scholarly journals Embodied Energy versus Operational Energy. Showing the Shortcomings of the Energy Performance Building Directive (EPBD)

2012 ◽  
Vol 730-732 ◽  
pp. 587-591 ◽  
Author(s):  
F. Pacheco-Torgal ◽  
Joana Faria ◽  
Saíd Jalali
Keyword(s):  
Power Plants ◽  
Building Materials ◽  
Energy Use ◽  
Energy Savings ◽  
Energy Performance ◽  
Hot Water ◽  
Embodied Energy ◽  
Mineral Admixtures ◽  
High Efficient ◽  
Operational Energy

Energy is a key issue for Portugal, it is responsible for the higher part of its imports and since almost 30% of Portuguese energy is generated in power stations it is also responsible for high CO2 emissions. Between 1995 and 2005 Portuguese GNP rise 28%, however the imported energy in the same period increased 400%, from 1500 million to 5500 million dollars. As to the period between 2005 and 2007 the energy imports reach about 10,000 million dollars. Although recent and strong investments in renewable energy, Portugal continue to import energy and fossil fuels. This question is very relevant since a major part of the energy produced in Portugal is generated in power plants thus emitting greenhouse gases (GHGs). Therefore, investigations that could minimize energy use are needed. This paper presents a case study of a 97 apartment-type building (27.647 m2) located in Portugal, concerning both embodied energy as well as operational energy (heating, hot water, electricity). The operational energy was an average of 187,2 MJ/m2/yr and the embodied energy accounts for aprox. 2372 MJ/m2, representing just 25,3% of the former for a service life of 50 years. Since Portuguese energy efficiency building regulation made under the Energy Performance Building Directive (2002/91/EC-EPBD) will lead to a major decrease of operational energy this means that the energy required for the manufacturing of building materials could represent in a near future almost 400% of operational energy. Replacement up to 75% of Portland cement with mineral admixtures could allow energy savings needed to operate a very high efficient 97 apartment-type building during 50 years.

scholarly journals Strategies to Improve the Energy Performance of Buildings: A Review of Their Life Cycle Impact

Buildings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 105 ◽  
Author(s):  
Nadia MIRABELLA ◽  
Martin RÖCK ◽  
Marcella Ruschi Mendes SAADE ◽  
Carolin SPIRINCKX ◽  
Marc BOSMANS ◽  
...  
Keyword(s):  
Life Cycle ◽  
Case Studies ◽  
Environmental Impacts ◽  
Energy Use ◽  
Ghg Emissions ◽  
Energy Performance ◽  
Environmental Benefits ◽  
Embodied Energy ◽  
Trade Offs ◽  
Operational Energy

Globally, the building sector is responsible for more than 40% of energy use and it contributes approximately 30% of the global Greenhouse Gas (GHG) emissions. This high contribution stimulates research and policies to reduce the operational energy use and related GHG emissions of buildings. However, the environmental impacts of buildings can extend wide beyond the operational phase, and the portion of impacts related to the embodied energy of the building becomes relatively more important in low energy buildings. Therefore, the goal of the research is gaining insights into the environmental impacts of various building strategies for energy efficiency requirements compared to the life cycle environmental impacts of the whole building. The goal is to detect and investigate existing trade-offs in current approaches and solutions proposed by the research community. A literature review is driven by six fundamental and specific research questions (RQs), and performed based on two main tasks: (i) selection of literature studies, and (ii) critical analysis of the selected studies in line with the RQs. A final sample of 59 papers and 178 case studies has been collected, and key criteria are systematically analysed in a matrix. The study reveals that the high heterogeneity of the case studies makes it difficult to compare these in a straightforward way, but it allows to provide an overview of current methodological challenges and research gaps. Furthermore, the most complete studies provide valuable insights in the environmental benefits of the identified energy performance strategies over the building life cycle, but also shows the risk of burden shifting if only operational energy use is focused on, or when a limited number of environmental impact categories are assessed.

Design and Performance of the Van Geet Off-Grid Home

2004 ◽  
Vol 126 (2) ◽  
pp. 738-743 ◽  
Author(s):  
C. Dennis Barley ◽  
Paul Torcellini ◽  
Otto Van Geet
Keyword(s):  
Computer Simulation ◽  
Energy Efficient ◽  
Performance Monitoring ◽  
Energy Use ◽  
Energy Savings ◽  
Energy Performance ◽  
Hot Water ◽  
Domestic Water ◽  
Heating And Cooling ◽  
And Performance

The Van Geet home near Denver, Colorado, demonstrates the successful integration of energy conservation measures and renewable energy supply in a beautiful, comfortable, energy-efficient, 295-m23,176-ft2 off-grid home in a cold, sunny climate. Features include a tight envelope, energy-efficient appliances, passive solar heating (direct gain and Trombe wall), natural cooling, solar hot water, and photovoltaics. In addition to describing this house and its performance, this paper describes the recommended design process of (1) setting a goal for energy efficiency at the outset, (2) applying rules of thumb, and (3) using computer simulation to fine-tune the design. Performance monitoring and computer simulation are combined for the best possible analysis of energy performance. In this case, energy savings are estimated as 89% heating and cooling (compared to 95 MEC), 83% electrical, and nearly 100% domestic water heating. The heating and cooling energy use is 8.96kJ/°Cs˙days˙m20.44Btu/°Fs˙days˙ft2.

scholarly journals Facade Design Process to Establish and Achieve Net Zero Carbon Building Targets

2021 ◽  
Vol 2069 (1) ◽  
pp. 012199
Author(s):  
Andrea Zani ◽  
Oluwateniola Ladipo ◽  
Antonio D’Aquilio ◽  
Carmelo Guido Galante ◽  
Matthew Tee ◽  
...  
Keyword(s):  
Building Materials ◽  
Energy Use ◽  
Embodied Energy ◽  
Design Development ◽  
Net Zero Energy ◽  
Net Zero ◽  
Operational Energy ◽  
Zero Carbon ◽  
Life Options ◽  
Energy Codes

Abstract As more stringent building energy codes and sustainability certification goals have become more prevalent in recent years, a focus for many building designers has been reducing the operational energy with the objective of reaching net-zero energy targets. More recently, as the efficiency in operational energy use has increased significantly, the focus is moving towards the environmental impact of building materials, primarily reflected in the embodied energy and emissions, and the potential (re)life options that allow circular material flows and reduced global warming potential. This paper investigates a methodology applied during early and advanced design development phases to assess and compare different façade typology carbon emissions. Embodied carbon is evaluated through Life Cycle Assessment (LCA) analysis, and operational carbon is analysed during the service life of the office building through energy simulation. Results show that overall carbon assessment of different facade solution can provide useful design feedback in the decision-making process.

scholarly journals Benchmarks for Embodied and Operational Energy Assessment of Hellenic Single-Family Houses

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4384
Author(s):  
Elena G. Dascalaki ◽  
Poulia A. Argiropoulou ◽  
Constantinos A. Balaras ◽  
Kalliopi G. Droutsa ◽  
Simon Kontoyiannidis
Keyword(s):  
Energy Use ◽  
Energy Intensity ◽  
Construction Materials ◽  
Energy Performance ◽  
Embodied Energy ◽  
Single Family ◽  
Zero Energy ◽  
Relative Significance ◽  
Climate Conditions ◽  
Operational Energy

Building energy performance benchmarking increases awareness and enables stakeholders to make better informed decisions for designing, operating, and renovating sustainable buildings. In the era of nearly zero energy buildings, the embodied energy along with operational energy use are essential for evaluating the environmental impacts and building performance throughout their lifecycle. Key metrics and baselines for the embodied energy intensity in representative Hellenic houses are presented in this paper. The method is set up to progressively cover all types of buildings. The lifecycle analysis was performed using the well-established SimaPro software package and the EcoInvent lifecycle inventory database, complemented with national data from short energy audits carried out in Greece. The operational energy intensity was estimated using the national calculation engine for assessing the building’s energy performance and the predictions were adapted to obtain more realistic estimates. The sensitivity analysis for different type of buildings considered 16 case studies, accounting for representative construction practices, locations (climate conditions), system efficiencies, renovation practices, and lifetime of buildings. The results were used to quantify the relative significance of operational and embodied energy, and to estimate the energy recovery time for popular energy conservation and energy efficiency measures. The derived indicators reaffirm the importance of embodied energy in construction materials and systems for new high performing buildings and for renovating existing buildings to nearly zero energy.

Design and Performance of the Van Geet Off-Grid Home

Solar Energy ◽  
2003 ◽  
Author(s):  
C. Dennis Barley ◽  
Paul Torcellini ◽  
Otto Van Geet
Keyword(s):  
Computer Simulation ◽  
Energy Efficient ◽  
Performance Monitoring ◽  
Energy Use ◽  
Energy Savings ◽  
Energy Performance ◽  
Hot Water ◽  
Domestic Water ◽  
Heating And Cooling ◽  
And Performance

The Van Geet home near Denver, Colorado, demonstrates the successful integration of energy conservation measures and renewable energy supply in a beautiful, comfortable, energy-efficient, 295-m2 (3,176-ft2) off-grid home in a cold, sunny climate. Features include a tight envelope, energy-efficient appliances, passive solar heating (direct gain and Trombe wall), natural cooling, solar hot water, and photovoltaics. In addition to describing this house and its performance, this paper describes the recommended design process of (1) setting a goal for energy efficiency at the outset, (2) applying rules of thumb, and (3) using computer simulation to fine-tune the design. Performance monitoring and computer simulation are combined for the best possible analysis of energy performance. In this case, energy savings are estimated as 89% heating and cooling, 83% electrical, and nearly 100% domestic water heating. The heating and cooling energy use is 8.96 kJ/°C·day·m2 (0.44 Btu/°F·day·ft2).

scholarly journals Energy and Greenhouse Gas Savings for LEED-Certified U.S. Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 749
Author(s):  
John H. Scofield ◽  
Susannah Brodnitz ◽  
Jakob Cornell ◽  
Tian Liang ◽  
Thomas Scofield
Keyword(s):  
Greenhouse Gas ◽  
Energy Use ◽  
Energy Savings ◽  
Electric Energy ◽  
Building Energy ◽  
Energy Performance ◽  
Office Buildings ◽  
Ghg Emission ◽  
Site Energy ◽  
New Construction

In this work, we present results from the largest study of measured, whole-building energy performance for commercial LEED-certified buildings, using 2016 energy use data that were obtained for 4417 commercial office buildings (114 million m2) from municipal energy benchmarking disclosures for 10 major U.S. cities. The properties included 551 buildings (31 million m2) that we identified as LEED-certified. Annual energy use and greenhouse gas (GHG) emission were compared between LEED and non-LEED offices on a city-by-city basis and in aggregate. In aggregate, LEED offices demonstrated 11% site energy savings but only 7% savings in source energy and GHG emission. LEED offices saved 26% in non-electric energy but demonstrated no significant savings in electric energy. LEED savings in GHG and source energy increased to 10% when compared with newer, non-LEED offices. We also compared the measured energy savings for individual buildings with their projected savings, as determined by LEED points awarded for energy optimization. This analysis uncovered minimal correlation, i.e., an R2 < 1% for New Construction (NC) and Core and Shell (CS), and 8% for Existing Euildings (EB). The total measured site energy savings for LEED-NC and LEED-CS was 11% lower than projected while the total measured source energy savings for LEED-EB was 81% lower than projected. Only LEED offices certified at the gold level demonstrated statistically significant savings in source energy and greenhouse gas emissions as compared with non-LEED offices.

scholarly journals UNDERSTANDING THE EMBEDDED CARBON CHALLENGES OF BUILDING SERVICE SYSTEMS

2021 ◽  
Vol 1 ◽  
pp. 3279-3288
Author(s):  
Maria Hein ◽  
Darren Anthony Jones ◽  
Claudia Margot Eckert
Keyword(s):  
Energy Use ◽  
Cooling System ◽  
Current System ◽  
Energy Performance ◽  
Service Systems ◽  
Carbon Footprints ◽  
Embodied Carbon ◽  
Study Results ◽  
Operational Energy

AbstractEnergy consumed in buildings is a main contributor to CO2 emissions, there is therefore a need to improve the energy performance of buildings, particularly commercial buildings whereby building service systems are often substantially over-designed due to the application of excess margins during the design process.The cooling system of an NHS Hospital was studied and modelled in order to identify if the system was overdesigned, and to quantify the oversizing impact on the system operational and embodied carbon footprints. Looking at the operational energy use and environmental performance of the current system as well as an alternative optimised system through appropriate modelling and calculation, the case study results indicate significant environmental impacts are caused by the oversizing of cooling system.The study also established that it is currently more difficult to obtain an estimate of the embodied carbon footprint of building service systems. It is therefore the responsibility of the machine builders to provide information and data relating to the embodied carbon of their products, which in the longer term, this is likely to become a standard industry requirement.

scholarly journals Influence of Lightweight Aggregate Concrete Materials on Building Energy Performance

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 94
Author(s):  
Tara L. Cavalline ◽  
Jorge Gallegos ◽  
Reid W. Castrodale ◽  
Charles Freeman ◽  
Jerry Liner ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Building Materials ◽  
Energy Savings ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Simulation ◽  
Building Energy Simulation ◽  
Building Energy Performance

Due to their porous nature, lightweight aggregates have been shown to exhibit thermal properties that are advantageous when used in building materials such as lightweight concrete, grout, mortar, and concrete masonry units. Limited data exist on the thermal properties of materials that incorporate lightweight aggregate where the pore system has not been altered, and very few studies have been performed to quantify the building energy performance of structures constructed using lightweight building materials in commonly utilized structural and building envelope components. In this study, several lightweight concrete and masonry building materials were tested to determine the thermal properties of the bulk materials, providing more accurate inputs to building energy simulation than have previously been used. These properties were used in EnergyPlus building energy simulation models for several types of commercial structures for which materials containing lightweight aggregates are an alternative commonly considered for economic and aesthetic reasons. In a simple model, use of sand lightweight concrete resulted in prediction of 15–17% heating energy savings and 10% cooling energy savings, while use of all lightweight concrete resulted in prediction of approximately 35–40% heating energy savings and 30% cooling energy savings. In more complex EnergyPlus reference models, results indicated superior thermal performance of lightweight aggregate building materials in 48 of 50 building energy simulations. Predicted energy savings for the five models ranged from 0.2% to 6.4%.

CITIES, ENERGY AND CLIMATE: SEVEN REASONS TO QUESTION THE DENSE HIGH-RISE CITY

2020 ◽  
Vol 15 (3) ◽  
pp. 197-214
Author(s):  
Chris Butters ◽  
Ali Cheshmehzangi ◽  
Paola Sassi
Keyword(s):  
Land Use ◽  
Energy Supply ◽  
Energy Use ◽  
Green Space ◽  
Embodied Energy ◽  
Heat Island ◽  
Medium Density ◽  
Ongoing Research ◽  
High Rise ◽  
Operational Energy

ABSTRACT Dense high-rise cities offer some advantages in terms of sustainability but have considerable downsides. Low-dense and medium-rise typologies have been shown to offer good social qualities; their potential energy and carbon advantages have received less attention. As the energy consumption, emissions of cities and heat island effects increase; we question whether dense, high-rise cities offer optimal sustainability. We discuss seven areas where medium density and lower rise typologies offer advantages in terms of energy and climate including: land use/density; microclimate/green space; energy supply; transports; operational energy/carbon; embodied energy/carbon; and resilience. The aim is to discuss the cumulative importance of these areas in the context of sustainable energy use and climate emissions. These areas are subject to ongoing research and are only discussed briefly, since the overarching synthesis perspective for urban planning is our focus. The picture that emerges when these points are seen together, suggests that medium density and lower rise options—like traditional European typologies—may offer, in addition to social qualities, very significant advantages in terms of energy, carbon and climate emissions.

scholarly journals The Performance Gap in Energy-Efficient Office Buildings: How the Occupants Can Help?

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1480 ◽  
Author(s):  
Qadeer Ali ◽  
Muhammad Jamaluddin Thaheem ◽  
Fahim Ullah ◽  
Samad M. E. Sepasgozar
Keyword(s):  
Energy Efficient ◽  
Behavioral Interventions ◽  
Energy Use ◽  
Energy Savings ◽  
Energy Performance ◽  
Office Buildings ◽  
Occupant Behavior ◽  
Energy Usage ◽  
Performance Gap ◽  
Energy Efficient Buildings

Rising demand and limited production of electricity are instrumental in spreading the awareness of cautious energy use, leading to the global demand for energy-efficient buildings. This compels the construction industry to smartly design and effectively construct these buildings to ensure energy performance as per design expectations. However, the research tells a different tale: energy-efficient buildings have performance issues. Among several reasons behind the energy performance gap, occupant behavior is critical. The occupant behavior is dynamic and changes over time under formal and informal influences, but the traditional energy simulation programs assume it as static throughout the occupancy. Effective behavioral interventions can lead to optimized energy use. To find out the energy-saving potential based on simulated modified behavior, this study gathers primary building and occupant data from three energy-efficient office buildings in major cities of Pakistan and categorizes the occupants into high, medium, and low energy consumers. Additionally, agent-based modeling simulates the change in occupant behavior under the direct and indirect interventions over a three-year period. Finally, energy savings are quantified to highlight a 25.4% potential over the simulation period. This is a unique attempt at quantifying the potential impact on energy usage due to behavior modification which will help facility managers to plan and execute necessary interventions and software experts to develop effective tools to model the dynamic usage behavior. This will also help policymakers in devising subtle but effective behavior training strategies to reduce energy usage. Such behavioral retrofitting comes at a much lower cost than the physical or technological retrofit options to achieve the same purpose and this study establishes the foundation for it.

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