Use standard air density to calculate oa mass flow rate in dual duct for consistency

[lgu1234]

Pull request overview

Addresses #5769.

StdRhoAir is used to calculate OA mass flow rates in DualDuct::CalcOAOnlyMassFlow and DualDuct::CalcOAMassFlow.

Differences were found in DOASDualDuctSchool.idf as expected.

Work Checklist

Add to this list or remove from it as applicable. This is a simple templated set of guidelines.

• Title of PR should be user-synopsis style (clearly understandable in a standalone changelog context)
• At least one of the following appropriate labels must be added to this PR to be consumed into the changelog:
  • Defect: This pull request repairs a github defect issue. The github issue should be referenced in the PR description
  • Refactoring: This pull request includes code changes that don't change the functionality of the program, just perform refactoring
  • NewFeature: This pull request includes code to add a new feature to EnergyPlus
  • Performance: This pull request includes code changes that are directed at improving the runtime performance of EnergyPlus
  • DoNoPublish: This pull request includes changes that shouldn't be included in the changelog

Review Checklist

This will not be exhaustively relevant to every PR.

• Code style (parentheses padding, variable names)
• Functional code review (it has to work!)
• If defect, results of running current develop vs this branch should exhibit the fix
• CI status: all green or justified
• Performance: CI Linux results include performance check -- verify this
• Unit Test(s)
• C++ checks:
  • Argument types
  • If any virtual classes, ensure virtual destructor included, other things
• IDD changes:
  • Verify naming conventions and styles, memos and notes and defaults
  • Open windows IDF Editor with modified IDD to check for errors
  • If transition, add rules to spreadsheet
  • If transition, add transition source
  • If transition, update idfs
• If new idf included, locally check the err file and other outputs
• Documentation changes in place
• ExpandObjects changes??
• If output changes, including tabular output structure, add to output rules file for interfaces

[nrel-bot-3]

@mjwitte @lgu1234 @lgentile it has been 16 days since this pull request was last updated.

[mjwitte]

@Myoldmopar OK to close #5769?