coverage on the window, partition geometry, floor materials, and the weather conditions, variations on the surface temperature distribution, air temperature, air velocity and thermal comfort of two manikins inside the office are analyzed based on Predicted Mean Vote (PMV) and Percentage of Dissatisfied (PPD) methods by Fanger.

Based on this study, a series of suggestions are made for the future designs of integrated solar shade systems.

Bio: 

Ali Can Yelekci was born in 1995 in Istanbul. He received his B.Sc. and his M.Sc. degrees in Mechanical Engineering from Ozyegin University in 2017 and 2021, respectively. He is currently employed by Kale Ar-Ge (R&D) at Tuzla, Istanbul as thermal and secondary air systems engineer for the development of turbojet engines. His research interest are thermal radiation in buildings and turbomachinery.