Air Flow Values

[ja1357]

Hi Revit MEP community

I am creating an air flow  schematic layout in Revit 2016 and have all 3 floors of ductwork showing correct values however just 1 extract fan I am using is coming out with no airflow at all even though the connections and values have been set up correctly.

The system comprises of 6 return air valves connected to a fan which extract to the roof

The settings are as follows: 

Air Valves

RETURN AIR

PRESET

OUT

FAN CONNECTION 1 (FROM AIR VALVES)

RETURN AIR

CALCULATED

IN

PARAMETER ADDED TO AIR FLOW  'CALLED FLOW'

FAN CONNECTION 2 (FROM AIR VALVES)

RETURN AIR

PRESET

OUT

FLOW PARAMETER ADDED TO AIR FLOW 

Any ideas would be appreciated as this is becoming very irritating. (I have attached a partial screen shot showing problem)

Thanks in advance

[Skelly_PLAISANCE · Accepted solution]

Hi ja1357,

Modify the mechanical parameters of your two onnector element, in bidirectional and global

[ja1357 · Accepted solution]

Skelly

I tried your suggestion and it worked thanks very much. 

I don't understand why this is the case but it definitely works