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Abstract: Solar CombiSystems (SCSs) are very efficient systems for reducing conventional energy consumption of building but their thermal performances are strongly dependent on the environment where they are installed (type of climate and thermal quality of the building). Currently it is impossible to predict the energy savings generated by a SCS as there is no standard test to characterise SCS performances. Currently, the Short Cycle System Performance Test (SCSPT), based on a 12days test of the complete SCS on a semi-virtual test bench, is able to predict annual energy savings with a good accuracy, but the performance prediction is limited to only one environment (the building and the climate corresponding with the test). Based on the SCSPT procedure, this paper proposes an improvement of the method by identifying a global SCS model from the test data. Then, the identified model would be able to simulate the tested SCS in any environment and thus to characterise its performances. The proposed model to identify is a “grey box” model, mixing a “White Box” model composed of known physical equations and a “Black Box” model, which is an Artificial Neural Network (ANN). A complete process is developed to train and select a relevant global SCS model from such a test. This approach has been validated through numerical simulations of three detailed SCS models. Compared to those annual results, “Grey Box” SCS models trained from a twelve days sequence are able to predict energy consumption with a good accuracy for 27 different environments. An experimental application of this procedure has been used to characterise a real system. [Copyright &y& Elsevier]

Abstract: This paper shows a new numerical model of earth-to-air heat exchanger. The system is discretized into “n” sections perpendicular to the exchanger pipe. In each section, the problem of conduction is solved using response factors method in order to reduce computational time. Each response factor is calculated using a finite elements program that solves 2D conduction problems. The particularity of this problem is that the time-constants are very high, making it impossible to use conventional properties of response factors to reduce the number of calculations. We will set out a new approach to solve this particular problem. Heat flux entering the pipe is then expressed as a function of the temperature of the air crossing the pipe and the external solicitations. A heat balance is then applied for each layer to find the resulting outlet air temperature. The model is then compared to an analytical model and a 3D model based on the dynamic finite volume approach. Finally an example of coupling between an earth-to-air heat exchanger and a low-consumption building is presented. [Copyright &y& Elsevier]

The analysis of the global energetic needs in an office building has to take into account the daylight and artificial lighting which are tightly coupled. The luminous and thermal behaviours of a room are influenced by the artificial lighting that generates thermal loads and by the natural lighting coming from the windows. This paper deals with the foreseen energy balance of an office building with regards to the technological and architectural solutions. This study has been conducted with EDF Research and Development, Services, energies and living spaces Department. A global analysis is needed for a consistent approach of Energy Demand Save Management [Etude de l’influence de la comple´mentarite´ entre l’e´clairage naturel et l’e´clairage artificiel sur le comportement thermique des baˆtiments tertiaires, The`se Universite´ de Savoie, March 2001, 213 pages]. [Copyright &y& Elsevier]

The modeling of the thermal behavior of buildings requires using relatively heavy data processing when it comes to reproducing reality accurately. Electrical analogy makes it possible to develop directly accurate and simplified models insofar as the temperatures within the walls are not required.We present the various stages, which led us to propose the global analogical model of the building. Initially, we have studied how to transform a multi-layer wall into a three resistances and four capacities model (3R4C). We will compare this model with other electrical models thanks to a time and frequency analysis. Then, we will deal with the principle of aggregation of several walls. In order to facilitate the iterative resolutions related to numerical simulations, the lumped model integrates a heating floor. [Copyright &y& Elsevier]