A numerical study of turbulent air flow in ventilated multi-room configurations, where both of buoyancy- and radiation-effects are of importance, is described in this paper. Our computer code solves, in finite difference form, the transient-state conservation equations for mass, momentum and thermal energy. The two equation k-e model with buoyancy terms (Boussinesq approximation) is employed for modelling of turbulence. In addition, a two-band model based on Gebhart's method has been implemented enabling the study of the effects of long wave radiation and solar radiation through windows.

While advanced models for combined heat and moisture transfer have been available in the community of building scientists within the last two decades, such models have not yet become an item in the toolbox of consultants, building designers or manufacturers of building components. Moisture dimensioning among the practitioners still takes place by rules of thumb or at best by use of the steady state Glaser method or modifications thereof.

This paper describes an operating hourly weather simulation model which is utilized to drive building energy simulation and equipment design software. The model contains both deterministic and probabilistic portions that perform sun angle calculations, sky opacity, dry-bulb temperatures, dewpoint temperatures, wind speed, and barometric pressures. Sample summary statistics have been shown to give good agreement with means, extremes, and distributions of real weather data records. A sample energy analysis is also included to illustrate the model's flexibility for different applications.

This paper describes the techniques used within the ESP environment# to simulate coupled heat and mass flows in integrated building and plant systems. In particular, it describes the equation-sets used to represent inter-zonal (building) and inter-component (plant) fluid flow, the method used for the simultaneous solution of these non-linear equations, and the solution coupling of the heat and mass conservation equation-sets. By means of a brief description of a case study, the application in a real building performance evaluation context is demonstrated.

Analytical solutions for coupled diffusion of heat and moisture through a material are used to develop a generalisation of the wellknown 2 x 2 matrix method for describing heat flow only. A new 4 x 4 matrix is derived which relates temperatures, humidities, heat flows and moisture flows at one surface of a slab with those at the other. Multilayer slabs and surface boundary conditions, including moisture-impermeable surfaces, are easily handled by multiplication of matrices.

This paper presents a new technique for the thermal systems modelling. This method, based on the structural modularity of a thermal system such as a building belongs to the modal methods family. It especially allows to obtain accurate enough reduced thermal models of large system. In this paper, the main advantages of this method are specified (recurrent, ...). Its funtamentals are given and the results are illustrated by two examples (three layers wall and bizone building).

The presentation of most HVAC simulation programs are out of date and batch processing type. Their use is complex and often requires a good data processing knowledge. Moreover, the data entry is usually long and the search for conceiving or typing mistakes is not easy. This present work shows how to update the simulation environment and how to satisfy the modem work station requirements by using a graphical manmachine interface.

As part of visualization of interior luminous environment in daylighting a programme (NATUREL) has been developed at CSTB. It allows to take into account complex shapes of building, furniture and apertures. These, located on facade and/or on roofing, are characterized with various parameters : area, thickness of wall (roof), luminous transmission, outdoor surroundings ... All surfaces (indoor and outdoor) of the scene are described in term of plane facets and are supposed to have perfectly diffuse reflection, which is advised for interior lighting. The software includes three main steps.

A new computer program has been written for comparing the annual energy and economic performances of different window systems in non-residential buildings. The program, called CSHADE, performs a sideby-side hourly energy performance simulation of a test window system compared to a reference one. A comprehensive report is printed out at the completion of each simulation. The program is much simpler and easier to use than large building simulation programs such as DOE-2 or BLAST, and has relatively more modest computer requirements.

Today energy saving rates due to retrofits in residential housing are either measured by experiment on site or predicted by system simulation. In the latter case mathematical models of the components are developed, verified by laboratory tests and combined to represent the thermal characteristics of the investigated system. Then energy demand is calculated before and after adopting the investigated retrofit. There still remains the question, are energy savings precalculated by system simulation: obtained in fact, in other words do they agree with results of field experiments.