108 Print Reading for HVACR
Copyright Goodheart-Willcox Co., Inc.
Wall louvers and registers can be drawn as shown in Figure 5-46.
The fi rst symbol represents a wall louver and is simply a rectangle that
is positioned on the side of the wall where the louver will be installed.
The second symbol is a wall register symbol. This is similar to that of the
wall louver, but the V-shaped lines indicate the slats on the register can
be adjusted.
Sometimes, transfer grilles are installed between rooms in the same
conditioned zone. Transfer grilles allow for free airfl ow between the
two rooms through a penetration in the wall between the two spaces.
Figure 5-47 shows two symbols commonly used to indicate transfer
grilles and louvers. Notice that the arrows on the transfer grille and lou-
ver symbols extend completely into both areas, separated by the wall.
This indicates that air is free to fl ow from one space, through the wall,
and into the other. Transfer grille symbols, therefore, differ from supply
register and return grille symbols, because the arrows in these do not
completely pass through the wall.
On systems with a single, centrally located return grille, air must
fl ow freely into the conditioned space and then freely back to the return
grille. In applications where there are doors that can be closed, airfl ow
back to the return grille can be impeded when the doors are closed.
To facilitate suffi cient airfl ow throughout the conditioned space, it
is often desirable to install grilles or louvers in the doors themselves,
Figure 5-48.
Wall supply louver Wall supply register
Goodheart-Willcox Publisher
Figure 5-46. Alternate wall supply air
symbols.
G L
A B
Goodheart-Willcox Publisher
Figure 5-47. A—Symbol for a transfer
grille. B—Symbol for a transfer louver.
G L U
A B C
Goodheart-Willcox Publisher
Figure 5-49. A—Symbol for a door grille. B—Symbol for a door louver. C—Symbol for
an undercut door.
Grille or
louver
Goodheart-Willcox Publisher
Figure 5-48. Door grille or louver is installed to improve airfl ow in the space.
B E T W E E N T H E L I N E S
Undercutting a Door
When grilles or louvers are installed
in doors, the drawing refl ects this by
using symbols, Figure 5-49. When
installing a grille or louver in a door
is not aesthetically pleasing, another
option is to undercut the door. The
“G”, “L”, and “U” represent grille,
louver, and undercut, respectively.
Undercutting a door is the process
of cutting the bottom of the door to
leave a gap through which air can
pass, even when the door is closed,
Figure 5-50.
Copyright Goodheart-Willcox Co., Inc.
Wall louvers and registers can be drawn as shown in Figure 5-46.
The fi rst symbol represents a wall louver and is simply a rectangle that
is positioned on the side of the wall where the louver will be installed.
The second symbol is a wall register symbol. This is similar to that of the
wall louver, but the V-shaped lines indicate the slats on the register can
be adjusted.
Sometimes, transfer grilles are installed between rooms in the same
conditioned zone. Transfer grilles allow for free airfl ow between the
two rooms through a penetration in the wall between the two spaces.
Figure 5-47 shows two symbols commonly used to indicate transfer
grilles and louvers. Notice that the arrows on the transfer grille and lou-
ver symbols extend completely into both areas, separated by the wall.
This indicates that air is free to fl ow from one space, through the wall,
and into the other. Transfer grille symbols, therefore, differ from supply
register and return grille symbols, because the arrows in these do not
completely pass through the wall.
On systems with a single, centrally located return grille, air must
fl ow freely into the conditioned space and then freely back to the return
grille. In applications where there are doors that can be closed, airfl ow
back to the return grille can be impeded when the doors are closed.
To facilitate suffi cient airfl ow throughout the conditioned space, it
is often desirable to install grilles or louvers in the doors themselves,
Figure 5-48.
Wall supply louver Wall supply register
Goodheart-Willcox Publisher
Figure 5-46. Alternate wall supply air
symbols.
G L
A B
Goodheart-Willcox Publisher
Figure 5-47. A—Symbol for a transfer
grille. B—Symbol for a transfer louver.
G L U
A B C
Goodheart-Willcox Publisher
Figure 5-49. A—Symbol for a door grille. B—Symbol for a door louver. C—Symbol for
an undercut door.
Grille or
louver
Goodheart-Willcox Publisher
Figure 5-48. Door grille or louver is installed to improve airfl ow in the space.
B E T W E E N T H E L I N E S
Undercutting a Door
When grilles or louvers are installed
in doors, the drawing refl ects this by
using symbols, Figure 5-49. When
installing a grille or louver in a door
is not aesthetically pleasing, another
option is to undercut the door. The
“G”, “L”, and “U” represent grille,
louver, and undercut, respectively.
Undercutting a door is the process
of cutting the bottom of the door to
leave a gap through which air can
pass, even when the door is closed,
Figure 5-50.