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 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.

scholarly journals The applicability of different energy performance calculation methods for building life cycle environmental optimization

2018 ◽  
Vol 9 (2) ◽  
pp. 115-121 ◽  
Author(s):  
B. Kiss ◽  
ZS. Szalay
Keyword(s):  
Life Cycle ◽  
Energy Use ◽  
Energy Performance ◽  
Computational Time ◽  
Calculation Methods ◽  
Apartment House ◽  
Building Stock ◽  
Operational Energy ◽  
Time Accuracy ◽  
Building Life Cycle

Building life cycle assessment is getting more and more attention within the topic of environmental impact caused by the built environment. Although more and more research focus on the embodied impact of buildings, the investigation of the operational energy use still needs attention. The majority of the building stock still does not comply with the nearly zero energy requirements. Also, in case of retrofitting, when most of the embodied impact is already spent on the existing structures (and so immutable), the importance of the operational energy rises. There are several methods to calculate the energy performance of buildings covering the range from simplified seasonal methods to detailed hourly energy simulations. Not only the accuracy of the calculations, but the computational time can be significantly different within the methods. The latter is especially important in case of optimization, when there is limited time to perform one calculation. Our research shows that the use of different calculation techniques can lead to different optima for environmental impacts in case of retrofitting. In this paper we compare these calculation methods with focus on computational time, accuracy and applicability to environmental optimization of buildings. We present the results in a case study of the retrofitting of a middle-sized apartment house in Hungary.

Simulated and Actual Energy Use of a Green Building: A Case Study on the Magic School of Green Technology

2013 ◽  
Vol 368-370 ◽  
pp. 1174-1178 ◽  
Author(s):  
Tzu Ching Su ◽  
Yu Chung Wang ◽  
Hsien Te Lin
Keyword(s):  
Energy Use ◽  
Green Building ◽  
Building Energy ◽  
Energy Performance ◽  
Green Technology ◽  
Zero Carbon

This is a case study on the Magic school of Green Technology (MSGT), the first zero-carbon building in Taiwan. This study simulated the energy performance of the MSGT by using eQUEST, a tool for simulating building energy, before the construction was complete. This study compared the simulated energy use with the actual energy use of the MSGT in 2011, and determined that the actual energy use was lower than the simulated energy use. Based on this comparison, the study proved that the MSGT consumed 65% less energy than do similarly sized buildings with the same functions.

The Environmental Footprint of Data Centers

2009 ◽  
Author(s):  
Amip Shah ◽  
Cullen Bash ◽  
Ratnesh Sharma ◽  
Tom Christian ◽  
Brian J. Watson ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Data Center ◽  
Energy Use ◽  
Data Centers ◽  
Evaluation Metrics ◽  
Environmental Footprint ◽  
Diverse Range ◽  
Use Of Data ◽  
Operational Energy

Numerous evaluation metrics and standards are being proposed across industry and government to measure and monitor the energy efficiency of data centers. However, the energy use of data centers is just one aspect of the environmental impact. In this paper, we explore the overall environmental footprint of data centers beyond just energy efficiency. Building upon established procedures from the environmental sciences, we create an end-to-end life-cycle model of the environmental footprint of data centers across a diverse range of impacts. We test this model in the case study of a hypothetical 2.2-MW data center. Our analysis suggests the need for evaluation metrics that go beyond just operational energy use in order to achieve sustainable data centers.

scholarly journals The Effect of Balcony Thermal Breaks on Building Thermal and Energy Performance: Field Experiments and Energy Simulations in Chicago, IL

Buildings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 190
Author(s):  
Irina Susorova ◽  
Brent Stephens ◽  
Benjamin Skelton
Keyword(s):  
Energy Consumption ◽  
Thermal Resistance ◽  
High Performance ◽  
Energy Use ◽  
Field Experiments ◽  
Building Energy ◽  
Energy Performance ◽  
Curtain Wall ◽  
Energy Simulations

A common envelope performance problem in buildings is thermal bridging through balcony slab connections, which can be improved with the use of commercially available thermal break products. Several prior studies have used simulation-based and/or hot box test apparatus approaches to quantify the likely effect of balcony thermal breaks on effective thermal resistance of building enclosures. However, in-situ measurements of thermal performance in real buildings remain limited to date. This study uses a combination of field measurements and models to investigate the effects of installing balcony thermal breaks on the interior surface temperatures, effective thermal resistance, and annual building energy consumption. For the field experiment, yearlong measurements were conducted on the 13th floor of a 14-story multi-family building in Chicago, IL, in which thermocouple sensors were embedded into eight balconies and their adjacent interior floor slabs just before concrete was poured to complete the construction. The eight balconies included four control balconies without thermal breaks and four thermally-broken balconies with a commercially available thermal break product installed. The experimental data were then combined with 2-D heat transfer modeling and whole building energy simulations to investigate the impacts of the thermal break product installation on the envelope thermal resistance and overall energy use in the case study building as well as in several more generic building designs with simpler geometries. The results demonstrate that although the balcony thermal breaks helped regulate interior slab temperatures and improved the effective thermal resistance of the curtain wall enclosure assembly by an estimated ~14% in the case study building, the predicted effect on annual energy consumption in all modeled building types was small (i.e., less than 2%). The results also highlight the importance of paying careful attention to envelope design details when using thermal break products and considering the use of thermal break products in combination with other energy efficiency strategies to achieve high performance enclosures.

Hybrid Solar and Wind Electric System for Romanian Nearly Zero Energy Buildings (nZEB) - Case Study

2016 ◽  
Vol 841 ◽  
pp. 110-115
Author(s):  
Gheorge Badea ◽  
Raluca Andreea Felseghi ◽  
Simona Răboaca ◽  
Ioan Aşchilean ◽  
Andrei Bolboacă ◽  
...  
Keyword(s):  
Energy Use ◽  
Residential Buildings ◽  
Energy Performance ◽  
Green Energy ◽  
Design Solution ◽  
Design Parameters ◽  
Zero Energy ◽  
Electric System ◽  
Zero Energy Buildings

For a good approach to new challenges recommended by EU Energy Performance of Buildings Directive, nearly Zero Energy Buildings (nZEB) concept for new residential buildings is conceived in order to drastically improving the overall performance of classical buildings, especially in terms of energy use, production and CO2 equivalent (CO2e) emissions. This paper shows the results of the case study where was investigated energy, economic and environmental performances of hybrid solar and wind system for neutral in terms of climate parameters nZEB. The aim of this study was to demonstrate the capability and feasibility of RES hybrid technology for the energy supply of Romanian nZEB, and also, was to establish new general criteria with the goal to determinate the optimal design solution and providing general principles for green energy production. The main results reveal that Romania has a potential for green energy to implement the new concept nZEB and the global technical optimum of a hybrid system for nZEB is determined by the optimal interaction between the design parameters. The hybrid solar and wind electric systems are functioned in operational stand alone mode, its are supplied 100% by energy from RES and embedded CO2 emissions are decreased by over 50% compared to the classics systems.

scholarly journals Examining the performance gap in LEED certified murbs

2021 ◽  
Author(s):  
Kaitlin Paige Carroll
Keyword(s):  
Energy Use ◽  
Residential Buildings ◽  
Energy Performance ◽  
Performance Outcomes ◽  
Design Stage ◽  
Contributing Factors ◽  
Performance Gap ◽  
Greater Toronto Area ◽  
Energy Modelling

This study assesses the performance gap between actual energy performance and desired energy performance outcomes for a case study of 19 LEED-certified multi-unit residential buildings in the Greater Toronto Area. The study examines 1) how accurately design-stage energy modelling predicts actual energy use, 2) how much variation of energy performance can be seen between buildings of the same level of certification, and 3) the key contributing factors of this performance gap. Using EUI as the basis of comparison, trend analysis was carried out. It was determined that a performance gap between modelled and actual building energy use does exist. When compared to a larger sample of existing buildings, the case study buildings show no real improvement, on average. Regression models revealed no strong correlation between LEED Level or LEED EAc1 credits and reduced EUIs.

Economic Analysis of Solar PV and Batteries for Common Residential Electricity Rate Structures Using Green Button Data

2013 ◽  
Author(s):  
Mithun Mohan Nagabhairava ◽  
Yin Ma ◽  
Kelly Kissock
Keyword(s):  
Energy Use ◽  
Solar Pv ◽  
Pv System ◽  
Flat Rate ◽  
Pv Systems ◽  
Study Results ◽  
Residential Electricity ◽  
Average Annual Cost ◽  
Utility Rate

Rising electricity prices, falling photovoltaic (PV) system costs and the availability of net metering are encouraging consumers to consider PV systems. However, the variety and complexity of utility rate structures can be a formidable barrier to consumers in making economically informed decisions. This paper describes a methodology to integrate Green Button energy use data from electric utilities, with solar and temperature data to analyze the economics of PV systems, with and without battery storage, under different rate structures. Case study results indicate that the economics of PV systems are nearly identical under PG&E’s time-of-use and inverted-block rate structures, and are more favorable than under flat rate structures with the same average annual cost per kWh. However, simple paybacks remain well short of the typical life of PV systems. The simple payback for the addition of batteries is initially competitive with PV systems, but rises rapidly as battery size is increased.

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.

scholarly journals Measured and Simulated Energy Use in a Secondary School Building in Sweden—A Case Study of Validation, Airing, and Occupancy Behaviour

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2325 ◽  
Author(s):  
Jessika Steen Englund ◽  
Mathias Cehlin ◽  
Jan Akander ◽  
Bahram Moshfegh
Keyword(s):  
Secondary School ◽  
Energy Use ◽  
Field Measurements ◽  
Energy Performance ◽  
Hot Water ◽  
Space Heating ◽  
School Building ◽  
Efficiency Measures ◽  
The 1960S

In this case study, the energy performance of a secondary school building from the 1960s in Gävle, Sweden, was modelled in the building energy simulation (BES) tool IDA ICE version 4.8 prior to major renovation planning. The objectives of the study were to validate the BES model during both occupied and unoccupied periods, investigate how to model airing and varying occupancy behaviour, and finally investigate energy use to identify potential energy-efficiency measures. The BES model was validated by using field measurements and evidence-based input. Thermal bridges, infiltration, mechanical ventilation, domestic hot water circulation losses, and space heating power were calculated and measured. A backcasting method was developed to model heat losses due to airing, opening windows and doors, and other occupancy behaviour through regression analysis between daily heat power and outdoor temperature. Validation results show good agreement: 3.4% discrepancy between space heating measurements and simulations during an unoccupied week. Corresponding monthly discrepancy varied between 5.5% and 10.6% during three months with occupants. Annual simulation indicates that the best potential renovation measures are changing to efficient windows, improved envelope airtightness, new controls of the HVAC system, and increased external wall thermal insulation.

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