duct work symbols

Meanings of commonly used HVAC Ductwork symbols

Outlined below are the most commonly used hvac ductwork symbols and their meanings.

Click here to view easy-to-use compiled charts of these symbols.

Duct Symbol

Straight duct

Ducts are conduits or passages used in hvac systems to move air.

Duct Branch symbol

branch duct

In order to split air passage among spaces, branch ducts are used.

Duct Bend

duct bend

In order to make smooth turns and avoid turbulence bend pieces are used in the air passage.

Duct Y junction

y-junction

3-way junction duct

3-way junction

duct junction

junction

duct beveled junction

beveled junction

Such junctions are used when a part of the air from the main passage is diverted to a certain space.

duct miter bend

miter bend

A miter bend(elbow) is made by mitering or bevel cutting two pipes or ducts usually to form a 90 degree turn.

Duct Transition

Duct Transition

Used to reduce to effective diameter of a duct. Transitions are required to change the overall size or shape of a duct.

Duct offset Transition

Duct offset Transition

Supply Ceiling Diffuser

Supply Ceiling Diffuser

Distributes conditioned air uniformly throughout the room. These are visible on the ceiling.

Return Ceiling Diffuser

Return Ceiling Diffuser

Collects return air from the room. These are visible on the ceiling.

Flexible Connector Duct

Flexible Connector

Flexible connectors are used as attachments between ducts and equipment in order to reduce noise and vibration.

VAV Box symbol

VAV Box

Variable Air Volume(VAV) boxes maintain the temperature of a space by controlling the supply of conditioned air through the duct into the space.

duct damper symbols

Duct Damper

Duct dampers are control devices in ducts that function like butterfly valves to control airflow.

Linear diffuser symbols

Linear Diffuser Supply/Return

Linear diffusers distribute air evenly throughout a space.

Floor Register

Floor Register

A register is a grille with air flow adjustment.

Air grilles symbols

Air grilles

Air grilles are used to evenly distribute air in a space.

duct heater symbol

Duct Heater

Used to heat air flowing through a duct.

duct flexible connection

Flexible Connection

Used to reduce noise and vibration.

duct louver opening

Louver Opening

Louver is a device used in hvac ventilation systems to allow air to pass through while keeping out dirt and debris.

new ductwork symbol

New Ductwork

insulated ductwork symbol

INSULATED DUCTWORK

Insulated ducts are used to reduce thermal energy loss and prevent condensation on ducts.

externally insulated duct symbol

EXTERNALLY INSULATED DUCTWORK

Insulated ducts are used to reduce thermal energy loss and prevent condensation on ducts.

fire rated duct symbol

FIRE RATED DUCT SYMBOL

Fire resistant ducts help maintain compartmentalization and divert smoke.

volume control damper symbol

volume control damper

Used to control volume of air passing through a duct.

fire damper symbol

fire damper

Fire dampers are fire protection devices used to prevent spread of fire through ducts.

duct flexible connection symbol

flexible connection

duct spigot with butterfly damper

duct spigot with butterfly damper

non return damper

non return damper

Non return dampers ensure airflow in single direction

duct attenuator symbol

duct mounted attenuator

Used near AHUs/FAHUs to reduce transmission of noise.

Motorised damper symbol

Motorised damper/ motorised smoke & fire damper

Performs the same function as a regular damper but is motorised and can be controlled automatically.

circular flexible duct symbol

circular flexible duct

duct riser symbol

DUCT RISER

Duct that rises vertically through a building or structure.

duct dropper symbol

DUCT DROPPER

Duct that drops vertically through a building or structure.

duct acoustic lining symbol

duct acoustic lining

Duct acoustic liners are primarily used for sound absorption.

vertical duct section symbol

vertical duct section

circular diffuser symbol

circular diffuser

supply duct section symbol

supply duct section

return duct section symbol

return duct section symbol