Enerji korunumlu yapıların yönlendirilmesi ve biçimlendirilmesi için yeni bir metod

Abstract

ÖZET Yapıların, enerji korunumu için yönlendirilmesi ve biçimlendirilmesinde, dış kabuk düşey yüzlerindeki doğrudan güneş ışınımına bağlı, güneşlenme yüzdeleri ve ısıl etkilerin Olgyay konfor bölgelerinde gözlemcinin 2. durumuna göre optimizasyonunun yapıldığı bu metod, iki kademeden meydana gelmektedir: Birinci kademede herhangi bir enlem, boylam ve biçimdeki yapının, düşey dış kabuk elemanları üzerindeki yıllık ortalama toplam güneşlenme yüzdeleri (güneşli alan/toplam alan), güneş ışınımı, bağıl nem, sıcaklık ve hava hareketlerine bağlı Olgyay konfor bölgelerindeki iki şiddet grubu, En Az Sıcak Dönem (EASD) ve En Sıcak Dönem (ESD) altında toplanmakta ve bu değerlerin yönlendirilişe göre değişimi incelenmektedir. Başka bir deyişle, yer, biçim ve yön değişkenlerinin birbirleri üzerindeki etkileri güneşlenme yüzdelerindeki farklılıklar ile belirlenmektedir. ikinci kademede yukarıdaki değişkenlere doğrudan güneş ışınımının düşey yüzeylerdeki ısıl etkileri de eklenmekte ve yapının bütünü ile ilgili, yer, biçim ve yön değişkenlerinin etkileşimine, beher duvarın konumuna ve üzerindeki saatlik güneşlenme yüzdelerine bağlı enerji kazançlarındaki farklılıkların ortalamaları da katılmaktadır. ikinci kademenin uygulamasında Liu- Jordan denklemleri, dünya sathında denenmiş ve kusurları ortaya çıkmış olduğu için, tercih edilmiş; ancak metod diğer araştırıcıların bağıntılarına da açık bırakılmıştır. Yeni metodun gelişimini hazırlayan konular başlıca üç bölüm içinde incelenmiştir. Birinci bölümde enerji korunumlu yapının tanımı pasif sistem metodolojisi içinde verilmekte; aynı bölümde, yapının dış kabuğunu etkileyen iklim elemanları kısaca ve bilgisayarlı ısıl enerji analiz metodları tarihsel gelişim içinde, ikinci bölümde metodun 2. kademesi için önem taşıyan güneş enerjisi verilerinin elde ediliş yolları incelikleri ile açıklanmaktadır, üçüncü bölümde ise yapılarda uygulanan gölge analizi metodları gözlemcinin durumuna göre tanıtılmaktadır. Dördüncü bölümde metod ve inceliklerinin anlaşılabilmesi için bir dizi uygulama sunulmakta, ayrıca birinci kademenin uygulanmasında yararlanılan JPCSHAD gölge algoritması tanıtılmakta ; sonuç bölümünde ise metod değerlendirilmekte ve ileriye dönük araştırmalar için önerilerde bulunulmaktadır. vii

SUMMARY A NEW METHOD FOR THE ORIENTATION AND DESIGN OF A BUILDING OF MINIMAL ENERGY CONSUMPTION Substitution of passive solar systems for the `dirty` combustion of fossil fuels for energy use in buildings to keep the environment biologically clean, can make important contributions to the health, both of individuals and of the global ecosystem, as well as contributing to the energy economy. Local outdoor chemical pollution, with all the damage it causes, can also be reduced with energy-cone ious design. A new method for design and orientation of an energy conservative building is presented for the use of architectural, urban planning, and energy engineering purposes. The precedure of the thesis is explained in five chapters. The concept of the energy conservative building is given in passive systems' methodology in Chapter 1. Also in the same chapter, the climatological effects on the building envelope and a review of current calculation procedures and computer programs with solar heating and cooling system capabilities are included. Successful passive solar architecture integrates energy conservation with passive solar heating, natural cooling and day lighting. The result can be a comfortable and economic building that uses 50%-90% less operating energy than most contemporary buildings. A world wide interest in passive solar architecture has developed since last five years because it provides an alternative to the trend toward an overdependence on lighting, heating, ventilating, and air conditioning equipment to maintain a livable and productive indoor environment in modern building. Building practitioners in many devoloping countries are interested in passive solar methods which may be integrated into the building design using familiar and readily available materials. Passive solar architecture has emphasized heating of residences in temperate climates; however, passive strategies have now spread to nearly all building types and most climates. The process is more complex for institutional and commercial buildings than for residential, but the same concepts always apply. viiiHour-by-hour simulation provides the backbone for design analysis. For smaller or simpler buildings simplified methods are usually based on monthly analysis. For larger or more complex buildings, the trend is to take full advantage of the inceased computing power of the current generation of powerful microcomputers in order to use simulation directly for design. Convenient design tools based on simulation are becoming available. The entire area of design tools appropriate to passive solar architecture needs much additional effort. Rasearch in the software design area, with powerful microcomputers, expert systems, and computer aided design techniques, promises to aid greatly in the spread of passive solar strategies. The second chapter is a review of the methods of estimation of hourly beam, diffuse and reflected solar radiation data for vertical and horizontal surfaces; whereas in this chapter Liu-Jordan's equations have a significant emphasis and are explained in full detail. There is evidence with the increasing emphasis on the use of solar energy in buildings, that much of the past solar radiation data will be rehabiliated and additional data will be collected in the future; however, it is unlikely that the hourly data to be taken will be extended to cover surfaces other than the horizontal for the majority of the stations. Liu and Jordan conducted extensive analyses during the early I960' s on the available solar radiation data and developed several emperical correlations that can be used to estimate the available solar radiation on `average` days for each month of the year and for a larger number of locations in the United States and Canada. Using the correlations, it is possible to take the monthly average daily total radiation on a horizontal surface, divide the daily total into direct and diffuse components, convert each component into hourly values, and then compute the hourly value of either component on a surface of any orientation desired. In the third chapter shadow analysis techniques for window and building energy studies are examined in detail. These techniques are examined under two parallel groups of classification. In the first group, roughly, the methods deal either with the building as a whole or only with the windows. In the second group, however, the methods are classified according to the first or second position of the observer. ixShading and solar influences on a building can be understood from two different observer positions. At the first position the observer stands at the ground or the building element and looks toward the Sun. The entire yearly movements of the Sun and relationship to the modifying intermediate conditions are seen at one time j thus, from the single station point, the observer has a yearly picture of solar movement. The disadavantage of this technique is that every position of the subject surface must be seperately analysed with a a new drawing and accompanying calculations. For a total analysis, a continious three-dimentional site volume must necessarily be broken into discrete representative points each of which is seperately analysed. Without intermediate obstructions any point on a site is equivalent in a solar analysis, since solar rays are parellel. However when the obstruction is large or close, its influence on different station points may be quite varied, such as on an urban. Since the proximity of the obstruction determines the the degree of variation in complex situations, differences may be considerable. Therefore, the movement or location of shadows is impossible to analyze, for only by accident can one determine whether the discrete object point is at a shadow edge. The crucial issue of total overshadowing effects and shadow patterns cannot be seen, nor can the entire building be examined at one time. In the second position, as used in the new method, the observer is located at a spot between the Sun and the building. By considering both the Sun and the entire building at once, all surfaces in any orientation can be observed under solar illumination. In this position, the relationship of of one portion of the site can be understood acting on another portion of the site. It is clearly seen from the examples that in the methods dealing only with the windows, the observer is, generally, in the first position, whereas in the methods which consider the building as a whole, the observer is in the latter position. The method is explained in details and step by step with a set of examples in Chapter 4. The method is an optimisation of the total percent of the sunlit area and the thermal effect due to the beam component of total solar energy on the vertical exterior surfaces of a building of minimal energy consumption, in Olgyay's bioclimatic chart which considers temperature, solar energy, wind, precipitation, relative humidity and vapor pressure. In other words, the method is a new and comprehensive interpretation of Olgyay's well known Overheated period charts. By replacing the secondposition of the observer in hourly simulation by the original gnomonic diagrams based on the first position of the observer, the metod gets closer to the aims of Olgyays' in the interpretation of architectural principles, site selection, sol-air orientation, solar control, environment and building forms, wind effects and air-flow patterns, and finally the thermal effects of materials. The method assumes that solar radiation does not penetrate the building; therefore it deals neither with the heat transfer problems nor the thermal storage capacity of the building, for the time being. The method does, however, generate relaible kernel data base for future research work on building heat transfer problems. The method is composed of two parts, the second being based on the first. The first part of the method deals with the changes in the sums of the total annual percents of sunlit areas (sunny portion of total exterior walls/total area of exterior walls) of a building at any location, relative to the changes in the orientation. In the second part, the thermal energy of the direct component is added to the variables mentioned above; e.i., location, geometrical design and orientation of the building. Thus, each wall is taken into consideration seperately, with the changes of intensity of solar energy and the percentages of sunlit area on it, due to the changes of the orientation of the building. The method is compiled in ten steps, of which the first five build the primary part, and the last five the secondary. The steps are as follows: 1. Olgyays' bioclimatic chart is adapted to the geographical place. The Overheated and the Underheated periods for selected hours of daytime are marked for selected days. For the selected hours of the selected days 2. percentages of sunlight on the walls of the building of a given orientation are computed, with any shading algorithm of parallel projection. 3. areas of sunlight (mE) on the walls of the building of a given orientation are computed, 4. total percentage of sunlight on the building is computed and grouped under two intensities, e.i. the Overheated and the Underheated. xi5. The annual sums of the total percentages of sunlight for the Overheated and Underheated periods are devided by the number of the Overheated and Underheated daytime hours respectively. 6. Solar thermal energy due to the beam component of hourly radiation is computed for each orientation (KJ/mz.h). 7. Solar thermal energy due to the beam component of hourly radiation is computed for each wall (KJ/h). 8. Total solar thermal energy gain of the building due to the beam component of hourly radiation is computed (KJ/h). 9. Hourly total solar thermal energy gains of the building are grouped under two intensities, the Overheated and the Underheated. 10. The annual sums of total solar thermal energy gains of the building for the Overheated and Underheated groups are devided by the number of Overheated and Underheated daytime hours respectively. application of the first part of the method is done by three blocks of passive apartment houses of the same area and hight, but of different design, for istanbul and Antalya, and for 1., 11., and 21. days of the months. For the second part, however, only the second block is examined for istanbul, and only for 21. days of the months. Hence comparisons of two sets of meteorological data and all the parameters mentioned above may be seen clearly from the graphics relative to the changes in eight orientations, e.i., North, North-East, East, South- East, South, South-West, West, and North-West. A minor modification was made in Olgyay's Overheated period charts in order to eliminate what was believed to be erroneous results by the use of Liu-Jordan equations near the sunrise and sunset hours for the application of the second part of the method. Although percentages of sunlight on the vertical exterior walls are computed with a shading technique based on Conlon's JPCSHAD parallel projection algorithm and the inclusion of the thermal effect mentioned above is done by Liu-Jordan's well known equations, the method is still applicable to other scientists' formulae and shadow analysis models as well. At the last chapter, the method is evaluated and further possible reseach work are pointed out. xiiThe method may be used to generate a wide variety of building blocks. The irradiance load on external surfaces of building blocks of any rectangular design may be evaluated for any orientation, time of day and for different localities. This evidently provides the designer with useful information, guide lines and design aids expanding his ability to manipulate the parameters of form for the control of solar environment and to develop practical indicators and building regulations for planning control. The method may furter be used in a generative process to define alternative proportion of block's sides, configuration of surroundings, street widths, physical characteristics of building surfaces for appropriate solar load criteria. Thus the method may be employed directly in conjunction with other performance criteria for a sythesis of an integrated architectural solution. xiii