Chapter 5 Basic Duct Symbols and Drawings 107
Copyright Goodheart-Willcox Co., Inc.
5.4.2 Ceiling Supply Registers
Ceiling supply registers can be confi gured in a number of different ways
and can take on many shapes. The most popular shape is square. Air can
be directed from the register in one or more directions. The desired air
patterns are indicated on duct drawings, Figure 5-43.
■ Four directions. When located in the middle of a room or area, these
registers often direct the supply airstream in all four directions.
■ Three directions. When located against a wall, the registers often
direct the supply airstream in three directions.
■ Two opposite directions. When located in a long, narrow space,
such as a hallway, the registers typically direct the supply airstream
in two opposite directions.
■ Two directions. For installations where the supply register is located
in a corner, the register is used to direct airfl ow in two directions,
creating a 90° angle.
■ One direction. Although not a popular option, square registers are
available that will direct the air supply in only one direction.
Return air inlets located in the ceiling are drawn similarly to supply
registers, but are not directional. These inlets are simply pulling air from
the conditioned space back to the air handling equipment. Some com-
monly used return air symbols are shown in Figure 5-44. The symbols are
used primarily on plan views to identify the location and type of ceiling
supply and return locations.
Return Grilles and Registers
A plan view indicates the location of the supply and return grilles and reg-
isters when an airstream enters or leaves the space from the wall. Drawings
for wall-mounted supply grilles are typically labeled with the size of the grille
and the amount of air intended to fl ow through the grille, Figure 5-45. This
fi gure represents a 20 × 6 supply grille, SG, and a 20 × 6 return grille,
RG. These are indicated by the direction of airfl ow and the device abbre-
viations. The two horizontal lines in the fi gure represent a wall, and the
arrow points either out of the wall, as in the case of the supply grille, or
into the wall, as with the return grille.
Four-way
One-way
Three-way
Two-way
opposing
direction
Two-way
corner
Goodheart-Willcox Publisher
Figure 5-43. Symbols that indicate
various air patterns for supply registers.
Return inlet Return linear diffuser
Return grille Return diffuser
Goodheart-Willcox Publisher
Figure 5-44. Various return air symbols.
20 x 6 SG
350 cfm
20 x 6 RG
350 cfm
A B
Goodheart-Willcox Publisher
Figure 5-45. A—Supply grille symbol
includes the size of the grille and the cfm
rating. B—Return grille symbol includes
the size of the grille and the cfm rating.
Copyright Goodheart-Willcox Co., Inc.
5.4.2 Ceiling Supply Registers
Ceiling supply registers can be confi gured in a number of different ways
and can take on many shapes. The most popular shape is square. Air can
be directed from the register in one or more directions. The desired air
patterns are indicated on duct drawings, Figure 5-43.
■ Four directions. When located in the middle of a room or area, these
registers often direct the supply airstream in all four directions.
■ Three directions. When located against a wall, the registers often
direct the supply airstream in three directions.
■ Two opposite directions. When located in a long, narrow space,
such as a hallway, the registers typically direct the supply airstream
in two opposite directions.
■ Two directions. For installations where the supply register is located
in a corner, the register is used to direct airfl ow in two directions,
creating a 90° angle.
■ One direction. Although not a popular option, square registers are
available that will direct the air supply in only one direction.
Return air inlets located in the ceiling are drawn similarly to supply
registers, but are not directional. These inlets are simply pulling air from
the conditioned space back to the air handling equipment. Some com-
monly used return air symbols are shown in Figure 5-44. The symbols are
used primarily on plan views to identify the location and type of ceiling
supply and return locations.
Return Grilles and Registers
A plan view indicates the location of the supply and return grilles and reg-
isters when an airstream enters or leaves the space from the wall. Drawings
for wall-mounted supply grilles are typically labeled with the size of the grille
and the amount of air intended to fl ow through the grille, Figure 5-45. This
fi gure represents a 20 × 6 supply grille, SG, and a 20 × 6 return grille,
RG. These are indicated by the direction of airfl ow and the device abbre-
viations. The two horizontal lines in the fi gure represent a wall, and the
arrow points either out of the wall, as in the case of the supply grille, or
into the wall, as with the return grille.
Four-way
One-way
Three-way
Two-way
opposing
direction
Two-way
corner
Goodheart-Willcox Publisher
Figure 5-43. Symbols that indicate
various air patterns for supply registers.
Return inlet Return linear diffuser
Return grille Return diffuser
Goodheart-Willcox Publisher
Figure 5-44. Various return air symbols.
20 x 6 SG
350 cfm
20 x 6 RG
350 cfm
A B
Goodheart-Willcox Publisher
Figure 5-45. A—Supply grille symbol
includes the size of the grille and the cfm
rating. B—Return grille symbol includes
the size of the grille and the cfm rating.