Soğuk iklim bölgelerinde ısıtma enerjisi korunumu açısından plastik doğramalı pencerelerin kullanılması durumunda uygun bina kabuğu alternatiflerinin belirlenmesi

Abstract

Bu tez çalışmasının konusu, dış cephelerde kullanılan plastik doğramalı pencerelerin, pasif ısıtma sistemi öğesi olarak ele alınması ve plastik doğramalı pencerelerin kullanılması durumunda ısıtma enerjisi korunumu açısından soğuk iklim bölgeleri için uygun bina kabuğu alternatiflerinin belirlenmesidir. Enerji tüketiminin büyük bir bölümünün binaların yapma (aktif) olarak ısıtılmasından oluştuğu bilinmektedir. Bu tür enerji tüketimini minimuma indirgemek, yerleşme birimlerini ve binaları optimal performans gösteren pasif ısıtma ve iklimlendirme sistemleri olarak tasarlamakla olanaklıdır. Yapı kabuğu ise bu sistemin en önemli öğesini oluşturur. Pasif ısıtma işlevi açısından bina kabuğunun tanımı. güneş ışınımına ilişkin yutuculuk (a) ve geçirgenlik (t) gibi optik ve. toplam ısı geçirme katsayısı (k), zaman geciktirmesi (), genlik küçültme faktörü (f) ve saydamlık oranı (x) gibi termofiziksel özellikleri ile yapılmaktadır. Dış iklim durumunun, iç çevre ikilim koşullarının oluşumundaki etkililik derecesi bu parametrelerin değerlerine bağlıdır. Dolayısıyla bu parametreler iç iklim durumu ve yapma ısıtma ve iklimlendirme yüklerinin belirliyicileridirler. Soğuk iklim bölgeleri için plastik doğramalı pencerelerin kullanılması durumunda uygun bina kabuğu alternatiflerinin belirlenmesinde kullanılan yöntem. İklimsel konfor açısından bina kabuğu termofiziksel özelliklerine ilişkin yeterli değerler kombinezonlarının belirlenmesi. belirlenen bina kabuğu termofiziksel özelliklerine ilişkin iklimsel konfor açısından yeterli değerler kombinezonlarının tanımladığı kabuk alternatifleri arasından enerji korunumu açısından en uygun olanların seçilmesi, adımlarından oluşmaktadır Sonuç olarak, bu çalışmada soğuk iklim bölgelerinde ısıtmanın istendiği dönem daha uzun olduğundan, ısıtma enerjisi korunumu açısından plastik doğramalı pencerelerin kullanılması durumunda belirlenen uygun bina kabuğu alternatiflerinin uygulanması ile, aktif ısıtma enerjisi tüketiminin azaltılması hedeflenmiştir.

The subject of this thesis is to determine the alternatives of the suitable building envelope using plastic (PVC) windows at cold climatic areas with respect to heating energy conservation. This thesis consist of five chapters. Chapter 1 In the first chapter the importance of the efficiency of heating energy in buildings is emphasized. In developing countries such as Turkey, while the concepts of efficiency and saving have not sufficiently grown, the fast disappearing natural resources are spent unconsciously. However,. the air-pollution caused by active heating of buildings and. the increasing energy costs constrains the buildings and the settlement units to be designed as passive heating systems. For the reasons mentioned above at cold climatic areas where the heating period is very long, the accomplishment of the heating energy conservation is inevitable. On the other hand it is seen that the use of plastic (PVC) windows are becoming widespread due to the heating energy conversation. Considering all the aspects mentioned above, in this thesis the determination of suitable building envelope alternatives are discussed while using the plastic (PVC) windows at cold climatic areas regarding the heating energy conservation. Chapter 2 In this chapter the parameters which effect the heating energy conservation are given. These parameters are discussed in two categories:. the physical environmental parameters (climatic variables) and. the design parameters due to the manmade environment. The outdoor climate is a resultant of air temperature, solar radiation, air humidity and wind effects which are physical environmental parameters. Consequently, the outdoors climate is defined by the values of these elements. xii The important design parameters due to manmade environment are given as:. Selection of location (site). Orientation of buildings. Distance between the buildings. Building form. Optical and thermophysica! properties of building envelope These parameters define the indoor climatic conditions, the active heating and the climatization loads. In order to design buildings and settlement units properly regarding energy conservation, suitable values must be suggested for these parameters. Selection of location is a parameter which is effective at location climate control and prevention of air pollution. It consist of the following sub parameters which are direction. inclination and cover (ability to reflect the solar radiation) of land. Orientation of buildings is a variable due to outdoors climatic conditions such as solar radiation and wind. The heating effect of solar radiation and the cooling effect of wind can be optimized by the suitable orientation of buildings. Distances between buildings and their heights may be solar radiation and wind obstacles to each other. Since radial location of sun varies throughout the day due to direction, it is clear that distances between buildings should be oriented considering direction of buildings as well. Solar radiation gains and necessary wind effects should be taken into consideration. Building form may be explained with the following geometrical variables belonging to a building;. the proportion of building length to its width on plan, building height, attic type, attic inclination, facade inclination. In this thesis, among these parameters mentioned above the optical and thermophysical properties of building envelope is examined to determine the suitable alternatives for building envelope. The definition of building envelope is made by the optical properties of building envelope which are absorbtivity (a), transmissivity ( t) and reflectivity ( r) and by the thermophysical properties which are overall heat transfer coefficient (k), transparency ratio (x), time lag () and decrement factor (f). xin For the transparent building component the equation of its optical properties is as follows; ac + rc + tc = 1 Among the thermophysical properties; overall heat transfer coefficient and transparency ratio are the main concern of this thesis, accordingly their definitions are as follows;. Overall heat transfer coefficient is a thermophysical property for both opac and transparent component of the building envelope. It is the overall heat amount transferred through the building component from unit (1m2) area, at unit (1 hour) time, where the difference of temperatures between the inner and outer air temperatures is 1°C.. Transparency ratio is the ratio of transparent components to the overall building component. Heat quantity gained and lost through out the building envelope and consequently the inner facade and inner air temperatures varies with the values of the given thermophysical properties. As the proper values of thermophysical properties are functions of sol-air radiation intensities which vary according to directions, the mentioned proper values also vary due to directions. Chapter 3 In this chapter the properties of plastic (PVC) windows and the various companies producing plastic (PVC) windows in Turkey are given. The overall heat transfer coefficients for only PVC profiles and for the whole window are obtained from several firms which are presented as a table. It is also mentioned how the various standards handle the overall heat transfer coefficient of plastic (PVC) windows. Chapter 4 In this chapter the method used to determine the building envelope alternatives using plastic (PVC) windows considering heating energy conservation is described. This method is developed at the research made by I.T.Ü. Architectural Faculty under the name of " Energy Emphasized Building and Settlement Design ". In this thesis the method is implemented for plastic (PVC) windows. xiv The method consist of. Determination of proper value combinations of building envelope thermophysical properties according to climatic comfort conditions,. Selection of the most suitable building envelope alternatives according to heating energy conservation, among the determined proper values combinations due to the climatic comfort of the building envelope thermophysical properties. Chapter 5 In this chapter the method is implemented for plastic (PVC) windows and its implementation results are discussed. First step of the method is applied considering the following acceptances:. This method is implemented to determine the combinations of values for thermophysical and optical properties for facade elements placed vertically.. These properties are determined due to the method described at section 4.1, for the cold climatic areas and for the outdoor conditions at the design period when heating is desired.. The characteristic day is taken as 21. of January.. The outdoor climatic conditions are based upon true atmospheric conditions for the hours of direct sunlight.. The indoor climatic conditions are based upon the suitable difference between the indoor air and surface temperatures which is taken as e = 3 °C, accordingly ti = 22°C and ti>0=22-30C The calculations are carried out considering;. the values for double glassed wood and metal windows are taken from the research made by the I.T.Ü. Research Committee mentioned before. For wood windows kc = 2.80 kcal/m2h°C (3.85 W/m2oC) For metal windows kc = 4.50 kcal/m2h C (5.23 W/m2oC). for plastic windows two firms are taken into consideration Internorm kc = 2.16 kcal/mVc (2.51 W/m^C) Pimapen kc = 2.24 kcal/m2h°C (2.60W/m2oC) After obtaining the values for thermophysical properties of building envelope using plastic (PVC) windows at cold climatic areas due to heating energy conservation, tables are constituted to compare the effectiveness of the plastic windows with the xv wood and metal windows. The necessary data is taken from the research made by the above mentioned Committee. Conclusion and suggestions As a result of comparison,. it is obtained that the heat loss through the building envelope at unit area and unit time while using plastic (PVC) windows with respect to other types of windows is less, consequently plastic windows may be considered more suitable for cold climatic areas such as Erzurum.. Also plastic windows present a higher K, - transparency ratio combinations compared with other types of windows which indicates that in practice easier produced opac component layer alternatives can be used. As the heating period at cold climate areas is longer, it is suggested that due to the heating energy conservation plastic (PVC) windows should be used at these regions. Consequently the energy gain for the land's economy should not be neglected.