Graphics Programs Reference
In-Depth Information
is to split the task of duct sizing into manageable sections, such as a floor
plan, a zone, or a group of air terminals fed from the same VAV box.
The various methods for sizing are as follows:
• Friction
• Velocity
• Equal Friction
• Static Regain
Friction and Velocity can be used independently of each other when using
the Only option. Alternatively, they can be used in conjunction with each
other with the And and Or functions.
These options allow the designer to force the sizing ducts to meet the
parametersspecifiedforbothVelocityandFriction.WiththeOrmethod,the
least restrictive of either of the parameters is used.
The Equal Friction and Static Regain methods use the ASHRAE duct fitting
database.
Air properties are set in the Mechanical Settings dialog box, as are the
available sizes of ducts used in the actual sizing calculations (see
Figure
10.38
and
Figure 10.39
).
