fan

Kind: Marker
Used With: equip, point, unit

Fan point or equip associated with an ahu, vav, or coolingTower.

From: VFDs | Fans

Fans may optionally be defined as either an equip or a point. If the fan motor is a VFD then it is recommended to make the fan a sub-equip. However in many cases a simple fan in a terminal unit such as a vav is better modeled as a point.

Fan Points

In simple cases where the fan is just a command and/or feedback sensor then it is best to model it as a point.

If annotated as an output with the cmd tag, then the point models the command status of the fan:

If annotated as an input with the sensor tag, then the point models a sensor used to verify if the fan status:

Fan Equips

When the fan motor is a VFD it should modeled as an equip entity using the standard VFD points described above. If you wish to standardize modeling all fans as equip, then simple non-VFDs fan should define their state via a run point.

Example of a VFD fan on an AHU:

id:@ahu ahu equip
id:@ahu-fan equipRef:@ahu discharge fan vfd equip
id:@ahu-fan-run    equipRef:@ahu-fan run cmd point
id:@ahu-fan-status equipRef:@ahu-fan run status point
id:@ahu-fan-speed  equipRef:@ahu-fan speed cmd unit:"%" point

Note that the fan is modeled as an sub-equip of the AHU via the equipRef tag. The VFD points are defined under the fan itself.