Advanced Building Simulation

Reality
Space averaged treatment of
conservative laws of
thermodynamics
Figure 1.2 Standard approach to simulation.
DAE
Model
Post-processing and interpretation
Trends in building simulation 7
Experiment
System
Simulation
combine forces in order to stop duplication of efforts. The launch of EnergyPlus
(Crawley et al. 1999) is another more recent indication of this. Until the mid-1990s the
landscape of tools was dominated by the large simulation codes that were generated
with research funding, for example, DOE-2, ESP-r ad TRNSYS. As new simulation
domains came along, these tools tried to expand into these domains and outgrow their
traditional energy origin. However, since the late 1990s, domains other than energy are
increasingly covered by specialized tools, for example, in air flow simulation, moisture
and mold simulation, and others. Specialized tools do generally a better job in these specialized
fields. Another new trend was the entry of commercial packages, some of which
were offered as shells around the existing computation kernels mentioned earlier, and
some of which were new offerings. These and all major tools are listed on (DOE 2003).
As to computational elegance, it cannot escape closer inspection that computational
kernels of the energy simulation tools (still the largest and most pronounced
category of building simulation tools) date back more than 15 years. Rather primitive
computing principles have remained untouched as the bulk of the development
resources have gone into functional extensions, user interfaces and coverage of new
transport phenomena. But thanks to the fact that Moore’s law (in 1965, Gordon
Moore promised that silicon device densities would double every 18 months) has held
over the last 25 years, current building energy simulation codes run efficiently on the
latest generation of Personal Computers.
The landscape of simulation tools for the consulting building performance engineer
is currently quite diverse, as a result of the hundreds of man-years that have been
invested. A skilled guild of tool users has emerged through proper training and education,
whereas the validation of tools has made considerable progress. As a result, the
design profession appears to have acquired enough confidence in the accuracy of the
tools to call on their expert use whenever needed. In spite of the growing specialization
and sophistication of tools, many challenges still remain to be met though before the
building performance discipline reaches the level of maturity that its vital and expanding
role in design decisions demands. Many of these challenges have been on the wish