ALLAN. SIMULATIONINEPTUNIX is a software designed at the GAZ DE FRANCE Research and Development Division and developed with the aid of CISI Ingenierie. It is a general software for the description and simulation of dynamic systems. ALLAN. Simulation is a pre-and post-processor. It is not a simulation software, and simulation is due to the choice of a solver. It is used at GAZ DE FRANCE and in other companies to describe and manage models for the NEPTUNIX 2 simulation program. It may also be used with ASTEC 4.

After a short description of the physical phenomena involved, unified expressions are worked out describing net airflow and net heat flow through large vertical openings between stratified zones. These formulae are based on those of Cockroft for bidirectional flow, but are more general in the sense that they apply to situations of unidirectional flow as well. The expressions are compatible with a pressure network description for multizone modelling of airflow in buildings. The technique has been incorporated in the flows solver of the ESP-r building and plant energy simulation environment.

Building performance simulation is reviewed, with and emphasis on its role as a means to bring buildings into a better balance with the human and natural environments.

A solar wall is a complex part of the building envelope, as it acts as an energy collector, passing solar energy from the exterior surface into the building with a time delay and in the same time reducing thermal losses during periods with no sunshine. A module for simulating solar walls in a Danish building simulation program (tsbi3) has been developed to analyze the interaction between a solar wall and the building behind.

The layout of air-conditioning systems in building varies dramatically owing to the differences in conceptual design and the relationship between building and plant topologies. Nevertheless all air-conditioning systems have the same basic components which are responsible for the underlying thermofluids and psychrometric functions. Based on a first principles approach, the mass and energy flow in various air-handling equipment has been investigated. 20 primitive parts have been identified which can be put into the ESP-r system to simulate real air han Wing systems.

We present the SYMBOL project which is based on a modular approach of modeling. The main objectives of this project is to develop a coherent set of modeling tools which can be assembled in order to simply build particular and adapted modeling programs and to allow handling of "natural" concepts during the modeling process. The paper will deal mainly with the modularity of the SYMBOL'environment, and the needed formalism and abstraction effort made in the SYMBOL project.

Building energy simulation is playing an increasingly important role in the development and implementation of building energy codes and standards in the United States. This trend parallels a progression over the past 15 years from the use of largely prescriptive methods for encouraging energy-efficient building design to reliance on more performanceoriented approaches. A multiyear research project is currently under way to develop a methodology on which to base future energy performance standards for the design of new commercial buildings.

In this paper, we develop a discrete approach to describe the transport of condensible vapors through a microporous substance. We consider only isothermal water migration under uniform atmospheric air pressure, at temperature lower than 100C with negligible gravity. The pore-structure which is supposed to be representative of the material is built on a 2D random network of tubes. The basic phenomena (adsorption/desorption, diffusion, condensation) that occur during the water vapor transport in a single cylindrical pore at the steady state are taken into account.

A set of statistical regression equations was developed to predict relative heating and cooling loads of external zones of commercial buildings. The equations were derived from the coil loads predicted by several thousand DOE-2 simulations.

The topic of this paper is the use of low temperature air (40 F or 5 C) for room cooling. Cold air systems can offer energy and space savings relative to higher temperature cooling systems. As the supply temperature and flowrate are reduced, considerations such as adequate flowrate, jet dumping or separation, condensation on duct walls, and decreased relative humidity become increasingly important. Cold air jet separation from the ceiling can be a problem resulting in unacceptable thermal discomfort in the occupied zone.