Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
If you have to model opening/closing only external doors and windows, there is a simple solution:
(A) You may specify ZoneInfiltration:EffectiveLeakageArea(s) for every zone,
and define a schedule for the flow fraction (0=closed, 1=fully open);
For more specialized requirements, the schedule values may be driven by an EMS program (by defining actuators on these schedules)
If you want to model air exchange through external and internal doors/windows, this can be done by setting up an AirflowNetwork for your zones:
(B) for each window/door specify a corresponding AirflowNetwork:MultiZone:Surface
and define Leakage Components:
set Window/Door Opening Factor >0 (<=1 );
set Ventilation Control Mode=constant
now define a VentingAvailability Schedule: this will dynamically drive the Venting Window/Door Opening Factor
by this formula: [AFN Surface Venting Window/Door Opening Factor] = [Window/Door Opening Factor] * [VentingAvailability]
(0=closed, 1= fully open). You can verify whether the air flows behave as intended e.g. by checking the output variables:
Key Value = AirflowNetwork:MultiZone:Surface Name
Variable Name = AFN Linkage Node 1 to Node 2 Mass Flow Rate
(from AirflowNetwork:MultiZone:Surface to the other side)
Variable Name = AFN Linkage Node 2 to Node 1 Mass Flow Rate
(from the other side to AirflowNetwork:MultiZone:Surface )
(C) If window/door openings should depend on special user defined conditions, define an EMS Actuator, e.g. myOpenFactor, for one surface of each Door/Window, with
Actuated Component Type = AirFlow Network Window/Door Opening
Actuated Component Control Type = Venting Opening Factor
The dynamic value of myOpenFactor then is determined by an EMS program.
More details can be studied in the Example file EMSAirflowNetworkOpeningControlByHumidity.idf
