> For the complete documentation index, see [llms.txt](https://support.powerio.com/hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.powerio.com/hub/codesys-hvac/en/glossary/symbols.md).
# Symbols
These symbols are also used in the HVACV Visu Library.
## HVAC/MSR symbols
| Symbol | German | English |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------- |
| 
| Fan (off/fault/on) e.g. ventilation system | fan (off/error/on) e.g. air handling unit |
|  | Pump (off/fault/on) | pump (off/error/on) |
|  | 2-way valve with actuator, shut-off damper, passage valve | 2-way valve with motor |
|  | 3-way valve/mixer with actuator | 3-way valve with motor |
|  | Filter (clean/dirty) e.g. in ventilation systems | air filter (normal/pollution) e.g. in air handling untis |
|  | Fire damper (normally open/closed) with motor | fire dampter (normal open/closed) with motor |
|  | Fire damper (normally open/closed) | fire dampter (normal open/closed) |
|  | Air damper with motor | air damper with motor |
|  | Volumetric flow controller (VVR/VVS) | variable air volume box (VAV) |
|  | Storage/buffer for heating or cooling | tank for cooling or heating |
|  | Rotary heat exchanger with motor in ventilation systems (two representations) | rotary heat exchanger in air handling untis (two representations) |
|  | Crossflow exchanger (in heating or ventilation technology) | cross flow exchanger (in heating or air handling systems) |
|  | Heating coil/heater in ventilation systems. Water or direct expansion heat pump. | heater in air handling units |
|  | Electric heating coil/heater in ventilation systems | electrical heater in air handling units |
|  | Cooling coil/cooler in ventilation systems. Water or direct expansion heat pump. | cooler in air handling units |
|  | Combined heating-cooling coil switchable on water side or direct expansion heat pump with heating/cooling function | combination cooler/heater or heat pump |
|  | Steam humidifier or spray humidifier in ventilation systems | vapor humidifier in air handling units |
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