The co-simulation of both urban and building-level models leverages the advantages of both platfo... more The co-simulation of both urban and building-level models leverages the advantages of both platforms. It better accounts for the localized effects of surrounding buildings, geography and climate conditions while maintaining high-fidelity building systems representation. This paper describes the co-simulation process of the building and urban-scale models of two university campuses in Switzerland using EnergyPlus and CitySim. In the first case study, on-site measured performance data is compared to the co-simulation results. The second case study examines the results of the two engines. The results show that coupling of EnergyPlus with CitySim resulted in a-15.5% and-7.5% impact on cooling consumption and a +6.5% and +4.8% impact on heating use as compared to solo simulations.The co-simulation process was able to better model realistic conditions for heating, but not cooling in one case study. It was able to substantially reduce the discrepancies in prediction between the engines in the other study.
Proceedings of the 2014 ASHRAE/IBPSA-USA Building Simulation Conference Atlanta, GA, Sep 12, 2014
Building retrofit analysis of buildings in Switzerland traditionally relies on expert heuristics ... more Building retrofit analysis of buildings in Switzerland traditionally relies on expert heuristics and best practices. These processes are not often supplemented by data or model-driven techniques that would enhance the accuracy and ability to quantify the impact of innovative technologies. We present a process of calibrated building energy model (BEM) analysis of a case study using a building information model (BIM) and measured data from a custom wireless sensor network. The case study is a mixed-use office and residential historically listed building in Zürich, Switzerland. A BIM model was first developed in Autodesk Revit and then extracted to an EnergyPlus model through the Design Performance Viewer (DPV) toolkit that uses the RevitPythonShell (RPS) plug-in to convert the BIM data model to a geometric representation for EnergyPlus. This model was further developed using the OpenStudio modeling suite and the collected sensor data was used for calibration. The geometry translation process from BIM to BEM included many difficult challenges with respect to zone creation and model simplification. The calibration process was implemented on various façade and heating system retrofit options and an option was chosen for the project that has a predicted energy savings of 32%. Other results of this calibration and lessons learned regarding model development and translation to EnergyPlus are discussed.
Building energy simulation has become an important method for reducing energy use and carbon diox... more Building energy simulation has become an important method for reducing energy use and carbon dioxide emissions in sustainable building design. In the last decade, we have witnessed the employment of building information model (BIM) and internet technologies to be harnessed for energy-efficient building design. In this research the data exchange between a Building Information Model (BIM) and a Building Energy Model (BEM) is investigated. In previous research energy simulation engines are integrated into the BIM application for BIM users to evaluate the design directly at the conceptual design stage. After the conceptual design stage the energy analysis task is shifted to professional engineers. In a conventional process, engineers analyse the BEM, which has been previously exported manually from the BIM, and optimize the parameters in the BEM. These results are then used to manually update the BIM used in design. However, this process is cumbersome and error-prone as it is hard to ke...
We present an approach for rapidly assessing the per-formance of early design stage building info... more We present an approach for rapidly assessing the per-formance of early design stage building information models (BIM) from both the building and urban sys-tems scale. This effort builds upon two previously de-veloped tools, the Design Performance Viewer (DPV) and the CitySim urban simulation engine. It couples them to produce a more informed model. The DPV is a plugin for Autodesk Revit Architecture that creates a model for the EnergyPlus building performance en-gine based on information contained in the BIM. We combine the two simulation engines using the Func-tional Mock-up Interface (FMI) co-simulation frame-work to improve the accuracy of both simulations. This work extends the DPV to extract a CitySim model in addition to the EnergyPlus model. The CitySim model contains not only the building being investi-gated, but also a simplified representation of the sur-rounding buildings. We extend the CitySim solver to use the FMI standard for co-simulation to exchange simulation variab...
Building retrofit analysis of buildings in Switzerland traditionally relies on expert heuristics ... more Building retrofit analysis of buildings in Switzerland traditionally relies on expert heuristics and best practices. These processes are not often supplemented by data or model-driven techniques that would enhance the accuracy and ability to quantify the impact of innovative technologies. We present a process of calibrated building energy model (BEM) analysis of a case study using a building information model (BIM) and measured data from a custom wireless sensor network. The case study is a mixed-use office and residential historically listed building in Zürich, Switzerland. A BIM model was first developed in Autodesk Revit and then extracted to an EnergyPlus model through the Design Performance Viewer (DPV) toolkit that uses the RevitPythonShell (RPS) plug-in to convert the BIM data model to a geometric representation for EnergyPlus. This model was further developed using the OpenStudio modeling suite and the collected sensor data was used for calibration. The geometry translation ...
This paper describes the implementation of long wave radiation (LWR) exchange as part of a co-sim... more This paper describes the implementation of long wave radiation (LWR) exchange as part of a co-simulation process of an urban scale simulation program, CitySim, and a building scale program, EnergyPlus. This coupling process was achieved through the use of functional mockup units (FMU) to exchange various weather, load, and environmental information between the two simulation engines. LWR is an important factor to exchange between the programs as CitySim has more advanced capabilities for radiation exchange calculations from a set of urban buildings and EnergyPlus has a more advanced building heating and cooling load calculation engine. The LWR exchange between surfaces is computed in CitySim by a linearization of the longwave energy balance at each surface around an average between the surface and its environmental temperatures. The environmental temperature for each surface is determined using the simplified radiation algorithm neglecting inter-reflections and is aggregated into a single, global environmental radiant temperature (T env). The LWR exchange process is implemented in EnergyPlus by CitySim sharing the variables T env and h env that are then used to calculate radiation gain or loss through the envelope as well as influence on the conductances of the surfaces. This approach overrides the conventional EnergyPlus ground, sky and air radiation calculations. Solo and coupled simulations are performed on a set of four scenarios and result in up to a 36% discrepancy in heating and 11% in cooling load calculations amongst solo and coupled simulations.
The co-simulation of both urban and building-level models leverages the advantages of both platfo... more The co-simulation of both urban and building-level models leverages the advantages of both platforms. It better accounts for the localized effects of surrounding buildings, geography and climate conditions while maintaining high-fidelity building systems representation. This paper describes the co-simulation process of the building and urban-scale models of two university campuses in Switzerland using EnergyPlus and CitySim. In the first case study, on-site measured performance data is compared to the co-simulation results. The second case study examines the results of the two engines. The results show that coupling of EnergyPlus with CitySim resulted in a-15.5% and-7.5% impact on cooling consumption and a +6.5% and +4.8% impact on heating use as compared to solo simulations.The co-simulation process was able to better model realistic conditions for heating, but not cooling in one case study. It was able to substantially reduce the discrepancies in prediction between the engines in the other study.
Proceedings of the 2014 ASHRAE/IBPSA-USA Building Simulation Conference Atlanta, GA, Sep 12, 2014
Building retrofit analysis of buildings in Switzerland traditionally relies on expert heuristics ... more Building retrofit analysis of buildings in Switzerland traditionally relies on expert heuristics and best practices. These processes are not often supplemented by data or model-driven techniques that would enhance the accuracy and ability to quantify the impact of innovative technologies. We present a process of calibrated building energy model (BEM) analysis of a case study using a building information model (BIM) and measured data from a custom wireless sensor network. The case study is a mixed-use office and residential historically listed building in Zürich, Switzerland. A BIM model was first developed in Autodesk Revit and then extracted to an EnergyPlus model through the Design Performance Viewer (DPV) toolkit that uses the RevitPythonShell (RPS) plug-in to convert the BIM data model to a geometric representation for EnergyPlus. This model was further developed using the OpenStudio modeling suite and the collected sensor data was used for calibration. The geometry translation process from BIM to BEM included many difficult challenges with respect to zone creation and model simplification. The calibration process was implemented on various façade and heating system retrofit options and an option was chosen for the project that has a predicted energy savings of 32%. Other results of this calibration and lessons learned regarding model development and translation to EnergyPlus are discussed.
Building energy simulation has become an important method for reducing energy use and carbon diox... more Building energy simulation has become an important method for reducing energy use and carbon dioxide emissions in sustainable building design. In the last decade, we have witnessed the employment of building information model (BIM) and internet technologies to be harnessed for energy-efficient building design. In this research the data exchange between a Building Information Model (BIM) and a Building Energy Model (BEM) is investigated. In previous research energy simulation engines are integrated into the BIM application for BIM users to evaluate the design directly at the conceptual design stage. After the conceptual design stage the energy analysis task is shifted to professional engineers. In a conventional process, engineers analyse the BEM, which has been previously exported manually from the BIM, and optimize the parameters in the BEM. These results are then used to manually update the BIM used in design. However, this process is cumbersome and error-prone as it is hard to ke...
We present an approach for rapidly assessing the per-formance of early design stage building info... more We present an approach for rapidly assessing the per-formance of early design stage building information models (BIM) from both the building and urban sys-tems scale. This effort builds upon two previously de-veloped tools, the Design Performance Viewer (DPV) and the CitySim urban simulation engine. It couples them to produce a more informed model. The DPV is a plugin for Autodesk Revit Architecture that creates a model for the EnergyPlus building performance en-gine based on information contained in the BIM. We combine the two simulation engines using the Func-tional Mock-up Interface (FMI) co-simulation frame-work to improve the accuracy of both simulations. This work extends the DPV to extract a CitySim model in addition to the EnergyPlus model. The CitySim model contains not only the building being investi-gated, but also a simplified representation of the sur-rounding buildings. We extend the CitySim solver to use the FMI standard for co-simulation to exchange simulation variab...
Building retrofit analysis of buildings in Switzerland traditionally relies on expert heuristics ... more Building retrofit analysis of buildings in Switzerland traditionally relies on expert heuristics and best practices. These processes are not often supplemented by data or model-driven techniques that would enhance the accuracy and ability to quantify the impact of innovative technologies. We present a process of calibrated building energy model (BEM) analysis of a case study using a building information model (BIM) and measured data from a custom wireless sensor network. The case study is a mixed-use office and residential historically listed building in Zürich, Switzerland. A BIM model was first developed in Autodesk Revit and then extracted to an EnergyPlus model through the Design Performance Viewer (DPV) toolkit that uses the RevitPythonShell (RPS) plug-in to convert the BIM data model to a geometric representation for EnergyPlus. This model was further developed using the OpenStudio modeling suite and the collected sensor data was used for calibration. The geometry translation ...
This paper describes the implementation of long wave radiation (LWR) exchange as part of a co-sim... more This paper describes the implementation of long wave radiation (LWR) exchange as part of a co-simulation process of an urban scale simulation program, CitySim, and a building scale program, EnergyPlus. This coupling process was achieved through the use of functional mockup units (FMU) to exchange various weather, load, and environmental information between the two simulation engines. LWR is an important factor to exchange between the programs as CitySim has more advanced capabilities for radiation exchange calculations from a set of urban buildings and EnergyPlus has a more advanced building heating and cooling load calculation engine. The LWR exchange between surfaces is computed in CitySim by a linearization of the longwave energy balance at each surface around an average between the surface and its environmental temperatures. The environmental temperature for each surface is determined using the simplified radiation algorithm neglecting inter-reflections and is aggregated into a single, global environmental radiant temperature (T env). The LWR exchange process is implemented in EnergyPlus by CitySim sharing the variables T env and h env that are then used to calculate radiation gain or loss through the envelope as well as influence on the conductances of the surfaces. This approach overrides the conventional EnergyPlus ground, sky and air radiation calculations. Solo and coupled simulations are performed on a set of four scenarios and result in up to a 36% discrepancy in heating and 11% in cooling load calculations amongst solo and coupled simulations.
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Papers by Daren Thomas