English

Thermal bridging is a problem that arises from using a thermosyphon. It is used as a passive part of the building envelope in south facing walls. A solution is proposed and investigated in this paper. SolidWorks 2011 is used to simulate the thermal performance of the thermosyphon. A finite element analysis, FEA, (4 points Jacobian) is employed to measure the temperature and heat flux at different surfaces of the thermosyphon. Simulation results showed that the backward maximum heat flux reduces 76 times when a Teflon piece is introduced.

This paper presents a simple all-weather sky radiance model (diffuse component). The model development was motivated by the intention to find a balance between the model's simplicity and ease of use on the one side and predictive capability on the other side. To develop the model, measured data collected at the microclimatic monitoring station of our institute (the Department of Building Physics and Building Ecology of the Vienna University of Technology) was deployed. To formulate the model, a formalism based on the concept of irradiance coefficient was used.

In the Swiss research project OptiControl (www.opticontrol.ethz.ch), new predictive building control strategies are developed and applied to a fully occupied, well instrumented demonstrator building. Here we report on the development and validation of the EnergyPlus building energy performance simulation model used in the project.

Recently façade systems have integrated passive solutions to reduce the energy consumption in buildings and improve their occupants’ comfort. This paper reports the results of the thermal performance of Trombe walls and daylighting of glazing modules of a façade system in Portugal. Trombe walls are massive walls separated from the outdoors by glazing and an air space, which absorbs the solar energy and releases it selectively to the inside of the building at night. Computational simulations were carried out with the Design Builder, Ecotect and Desktop Radiance programs.

Traditional uncertainty quantification (UQ) in the design of energy efficient buildings is limited to the propagation of parameter uncertainties in model input variables.  Some models inside building simulation are inherently inaccurate, which introduces additional uncertainties in model predictions. Therefore, quantification of this type of uncertainty (i.e., modelling, or more strictly speaking model form uncertainty) is a necessary step toward the complete UQ of model predictions.