Comparison between two genetic algorithms minimizing carbon footprint of energy and materials in a residential building

The emergence of building performance optimization is recognized as a way to achieve sustainable building designs. In this paper, the problem consists in minimizing simultaneously the emissions of greenhouse gases (GHG) related to building energy consumption and those related to building materials. This multi-objective optimization problem involves variables with different hierarchical levels, i.e. variables that can become obsolete depending on the value of the other variables. To solve it, NSGA-II is compared with an algorithm designed specifically to deal with hierarchical variables, namely sNSGA. Evaluation metrics such as convergence, diversity and hypervolume show that both algorithms handle hierarchical variables, but the analysis of the Pareto front confirms that in the present case, NSGA-II is better to identify optimal solutions than sNSGA. All the optimal solutions are made of buildings with wooden envelopes and relied either on heat pumps or on electrical heaters for proving heating

Automated collocation of simulation modules in FMI-based Building Energy Co-Simulation

Die eröffnete Modularität durch das Functional Mock-up Interface (FMI) ermöglicht es einzelne Simulationsmodule individuell zu erstellen. Es ist jedoch notwendig die entstehenden Functional Mockup Units im Rahmen einer Gesamtsimulation zu organisieren. Die vorliegende Arbeit beschreibt ein Verfahren um dieses Problem im Sinne einer automatisierten Initialisierung von FMUs in einer energetischen Gebäudesimulation zu lösen. Die Definition eines FMU Netzwerks, indem jede Einheit gemäß einem vorgegebenen Schema nach ihrem Zweck klassifiziert werden kann, erlaubt zudem einen reibungslosen Austausch von Komponenten gleichen Typs. Dies ermöglicht schnelle Evaluierungen von Planungsalternativen durch die Nutzung von vorkompilierten Bibliotheksmodellen. Eine Beispielstudie dient zur Demonstration des Verfahrens

Digitale Revolution

Um die Zusammenarbeit von Bauherren, Planern und Ausführenden zu optimieren, müssen die erforderlichen Kommunikations- und Informationsprozesse möglichst effizient gestaltet werden. Vor diesem Hintergrund spricht man seit einiger Zeit von einer bevorstehenden "digitalen Revolution", die sich unter anderem durch die flächendeckende Einführung des Building Information Modeling (BIM) zeigen wird

Model driven engineering methods for integrated building performance optimization

Tool interoperability is a vital technical requirement for any integrated building performance assessment in early building design stages. Architects and planners use tools with proprietary geometric representations and domain specific computational intelligence. On the other side, there is a multitude of sophisticated tools for simulating and assessing building performance. For obtaining reliable results, such tools need to be operated by qualified personnel only. In order to bridge the gap between expert domains, this study proposes the deployment of a central building information model (BIM) on top of a conventional database system. We present novel methods and a comprehensive tool chain that supports a multidisciplinary design optimization process. A new way of addressing the challenges of poor software interoperability is to apply existing solutions from model driven engineering. The main focus of the research is on the formulation of model-to-model transformations that can be reused for BIM based tool coupling in general

Effiziente Strahlungssimulation für ein thermisches Behaglichkeitsmodell

The presented work analyses the local effects of asymmetric shortwave and longwave radiation in complex 3D building models. The new simulation tool provides thermal loads caused by non-uniform radiant temperatures and solar irradiation in indoor environments. The method implements efficient raytracing and viewfactor calculation on programmable graphic processing units. Therefor temperature based longwave radiation exchange and heat gains from direct and diffuse solar radiation are computed. Models of globe-thermometers are placed in selected room positions, in order to investigate local radiation impacts. Accurate analysis of local thermal conditions is enabled by detailed virtual manikin models. Radiant temperatures are evaluated by means of directional quantities, since asymmetric radiation is known to effect thermal comfort

Towards design tools for holistic assessment of indoor environmental quality

We present an approach for holistic indoor environmental quality (IEQ) assessment in corporating dynamic heat and moisture transport effects, indoor air flow and pollutant distribution. A common tool infrastructure provides interfaces to multidisciplinary models that are using product and material specific data stored in Building Information Models (BIM) for early design assessment. Hence, we present the results of a prototype tool development utilising integrated dynamic simulation models on the basis of the Modelica language. The sub-domain models for airflow and hygrothermal BPS are cross validated with state-of-the-art tools and experimental results. The properties of innovative multi-functional eco-materials and components are provided in a structured database to provide high quality predictions of IEQ under a broad range of boundary conditions and implementations. In an integrated design process (IDP) the procedures for simulations and results evaluation are automated and comparable figures for overall IEQ ratings are provided by a user friendly front-end

Concepts for comfortable air-conditioning - simulation using a zonal cabin model and a metrological evaluation based on equivalent temperature

In the design of future electric vehicles, the air conditioning of the passenger compartment is considered as the largest auxiliary consumer. To test new climate control concepts and quantify their effectiveness in terms of user acceptance, energy efficiency and driving range, corresponding methods and tools are needed. This includes the numerical, experimental and subject-supported study regarding human thermal comfort. New developed zonal models simulate air flow and temperature, surface temperature, pressure and also humidity in a closed environment. Predicting indoor environmental conditions in vehicle cabin is achieved in transient inhomogeneous load cases. With the combination of a radiation model, the long-wave radiation exchange between human and cabin is included in the heat balance equation with a high level of detail. In order to improve the assessment of the local thermal conditions near the passenger, a climate measurement system (DressMAN 2.0) was developed by the Fraunhofer Institute for Building Physics (IBP). Using dedicated controllers and sensor devices the DressMAN is able to measure equivalent temperature on local segments for evaluation according to DIN EN ISO 14505-2. Based on these methods novel and existing concepts for heating have been tested with subjects in a cabin mock-up. The experiments used simulation-based methods and local climate measurement devices to compare and evaluate different climate control concepts