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HVAC \u00b7 UK

HVAC & Ventilation Symbols — UK (CIBSE)

These symbols are used on HVAC installation drawings, ventilation design documents, and commissioning certificates in the UK. They follow CIBSE Guide B (Heating, Ventilating, Air Conditioning and Refrigeration) conventions. HVAC engineers and ductwork installers use these on design and as-installed drawings.

CIBSE Guide B / BS EN 15232 / BS EN 1679812 symbols

Ductwork

Supply Air Duct

Rectangular supply air ductwork

CIBSE Guide B

Extract Air Duct

Rectangular extract air ductwork

CIBSE Guide B

Circular Duct

Circular / spiral ductwork section

CIBSE Guide B

Controls

Volume Control Damper

Manual or motorised air volume control damper

CIBSE Guide B

Fire Damper

Fire-rated damper in ductwork penetrating fire compartment wall

BS EN 15650 / CIBSE

Room Thermostat

Room temperature sensor / thermostat

CIBSE Guide H

Thermostatic Radiator Valve

TRV for individual radiator temperature control

CIBSE / BS EN 215

Terminals

Supply Air Grille

Wall or ceiling mounted supply air grille / diffuser

CIBSE Guide B

Extract Air Grille

Wall or ceiling mounted extract air grille

CIBSE Guide B

Equipment

Air Handling Unit (AHU)

Central air handling unit with filter, coil, and fan sections

CIBSE Guide B

Fan (Axial)

Axial or centrifugal fan

CIBSE Guide B

Heat Exchanger

Plate or cross-flow heat exchanger / heat recovery unit

CIBSE Guide B

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Frequently asked questions about hvac symbols

Where are HVAC symbols officially defined in the UK?
CIBSE Guide B and the associated technical memoranda provide the standard symbol conventions for HVAC drawings. BS EN 12792 covers ventilation terminology.
What is the difference between supply and extract ductwork symbols?
Supply ductwork is drawn with solid lines and shows airflow direction into the space. Extract ductwork uses dashed lines and shows air being removed from the space.
What is a fire damper?
A fire damper is installed where ductwork passes through a fire-rated wall or floor. It closes automatically in a fire to maintain the fire compartment integrity. Typically rated at 1 or 2 hours.

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