Controller:MechanicalVentilation ProportionalControlBasedOnDesignOccupancy possible error for more than one zone

[mjwitte]

Issue overview

1. While working on OA Limiting Factor enum and Related Cleanup #9947, noticed that CO2PeopleGeneration is initialized to zero at the top of MixedAir::CalcMechVentController is accumulated across all People objects for a given zone, but never reset to zero when looping on to the next zone. This applies only to SystemOAMethod == DataSizing::SysOAMethod::ProportionalControlDesOcc.
2. The accumulating loop is inefficient, because it loops over all people statements for every zone on the controller looking for a matching zone number.
3. This loop is not covered by integration tests.
4. This is kind of covered by unit test CO2ControlDesignOccupancyTest except the CO2 values are zero, because the test setup is incomplete (People activity schedule and CO2 generation rate are both zero).
5. The documentation for Controller:MechanicalVentilation System Outdoor Air Method is not completely clear, implies this option is only for single-zone system, and this could use some reformatting to make it more readable.

Details

Some additional details for this issue (if relevant):

• Version of EnergyPlus 23.1
• Related to OA Limiting Factor enum and Related Cleanup #9947

Checklist

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• Defect file added (list location of defect file here)
• Ticket added to Pivotal for defect (development team task)
• Pull request created (the pull request will have additional tasks related to reviewing changes that fix this defect)