Hi,
I'm trying to fill-out the above form. I checked all the calculations for each fields. However, i can always get warning sign of " Would need over 100% OA Intake". Our project does not apply for this.
Please help which item should i need to adjust or correct. This form is frustrating, they did not even refer you which is wrong, instead they will keep you guessing until you waste your time.
Anyway, these are the values that i have for IEQp1 and IEQc2:
System Population w/o diversity (Ps) = 31/31
Occupancy Diversity (D) % = 100/100
System Population with diversity (Ps) = 31/31
Design System Primary Supply Airflow = 505/505
Uncorrected Outdoor Air Intake = 187/243
System Ventillation Efficiency = 0.5/0.35
Required Outdoor Intake Flow = 373 / 691
Project Design Outdoor Airflow = 755
Appreciate any assistance on this.
Regards,
Susan
Andrew Mitchell, P.E.
PrincipalMitchell Gulledge Engineering, Inc.
LEEDuser Expert
126 thumbs up
November 15, 2012 - 2:58 pm
Susan, I think the error is coming in because you have listed your OA flow as being higher than the total system supply flow.
susan eguia
LEED Coordinator/Construction Administrator/Business DevelopmentBuilding Solutions Group, Inc.
59 thumbs up
November 15, 2012 - 4:05 pm
Andrew,
Thanks for respond.
So, i need to adjust my OA flow? If so, then i cannot meet the IEQc2 requirement which is 691.
Susan
Andrew Mitchell, P.E.
PrincipalMitchell Gulledge Engineering, Inc.
LEEDuser Expert
126 thumbs up
November 16, 2012 - 2:53 pm
Susan, you cannot simply adjust your OA flow. It cannot be higher than the total system flow. You need to size the system based on the ventilation requirement at minimum. Once you do that then you just input the data and the template should be satisfied.
susan eguia
LEED Coordinator/Construction Administrator/Business DevelopmentBuilding Solutions Group, Inc.
59 thumbs up
November 16, 2012 - 4:46 pm
Andrew, sorry which one should i size up? Mind if you could refer to what field from V4.0 form it is? thanks!
Dylan Connelly
Mechanical EngineerIntegral Group
LEEDuser Expert
472 thumbs up
December 4, 2012 - 12:10 pm
Susan,
"Would need over 100% OA Intake" - Is a typical error on the form. This means that you have a zone (typically your critical zone) that has less SA (during the condition analyzed) then the required OA for that zone.
Example: Cooling only Conference Room
SA =600, Ds = 30%, OA Requirement = 200 CFM.
When your VAV is turned down to minimum (worst case), your SA is 180 CFM. This is below your OA requirement. Therefore your full system would need over 100% OA to provide enough ventilation for your worst (critical) zone.