IBPSA2013

This paper reports on how sensitivity analysis techniques, applied to the inputs of calculation engines for energy certification and regulation compliance purposes, can provide guidance for simplifying their user interfaces.Two different techniques were employed: the Morris Method, used to screen the input factors, and Monte Carlo Analysis, used to assess the effects of approximations on groups of parameters.It is shown that this analysis approach can lead to useful reductions in user effort without significant loss of accuracy. 

Occupants have influence on buildings performances due to their presence and their behavior towards in-door environmental conditions controls. However, most building energy models consider occupants in an over-simplified way. Many experiences feedbacks have shown that this assessment leads to huge dif-ferences between simulation results and actual energy consumption. In this paper we propose a new method aiming at reducing this uncertainty.

The European energy policies about climate and energy packages, known as the “20-20-20” targets, define ambitious, but achievable, national energy requirements.

This paper presents helical heat exchangers for geothermal use. The differences with more widespread geothermal exchangers are given, and a complete thermal model for the underground such as for the exchanger is developed, including the local freezing of water contained in the underground when temperatures are lower than 0◦C. This model is com-pared with published data and with experimental re-sults. In a second part, the model is applied to the heating and the cooling of buildings.

Moisture transfer in porous construction materials car-ries many causes for their degradation: mould devel-opment and freeze-thaw damage are favoured by the accumulation of water, and chemicals such as chlo-ride ions and carbon dioxide may accelerate the frac-turing of cementitious composites. Over time, mi-croscopic and macroscopic cracks progressively de-velop under the effects of mechanical loading and sorption/desorption cycles: their influence is to be ac-counted for in long-term hygrothermal performance assessments of the building envelope.

This paper proposes to apply the celebrated Proper Or-thogonal Decomposition (POD) approach in order to obtain a short-term control model for the temperature dynamics of the borehole system. The main idea be-hind POD-based modeling is the extraction of a set of optimal basis functions containing the main char-acteristics of the system from snapshots of the system dynamics at various time instants. This way, POD al-lows an accurate description of the heat diffusion pro-cess where the POD modes can be used as states of the control model.

This investigation proposed a two-step model to inversely identify release location and temporal rate profile of an indoor pollutant source in an arbitrary release form. The first step is to run inverse solution of the release rate profiles based on Tikhonov regularization for all possible source locations with concentration information provided by one sensor. The second step is to interpret occurrence probability of each solution obtained in the first step according to the Bayesian probability model, by matching the concentration at the other sensor.

In the frame of a research project, the energy production for a residential unit including its mobility by micro-CHP was simulated in detail. Several variations of energetic building standards, of types of energy generation and of energy carriers were inves-tigated. They were compared to reference scenarios in respect of primary energy consumption and envi-ronmental impact. For the building use, standard data published in Swiss standards were used.