Sizing warning outside of sizing period

asked 2024-04-23 10:04:17 -0500

msfer's avatar

updated 2024-04-23 18:28:46 -0500

This warning occurs when adapting the original high-rise apartment building from IECC ( to include a 'HVAC Template Ideal Loads Air System' instead of the detailed HVAC system. By considering the 'Sizing Period Weather File Condition Type' for Winter and Summer Design Days, respectively, as Winter Extreme and Summer Extreme, the following warning is generated during sizing (one per thermal zone):

** Warning ** ZoneHVAC:IdealLoadsAirSystem "G NW APARTMENT IDEAL LOADS AIR SYSTEM" Requested outdoor air flow rate = 2.59543E-002 [m3/s] exceeds limit.
**   ~~~   **  Will be reduced to the Maximum Cooling Air Flow Rate = -99998.99999 [m3/s]
**   ~~~   **  During Sizing, Environment=SUMMERDESIGNDAY, at Simulation time=07/05 24:00 - 24:10

Independently of the weather file used, the warning reports to the time step immediately after the Summer Sizing Period ending; in the case, the Summer Extreme Week (in this example, the summer extreme week ends at 07/05 24:00, for the 'USA_NY_New.York-Kennedy.Intl.AP.744860_TMYx.2004-2018.epw' weather file, from

The ideal loads air system is defined with an autosized limited flow rate for cooling together with a 'Design Specification Outdoor Air', which seems to cause the warning. But the issue here is the fact that the warning is reported outside of the sizing period itself. What can be the cause of such warning?

Thank you.

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