Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
The input in Controller:OutdoorAir object field "Minimum Outdoor Airflow Rate" and "Maximum Outdoor Airflow Rate" are both set to "Autosize".
The Autosizing for "Minimum Outdoor Airflow Rate" is based on your inputs in the DesignSpecification:OutdoorAir object referenced by the Sizing:Zone object, and is also influenced by your input in the "System Outdoor Air Method" field of the Sizing:System object. Given that you have selected "NoEconomizer" for the input to "Economizer Control Type" it may be reasonable the "Maximum Outdoor Airflow Rate" when Autosized could be identical to the "Minimum Outdoor Airflow Rate" but I have not confirmed this. You might want to try including an economizer to see if that impacts the Autosizing of "Maximum Outdoor Airflow Rate"? Once there is an Economizer I'd expect that would Autosize to the system design flow rate.
Change the input the in Controller:OutdoorAir object field "Minimum Outdoor Airflow Rate" from "Autosize" to zero ("0") to allow modulation of outdoor airflow based on the IndoorAirQualityProcedure input in the Controller:MechanicalVentilation object.
You can also assess the CO2 setpoint you have used relative to the design sizing of OSA per person that you are delivering ( specified in the DesignSpecification:OutdoorAir object) by looking at the steady state CO2 concentration maintained by the OSA/person delivered.
And look at the output:variable for Zone Air CO2 Concentration to see if your setpoint is maintained.
