Foreword
BSim is a user-friendly, flexible computer program for calculating and analyzing indoor climate conditions, power demand and energy consumption in buildings. By developing a detailed mathematical model for the building, it is possible to simulate even highly complex buildings with advanced heating and ventilation systems and operating strategies that vary over the course of the day and year.
Engineers and architects can use BSim as a useful tool when planning and designing buildings, particularly when comparing and analyzing alternative design proposals with regard to energy consumption, thermal indoor climate and daylight conditions. The software also simulates operating conditions and the dynamic interplay between the building, the installations and their automatic control systems. In terms of analysis, the software is particularly suitable for parameter studies concerning, for example, incident solar radiation, exploitation of passive solar heat and the size and orientation of windows.
Building authorities and legislators can make use of the software suite to analyse the consequences of new requirements with regard to energy and indoor climate conditions and verify conformance with requirements.
The software calculates power outputs and energy flows within the building and between the building and its surroundings. For all the spaces or zones being simulated, the software will therefore calculate heat loss through transmission, infiltration and ventilation, heat input in the form of solar heat, heat and moisture given off by people and equipment, electricity consumption for lighting, and power demand and energy consumption for every component of the heating, cooling and ventilation systems. Indoor climate is calculated using hourly values for indoor air temperatures, surface temperatures, relative atmospheric humidity and air exchange for each zone.
The software uses data from the Danish Reference Year, DRY, by way of climate data, but it is also possible to use weather data for other locations and data gathered by the users themselves.
The software can be run on PCs using the Microsoft Windows 98 (SE), Windows NT, Service Pack 3, Windows 2000 or Windows XP operating system. Microsoft Data Access Components, MDAC, must also be installed on the PC.
The software was developed validated and documented by the following employees at the Danish Building Research Institute: Karl Grau, M.Sc., senior researcher (software development), Kjeld Johnsen, M.Sc., senior researcher (validation), Kim B. Wittchen, M.Sc., senior researcher (documentation and validation), and M.Sc. PhD, senior researcher Jørgen Rose (software development). Carsten Rode of the DTU*BYG at the Technical University of Denmark also helped with the development of the joint building model and data models.
Erwin Petersen of the Danish Building Research Institute developed a model for calculating solar radiation on inclined surfaces, as well as models for calculating daylight conditions on the basis of solar light factors. An alternative model for calculating solar radiation on inclined surfaces, developed by Tariq Muneer, has been incorporated in the software. Rolf Djurtoft and Gitte Blaagaard of Birch & Krogboe, Henrik Ryberg and Tom Jepsen of Carl Bro as and Henrik Brohus of the Department of Building Technology and Structural Engineering at Aalborg University assisted with testing, validation and preparation of the learning examples. The models for calculating daylight in a room were developed by Troels Ravn.
Various persons have participated by developing different parts of BSim. These are mentioned in the help pages that are relevant for their parts of BSim.
All the models included in BSim have been evaluated either by analytical means, by comparison with equivalent models in other thermal simulation programs or by direct comparison with measuring results from different types of building. During these evaluations the software produced satisfactory calculation results, i.e. results with modest deviations from the theoretically correct, expected or measured values. The flexibility and number of possible combinations offered by the software are virtually infinite, however, so it will always be necessary to subject the results of calculations for complex buildings to a critical engineering assessment.
Danish Building Research Institute, SBi
AALBORG UNIVERSITY
Department of Energy and Environment, 2008
Søren Aggerholm, Head of Research