The application of system identification techniques to the energy performance assessment of buildings and building components requires a high level of knowledgeof physical and mathematical processes. This factor,combined with the quality of the data, the descriptionof the monitoring procedure and test environment, together with the experience of the user of the analysis software itself, can produce varying results from differentusers when applying different models and software packages.
The CLIM 2000 software environment [1] was developed by the Electricity Applications in Buildings Branch of the French utility company, Electricité de France. This software which has been in operation since June 1989, allows the behavior of a whole buildi
In 1993, the R & D Division launched the IntelChaud project with a view to improving the comfort provided by individual gas-fired boilers used for domestic hot water production. This study was conducted in partnership with two French boiler manufacturers and was therefore applied to two particular cases. The work performed for this study has led to substantial improvements in boiler control through the use of sophisticated numerical control systems.
French buildings highly contribute to the total national energy consumption. In order to inflect theincreasing tendency, significant efforts have been encouraged by public institutions.Accordingly, the GENHEPI concept, hereunder described, aims at methodically investigate retrofitoperations to ensure an effective renovation of existing buildings. Its first phase consists in preparingand elaborating projects development by a global energy approach. Modelling and sensitivity studiesof various technical solutions permit this analysis.
In this paper the authors in order to reach the objective of a global approach of comfort by a spatial statistical study of the various discomforts, apply a multi-criteria analysis based on ELECTRE II method adapted to the comfort of air-conditioned indoor environment.
This thesis is based on studies undertaken during the period 1998-2003 at the HVAC laboratory of Helsinki University of Technology.The thesis focuses on dust accumulation in, and removal from, recently installed supply air ducts and on the bristle behaviour of rotating duct cleaning brushes. The results of dust accumulation, measured using three different methods, were compared and the amount of dust in newly installed air ducts was evaluated. The vacuum tests was found to be an efficient method of collecting dust samples on the duct surface.
A simple model of a rotating duct cleaning brush was presented using large deformation elastic theory. The results obtained by the model were compared with the results obtained by a laboratory test. Especially, the effect of air drag on the brush behaviour was considered.
Rotating brushes are commonly used in cleaning air ducts. A very simple model simulating the behaviour of a typical brush bristle is presented. The model consists, in effect, of a combination of a polynomial trial solution, the point collocation method, Simpson's integration rule and a Mathcad code. The main interest from the cleaning point of view is in determining the contact force and the contact angle between the bristle tup and the duct surface. The effect of the degree n of the polynomial trial solution - n=4, n=6, n=8 - is studied.
The bristle of a rotating cleaning brush for air ducts was modelled using large deformaion elastic theory. The point collocation method with a trial solution consisting of undertermined parameters was employed to discretize the resulting non-linear problem. The main interest was in determining the value of the bristle tip contact normal force N, the bristle tip contact angle B and the torque T needed to rotate a brush. The results obtained using the simple model were compared with the results obtained from a laboratory test.
The proposed local dynamic similarity model can select an adequate discharge coefficient to match the approaching flow angle. This is an improvement over the conventional orifice flow model where the discharge coefficient is set to a fixed value. The accuracy of predicting ventilation flow rates for an isolated cross-ventilation model is greatly improved when the discharge coefficients actually decrease with change of wind direction.
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