Hello,

I think you are looking for the AFN Linkage Node Volume Flow Rates. DesignBuilder will generate the necessary output variables and send them to the EnergyPlus engine.

Output:Variable, *, AFN Linkage Node 1 to Node 2 Volume Flow Rate, Hourly;
Output:Variable, *, AFN Linkage Node 2 to Node 1 Volume Flow Rate, Hourly;