Advanced Building Simulation

(a)
(b)
zone 6
5
4
3
2
1
3
1 Pre-heating/cooling
2 Re-heating/cooling
3 Cooled ceiling
S
Outside
2 1
S = sensor air temperature
Integrated building airflow simulation 89
Zone 1
Outside
2 1
Figure 4.2 Glasgow’s Peoples Palace museum with corresponding simplified airflow model based on
rules of thumb; numbers indicate average air change rate per hour (Hensen 1994). (See
Plate I.)
In these types of approaches airflow is modeled conceptually. Based on rules of
thumb, engineering values and/or empirical relationships as exemplified earlier, it is
up to the user to define direction and magnitude of airflows. A typical application
example is shown in Figure 4.2.
In everyday building performance simulation, it is these types of approach that are
most commonly used. The main reasons are that they are easy to set up, they are readily
understood because they originate from “traditional” engineering practice, and
they can easily be integrated with thermal network solvers in building performance
simulation software.
4.1.2 Zonal models
In a zonal method, the building and systems are treated as a collection of nodes
representing rooms, parts of rooms and system components, with internodal connections
representing the distributed flow paths associated with cracks, doors, ducts, and
the like. The assumption is made that there is a simple, nonlinear relationship between
S