[Equest-users] Another DCV question - when to claim credit per G3.1.2.5?

[Bishop, Bill]

[This is a LEED/Appendix G question - not an eQUEST-specific issue. My apologies if this has been answered before. I didn't see it in the archives.]

Can a proposed design claim credit for DCV if DCV is not required for the proposed design per 6.4.3.9, even though DCV would be required for the baseline under the same criteria?

Proposed designs modeled for LEED and/or Appendix G can claim credit for reduced ventilation rates per the exception to ASHRAE Standard 90.1, G3.1.2.5.
The exception is "When modeling demand-control ventilation in the proposed design when its use is not required by Section 6.4.3.8." [The typo appears in App. G. 2007 - should be "6.4.3.9".]

My proposed design does not require DCV per 6.4.3.9, because all of the systems that serve spaces meeting the DCV requirement also have energy recovery, which is exception (a.) for 6.4.3.9.
Therefore, I would argue that the proposed design can claim credit for DCV.
However, none of the baseline systems that serve the same spaces meet the G3.1.2.10 requirement for energy recovery. The baseline systems do not meet any of the exceptions to 6.4.3.9.

Does the exception to G3.1.2.5 imply "...when its use is not required in either the proposed or baseline design"?
I'm hoping not, otherwise this is a blue Monday<http://www.youtube.com/watch?v=FYH8DsU2WCk>. Tell me how you feel.

Thanks,
Bill

William Bishop, PE, BEMP, LEED AP | Pathfinder Engineers & Architects LLP
Senior Energy Engineer

134 South Fitzhugh Street                 Rochester, NY 14608
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bbishop at pathfinder-ea.com<mailto:wbishop at pathfinder-ea.com>           www.pathfinder-ea.com<http://www.pathfinder-ea.com/>
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