scholarly journals Life Cycle Energy Assessment of a School Building under Envelope Retrofit: An Approach towards Environmental Impact Reduction

2019 ◽  
Vol 111 ◽  
pp. 03028
Author(s):  
Nazanin Moazzen ◽  
Mustafa Erkan Karagüler ◽  
Touraj Ashrafian

Energy efficiency of existing buildings is a concept to manage and restrain the growth in energy consumption and one of the crucial issues due to the magnitude of the sector. Educational buildings are in charge of about 15% of the total energy consumption of the non-residential building sector. However, not only operational but also embodied energy of a building should be reduced to get the overall benefits of energy efficiency, where, using energy efficient architectural measures and low emitting materials during every retrofit action can be a logical step. The majority of buildings in Turkey and EU was built earlier than the development of the energy efficiency in the construction sector, hence, without energy retrofit, consume an enormous amount of energy that can be averted significantly by the implementation of some even not advanced retrofit measures. Furthermore, demolishing of a building to construct a new one is not a rational approach concerning cost, time and environmental pollution. The study has been focused on the impact assessment of the various architectural scenarios of energy efficiency upgrading on the Life Cycle Energy Consumption (LCEC) and Life Cycle CO2 (LCCO2) emission. Within the scope of the study, a primary school building is selected to be analysed. Through analysis, the total embodied and operational energy use and CO2 emission regarding the life cycle phase of the building is quantitatively defined and investigated in the framework of life cycle inventory. The paper concentrates on the operation and embodied energy consumption arising from the application of a variety of measures on the building envelope. An educational building with low LCCO2 emissions and LCEC in Turkey is proposed. To exemplify the approach, contributions are applied to a case study in Istanbul as a representative school building. The primary energy consumption of the case study building is calculated with a dynamic simulation tool, EnergyPlus. Afterwards, a sort of architectural energy efficient measures is implemented in the envelope while the lighting and mechanical systems remain constant. The energy used in the production and transportation of materials, which are the significant parts of the embodied energy, are taken into account as well.

2019 ◽  
Vol 887 ◽  
pp. 335-343
Author(s):  
Nazanin Moazzen ◽  
Mustafa Erkan Karaguler ◽  
Touraj Ashrafian

Energy efficiency has become a crucial part of human life, which has an adverse impact on the social and economic development of any country. In Turkey, it is a critical issue especially in the construction sector due to increase in the dependency on the fuel demands. The energy consumption, which is used during the life cycle of a building, is a huge amount affected by the energy demand for material and building construction, HVAC and lighting systems, maintenance, equipment, and demolition. In general, the Life Cycle Energy (LCE) needs of the building can be summarised as the operational and embodied energy together with the energy use for demolition and recycling processes.Besides, schools alone are responsible for about 15% of the total energy consumption of the commercial building sector. To reduce the energy use and CO2 emission, the operational and embodied energy of the buildings must be minimised. Overall, it seems that choosing proper architectural measures for the envelope and using low emitting material can be a logical step for reducing operational and embodied energy consumptions.This paper is concentrated on the operating and embodied energy consumptions resulting from the application of different architectural measures through the building envelope. It proposes an educational building with low CO2 emission and proper energy performance in Turkey. To illustrate the method of the approach, this contribution illustrates a case study, which was performed on a representative schoold building in Istanbul, Turkey. Energy used for HVAC and lighting in the operating phase and the energy used for the manufacture of the materials are the most significant parts of embodied energy in the LCE analyses. This case study building’s primary energy consumption was calculated with the help of dynamic simulation tools, EnergyPlus and DesignBuilder. Then, different architectural energy efficiency measures were applied to the envelope of the case study building. Then, the influence of proposed actions on LCE consumption and Life Cycle CO2 (LCCO2) emissions were assessed according to the Life Cycle Assessment (LCA) method.


2021 ◽  
Author(s):  
◽  
Rajesh Haripersad

South Africa is a developing country with various construction projects that are being undertaken both by government and the private sector. The requirements for the construction of energy-efficient buildings as well as the selection methods for providing construction materials have hence become important. Energy efficiency improvements needs to be implemented in the construction of these buildings in order to decrease energy usage and costs and provide more comfortable conditions for its occupants. Previous studies revealed that most of the focus for improving energy efficiency in buildings has been on their operational emissions. It is estimated that about 30% of all energy consumed throughout the lifetime of a building is utilized as embodied energy (this percentage varies based on factors such as age of building, climate and materials). In the past this percentage was much lower, but with increased emphasis placed on reducing operational emissions (such as energy efficiency improvements in heating and cooling systems), the embodied energy contribution has become more significant. Hence, it is important to employ a life-cycle carbon framework in analysing the carbon emissions in buildings. The study aims to augment energy efficiency initiatives by showcasing energy reduction strategies for buildings. The study assessed the thermal performance of selected construction materials by analysing different buildings using energy modelling program, EnergyPlus and TRNSYS. The parametric study was set in the central plateau region of South Africa and was performed to determine appropriate energy efficiency improvements that can be implemented for maximum savings. A life cycle cost analysis was performed on the selected improvements. The models created are representative of the actual buildings when simulated data is compared to recorded data from these buildings. Results showed a significant variation in energy and construction costs with varying construction materials over the buildings’ life cycle. Findings suggest that there is a significant reduction in energy usage when simple efficiency measures are implemented. The study recommends the use of different energy efficient building materials and the implementation of passive interventions in the constructing of buildings; the thermal performance of a building be optimized to ensure thermal comfort and the developed model be adopted for use in the engineering and construction industry for the reduction of energy consumption.


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.


2021 ◽  
Author(s):  
Philip McKeen ◽  
Alan S. Fung

This paper examines the energy consumption of varying aspect ratio in multi-unit residential buildings in Canadian cities. The aspect ratio of a building is one of the most important determinants of energy efficiency. It defines the building surface area by which heat is transferred between the interior and exterior environment. It also defines the amount of building area that is subject to solar gain. The extent to which this can be beneficial or detrimental depends on the aspect ratio and climate. This paper evaluates the relationship between the geometry of buildings and location to identify a design vernacular for energy-efficient designs across Canada.


2019 ◽  
Vol 27 (2) ◽  
pp. 441-457 ◽  
Author(s):  
Filipa Salvado ◽  
Nuno Almeida ◽  
Alvaro Vale e Azevedo

Purpose Both financial and non-financial functions are imbedded in the life-cycle management activities of building assets. These functions provide relevant information for the establishment of operational and maintenance strategies and for decision-making processes related with the timing of major repairs, replacements and rehabilitations. The purpose of this paper is to focus on improving the alignment of financial and non-financial functions related to the recognition that the service potential of buildings should be appropriately funded as it is consumed over its life cycle. Design/methodology/approach Authors undertake an analysis of depreciation rates used to accommodate a systematic allocation of the depreciable amount of building assets over its useful life. Different depreciation approaches and calculation methods are explored. A case study of a school building portfolio is used to debate situations of misalignment of financial and non-financial depreciation rates. Data mining methods including decision tree and clustering are used to predict equivalent functional depreciation rates of buildings system and subsystems and promote an enhanced alignment with regulated financial depreciation rates toward an optimized life-cycle management of the school building portfolio. Findings Historical data show the relevance of considering technical and functional characteristics of the building system and their subsystems (landscaping; structure; external elevations and roofs; interior divisions; and services and equipment) when determining depreciation rates for the building assets The case study showed a misalignment of equivalent functional and financial depreciation rates used in the life-cycle management activities of the school building portfolio ranging between 1/1.26 for external elevations and roofs and 1/5.21 for landscaping. Originality/value Buildings initial technical and functional attributes are affected with its wear, aging or decay, causing loss of value until they reach end-of-life. This paper demonstrates the impact of the different interpretations of the concept of useful life and the subsequent misalignment that it generates between financial functions based on financial depreciation rates and non-financial functions based on historical data and the functional equivalent (technical and functional) depreciation rates. Economic data of 158 public school buildings constructed in Portugal since the 1940s, that sound life-cycle thinking enhances the alignment of both financial and non-financial functions.


2019 ◽  
Author(s):  
Gianandrea Mannarini ◽  
Lorenzo Carelli

Abstract. VISIR-I.b, the latest development of the ship routing model published in Mannarini et al. (2016a), is here presented. The new model version targets large ocean-going vessels by accounting for both waves and ocean currents. In order to effectively use currents in a graph-search method, new equations are derived and validated versus analytical benchmarks. A case study is computed in the Atlantic Ocean, on a route from the Chesapeake Bay to the Mediterranean Sea and vice versa. Ocean analysis fields from data-assimilative models (for both ocean state and hydrodynamics) are employed. The impact of waves and ocean currents on transatlantic crossings is assessed through mapping of the spatial variability of the routes, analysis of their kinematics, distribution of the optimal voyage duration vs. its length, and impact on the Energy Efficiency Operational Indicator of the International Maritime Organization. It is distinguished between sailing with or against the main ocean current. The seasonal dependence of the savings is evaluated, indicating, for the featured case study, larger savings during the summer crossings and larger intra-monthly variability in winter. The monthly-mean savings sum up to values between 3 and 12 %, while the contribution of ocean currents is between 1 and 4 %. Also, several other ocean routes are considered, providing a pan-Atlantic scenario assessment of the potential gains in energy efficiency from optimal tracks and linking them to regional meteo-oceanographic features.


2019 ◽  
Vol 27 (4) ◽  
pp. 567-578
Author(s):  
Marcin Zygmunt ◽  
Marcin Piczulski

The aim of the article is to presents the results of calculations regarding the: economic – based on the life cycle costing (LCC) approach, environmental – based on the life cycle assessment (LCA) approach and social aspects of modeled refurbishment of residential and non-residential stock of buildings. Particular emphasis was placed on the impact of energy efficiency of the modeled buildings on environmental aspects and the selection of renewable and non-renewable energy sources. The article presents an analysis of an area of energy cluster in terms of environmental aspects and a detailed analysis of an offi ce building using advanced energy simulations. The calculations for energy cluster was made using Polish energy certifi cate methodology (monthly calculations) while analysis of an office building was performed using dynamic hourly simulations with use of Energy Plus software. Performed analysis results in reaching energy efficiency scenarios for both cases according to meeting sustain development idea.


Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1732 ◽  
Author(s):  
Yasmeen Hossain ◽  
Tom Marsik

Buildings are responsible for a large portion of global greenhouse gas emissions. While energy efficiency features can significantly reduce the greenhouse gas emissions during a building’s operational stage, extra materials and processes associated with these features typically involve higher greenhouse gas emissions during the construction phase. In order to study this relationship, a case study of a highly energy-efficient house in rural Alaska was performed. For the purposes of this case study, a theoretical counterpart home was designed that has the same interior space, but insulation values close to the code minimum requirements. Using computer simulations, a Life Cycle Assessment (LCA) was performed for the case study home as well as its conventional counterpart. The extra greenhouse gas emissions associated with the construction of the case study home were compared to the annual savings in greenhouse gas emissions achieved thanks to the energy efficiency features, and carbon payback was calculated. The carbon payback was calculated to be just over three years, which is only a small fraction of the life of the building. The results of this study show that despite higher greenhouse gas emissions during the construction phase, highly energy-efficient homes can play an important role in addressing climate change.


Author(s):  
Abdelrahman Arbi ◽  
Timothy O'Farrell ◽  
Fu-Chun Zheng ◽  
Simon C. Fletcher

Network densification by adding either more sectors per site or by deploying an overlay of small cells is always considered to be a key method for enhancing the RAN coverage and capacity. The impact of these two techniques on cellular network energy consumption is investigated in this chapter. The aim is to find an energy efficient deployment strategy when trading-off the order of sectorisation with the intensity of small cell densification. A new enhanced base station power consumption model is presented, followed by a novel metric framework for the evaluation of the RAN energy efficiency. The use of the power model and the proposed metrics is demonstrated by applying them to a RAN case study when the two techniques are used to improve the network capacity. In addition, the chapter evaluates the amount of network energy efficiency improvement when various adaptive sectorisation schemes are implemented. The results show that the strategy of adding more sectors is less energy efficient than directly deploying an overlay of small cells, even when adaptive sectorisation is implemented.


Author(s):  
Igor Tucaković ◽  
Marina Nikolić Topalović ◽  
Tanja Trkulja

The aim of the research is to obtain optimal ranges of thermal envelope for the desired energy classes, which will contribute to a more economical and rational approach to the design of buildings, as well as to prove that with the increase of thermal envelope there is an increase of the energy class. The model on which the research was formed and applied is a typical semi-detached house in Belgrade. By comparing the results of the reference family house, the framework parameters for the satisfaction of a certain energy class have been formed, based on the fulfillment of the energy efficiency requirements established by national regulations.


Sign in / Sign up

Export Citation Format

Share Document