IBPSA1991

A "detailed" model of a heat emitter in hot water circulation has been developed considering, two phases (liquid and metal), the non linear heat transfer and the enthalpy transport by the fluid. A reduced order state model ( order two or three) has been then formed, linearising the initial "detailed" model and using a model reduction technique developed in our laboratory which is especially based on modal analysis. The simulated results from both the models for a step input of the inlet temperature have been presented and discussed.

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.

This paper deals with the validation methodology used within the PASSYS project focusing on the developed method for empirical whole model validation of building energy simulation programs. The paper further discusses and describes how high quality data sets for empirical whole model validation are obtained within PASSYS.

Three complementary approaches may be used in the evaluation of the performance of building control systems-simulation, emulation and field testing. In emulation a real-time simulation of the building and HVAC plant is connected to a real building energy management system (BEMS) via a hardware interface. Emulation has the advantage of allowing controlled, repeatable experiments whilst testing real devices that may contain proprietary algorithms.

This paper discusses the use of the computer program DAYLIGHT, as a method of analysing and evaluating the natural lighting in buildings. The computer's design parameters and outputs are discussed in some detail, and the program is then used to examine some of the standard design criteria. The paper concludes with a case study of a primary school building to evaluate the accuracy and usefulness of the program.

Presently, the building performance analysis requires to take accuratly into account the coupling effects between building, HVAC and control. For large scale systems, this implies the intensive use of the simulation tools.Today, the existing tools are not flexible enough for this purpose. The present paper describes the development of a more adequate tool : CSTBt. This tool is built on the TRNSYS core (University of Madison), but offers a more adapted library of solvers and component models concerning the building envelope and the hot water heating network.

The simplified thermaI simulation of buiIdings is particularly useful for both bioclimatic design and the selection of the most suitable HVAC systems. The LEGO computer program was prepared in order to simulate the conventional HVAC plant-building systems and the complex systems Iike seasonal storage tank and solar collector plants. Therefore, it is possible with this kind of program to study the interaction among the various systems by means of combination of different simulation subroutines. In this way, a more accurate dimensioning of the systems can be achieved.

The model coupling problem (MCP) is a general non trivial problem raised by the universal choice of modularity as a conceptual base for object programming and search for efficiency in software tools development. Despite the apparent universality of the problem, it does not lead to a clear common formulation; on the contrary numerous "schools" of developers seem to dig gaps among the IBPSA community. We explore in this paper the origin of the misunderstanding, and propose a tentative conceptual tool aiming towards an international comprehensive articulation of BPSA projects.

Dimensioning programs for heating radiator networks are still today cumbersome to use. This project is trying to develope easy to use and fast calculation methods for the dimensioning and balancing of radiator networks. The main idea is to integrate the dimensioning and balancing program with the CAD software. Objectoriented programming and building product modelling methods are utilized in the prototype program.

CAD manufacturers are providing an increasing amount of integrated building design software. These integrated CAD systems have few, if any, facilities to assess building performance. The building design profession is increasing its use of performance assessment tools for traditional and refurbishment design and not just technologically advanced design. Performance assessment tools will continue to grow in importance as building technology moves towards providing Intelligent Buildings.