This paper presents the application of multi-inputs single-output (MISO) models to estimate thethermophysicals parameters of a building. ARARMAX, Box-Jenkins and the general MISO models areused to identify the U value, the time constant and the equivalent solar surface of the building.Optimization-based prediction error method (PEM) algorithm is used to estimate model parameters.This approach has been tested to analyze a passive solar house in Tunis. The identified parameterswere compared to theoretical values; good results have been obtained for the tested building.
As overheating problems in glassy buildings came up more and more, EMPA put a focus on the determination and modelling of the total solar energy transmittance (TSET) of multiple glazing combined with different shading systems within the framework of IEA Task 27 "Performance, durability and sustainability of solar faade components". Experimental data were produced by a calorimetric outdoor test facility near Zurich (Switzerland).
This paper presents the application of IDENT Graphical User Interface of MATLAB to estimate the thermal properties of building components from outdoors dynamic testing, imposing appropriate physical constraints and assuming linear and time invariant parametric models. Theory is briefly described to provide the background for a first understanding of the used models. The relationship between commonly used RC-network models and the parametric models proposed is deduced. The analysis is generalised for different possibilities in the assignment of inputs and outputs and even multioutput.
This paper presents two approaches used to develop a model of Room Storage Heater. The first one consists of a dynamic model of the RSH developed by the authors using the results obtained from tests performed in a calorimetric chamber. The model was verified against the results obtained during five different charge-discharge test periods. The second approach is a new concept based on Neural Networks applications. In this approach, we suppose that we do not have a description of the RSH itself.
Dynamic analysis is very useful to obtain thermal properties of building components. However different methodologies can be applied, and several software tools based on these methodologies are available which application requires certain degree of experience. The main differences between methodologies are the numerical procedure and the model assumed to estimate the required parameters. Different approaches can lead to different and even wrong estimations of the parameters.
Together with the definition of innovative plant and envelope technological solutions for buildings, many simulation tools (models) have been developed to make the design choices easier. However the definition of analytical structures able to describe the characteristics of building components installed under real conditions is still difficult. The paper presents some experiences made by ITC. They have been carried out by using System Identification techniques to simulate and predict the performances of various components analysed also through experimental campaigns under real conditions.