IBPSA1999

Internal   melt   ice-on-coil   tank   with   built-in horizontal tubes is a kind of ice tank used widely. Its discharge process is effected greatly by density different between ice and water. The existing models developed for internal melt ice-on-coil tank are concentric cylinder models which are applicable to tank with built-in vertical tube or to case when all water in tank is frozen, but is not applicable to describing the effect of density difference between ice and water on discharge.

An experimental apparatus (in-situ thermal test unit) and an analysis method have been developed for evaluating the thermal resistance of the building envelope on site. This system estimates the thermal resistance of a wall by heating the outside wall surface and measuring the surface heat fluxes and temperatures on both sides of the wall. The heating panel is attached to the outside surface to avoid the effect of outside weather and to keep the surface temperature constant. The inevitable problem of this kind of testing method is, however, the error caused by the lateral heat loss.

A practical way to estimate the accuracy of sound field analysis by the finite element method in building environments is presented here. The error characteristics curves of several acoustic finite elements are proposed first, then a guideline is given for the 27-node acoustic finite element, developed by the authors, to be employed in the analysis where high accuracy is required. With the issue, sound fields in a reverberation room (179m3) with several absorbent conditions are analyzed by the method to be compared with the measured values, which showed fair agreement.

This communication presents a tool, m2m&Roofsol, which has been developed in the framework of a European project, ROOFSOL, dedicated to the study of passive cooling by roof components. This tool is based on an existing simulation tool, m2m, which allows detailed analysis and simulation of the thermal dynamic behaviour of large building envelopes, and model size reduction techniques[2][3]. Two main problems have been solved in this software extension.

It is necessary to predict the load of the following day and hours to establish optimal thermal storage. In this paper, three kinds of load prediction models, the Kalman filter, GMDH and neural network are used and characteristics and usability of each method were compared. It has been shown that proper selection of input variables, method of preprocessing the meas- urement data and the form of prediction equation gave a large influence on the prediction accuracy, and that each of them could predict the cooling load for thermal storage operation with sufficient accuracy.

This paper describes an effort to link the COMIS 3.0 multi-zone airflow model with the EnergyPlus building energy simulation program. COMIS 3.0 is a network-based multi-zone airflow model developed by a multinational team in the framework of International Energy Agency’s Annex 23 for simulating airflows through the building fabric due to infiltration or natural ventilation, and from zone to zone, as well as the interactions of the HVAC system, ducts, and exhaust hoods and fans.

The high thermal insulation of housing construction has been spreading all over Japan, for the improvement of indoor environment and the efficiency of energy consumption. From the view point of global warming, it is acknowledged that the high thermal insulation reduces CO2 emission in the heating and cooling phase, but it increases CO2 emission at construction phase since the amount of materials for thermal insulation increases.

Currently used design tools for kitchen design are often complicated, have poor interfaces and limited capabilities to exchange data between different applications. No integrated kitchen design environment is available although kitchen design requires the expertise of many different specialists and the decisions of various designers strongly affect each other. The complex design, build, maintain and retrofit process has been mapped in order to provide a logical structure and flow for the kitchen design system.

This paper reports on two case studies that explore the current use of computational tools in building design scenarios. Goal of the project is to gain insight into the role of tools in the design process and to investigate and capture the designer’s viewpoint concerning building simulation. This viewpoint is essential for a successful application of simulation in the design process, but might differ from the viewpoint of the developer of simulation  tools.