IBPSA2001

Windows strongly influence the energy performances of buildings, especially in the new hugely glazed constructions. Many  advanced glazings were produced to improve the thermal and optical properties of windows, but for these products the angular dependence of optical and solar parameters are from the traditional glass decay curves. Computer tools often do not solve the problem of the inputting of effective solar and luminous parameters of transparent surfaces, since they consider only the traditional glazings behavior.

In the paper, based on MS Thesis by Richtr, 2000, the authors describe CFD modeling of a computer room with regard to thermal comfort of workers. The room was equipped with an additional A/C and people felt uncomfortable in certain places after the installation. As input data for CFD simulation, individual heat loads measured on computers and monitors were used. Different scenarios of adjustable vanes of the A/C diffuser and further modifications were studied.

Solar radiation induced convection occurs quite often in glazed spaces. In spite of that the impact of solar radiation to airflow inside rooms and buildings is not usually taken into account when airflow patterns are studied. However, there are many cases when this impact cannot be neglected. The paper deals with the CFD modeling of airflow and temperature fields inside a glazed attic, and comparison of results with experimentally obtained data. The main goal is to find optimal locations of ventilation  system  inlets  in  order  to  increase  the efficiency of solar energy utilization.

Most photovoltaic (PV) facades are built as curtain facades in front of thermally insulated buildings with air ducts in between. This causes additional costs for support    structure    and    installation,    while    heat dissipation from the solar cells is often not optimal. Measurements carried out are facing both concerns: Integration of a thermal insulating layer (which meets the latest German heat preserving regulation WSV 95) into the PV facade plus additional cooling by active ventilation   or   water   flow.

This paper discusses the first full version of IDEA-l, a new natural-lighting design tool for the early stages of the architectural design process. This computer program, which is part of the larger IDEA+ research project, allows the user to judge the impact of natural light on his architectural design. For this purpose a number of tests are provided, covering different aspects of natural lighting. This paper will discuss each of the tests and the involved algorithms.

This  paper  presents  the  multiple-view performance assessment of an existing office building undertaken with an integrated application. It includes the assessment of the energy consumption,  room acoustics, occupant comfort, and the environmental impacts (fuel, materials, transport,  and  processes)  . The simulation results have been compared with in- situ measurements monitored in the building during the post-occupancy phase to analyse the conformity of the results.

The present  work  deals with  the  determination  of a mathematical correlation for conductivity in the fully water-saturated state in  terms  of  dry-basis conductivity and porosity. In the mathematical model, the material microstructure is taken into account in a multiscale percolation system and the macroscopical conductivity is obtained with a renormalization technique. The model is presented and the obtained correlation is tested for some porous  building materials .  To  conclude,  we  show  how  porosity  can affect thermal conductivity.

Advances  in  psychoacoustics  through  the  years, have made it possible to evaluate the acoustical quality of a room, based on several numerical parameters that have been developed. Even though there is not a total agreement about which parameters are truly important, some of them are accepted by most of the acousticians. When designing a concert hall, ray-tracing softwares can be used to calculate some of these parameters. However,some input data carry some uncertainties.

We give an overview of how windows are modeled in the EnergyPlus whole-building energy simulation program. Important features include layer-by-layer input of custom glazing, ability to accept spectral or spectral-averaged glass optical properties, incidence angle-dependent solar and visible transmission and reflection, iterative heat balance solution to determine glass surface temperatures, calculation of frame and divider heat transfer, and modeling of movable interior or exterior shading devices with user-specified controls. Example results of EnergyPlus window calculations are shown.

The  important  variation  of  the  urban  morphology has direct effects on the disparity of the outdoor climates, as well as indoor climates. In this context, this work aims at answering at  the  following question : how to simulate, in an operational way, the relation between urban form and climate, at an intermediate scale corresponding to the neighbourhood ? Our  approach  tries  to  answer  to  this  question,1by working at the neighbourhood scale, and by proposing a complete and operational system of morphological indicators of the built environment.