I have a project where the proposed design has demand controled ventilation. I modeled the VAV baseline for these systems complying with the ASHRAE 62.1 table "Minimum Ventilation Rates in Breathing Zone" to comply with the USGBC's additional requirements. I did not apply the "system efficiency" even though the Baseline was VAV because it would end up having a very large correction due to the minimum's required for a System Type 5. The reviewer has commented that my baseline does not comply with ASHRAE 62.1 as is required by their additional requirements. The related IEQ credit has a comment that the baseline 62.1 calculation was not performed properly because it was not properly documented the proposed VAV systems have active constant outdoor air damper actuators rather than the traditional proportional fixed opening damper actuators.
Can anyone provide some feed back as to how to proceed? Should I do a critical zone calculation using the baseline systems as designed to comply with ASHRAE 90.1, or am I over thinking this & I just need to comply with any revisions to the IEQ calculations?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
December 4, 2013 - 8:14 am
After you correct the ASHRAE 62.1 ventilation calculations for IEQp1, the outdoor airflow rates in the baseline model should match the 62.1 minimum rates as calculated in IEQp1 for the proposed systems. You do not need to complete separate ventilation calculations for the fictitious baseline systems.