Mevcut bir apartman binasının alüminyum giydirme cephe sistemiyle yenilenmesinin enerji tüketimi ve CO2 emisyonu açısından değerlendirilmesi
Evaluating the renovation of an existing apartment building with an aluminum facade system in terms of energy consumption and CO2 emissions
Yazar: İSMAİL KAMIŞ
Danışman: PROF. DR. HATİCE SÖZER
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Enerji Bilim ve Teknoloji Ana Bilim Dalı / Enerji Bilim ve Teknoloji Bilim Dalı
Derece: Yüksek Lisans, 2023
Konu: Enerji = Energy
Dizin: Alüminyum = Aluminum ; Apartman = Apartment ; Enerji tüketimi = Energy consumption ; Giydirme cepheler = Curtain walls ; İstanbul-Kağıthane = İstanbul-Kağıthane

Özet:
Dünya nüfusunun günden güne artışıyla birlikte enerji tüketimi de aynı ölçüde giderek artmaktadır. Enerji toplumun ihtiyaçları doğrultusunda birçok alandan tüketilmektedir. Ulaşım, üretim, konutlar, turizm gibi alanlar bu tüketimlere örnek olarak gösterilebilmektedir. Binaların tükettiği enerji yayınlanan güncel raporlara göre yadsınamaz büyüklüğe ulaşmıştır. Buna istinaden bina zarflarının optimal bir düzeyde yalıtılması binalar tarafından tüketilen enerjinin daha mimimal seviyelere indirilebilmesinin de önünü açacaktır. Bina zarflarının optimal düzeyde yalıtılabilmesi için birçok stratejinin uygulanması mümkündür. Binaların yalıtılmasının en önemli metodlarından biri dış cephe tercihidir. Binaların enerji tüketimine doğrudan sebep olabilecek dış faktörlerin kullanıcı konfor alanlarına bariyer görevi gören elemanı dış cepheler olduğundan bu bina zarfında yapılacak tasarım oldukça önem taşımaktadır. Buna istinaden, binaların mevcut dış cephe yalıtım yöntemlerinin yerine kullanılabilecek alüminyum giydirme cephe sistemleri bina için iyi bir yalıtım sistemi olarak yapının enerji performansını iyileştirilebilmektedir.
Giydirme cepheler, cam, metal paneller, kompozitler ve ince taş dolgular içeren genellikle alüminyum çerçeveye sahip bina yalıtım elemanı olarak tanımlanır. Alüminyum çerçeve, bina strüktürüne takılır ve binanın zemin veya çatı yüklerini taşımaz. Alüminyum çerçeveli duvar sistemlerinin geçmişi 1850'li yıllara dayanmaktadır ve II. Dünya Savaşı'ndan sonra alüminyumun kullanımının uygun hale gelmesiyle hızla gelişmiştir. Alüminyumun bir metal olmasından kaynaklı termal geçirgenliği yüksektir ancak giydirme cephelerde alüminyumun kullanılmasının ardında yapısal özelliği, durabilitesi, bakım maliyetleri, malzeme çeşitlilikleri yangın dayanımı ve yüksek mukavemet/ağırlık oranı gibi özellikleri bulunmaktadır. Giydirme cephe sistemleri monotolik bir bina elemanı olarak çalıştığı için genel olarak sistemin termal geçirgenliği mimarlar tarafından optimal seviyelerde tasarlanabilmektedir. 
Bu çalışmada, alüminyum giydirme cephelerin binalar üzerinde oluşturabileceği enerji verimliliğini tespit etmek adına İstanbul ili Kağıthane ilçesinde bulunan bir rezidans binanın mevcut mantolama şeklinde yalıtılmış dış cephesi, ısıl performansı iyileştirilerek alüminyum giydirme cephe sistemi yöntemiyle tekrar dizayn edilmiştir. Binanın enerji tüketim farkları ve ısıl değerlerini analiz etmek için bir araç olarak DOE 2.2. tabanlı enerji simülasyon yazılımı olan e-Quest üzerinden modeller oluşturulmuştur. Binanın tam olarak konumunun iklim verileri, HVAC sistemi, kullanıcı profilleri, yapı malzemeleri, bina mimari planı, mantolama dış cephe yalıtımı verileri data olarak toplanmış ve sisteme girdi olarak tanımlanmıştır. 2 farklı model operasyonel tüketim değerlerinin saptanması için simüle edilmiş ve 365 günlük ısınma ve elektrik tüketimine yönelik harcanan enerji verileri elde edilmiştir.
Mevcut binanın dış duvar yalıtımı olan mantolama detayında iç duvarlarda sıva ve boya, duvar elemanı olarak delikli bims bulunmaktadır. Dış katmanda EPS, sıva ve boya bulunmaktadır. Mantolama binanın ısıl geçirgenlik katsayısı U=0,554 W/m2K olarak hesaplanmış ve enerji tüketimi 134,44 kWh/m2 olarak bulunmuştur. Alüminyum giydirme cephe sistemi dış duvar yalıtım detayında sıva ve boya, duvar elemanı olarak delikli bims bulunmaktadır. Dış katmanda betonarme elemana ankrajlanmış alüminyum profiller, profillerin arasında taşyünü, sıva ve alüminyum kompozit bulunmaktadır. Alüminyum giydirme cephenin ısıl geçirgenlik katsayısı Güney, Doğu, Batı cephede U=0.468 W/m2K, Kuzey cephede daha kalın taşyünü olması sebebiyle U=0.423 W/m2K olarak hesaplanmış ve enerji tüketimi dizayn bina için 102,86 kWh/m2 olarak hesaplanmıştır. Alüminyum giydirme cephelerde pencereler de mantolama sisteme göre çift katman şekilde dizayn edilmiş ve pencere önlerine güneşlikler yerleştirilerek konfor koşulları iyileştirilmiştir. 
Binanın alüminyum giydirme cepheyle kaplanmış ve mevcut mantolama yalıtımlı hali, YDA çalışmasıyla çevresel etkilerini, malzemeleri, operasyonel enerji tüketimi ve yaşam sonu aşamaları analiz edilerek yalıtım değişikliğiyle ortaya çıkacak karbon emisyon değerleri tespit edilmiştir. Tüm yapı malzemeleri değiştirme, onarım, enerji tüketimi ve atık yönetimi stratejileri bu çalışmanın sınırlarına dahil edilmiştir. Çalışmanın yürütülmesi için One Click LCA sitesinden faydalanılmıştır. Analiz sonuçlarına göre mevcut bina ve alüminyum giydirme cephe sistemli binanın karbon emisyon değerleri 444 kg CO2e/m2 ve 522 kg CO2e/m2 olarak bulunmuştur. Mevcut kullanılan malzeme ve operasyonel enerjisiyle mantolama yalıtıma sahip bina, somutlaştırılmış karbon kıyaslamasında "D" sınıfında orta düzey bir kategorisinde bulunmaktadır. Ayrıca alüminyum giydirme cepheye sahip bina ise malzeme modifikasyonları ve operasyonel enerjideki değişikliklerle, somutlaştırılmış karbon kıyaslamasında "E" sınıfında yüksek karbon ayakizi kategorisinde bulunmuştur.
Bu çalışma sonucunda yıllık enerji yoğunluğu bazında binada alüminyum giydirme cephe sisteminin mevcut mantolama sistemi yerine kullanılmış olsaydı yaklaşık %25 oranında bir enerji tasarrufu yaşanacağı anlaşılabilmektedir. Enerji tüketim değerleri yıllık olarak hesaplanmaktadır, ancak optimum koşullar için bir binanın ömrünün 60 ila 80 yıl arasında değiştiği düşünülürse, bu düşüşlerin 60 ila 80 yıl ile çarpılması sonucunda ciddi enerji tasarrufu sağlanabileceği anlaşılmaktadır. Bir diğer yandan binalarda yalıtımın iyileştirilmesi çevresel faktörler açısından her zaman iyi sonuçlar vermeyebilmektedir. Nitekim, alüminyum profiller ve kompozitlerin kullanımı ile cephede montajı yapılan alüminyum malzemenin artması, yapının somutlaştırılmış karbon kıyaslama sınıflandırmasında "D" sınıfından "E" sınıfına düşmesine neden olmuştur. Ayrıca çevresel etki değerlendirmesi bazında alüminyum giydirme cephe sistemi kullanılmasının yalıtım açısından binaya sağladığı olumlu etkinin karbon emisyon değerlerine olumlu etkisi olmadığı sonucu da anlaşılmıştır.
Çalışma ilerki boyutlarda değerlendirilecek olursa, tasarımın alüminyum giydirme cephe sistemlerinin yenilikçi çözümleriyle çeşitlendirilerek daha enerji verimli hale getirilebilmesi de mümkün olabilecektir.

Abstract:
In recent years, with the rapid increase of the world population, energy consumption has reached very high levels throughout the world. As many sectors have a share in this energy consumption, the amount of energy consumed by buildings is undeniable. Many strategies are followed to reduce building's energy consumption, such as good envelope insulation. Making the right decision on the building exterior preferences is very important. Correspondingly, aluminium curtain wall systems could be a good alternative structurally as well as their energy performance could be improved with the insulation integration. 
The architectural development and change of the buildings have varied since the first period of human history. In order to know any period or culture, it may be sufficient to shed light on the architectural structures and artistic understanding of this period. Curtain facades have also appeared in many forms in this long historical process, and have completed the skeleton of the building in different ways as physically and aesthetically as time passed.
Curtain walls are lightweight, circumferential structure made up of industrially produced elements, usually glass and metal that takes on all the functions of an exterior wall without providing a support to the building's stability. It is a system that can be built quickly in front of the load-bearing structure of a building and can work in integration with the building without occupying the useful area of the building. Sometimes, an aesthetic appearance emerges when the mission of providing insulation to users with basic functions is integrated with architectural details. The curtain wall structure, unlike the main structure, which resists all the loads of a building, must be able to withstand, transmit and at the same time sustain the loads acting on it through the carefully designed vertical and horizontal carrier elements of the facade. Curtain walls can be classified into three categories according to their construction and assembly methods; stick system, unit system, unit and mullion system.
There are certain reasons behind the use of aluminum in curtain walls. The first known alumimium application in buildings dates back to 1898, when the dome of the Church of San Gioacchino in Rome was covered with aluminum sheets. Today, it is the most used metal in the construction industry after steel. Aluminum can be preferred for curtain walls, window frames, roofs, interior architecture in buildings. In terms of curtain walls, it is used in skeleton profiles, composite panels, sunshades and sheet metal plates. Structural feature, durability, maintenance costs, material variety, fire resistance and high strength/weight ratio factors are the main preference of aluminium using for curtain walls. 
Models were made in this study in order to show the insulation effect of aluminum curtain walls on buildings. These studies were carried out on DOE 2.2 based software. DOE-2.2 is a widely used system that can predict energy use and cost for any type of building. DOE-2 analyzes weather data, user-entered building layout, building materials, building air conditioning systems (lighting, HVAC, etc.) and comfort usage areas to perform a 1-year energy simulation of the building. eQUEST is the currently most used interface of DOE-2.2. eQUEST has two different model wizards, a schematic design wizard and a design development wizard, where users can enter various parameters of the building. A schematic design wizard is a model created with little knowledge of building parameters and used in the early stages of design. The design development wizard is the model created with more specific information about the building parameters. Both represent well-known stages during design that differ significantly in the level of detail they involve. The accuracy of the results obtained from building energy modeling software such as eQUEST depends on the accuracy of the information entered into the software.
The main lines of the study were determined as follows. The existing insulated façade of a residence building in the Kağıthane district of Istanbul has been redesigned with the aluminum curtain wall system method by improving its thermal performance. The 365-day energy consumption differences and thermal values of the building were determined through the e-Quest program. Climatic data of the exact location of the building, HVAC system, user profiles, building materials, building architectural plan, sheathing exterior insulation data were collected as data and transferred to the e-Quest program to model the building. During the study, one-to-one building plans prepared on Autocad were included in the model, so that the building design overlapped with the existing structure. 
The insulation areas to be focused on in the model are floor slab, doors, windows, roof and exterior insulation. While creating the building model, the thermal conductivity coefficients and thermal transmittance values of the regions should be calculated and included in the model. The first modelled as sheathing (U=0,554 W/m2K), which is the external wall insulation of the existing building. Since the effect of the exterior cladding of the building on the energy consumption of the building was investigated, the U values of the windows and the outer shell were changed. No changes were made to the roof, floor and doors. Since the building model with aluminum curtain wall system is designed with different thicknesses for the East, West, South facades and for the North facade, the thermal permeability value on these facades differs (South, East, West facade U=0.468 W/m2K, North facade U=0,423 W/m2K). Since the results of the differences in the insulation details will be emphasized in the study, the types, thicknesses and sequences of the materials should be examined separately. The existing building insulation is considered to have been constructed in accordance with TS825 standards and other standards it must meet, since the necessary permits have already been obtained from the competent authorities and the residence has begun. In the sheathing detail of the existing building, there is plaster and paint on the interior walls, and perforated pumice as a wall element. The outer layer contains EPS, plaster and paint. The outer layer element EPS (λ= 0.04 W/mK) is used as the main material that improves the heat transmission value of the building.
The sheathing insulation in the existing building prevents the formation of thermal bridges by covering reinforced concrete elements such as columns, beams and beams on the exterior. At the same time, by providing waterproofing to the building, it both prevents damage to comfort conditions and prevents corrosion risks of reinforcements in reinforced concrete elements. In the aluminum curtain wall system, there is a more detailed insulation than sheathing. There is plaster and paint on the interior walls as in the existing building insulation. Wall element perforated pumice, aluminum profile as insulation layer, rock wool, plaster and composite materials constitute the system.
The cladding method of the curtain wall, the frame made of aluminum profiles, is anchored to the reinforced concrete beam elements as the carrier of the facade, and these anchors are completed at each floor opening and profile width. In the anchors, there is a fixed anchor to the beam element and a movable dowel in the profile, thanks to the movable dowel, the displacement shares that may occur in the aluminum profile due to temperature differences can also be balanced. Reinforced concrete elements and pumices in the outer wall cladding are completely insulated with rockwool, and the rockwool pumices are mounted with carrier dowels. In the design of the aluminum curtain wall, the rockwool thickness in the building is 80 mm on the South, East and West facades, while 100 mm on the North facade is used. Since rockwool is placed between aluminum profiles by compressing, thermal bridges at the junction of aluminum profiles and reinforced concrete elements are also prevented. In front of the rockwool, there is an aluminum composite material of 24 mm thickness, which forms the visible face of the building.
The surface areas of the building glazing were measured from the building plans and included in the model. In addition to the thermal transmittance values of the glasses, their solar radiation transmittance, shading coefficient, and heat gain values from sunlight are decisive in terms of their insulation properties. Existing building glazing is single layer and the glass in the aluminum curtain wall system is double layer Low-E. In addition, in front of the windows in the curtain wall system, there are sun breakers on all facades, except for the North facade.
After the model specifications were completed in the e-Quest model, the annual energy profiles of the existing building and the buildings covered with the aluminum curtain wall system were simulated. Under the title of electricity consumption, space heating and water heating data were obtained under the title of area lighting, equipment, pumps and gas consumption. Electricity consumption values are calculated in kWh, gas consumption data in btu. Due to the climatic conditions in the current location of the building, gas consumption is not required for heating during the summer months. When the energy consumption values are compared, it can be understood that the aluminum curtain wall system has a significant contribution to the building in electricity and gas consumption values. While the electricity consumption in the existing building with sheathing insulation is 282.59 kWh, gas consumption is 488.78 kWh, the electricity consumption in the building with aluminum curtain wall system is 237.74 kWh and gas consumption is 331.78 kWh. In other words, when viewed as a percentage, there was a 15.87% decrease in electricity consumption and a 32.12% decrease in gas consumption compared to the existing building.
In addition to these, the LCA analyses of the building models were performed and the results were analysed to find the reduction in carbon emission. Life cycle assessment is a methodology used to assess the environmental impacts associated with all phases of the life cycle of a commercial product, process or service. The term "life cycle" refers to significant periods in the life of the product from raw material extraction to final conversion, including production, use, maintenance and end-of-life stages. It is aimed to analyze the environmental effects, materials, operational energy consumption and end-of-life stages of the CK Residence building, covered with aluminum curtain wall and existing sheathing insulated state, with the LCA study. All building materials replacement, repair, energy consumption and waste management strategies are included in the boundaries of this study however One Click LCA site was used to conduct the study.
The quantity of materials used in the CK Residence building was calculated and these data were defined in One Click LCA. The service life of the materials that need to be replaced at the end of a certain year has been determined by both the literature data and the One Click LCA database. In addition to the materials used in the building, the energy consumption of the building is critical for LCA. Operational energy consumption is taken from building energy performance models developed on eQuest software. After the inputs such as materials used for the building, area information, operational energy are defined on One Click LCA, this information is processed and results are obtained through specific references for the building. The evaluation method used for reference values is embedded energy comparisons.
According to the result obtained after the building information and operational energy consumptions defined through One Click LCA, the emission values of the building with the existing sheathing coating and the aluminum curtain wall design building were determined. The carbon emission values of the existing building and the building with aluminum curtain wall system were found to be 444 kg CO2e/m2 and 522 kg CO2e/m2. With the currently used materials and operational energy, the building with sheathing insulation is in the middle level category in the "D" class in the embodied carbon comparison. In addition, the building with aluminum curtain wall was found in the "E" class high carbon footprint category in the embodied carbon comparison, with material modifications and changes in operational energy.
As a result of these comparisons, it can be seen that if the aluminum curtain wall system was used in the building on the basis of annual energy density, there would be an energy saving of approximately 25%. Energy efficiency values are calculated annually, but considering that the life of a building varies between 60 and 80 years for optimum conditions, it is understood that serious energy savings can be achieved as a result of multiplying these decreases by 60 to 80 years. On the other hand, improving insulation in buildings does not always give good results in terms of environmental factors. The increase in the aluminum material used in the facade with the use of aluminum profiles and composites has caused the structure to fall from the "D" class to the "E" class in the embodied carbon comparison classification. On the basis of environmental impact assessment, the positive effect of using aluminum curtain wall system on the building in terms of insulation did not have a positive effect on carbon emission values.
If the study is evaluated in the more detailed ways, it will be possible to diversify the design with innovative solutions of aluminum curtain wall systems and make it more energy efficient.