Three-Dimensional Numerical Evaluation of Thermal Performance of Uninsulated Wall Assemblies

2011 ◽  
Author(s):  
El Hassan Ridouane ◽  
Marcus V. A. Bianchi
Keyword(s):  
Thermal Performance ◽  
Energy Savings ◽  
Three Dimensional ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Simulation ◽  
Cavity Surface ◽  
Building Energy Simulation ◽  
Simulation Tools ◽  
Whole Building Energy Simulation

Uninsulated wall assemblies are typical in older homes, as many were built before building codes required insulation. Building engineers need to understand the thermal performance of these assemblies as they consider home energy upgrades if they are to properly predict pre-upgrade performance and, consequently, prospective energy savings from the upgrade. Most whole-building energy simulation tools currently use simplified, 1D characterizations of building envelopes and assume a fixed thermal resistance that does not vary over a building’s temperature range. This study describes a detailed 3D computational fluid dynamics model that evaluates the thermal performance of uninsulated wall assemblies. It accounts for conduction through framing, convection, and radiation and allows for material property variations with temperature. Parameters that were varied include ambient outdoor temperature and cavity surface emissivity. The results may serve as input for building energy simulation tools that model the temperature-dependent energy performance of homes with uninsulated walls.

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%.

Exploring and verifying BIM-based energy simulation for building operations

2020 ◽  
Vol 27 (8) ◽  
pp. 1679-1702
Author(s):  
Hong Xian Li ◽  
Zhiliang Ma ◽  
Hexu Liu ◽  
Jun Wang ◽  
Mohamed Al-Hussein ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Simulation ◽  
Information Modeling ◽  
Building Energy Simulation ◽  
Content Type ◽  
Simulation Tools ◽  
Building Information ◽  
Simulation Results

PurposeThe operational phase of a building's lifecycle is receiving increasing attention, as it consumes an enormous amount of energy and results in tremendous detrimental impacts on the environment. While energy simulation can be applied as a tool to evaluate the energy performance of a building in operation, the emergence of Building Information Modeling (BIM) technology is expected to facilitate the evaluation process with predefined and enriched building information. However, such an approach has been confronted by the challenge of interoperability issues among the related application software, including the BIM tools and energy simulation tools, and the results of simulation have been seldom verified due to the unavailability of corresponding experimental data. This study aims to explore the interoperability between the commonly used energy simulation and BIM tools and verifies the simulation approach by undertaking a case study.Design/methodology/approachWith Autodesk Revit and EnergyPlus selected as the commonly used BIM and energy simulation tools, respectively, a valid technical framework of transferring building information between two tools is proposed, and the interoperability issues that occur during the data transfer are studied. The proposed framework is then employed to simulate the energy consumption of a single-family house, and sensitivity analysis and analysis on such parameters as schedule are conducted for building operations to showcase its applicability.FindingsThe simulation results are compared with monitored data and the results from another simulation tool, HOT2000; the comparison reveals that EnergyPlus and HOT2000 predict the total energy consumption with a difference from the monitoring data of 8.0 and 7.1%, respectively.Practical implicationsThis research shows how to efficiently use BIM to support building energy simulation. Relevant stakeholders can learn from this research to avoid data loss during BIM model transformation.Originality/valueThis research explores the application of BIM for building energy simulation, compares the simulation results among different tools and validates simulation results using monitored data.

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