[Equest-users] GBCI comments on DCV (Carol Gardner)

[Karen Walkerman]

Can anyone find documentation requiring the baseline to use ASHRAE 62.1
ventilation rates?  The table in EA Credit 1 under HVAC System Selection for
the baseline design states:

"Outdoor ventilation rates should be identical to the proposed case"

There are no exceptions listed anywhere in the LEED documentation (I am
currently looking at LEED 2009, but have reviewed this in the past under
LEED 2.2).

We have had DCV be approved in the past with no questions.

--
Karen

On Mon, Jul 26, 2010 at 11:08 AM, Tom Serra <tserra at emoenergy.com> wrote:

> I've had many comments.  They have changed their perspective as the rating
> authority and are requiring outside air treatment procedures that are
> outside of ASHRAE 90.1 section G procedures.  Typically design outside air
> volume is the same between the baseline and proposed, but if you are using
> DCV they now require you to model the baseline with the minimum ASHRAE 62.1
> volume.  So, if you have greater OA volume in your proposed model, you may
> be penalized depending on your DCV method and diversity schedule for
> occupants in the area with DCV control.
>
> Here is an example  clarification question:
>
> *1.       **CLARIFY:*  Demand control ventilation was modeled for credit
> for RTU1 and RTU2 in the Proposed case as indicated in Table 1.4 of the
> Template; however, the outdoor air volume for RTU1 and RTU2 in the Baseline
> model was not modeled at the ASHRAE 62.1-2004 minimum rates (1,066 cfm for
> each RTU) as determined in EQp1: Minimum IAQ Performance. Appendix G allows
> schedule changes for demand control ventilation as approved by the rating
> authority (Table G3.1.4(Baseline)). As the rating authority, GBCI requires
> that the outside air ventilation rates for the Baseline Case be modeled
> using minimum ASHRAE 62.1-2004 rates wherever credit is taken for demand
> control ventilation in the Proposed Case. The Proposed case minimum rates at
> design conditions must be modeled as designed.
>
>
> *TECHNICAL ADVICE:*  Revise the Baseline model so the minimum outdoor air
> volume is modeled at 1,066 cfm for RTU1 and RTU2 in the Baseline model. In
> addition, provide revised SV-A reports for RTU1 and RTU2 reflecting the
> changes. Further, verify that all systems in both the Baseline and Proposed
> case are modeled with zero outside air flow when fans are cycled on to meet
> unoccupied setback temperatures unless health or safety regulations mandate
> an alternate minimum flow during unoccupied periods (in which case, the
> unoccupied outside air rates must be modeled identically in the Baseline and
> Proposed Case).
>
>
> Thomas Serra
> Project Manager
> EMO Energy Solutions, LLC
> 3141 Fairview Park Drive, Suite 450
> Falls Church, VA 22042
> voice 703-205-0445 ex-113
> fax 703-205-0449
>
>
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