Graphics Programs Reference
In-Depth Information
one of their own choosing. In Figure 10.3 , you can see, however, that after
the air terminals have been copied/monitored, regardless of the type of
host association, this ceiling-hosted family has no host but is in the correct
location specified by the architect.
Cushion Head Boxes
A cushion head box is used as a connection to the air distribution
components to assist in their performance and help in noise reduction.
They can be built into the diffuser or can be supplied separately. So
what is the best way to show them in the model? It may seem easier to
create the diffuser family with the cushion head box included because
then you won't have to add the cushion head box for each diffuser in the
project. This is true. However, there are some variations to account for.
Not every diffuser has a cushion head box; also, there could be multiple
spigot connections to the box, and those connections—usually round
for flexible duct connection—could be oval or rectangular, especially
when low height is required or flexible ductwork not allowed.
The standard cushion head box may cover 90 percent or more of your
project requirements, but having to create different diffuser families, or
family types, for each cushion head type would be time consuming each
time the diffuser family needs upgrading, and it would be confusing in
the project both for selecting the correct family and when trying to
create a diffuser schedule.
Whether as part of the diffuser family or separate, the spigot
connection to the cushion head box can be sized automatically to your
company standards or to manufacturer's requirements using an IF
statement. For more information on using formulas and conditional
statements, refer to Chapter 6, “Parameters.” If the cushion head is
built into the family, the connection will be sized as soon as you input
the flow rate. If the cushion head is separate from the diffuser, then you
must ensure that the diffuser is a part of a system and that the system
calculations are set to Flow Only or All. Otherwise, the cushion head
will not pick up the flow for the diffuser. Once your cushion heads are
all in place and the sizes calculated, you can turn the calculations to
None again.
 
Search WWH ::




Custom Search