Mevcut Ticari Binaların Aydınlatma Sistemlerinde Enerjiverimliliği Analizi İçin Örnek Bir Çalışma

Abstract

Ticari binaların elektrik enerjisi tüketimleri yıllar içerisinde giderek artış göstererek genel tüketim içerisindeki payları %19'a ulaşmıştır. Aydınlatma sistemlerinin bu tüketimdeki payı ise %20 civarındadır. Aydınlatma Enerjisi Sayısal Göstergesi (AESG) bina enerji performansında, aydınlatma sistemlerinin performansını göstermektedir. AESG hesaplanırken aydınlatma sisteminin kurulu gücü, hacimlerin mimari ve fiziksel özellikleri, kullanım süreleri gibi birçok etken göz önüne alınmaktadır. Mevcut binaların enerji tasarruf analizi yapılırken, elektrik enerjisi tüketiminde önemli bir paya sahip aydınlatma sistemleri de mutlaka ele alınmalıdır. Binalarda mevcut tesisatlarla kurulu olan aydınlatma armatürlerinin verimliliği incelenerek aydınlatma sistemlerinde enerji tasarrufu potansiyeli de net olarak hesaplanmalıdır. Bu çalışmaların yetkin kişilerce yapılması ile, bu alanda yapılabilecek yatırımların geri dönüş süreleri de net olarak belirlenebilecektir. Binalar kullanım amaçları birbirinden farklı çok çeşitli hacimlerden oluşmaktadırlar. Bu hacimlerin kullanım amaçlarına göre aydınlatma tasarım kriterleri de farklılık göstermektedir. Binaların hacimlerinin gruplandırılması, tasarruf hesaplarının daha doğru yapılabilmesi için önemli rol oynamaktadır. Aydınlatma tasarımının maliyet sebebi ile standartların dışında yapılması zamanla daha büyük kayıplara neden olmaktadır. Günümüzde ofis ortamlarının aydınlatmasında sıradışı uygulamalar da görünmektedir. Ülkemizde TS EN 12464-1 standardı ile iç aydınlatma ile ilgili tanımlar, kriterler ve limitler belirtilmiştir. TS EN 12464-1 standardındaki aydınlatma tasarım kriterlerini her bir hacme uygulayarak enerji tasarruf analizi yapmak çok daha gerçekçi bir sonuç çıkaracaktır. Aydınlatma sektöründe yaşanan değişimler ve teknolojik gelişmeleri göz önüne alarak yapılacak hesaplamalar neticesinde geri ödeme sürelerinin çok kısaldığı görünmektedir. Kullanılacak ürünlerin erişilebilir olması, belirlenen standartlara uygunluğu ve maliyeti, verimlilik ve tasarruf uygulamalarına yön verecek ana unsurlardır. Özellikle LED teknolojisinin günümüzde ulaştığı nokta dikkate alınacak olursa LED ışık kaynaklı armatürlerin enerji verimliliği uygulamalarında kullanım olasılığı yükselmektedir. Gün ışığından yararlanmanın şüphesiz ki, aydınlatma sistemlerinde elde edilecek enerji tasarrufuna olumlu etkileri olacaktır. Bina aydınlatmalarında gün ışığından, aydınlatma kontrol sistemlerine entegre edilen algılayıcılar yardımı ile faydalanılmaktadır. Aydınlatma kontrol sistemlerinin maliyeti bu çalışmaya dahil edilirken binada kurulu olan tesisat dikkate alınmıştır. Kontrol sistemlerinin maliyeti ve aydınlatmada enerji tasarrufuna katkıları, her bina için ayrı ayrı incelenmesi gereken bir konudur. Enerji tasarrufu için yapılacak yatırımların finansal kaynakları, bu alandaki teşvik ve destekler ayrıntılı incelenmeli, yatırım maliyetleri mümkün olduğunca aşağı çekilmelidir. Ülke ekonomisinde yaşanan gelişmeler ve döviz kurlarındaki hareketlilik maliyet hesaplamalarını zorlaştırmaktadır. Bu sebeple yatırım maliyetleri zamanla değişmektedir. Bu tez kapsamında, İstanbul Teknik Üniversitesi'nde yapılan doktora çalışması sonucu geliştirilmiş enerji tasarruf analizi hesaplama yöntemi kullanılarak yeni teknoloji LED aydınlatma armatürlerinin mevcut bir binaya uygulanması sonucu elde edilecek elektrik enerjisi tasarrufunun hesaplanması amaçlanmıştır. Mevcut binanın hacimleri gruplandırılarak, bu gruplar için standartlara uygun aydınlatma sistemleri detaylandırılmıştır. Kurulu olan aydınlatma sisteminin gerekli standartları sağlayıp sağlayamadığı, hem ölçümler yapılarak hem de hesaplamalar yardımıyla incelenmiştir. Ölçümler sonucu mevcut sistemin gerekli standartları sağlayamadığı tespit edilmiştir. Bu kapsamda hem birebir değişim sonrası elde edilen veriler incelenmiş, hem de standartları sağlayacak aydınlatma sisteminin maliyeti hesaplanmıştır. Bu koşullar altında elde edilebilecek enerji tasarrufu hesaplanmış, geri ödeme süreleri esas alınarak değerlendirmeler yapılmıştır. Bu tezin, aydınlatmada tüketilen elektrik enerjisinin toplam tüketim içinde payının yüksek olduğu ofis binalarında mevcut sistemlerin LED aydınlatma armatürleri ile dönüşümü sonucu sağlanacak enerji tasarrufu hakkında yol gösterici olması beklenmektedir.

Energy cost is the one of the geratest expenditure of Turkey's economy. All the studies shows that all the sectors have bigger potential for the energy saving. Therefore energy efficiency has become very important subject in our country like all the world. In Turkey, the building sector has a share of 45%, industry 47% and others 8% in the electrical energy consumption. In recent years buildings electrical consumption increase regularly. For example commercial buildings has a share of %9,5 in the year 2000. When we came 2016 this share increase to the %18,8 of the net electrical energy consumption of Turkey. Buildings have an important share in energy consumption. Some systems use conventional energy like natural gas, the other systems generally use clectrical energy. Lighting systems have a large share between %10 and %50 in electical consuption of buildings. For this reason we can say that there could be important energy saving potential by replacing older lighting systems to new systems. Recent lighting systems like LED light sources have improved energy efficiency. We can also save energy by integration of occupancy and daylight control systems. Lighting energy numeric indicator (LENI) indicates the energy performance of the lighting systems. Lower LENI indicates more efficient lighting systems, higher LENI indicates less. Turkish Standard by considering Turkish national conditions is transformed from EN 15193 standard. In Turkey, a calculation methodology has named "BEP-TR" adopted to determine the energy performance for buildings. We need several information of the rooms, like physical and geometrical structure. And also lighting systems like daylight control systems is needed for this methodology. The electrical energy consumption is calculated by considering the installed power. LENI is an indicator of the lighting systems but we could not get the energy saving potential information clearly every time using LENI. For example, LENI can be lower for a building but lighting system could not supports the lighting criterias in EN 12464-1 (Light and lighting – Lighting of work places, Part 1: Indoor work places). Rooms of the buildings have different functionalities. TS EN 12464-1 determines the criteria of the lighting desing for all types of the rooms. Because of this, we must calculate the energy efficiency analysis for each room. The methodology of calculating of energy saving potential was defined by a PhD study in 2012. We focus on the energy efficiency analysis when using new LED lighting luminaires instead of luminaires with traditional lamps for a existing commercial building in Istanbul in this study. Firstly the rooms of this commercial building grouped by their functionality in to four groups. Classical office rooms where needs generally 500 lx of illumination level is in the first group "G1". General using areas like corridors, WC which need between 100 and 300 lx of illumination level participate in the second group "G2". Rooms like loundries, and kitchens participate in third group "G3". Mostly technical rooms stays in the fourth group "G4". Classical office rooms has a share of 93% in the building. For this reason the building is analyzed by considering the rooms which placed in the first and second groups. The building lighting system was designed to provide to 300 lx of illumination level. In the the first and second group the same luminaire is used. Luminaires in some rooms was retrofitted with LED luminaires to analyze energy efficiency. But because of economical reasons this retrofit could not applied for all the rooms. Also several lighting measurements were taken in the rooms of this commercial building. These measurements showed that, the existing lighting system can provide approximately 250 lx avarage illumination level the rooms. The average illumination level in some rooms, which was retrofitted with LED luminaires is approximately 290 lx. Five different type of luminaires have analyzed to determine the most energy efficiency luminaire for this commercial building. First luminaire is 60cm x 60cm "Panel" type, which has 27,1 W total energy concumption with 122,1 lm/W efficacy factor. Second luminaire is again 60cm x 60cm "Panel" type, which has 23W total energy concumption, 147,8 lm/W efficacy factor. Third luminaire is 30cm x 120cm "Linear" type, which has again 23W total energy concumption and 147,8 lm/W efficacy factor. Fourth luminaire is 8cm x 120cm "Linear" type, which has again 24W total energy concumption, 141,6 lm/W efficacy factor. Fifth "Downlight" type, which has 26,7W total energy concumption and 108,7 lm/W efficacy factor. We also aimed to determine a luminaire that supports all the criterias for all the rooms and which does not requires different installation. Dialux software was used for this analyze. For the classical office rooms where needs generally 500 lx of illumination level, LED Panel luminaire provides the best energy efficiency. Calculation showed that Linear LED luminaire is second, Downlight LED luminaire is the third energy efficient luminaire. At the same time for general using areas like corridors, LED Panel luminaire provides the best energy efficiency again. Calculation showed that Downlight LED luminaire is second, Linear LED luminaire is the third energy efficient luminaire for gereral using areas. After these calculation results, LED Panel luminaire is determined to use in economical analyze in this study. Computer software named "BEP-ETA" is used in this study to calculate performance of lighting system based on EN 15193. It has been possible to calculate the amount of electrical energy saving by comparing the existing install powers with the calculated powers for each room. In addition to this, an economical analyze method is expressed for calculation of invesment costs and simple payback time. We analyzed the installed luminaires how much they support the lighting criterias. It has seen that, the lighting system used in the building does not meet the criterias of lighting design defined in the EN 12464-1. Then we calculate the energy efficiency by changing the same number of LED luminaires for each installed luminaires and the number of luminaires how much they supports the criterias of lighting design. After this replacing, by using "BEP-ETA" we had only approximately 290 lx avarage illumination level in all the rooms. Under this situation 2,3 years payback time indicates that replacing recent luminaires to the LED luminaires one to one is very investable. When control system is installed with the LED luminaires in this time payback time improves to 3,6 years. Control systems increase the cost very much, for this reason payback time increase linear. Studies indicate that improving illumination level has lost of different benefits like quality and efficiency of works. For this reason, we calculated also the energy efficiency by changing number of LED luminaires how much they supports the criterias of lighting design. After this replacing, we had approximately 500 lx avarage illumination level in all the rooms. The result of calculation showed that this replacement needs 45% more luminares. We must add installation cost to the luminaries cost under this situation. All of the electrical wiring must be changed in this situation. This cost is 78 TL for each luminaire. By the way, 4,9 years payback time indicates that replacing recent luminaires to the LED luminaire is not investable as one to one replacing. When control system is installed with the LED luminaires in this time payback time improves to 6,4 years. Lighting control systems increase the payback time approximately 1,3 year more in the first situation, but in the second situation increase of payback time is only 1,5 year. Lighting energy saving improves because of the increase of the installed lighting power. In the literature there are some studies which except that LEDs have a linear relation between driving current and luminaire power consumption especially in mid-power LEDs used in the luminaires for office lighting. We used this relation in all analyzes to decrease total power consumption in G1 and G2 type rooms which have 10% more avarage illumination level than criterias of lighting design. Financial sources are very important point of an investment and must be studied detailed. Integration of control systems would save energy more. But the cost of control systems would be uninvestable after last economic situations and exchange rates in Turkey. We need also clear information aboout the contribution of the control system to the lighting energy saving. As a result this study expressed lighting energy saving potential, payback time and the investment costs of LED luminaire transform in a existing commercial building. Energy efficiency calculated by retrofitting of the luminaires in the rooms which participate in the first and second groups of this building. This study indicates that there is an important energy saving potential for the lighting systems in the commercial buildings. Energy saving potential increase with the age of the building. Mostly lighting systems are installed before last 10 years. They have use lower efficiently light sources, lower efficiently components and the old luminaires. LED luminaires have advantages in these subjects.