Now showing 1 - 6 of 6
- PublicationModel View Definition for Advanced Building Energy Performance SimulationRecent demand for higher energy efficiency within the building sector has led to the use of Building Energy Performance Simulation (BEPS) tools. These powerful predictive tools enable investigation of environmental and energy performance for different design and retrofit design alternatives. However, integrating BEPS with Building Information Modelling (BIM) based building design tools still experiences limitations due to a lack of standardised methods of information exchange between these domains. As a result, this paper presents a Model View Definition (MVD) for advanced BEPS. In doing so this work enables a standardised exchange of data from BIM to BEPS tools, such as Modelica, using the Industry Foundation Classes (IFC) standard. The entire process becomes available through the open source software framework emerged from the IEA EBC Annex 60.
- PublicationBIM - Geometry modelling guidelines for building energy performance simulationBuilding Information Models (BIM) are increasingly used as a central data repository from which designers transfer data from 3D CAD applications to building performance simulation (BPS) tools. For a widespread use of BIMs for this purpose, these models need to comply with a certain data quality standard. Based on a thermal viewpoint and underlying physical principles the authors develop data requirements for these models. These requirements are used to evaluate current data standards and to develop guidelines for the creation of these models. This paper will also describe several case studies and problems found in models that did not comply with those guidelines. Finally, the authors describe current limitations of tools and processes and propose future developments.
- PublicationTransforming BIM to BEM: Generation of Building Geometry for the NASA Ames Sustainability Base BIMTypical processes of whole Building Energy simulation Model (BEM) generation are subjective, labor intensive, time intensive and error prone. Essentially, these typical processes reproduce already existing data, i.e. building models already created by the architect. Accordingly, Lawrence Berkeley National Laboratory (LBNL) developed a semi-automated process that enables reproducible conversions of Building Information Model (BIM) representations of building geometry into a format required by building energy modeling (BEM) tools. This is a generic process that may be applied to all building energy modeling tools but to date has only been used for EnergyPlus.
- PublicationBIM to Building Energy Performance Simulation: An Evaluation of Current Transfer ProcessesFor over 25 years, data exchange between architectural BIM-based designs and Building Energy Performance Simulation (BEPS) have been proposed as a solution to reduce the amount of manual and error prone rework required to create typical BEPS models. The current state of the art lacks an effective, universal and robust system of data collation, processing, quality assessment and analysis while interfacing with existing tool-chains through a streamlined data transfer process.This paper investigates the reproducibility of current BIM to BEPS transfer processes through an experiment that compares these transfer processes, as used in industry, against each other. The experiment uses five residential archetype buildings and results from BEPS models in EnergyPlus indicate that there are many barriers, both technical and methodological, to achieving reproducible results between commonly available software tools. In some cases difficulties could not be overcome as the transformation process itself did not complete, leading to inconclusive results. In cases where successful transformations occurred, variations of up to 25.89% in annual energy consumption were discovered between processes. This hints to issues and limitations of the current processes and results.
- PublicationData-Requirements Specification to Support BIM-Based HVAC-Definitions in ModelicaRecent developments in Building Information Model (BIM) capable software are leading to increased interoperability among heterogeneous tools. The results are representing greater levels of data available for all stakeholders involved in the building industry. The increasing range of data within BIMs enables the reuse of data for downstream applications such as Building Energy Performance Simulation (BEPS). Current BEPS tools work well in many modeling scenarios, but fail to support innovative and flexible model configurations due to existing tool limitations. Modelica is an object-oriented, equation-based programming language used for detailed dynamic simulation purposes across different industries. The use of Modelica in the building industry is increasing and it is a promising and flexible tool to provide modeling solutions addressing the upcoming challenges in the building industry and beyond. This paper illustrates a method of using BIM based information as the primary data source for a flexible simulation application. It includes an implementation for a defined generic use case.
- PublicationModel Transformation from SimModel to Modelica for Building Energy Performance SimulationThis paper demonstrates a model transformation tool between the Building Information Model (BIM) and Modelica schemas for Building Energy Performance Simulation (BEPS) purposes. Automated reuse of data in BIMs to accelerate BEPS model development is now a promising approach for engineers. However, using BEPS tools such as Modelica to generate building simulation models is currently difficult and time consuming due to the largely manual data input. The ability to import data of a BIM into Modelica-based BEPS tool would improve this process significantly. In order to address the challenge, this paper proposes a model transformation prototype to convert Industry Foundation Classes (IFC) based BIMs into object-oriented Modelica simulation models. The proposed approach uses SimModel data model as a placeholder for IFC. SimModel currently contains richer HVAC data definitions than IFC for the purposes of BEPS and can be easily extended to store the additional data required by Modelica. This prototype demonstrates the potential to reduce development time of Modelica models by reusing building information data stored in BIMs.