Multi-Criteria Analysis of Material Compositions of External Walls

2013 ◽  
Vol 664 ◽  
pp. 485-490 ◽  
Author(s):  
Monika Čuláková ◽  
Silvia Vilčeková ◽  
Eva Kridlova-Burdova ◽  
Jana Katunská

Intensity of building development increases by growing population and their requirements on living. Buildings belong to the largest energy consumers and greenhouse gases emitters. Current energy strategy of European Union is focused especially on reduction of operational energy of buildings. Although operational energy participates the highest proportion in total energy consumption over whole life cycle of building, it is important to take into account embodied energy. Values of embodied energy and associated emissions grow by improving energy quality of building envelope by using extra components and insulation materials. This paper demonstrates significance of correct selection of materials in order to environmental and energy optimalization of building structures. The designed material compositions of external wall alternatives are evaluated by methodology LCA and also in the view of impact on future energy consumption though thermal-physical parameters. Results of assessments are compared by multi-criteria decision analysis. The optimized alternative achieves very low embodied energy (218 MJ/m2) and high reduction of embodied CO2 (-114 kg CO2eq/m2).

2014 ◽  
Vol 1008-1009 ◽  
pp. 1320-1325
Author(s):  
Zhao Dong Li ◽  
Yu Rong Yao ◽  
Geng Dai ◽  
Yi Chu Ding

In recent years, continues development of China urbanization gradually increases the energy consumption of buildings. Studies on the life cycle energy distribution of buildings have practical significance to determine energy policy formulation and adjustment. Based on previous studies and the composition of the life cycle energy consumption of buildings, this article constructed a life-cycle energy consumption model, and established the calculation methods of initial embodied energy, operational energy, reset embodied energy ,dismantle embodied energy and recycle embodied energy separately. Based on ICE material energy data and combined rating per machine per team, this article calculated the life cycle energy distribution of a building in Nanjing. We found that the life cycle energy of buildings obeyed normal distribution, the operational energy accounts for a large proportion and it decreases with the decreased life cycle of buildings. The recovery of operational energy can reduce the proportion of the initial embodied energy. Considering the studies, in order to meet the characteristic of the buildings in China which have short life cycle, we should focus on the development of building materials recycling and reusing.


2010 ◽  
Vol 168-170 ◽  
pp. 1735-1741
Author(s):  
Mao Yan ◽  
Li Zhu ◽  
Yi Ping Wang ◽  
Ming Ze Zhu

With the high proportion of building energy consumption in the total energy consumption, it is of great importance to relieve the shortage of conventional energy resources and improve the building environment by incorporating solar energy into buildings. A new type solar roof panels were designed and tested in the present paper, which perfectly achieves the integration of solar equipment with building envelope. This panel can act as the construction component for building envelope and completely removes the double-skin mode for conventional solar equipment, as well as the functional equipment for heating and cooling collecting. Corrugated colored steel roof panel was tested under various climate conditions and operation conditions. The results show that in a typical sunny day the average heat collecting efficiency is 49% and the average cooling capacity is 100W/m2. In a cloudy day, the average heat collecting efficiency is 41% and the average cooling capacity is 84W/m2.


2014 ◽  
Vol 32 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Zaid Alwan ◽  
Paul Jones

Purpose – The construction industry has focused on operational and embodied energy of buildings as a way of becoming more sustainable, however, with more emphasis on the former. The purpose of this paper is to highlight the impact that embodied energy of construction materials can have on the decision making when designing buildings, and ultimately on the environment. This is an important aspect that has often been overlooked when calculating a building's carbon footprint; and its inclusion this approach presents a more holistic life cycle assessment. Design/methodology/approach – A building project was chosen that is currently being designed; the design team for the project have been tasked by the client to make the facility exemplary in terms of its sustainability. This building has a limited construction palette; therefore the embodied energy component can be accurately calculated. The authors of this paper are also part of the design team for the building so they have full access to Building Information Modelling (BIM) models and production information. An inventory of materials was obtained for the building and embodied energy coefficients applied to assess the key building components. The total operational energy was identified using benchmarking to produce a carbon footprint for the facility. Findings – The results indicate that while operational energy is more significant over the long term, the embodied energy of key materials should not be ignored, and is likely to be a bigger proportion of the total carbon in a low carbon building. The components with high embodied energy have also been identified. The design team have responded to this by altering the design to significantly reduce the embodied energy within these key components – and thus make the building far more sustainable in this regard. Research limitations/implications – It may be is a challenge to create components inventories for whole buildings or for refurbishments. However, a potential future approach for is application may be to use a BIM model to simplify this process by imbedding embodied energy inventories within the software, as part of the BIM menus. Originality/value – This case study identifies the importance of considering carbon use during the whole-life cycle of buildings, as well as highlighting the use of carbon offsetting. The paper presents an original approach to the research by using a “live” building as a case study with a focus on the embodied energy of each component of the scheme. The operational energy is also being calculated, the combined data are currently informing the design approach for the building. As part of the analysis, the building was modelled in BIM software.


2013 ◽  
Vol 689 ◽  
pp. 54-59 ◽  
Author(s):  
Usep Surahman ◽  
Tetsu Kubota

This study aims to develop a simplified life cycle assessment model for residential buildings in Indonesia, which can be used under relatively poor data availability conditions. In order to obtain material inventory data and household energy consumption profiles for constructing the above model, a survey was conducted in Bandung in 2011. This paper analyzes life cycle energy and CO2 emissions employing an input-output analysis-based method within unplanned houses (n=250), which are classified into three categories, namely simple, medium and luxurious houses. The results showed that the average embodied energy of simple, medium and luxurious houses was 36.3, 130.0 and 367.7 GJ respectively. The cement consumed the largest energy and emitted the most CO2 emissions among all materials. The annual average operational energy of simple, medium and luxurious houses varied widely at 11.6, 17.4 and 32.1 GJ/year respectively. The energy consumption for cooking accounted for the largest percentage of operational energy. The profiles of life cycle CO2 emissions were similar with those of life cycle energy. The factors affecting embodied, operational and life cycle energy were also studied.


2013 ◽  
Vol 368-370 ◽  
pp. 607-610 ◽  
Author(s):  
Xue Yan Zhang ◽  
Bin Chen ◽  
Yan Qing Liu ◽  
Xv Liang Han

In cold rural areas of Eastern China, heating energy consumption was increased year by year, affected by some factors such as building materials, different courtyard layouts and residential constructions. Based on field measurements and multiple perspectives analysis of typical houses, the heat of cold air infiltration in one house could be reduced by 18.3 %, while the courtyard design was adapted to local climatic conditions. Heating energy consumption could be reduced by 15% for reasonable energy utilization, and which could be reduced by 50% for rational design of building layout and correct selection of materials for building envelope.


Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 633
Author(s):  
Mirzhan Kaderzhanov ◽  
Shazim Ali Memon ◽  
Assemgul Saurbayeva ◽  
Jong R. Kim

Nowadays, the residential sector of Kazakhstan accounts for about 30% of the total energy consumption. Therefore, it is essential to analyze the energy estimation model for residential buildings in Kazakhstan so as to reduce energy consumption. This research is aimed to develop the Overall Thermal Transfer Value (OTTV) based Building Energy Simulation Model (BESM) for the reduction of energy consumption through the envelope of residential buildings in seven cities of Kazakhstan. A brute force optimization method was adopted to obtain the optimal envelope configuration varying window-to-wall ratio (WWR), the angle of a pitched roof, the depth of the overhang shading system, the thermal conductivity, and the thicknesses of wall composition materials. In addition, orientation-related analyses of the optimized cases were conducted. Finally, the economic evaluation of the base and optimized cases were presented. The results showed that an average energy reduction for heating was 6156.8 kWh, while for cooling it was almost 1912.17 kWh. The heating and cooling energy savings were 16.59% and 16.69%, respectively. The frontage of the building model directed towards the south in the cold season and north in the hot season demonstrated around 21% and 32% of energy reduction, respectively. The energy cost savings varied between 9657 to 119,221 ₸ for heating, 9622 to 36,088 ₸ for cooling.


Author(s):  
Lucas Rosse Caldas ◽  
Rosa Maria Sposto ◽  
Alexandre Mendonça Souto Lopes ◽  
Werner Castro Tavares

RESUMO: Como forma de mensurar o consumo de energia ao longo do ciclo de vida dos diversos sistemas construtivos existentes, entre eles o light steel framing (LSF), tem sido aplicado a avaliação do ciclo de vida energético (ACVE). A ACVE foi aplicada em diversos estudos nacionais e internacionais, e no caso do LSF já foi verificado em alguns estudos nacionais. No entanto, ainda existe uma lacuna de estudos relacionados com o desempenho térmico e com os isolantes térmicos utilizados, principalmente por meio de simulações termoenergéticas. Neste sentido, o presente trabalho teve como objetivo avaliar a energia consumida ao longo do ciclo de vida de uma habitação de LSF, comparando o desempenho térmico deste sistema sem e com três isolantes térmicos, sendo eles: lã de vidro, lã de rocha e poliestireno expandido (EPS). A metodologia utilizada foi a pesquisa bibliográfica e simulação computacional em um software de simulação termoenergético. Ao final foi levantada a energia incorporada dos materiais utilizados nas fachadas, energia consumida nos transportes e energia gasta pelos equipamentos eletrônicos (energia operacional). A soma de todos estes consumos resultou na energia total, esta que foi maior para o sistema sem isolamento térmico e menor para o sistema com EPS. Neste sentido, a principal contribuição deste trabalho foi apresentar um critério de sustentabilidade energética para a especificação de isolantes térmicos para o sistema de LSF. Este critério poderá subsidiar, durante a etapa de projeto, a escolha do sistema mais vantajoso tanto do ponto de vista térmico como do consumo de energia ao longo do ciclo de vida da edificação. ABSTRACT: As a way to measure the energy consumption over the life cycle of the various existing building systems, including light steel framing (LSF), has been applied to evaluate the life cycle energy assessment (LCEA). The LCEA was applied in several national and international studies, and in the case of LSF has already been verified in some national studies. However, there is still a lack of research related to thermal performance and thermal insulation used, mainly through thermal-energetic simulations. In this context, this study aimed to evaluate the energy consumed throughout the life cycle of a LSF house, comparing the thermal performance of this system without and with three thermal insulations, which are: glass wool, rock wool and polystyrene expanded (EPS). The methodology used was the bibliographical research and computer simulation on a thermal-energetic simulation software. It was assessed the embodied energy of the materials used on the facades, energy consumed in transport and energy consumed by electronic equipment (operating energy). The sum of all these resulted in total energy consumption, this one was higher for the system without thermal insulation and lower to the system with EPS. In this sense, the main contribution of this paper is to present an energy sustainability criteria for the specification of thermal insulation for the LSF system. This criteria can support, during the design stage, the choice of the most advantageous system in terms of the thermal performance and the energy consumption throughout the life cycle of the building.


2019 ◽  
Vol 111 ◽  
pp. 03052 ◽  
Author(s):  
Mohammed Khalaf ◽  
Touraj Ashrafian ◽  
Cem Demirci

The energy conversations methods and techniques take a significant role in the energy performance of the buildings. Façade and shading systems are in continuous development, and recent studies are showing the importance of implementation of such systems to reduce energy consumption and enhance the effectiveness of the building performance. School buildings are mostly being used during daytime, hence, require active use of sunlight. A measure that is taken on a school building envelope can prevent overheating and overcooling and reduce the heating and cooling energy consumption but at the same time can increase the lighting energy consumption vice versa. Thus, it is necessary to optimise the energy required for climatisation of a building with lighting energy demand. The main aim of the paper is to provide analysis for façade and shading systems applied to a school building and study the effectiveness of it on energy consumption and conservation. The case study for this paper is a typical building project designed to be located in Istanbul, Turkey and has a traditional façade system which is clear double layer windows without any shading devices. The analyses of the energy efficiency of these systems will be presented. The different glazing types and shading systems alternatives will show the most efficient one to be used as some optimised alternatives for the systems. Findings indicate that proper glazing and shading systems can reduce the needed energy for heating and lightening and thus total energy consumption of a school building significantly.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4577 ◽  
Author(s):  
Danijela Nikolic ◽  
Slobodan Djordjevic ◽  
Jasmina Skerlic ◽  
Jasna Radulovic

It is well known that nowadays a significant part of the total energy consumption is related to buildings, so research for improving building energy efficiency is very important. This paper presents our investigations about the dimensioning of horizontal overhangs in order to determine the minimum annual consumption of building primary energy for heating, cooling and lighting. In this investigation, embodied energy for horizontal roof overhangs was taken into account. The annual simulation was carried out for a residential building located in the city of Belgrade (Serbia). Horizontal overhangs (roof and balcony) are positioned to provide shading of all exterior of the building. The building is simulated in the EnergyPlus software environment. The optimization of the overhang size was performed by using the Hooke Jeeves algorithm and plug-in GenOpt program. The objective function minimizes the annual consumption of primary energy for heating, cooling and lighting of the building and energy spent to build overhangs. The simulation results show that the building with optimally sized roof and balcony overhangs consumed 7.12% lessprimary energy for heating, cooling and lighting, compared to the house without overhangs. A 44.15% reduction in cooling energy consumption is also achieved.


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