Please use this identifier to cite or link to this item: http://hdl.handle.net/11527/16957
Title: Isıtma Enerjisi Korunumu Açısından Hacimler İçin Uygun Yönlendirilmiş Durumların Belirlenmesi
Other Titles: Determining Appropriate Orientation Of Rooms From The Viewpoint Of Heating Energy Conservation
Authors: Koçlar, Gül
Çaştaban, Pelin
75306
Mimarlık
Architecture
Keywords: Isıtma enerjisi
İstanbul
Heating energy
Istanbul
Issue Date: 1998
Publisher: Fen Bilimleri Enstitüsü
Institute of Science and Technology
Abstract: Bu çalışmada, ısıtma enerjisi korunumu açısından hacimler için uygun yönlendiriliş durumlarının belirlenmesi hedeflenmiştir. Bir başka deyişle, hacimlerde yıl boyunca gerçekleşen iç hava sıcaklığı değerlerinin değişimine bağlı olarak belirlenen yıllık ısıtma sürelerine göre, en kısa ısıtma süresini gerçekleştiren yönlendiriliş durumunun, ısıtma enerjisi korunumu açısından en uygun yönlendiriliş durumu olarak nitelendirilmesi amaçlanmıştır. Buna göre, önerilen yaklaşımda, yıllık ısıtma sürelerinin belirlenebilmesi için dış çevre iklim koşullarına ait verilerin ve hacimlerde herhangi bir yapma ısıtma sistemi olmadığı durumlarda, iç hava sıcaklıklarının saatlik değişimlerinin hesaplanabilmesi için hacme ilişkin yapma çevre değişkenlerinin değerlerinin belirlenmesi gerekmektedir. Bu hesaplamaların yapılabilmesi için zamana bağlı ve tek boyutlu ısı geçişi denklemlerinin çözümünde sonlu farklar yönteminin ele alındığı bir bilgisayar programından yararlanılmıştır. özellikle ılımlı ve soğuk iklim bölgeleri gibi ısıtma süresinin uzun olduğu bölgelerde, hacme ilişkin diğer yapma çevre değişkenlerinin değerleri de gözönünde bulundurularak, hacimlerde en kısa ısıtma süresini gerçekleştiren, dolayısıyla ısıtma enerjisi harcamalarının minimum düzeye indirilebilmesini sağlayan yönlendiriliş durumlarının belirlenebilmesi gerekli olmaktadır.
In a particular period of year, the use of active heating systems in rooms is needed because of the effects of the outdoor climatic elements. To create an indoor climate which satisfies users' climatic comfort for health while using minimum heating energy, the determination of the optimum combination of design parameters affecting indoor climate is required. Orientation is also one of the most important parameters to benefit from heating effect of solar radiation. This study suggests an approach for determining appropriate orientation of rooms from the viewpoint of heating energy conservation. The approach is based on heating periods in rooms related to annual variation of indoor air temperature. The aim is to determine orientation which minimizes heating period. The study consists of seven chapters. Chapter 1 In the first chapter, the significance of the subject is touched upon and the content of the study is explained. Chapter 2 In this chapter, the factors which require the use and conservation of heating energy in rooms are touched upon. One of the primary requirements in the room for health is to provide users' climatic comfort. Therefore, the main factor that requires the use of heating energy in the room is the necessity of climatic comfort. Climatic comfort is defined as conditions in which %80 or more of the users find the environment thermally acceptable. Climatic comfort is defined with combinations of different values of the parameters as follows. Environmental parameters (Indoor climatic elements) * Air temperature * Mean radiant temperature * Air velocity XI * Air humidity Personal parameters * Activity * Clothing Definition of climatic comfort can be made by means of Bioclimatic Chart. However, in the underheated period, climatic comfort condition in a room can be met using active heating systems. The reduction of active heating cost is needed because of limited energy sources, increasing prices and air pollution. In order to reduce active heating cost rooms should be designed as passive heating systems. Chapter 3 This chapter deals with the factors that are effective in process of heating energy conservation in rooms. These factors are classified such as; * Outdoor climatic elements - Radiation - Air temperature - Relative air humidity -Wind * Design parameters related to the built environment Built environment is considered at the city, building, room, component or material scale. So there are a lot of parameters that should be paid attention. The unit of built environment analyzed in this study is the room. The design parameters at the room scale are as follows. - Location of the room in the building - Dimensions and shape factor of the room - Orientation of the room - Optical and thermophysical properties of the room envelope Location of the room determines the number of external wall elements surrounding the room and consequently effects the amount of heat gain or loss by means of external elements. The shape factor of the room is described as the ratio of external wall length to room depth. The surface area of external walls that has an important effect on heat gain or loss changes with the shape factor. Orientation is one of the most important parameters because of the variation of solar angles and solar radiation intensity with orientation. XII Optical parameters of the room envelope are * absorptivity * transmissivity Thermophysical properties are * overall heat transfer coefficient * transparency ratio * time lag * decrement factor All these parameters are effective on determining the amount of heat which is gained or lost by the room and also the amount of energy for providing climatic comfort in the room. Chapter 4 In this chapter, heating period is described and the relationship of heating energy conservation and heating period is explained. Heating period covers the period in which during the active heating systems are required in order to provide climatic comfort conditions for the users. Heating period may be defined by basing on the lowest indoor air temperature value from the climatic comfort point of view or the outdoor air temperature value which are given by Turkish Standards, Regulation for Protection of Air Quality, Codes of Municipal Police of Greater Istanbul. In this study, heating period is defined basing on the lowest indoor air temperature value from the climatic comfort point of view. The lowest indoor air temperature value from the climatic comfort point of view is determined as 21 °C by means of the Bioclimatic Chart. By taking as the basis the lowest indoor air temperature from the climatic comfort viewpoint, heating period is defined as the period during which the indoor air temperature is under 21 °C. If the heating period is long, energy cost increases proportionally. Therefore heating period is one of the criteria which are used for the determination of rooms that give the best performance from the viewpoint of heating energy conservation. Chapter 5 In this chapter, previous approaches that are used for determination appropriate orientation of rooms are introduced and discussed. The majority of previous approaches base the calculations on the intensity of solar radiation effecting either the unit area or the total area of the outer building surface. Also one of the previous approaches is based on XIII temperature differences between the actual and the required inner surface temperature of the opaque envelope. These approaches are not based on the heating period criterion. But thermal effects of solar radiation on the indoor climate can be clearly determined when an approach based on heating period is used. The orientation that enables the minimum level of heating energy requirement can be also determined especially for moderate and cold regions which have long heating period. Chapter 6 This chapter covers the steps of the approach used to be determined appropriate orientation of rooms from the viewpoint of heating energy conservation. The main steps of the approach are as follows;. Gathering the outdoor climatic data such as solar radiation intensities, hourly air temperature values for the calculations included in the approach.. Assumption on the orientation alternatives for the room.. Determination of the values of design parameters. - determination of the location of the room in the building. - determination of dimensions and shape factor of the room. - determination of the room envelope.. Calculation of the hourly values of the indoor air temperature and preparation of the annual variation chart of indoor air temperature occuring in the rooms which have various orientation alternatives. In this approach, it is assumed that there is no supplementary heating system in the room. Time dependent heat flow calculations to determine indoor air temperature and inner surface temperatures are basing on the finite difference method. Thus the indoor air temperature at any particular time can be calculated by means of the following equation. A~T n m m t* = tj + (LA0ctj (toj - tj) + ZAp. ctj (tci - tj) + bh. I (lx. Ap) + Qv + Qk) m.ch 11 1 tj* indoor air temperature at any particular time, °C. tj indoor air temperature before a time increment At, °C. m mass of the air in the room, kg. XIV ch specific heat of the air, J / kg°C. n EAoctj (t0j - tj) amount of heat exchange between the indoor air and the 1 inner surfaces of opaque components of the envelope within the time increment At, W. m EApcq (tCj - tj) amount of heat exchange between the indoor air and the 1 inner surfaces of transparent components of the envelope within the time increment At, W. bh absorptivity coefficient of the indoor air which is transmissed through the transparent components, m £ Ox. Ap) amount of solar heat gain from the transparent components 1 within the time increment At, W. Qv amount of heat exchange between the indoor environment and outdoor environment by means of ventilation and infiltration within the time increment At, W. Qk amount of heat gain to the indoor air from the heat sources in the room within the time increment At, W. Then the annual variation chart of indoor air temperature is prepared by means of hourly values of indoor air temperature.. Determination of heating periods in the room alternatives by taking as the basis the lowest indoor air temperature value from the climatic comfort point of view. The dates and hours on which the indoor air temperature is below 21 °C constitute the heating period. Accordingly, the 21 °C indoor air temperature curves on the annual variation chart also the boundaries of heating period.. Comparison of the room alternatives according to heating period and determination of the orientation which provides the shortest heating period. In this step, the rooms are compared to each other according to heating period. The room which provides the shortest heating period is determined. The orientation of this room is qualified as the most appropriate orientation. Chapter 7 This chapter deals with the application of the approach to the İstanbul region and the results of the application. By means of the approach,. The effect of code particular orientation on indoor climate can be studied. xv . The orientation which enable the maximum heating effect of the solar radiation can be determined for especially moderate and cold regions which have a long heating period..The optimal combination of the orientation and other design parameters related to the room can be determined from the viewpoint of heating energy conservation.. In case of other design parameters have been selected at certain values mandatoryly, the room which provides the optimal performance in heating energy conservation can be described by determining appropriate orientation.
Description: Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1998
Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 1998
URI: http://hdl.handle.net/11527/16957
Appears in Collections:Mimarlık Lisansüstü Programı - Yüksek Lisans

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