Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
I think the problem is that you set Always On Discrete fir the "Minimum/Maximum Fraction of Outdoor Air Schedules" in your Controller:OutdoorAir. Try resetting them (leave them blank).
See the I/O reference Guide here:
Minimum Fraction of Outdoor Air Schedule Name
The name of a schedule with decimal values which are limited between 0.0 and 1.0. The current schedule value is multiplied by the current system mixed air flow rate to set the minimum outdoor air flow rate. If this schedule name is blank, then it is not applied.
If this schedule is 1.0 (and there is no Maximum Fraction of Outdoor Air Schedule Name), then the system works at 100% outdoor air regardless of any other condition as long as the Maximum Outdoor Air Flow Rate is ≥ the system supply air flow rate.
Note: You might also want to pay close attention to the System Outdoor Air Method in Controller:MechanicalVentilation
| | 2 | No.2 Revision |
I think the The problem is that you set Always On Discrete fir the "Minimum/Maximum Fraction of Outdoor Air Schedules" in your Controller:OutdoorAir. This is forcing your system to run with an outdoor air flow fraction of 1 when the system is enabled. Try resetting them (leave them blank).blank)
Also, you should plot the Outdoor Air Mass Flow Rate rather than the outdoor fraction.
See the I/O reference Guide here:
Minimum Fraction of Outdoor Air Schedule Name
The name of a schedule with decimal values which are limited between 0.0 and 1.0. The current schedule value is multiplied by the current system mixed air flow rate to set the minimum outdoor air flow rate. If this schedule name is blank, then it is not applied.
If this schedule is 1.0 (and there is no Maximum Fraction of Outdoor Air Schedule Name), then the system works at 100% outdoor air regardless of any other condition as long as the Maximum Outdoor Air Flow Rate is ≥ the system supply air flow rate.
Note: You might also want to pay close attention to the System Outdoor Air Method in Controller:MechanicalVentilation
