Urban-Scale Energy Models: relationship between urban form and energy performance

2020 ◽  
Author(s):  
Guglielmina Mutani ◽  
Marta Carozza ◽  
Valeria Todeschi ◽  
Andrea Rolando
Keyword(s):  
Urban Form ◽  
Energy Performance ◽  
Energy Models

scholarly journals Informing the design of courtyard street blocks using solar energy models: a case study of a university campus in Singapore

2021 ◽  
Vol 2042 (1) ◽  
pp. 012050
Author(s):  
Ekaterina Vititneva ◽  
Zhongming Shi ◽  
Pieter Herthogs ◽  
Reinhard König ◽  
Aurel von Richthofen ◽  
...  
Keyword(s):  
Solar Energy ◽  
Urban Form ◽  
Energy Performance ◽  
University Campus ◽  
Quasi Monte Carlo ◽  
Energy Models ◽  
Simulation Based ◽  
Input Variables ◽  
The City

Abstract This study discusses the interplays between urban form and energy performance using a case study in Singapore. We investigate educational urban quarters in the tropical climate of Singapore using simulation-based parametric geometric modelling. Three input variables of urban form were examined: street network orientation, street canyon width, and building depth. In total, 280 scenarios were generated using a quasi-Monte Carlo Saltelli sampler and Grasshopper. For each scenario, the City Energy Analyst, an open-source urban building energy simulation program, calculated solar energy penetration. To assess the variables’ importance, we applied Sobol’ sensitivity analysis. Results suggest that the street width and building depth were the most influential parameters.

scholarly journals Energy assessment of different cooling technologies in Ti-6Al-4V milling

2021 ◽  
Vol 112 (11-12) ◽  
pp. 3279-3306
Author(s):  
Paolo Albertelli ◽  
Michele Monno
Keyword(s):  
Energy Performance ◽  
Primary Energy ◽  
Cryogenic Cooling ◽  
Model Parameters ◽  
Tribological Behaviour ◽  
Dry Cutting ◽  
Sustainable Solutions ◽  
Energy Assessment ◽  
Energy Models ◽  
Conventional Cooling

AbstractManufacturing craves for more sustainable solutions for machining heat-resistant alloys. In this paper, an assessment of different cooling lubrication approaches for Ti6Al4V milling was carried out. Cryogenic cutting (liquid nitrogen) and conventional cooling (oil-based fluid) were assessed with respect to dry cutting. To study the effects of the main relevant process parameters, proper energy models were developed, validated and then used for comparing the analysed cooling lubrication strategies. The model parameters were identified exploiting data from specifically conceived experiments. The power assessment was carried out considering different perspectives, with a bottom-up approach. Indeed, it was found that cryogenic cooling, thanks to a better tribological behaviour, is less energy demanding (at least 25%) than dry and conventional cutting. If the spindle power is considered, lower saving percentages can be expected. Cryogenic cooling showed its best energy performance (from 3 to 11 times) with respect to conventional cutting if the machine tool perspective is analysed. Considering even the primary energy required for producing the cutting fluids, the assessment showed that cryogenic cooling requires up to 19 times the energy required for conventional cutting.

scholarly journals Understanding the energy performance GAP: case studies of energy efficient homes

2021 ◽  
Author(s):  
Moe Otsubo
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Energy Performance ◽  
Initial Energy ◽  
Energy Simulation ◽  
Design Stage ◽  
Performance Gap ◽  
Energy Models ◽  
Dynamic Energy Simulation ◽  
Actual Energy Consumption

The energy performance gap between the predicted and actual energy consumption of 3 LEED for Homes certified buildings were investigated. The actual energy consumptions of the homes were found to be 23 to 77% higher than the initial energy consumption predictions made during the design stage. Revisions to the HOT2000 models to account for changes made between the design and occupancy phase of the buildings helped reduce the gap (9 to 40%). The sources of the discrepancies were found to be related to the energy modeling program’s limitations, inconsistency between the energy model and the actual building, and additional loads in the homes. The HOT2000 program, which is used for obtaining the EnerGuide rating for LEED certified homes, was compared against a dynamic energy simulation program to assess the applicability of the use of the former for energy efficient homes. The use of EnergyPlus not only allowed for a more accurate representation of the actual homes in the energy models, but an increase in the EnerGuide rating for the home was seen, which in turn equates to additional points for the home under the “Energy & Atmosphere” category for the LEED for Homes certification process

scholarly journals Investigating Bundled Approaches To Reduce Greenhouse Gas Emissions in the Toronto 2030 District

2021 ◽  
Author(s):  
Patrick Ritsma
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Energy Demand ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Reduction ◽  
Building Stock ◽  
Gas Emissions ◽  
Urban Core ◽  
Energy Models

Building energy models are an effective tool for evaluating energy reduction opportunities in both design phase and post-occupancy scenarios. By merging building energy models with city scale building stock data, it is possible to analyze energy performance at a greater breadth, providing more informed policy decisions and solutions to energy demand asymmetries in urban metropolises. This study examines the energy reduction potential for office buildings in the Toronto 2030 District, by testing individual and bundled energy conservation measures and greenhouse gas reduction strategies using a reference building energy model. When extrapolated across Toronto’s urban core, simulation results determined that standard interventions on the existing office building stock have the potential to reduce greenhouse gas emissions by as much as 91.5%, in line with 2030 District initiatives.

scholarly journals Exploring the Connection between Urban 3D Form and Building Energy Performance and the Influencing Mechanism

2021 ◽  
Vol 10 (10) ◽  
pp. 709
Author(s):  
Deng Wang ◽  
Guoqin Zhang ◽  
Tao Lin ◽  
Xinyue Hu ◽  
Zhuoqun Zhao ◽  
...  
Keyword(s):  
Urban Form ◽  
Building Energy ◽  
Energy Performance ◽  
Partial Least Square ◽  
Socioeconomic Condition ◽  
Continuous Growth ◽  
Building Energy Performance ◽  
2D And 3D ◽  
The Impact ◽  
Compactness Index

Continuous growth of building energy consumption CO2 emission (BECCE) threatens urban sustainable development. Urban form is an important factor affecting BECCE. Compactness is a significant urban morphological characteristic. There is currently a lack of research on the effect of urban three-dimensional (3D) compactness on BECCE. To clarify the research value of 3D compactness, we investigated whether 3D compactness has a stronger impact on BECCE than two-dimensional (2D) compactness. A total of 288 buildings of the People’s Bank of China (PBOC) were divided into 5 zones according to building climate demarcation. As BECCE is affected mainly by four aspects (socioeconomic condition, building features, macroclimate, and urban form), the BECCE driven by urban form (BECCE-f) in each zone was calculated firstly using the partial least square regression model. Normalized compactness index (NCI) and normalized vertical compactness index (NVCI) were calculated with Python to quantify urban 2D and 3D compactness within a 1 km buffer of PBOC buildings. The mean NCI and NVCI values of each zone were adopted as 2D and 3D compactness of this zone. Gray correlation analysis of the five zones showed that the connection between the NVCI and BECCE-f is stronger than that between NCI and BECCE-f. Based on this, we believe that the emphasis of later research should be shifted to urban 3D form, not just 2D elements. 3D form can describe the real urban form in a more accurate and detailed manner. Emphasizing 3D morphological characteristics in studies of the relationship between urban form and building energy performance is more meaningful and valuable than only considering 2D characteristics. The impact mechanism of urban form on BECCE-f should also be analyzed from the perspective of 3D form. This study also provides beneficial solutions to building energy saving and low-carbon building construction.

scholarly journals An evaluation of the effects of thermal insulation levels on the energy performance of New Zealand office buildings- exploring the impact of building attributes on the performance of thermal insulation

2021 ◽  
Author(s):  
◽  
Brittany Grieve
Keyword(s):  
Energy Consumption ◽  
New Zealand ◽  
Thermal Insulation ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Office Buildings ◽  
Building Performance ◽  
Energy Models ◽  
The Impact

<p>This thesis explored the impact of thermal insulation on the energy performance of New Zealand air-conditioned commercial office buildings. A sample of calibrated energy models constructed using real building performance data and construction information was used to ensure that the results produced were as realistic as possible to the actual building performance of New Zealand commercial office buildings. The aim was to assess how different climates and building attributes impact thermal insulation's ability to reduce energy consumption in New Zealand commercial office buildings.   Driven by the ever increasing demands for healthier, more comfortable, more sustainable buildings, building regulations have steadily increased the levels of insulation they require in new buildings over time. Improving the thermal properties of the building envelope with the addition of thermal insulation is normally used to reduce the amount of heating and cooling energy a building requires. Thermal insulation reduces the conductive heat transfer through the building envelope and with a higher level of thermal resistance, the less heat would transfer through the envelope. Consequently, the common expectation is that the addition of thermal insulation to the building envelope will always reduce energy consumption. However, this assumption is not always the case. For internal load dominated buildings located in certain climates, the presence of any or a higher level of thermal insulation may prevent heat loss through the wall, increasing the cooling energy required. This issue is thought to have not been directly examined in literature until 2008. However, an early study undertaken in New Zealand in 1996 found that for climates similar or warmer than Auckland, the addition of insulation could be detrimental to an office building's energy efficiency due to increased cooling energy requirements.  The energy performance of a sample of 13 real New Zealand office building energy models with varying levels of thermal insulation in 8 locations was examined under various scenarios. A parametric method of analysis using building energy modelling was used to assess the energy performance of the buildings. Buildings were modelled as built and standardised with the current NZS4243:2007 regulated and assumed internal load and operational values. The effect the cooling thermostat set point temperature had on the buildings' energy performance at varying levels of insulation was also tested.   The study concluded that the use of thermal insulation in New Zealand office buildings can cause an increase in cooling energy for certain types of buildings in any of the eight locations and thermal insulation levels explored in the study. The increase in cooling energy was significant enough to increase the total energy consumption of two buildings when modelled as built. These buildings were characterised by large internal loads, low performance windows with high window to wall ratios and low surface to volume ratios. The current minimum thermal resistance requirements were found to not be effective for a number of buildings in North Island locations.</p>

scholarly journals An evaluation of the effects of thermal insulation levels on the energy performance of New Zealand office buildings- exploring the impact of building attributes on the performance of thermal insulation

2021 ◽  
Author(s):  
◽  
Brittany Grieve
Keyword(s):  
Energy Consumption ◽  
New Zealand ◽  
Thermal Insulation ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Office Buildings ◽  
Building Performance ◽  
Energy Models ◽  
The Impact

<p>This thesis explored the impact of thermal insulation on the energy performance of New Zealand air-conditioned commercial office buildings. A sample of calibrated energy models constructed using real building performance data and construction information was used to ensure that the results produced were as realistic as possible to the actual building performance of New Zealand commercial office buildings. The aim was to assess how different climates and building attributes impact thermal insulation's ability to reduce energy consumption in New Zealand commercial office buildings.   Driven by the ever increasing demands for healthier, more comfortable, more sustainable buildings, building regulations have steadily increased the levels of insulation they require in new buildings over time. Improving the thermal properties of the building envelope with the addition of thermal insulation is normally used to reduce the amount of heating and cooling energy a building requires. Thermal insulation reduces the conductive heat transfer through the building envelope and with a higher level of thermal resistance, the less heat would transfer through the envelope. Consequently, the common expectation is that the addition of thermal insulation to the building envelope will always reduce energy consumption. However, this assumption is not always the case. For internal load dominated buildings located in certain climates, the presence of any or a higher level of thermal insulation may prevent heat loss through the wall, increasing the cooling energy required. This issue is thought to have not been directly examined in literature until 2008. However, an early study undertaken in New Zealand in 1996 found that for climates similar or warmer than Auckland, the addition of insulation could be detrimental to an office building's energy efficiency due to increased cooling energy requirements.  The energy performance of a sample of 13 real New Zealand office building energy models with varying levels of thermal insulation in 8 locations was examined under various scenarios. A parametric method of analysis using building energy modelling was used to assess the energy performance of the buildings. Buildings were modelled as built and standardised with the current NZS4243:2007 regulated and assumed internal load and operational values. The effect the cooling thermostat set point temperature had on the buildings' energy performance at varying levels of insulation was also tested.   The study concluded that the use of thermal insulation in New Zealand office buildings can cause an increase in cooling energy for certain types of buildings in any of the eight locations and thermal insulation levels explored in the study. The increase in cooling energy was significant enough to increase the total energy consumption of two buildings when modelled as built. These buildings were characterised by large internal loads, low performance windows with high window to wall ratios and low surface to volume ratios. The current minimum thermal resistance requirements were found to not be effective for a number of buildings in North Island locations.</p>

scholarly journals Uncertainy’s Indices Assessment for Calibrated Energy Models

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2096 ◽  
Author(s):  
Vicente Gutiérrez González ◽  
Lissette Álvarez Colmenares ◽  
Jesús Fernando López Fidalgo ◽  
Germán Ramos Ruiz ◽  
Carlos Fernández Bandera
Keyword(s):  
Distributed Generation ◽  
Thermal Inertia ◽  
Cost Effective ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Performance Of Buildings ◽  
Energy Models ◽  
Effective Manner ◽  
New Generation ◽  
And Storage

Building Energy Models (BEMs) are a key element of the Energy Performance of Buildings Directive (EPBD), and they are at the basis of Energy Performance Certificates (EPCs). The main goal of BEMs is to provide information for building stakeholders; they can be a powerful market tool to increase demand for energy efficiency solutions in buildings without affecting the comfort of users, as well as providing other benefits. The next generation of BEMs should value buildings in a holistic and cost-effective manner across several complementary dimensions: envelope performances, system performances, and controlling the ability of buildings to offer flexible services to the grid by optimizing energy consumption, distributed generation, and storage. SABINA is a European project that aims to look for flexibility to the grid, targeting the most economic source possible: existing thermal inertia in buildings. In doing so, SABINA works with a new generation of BEMs that tend to mimic the thermal behavior of real buildings and therefore requires an accurate methodology to choose the model that complies with the requirements of the system. This paper details our novel extensive research on which statistical indices should be chosen in order to identify the best model offered by the calibration process developed by Fernandez et al. in a previous paper and therefore is a continuation of that work.

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