On LEED Online they suggest that you only need to identify critical spaces and enter that into the spreadsheet, whereas ASHRAE 62 wants you to list all zones, not just critical zones. If we do ASHRAE 62, I'm assuming we'd be fine. Do we have to fill out the abbreviated one as well?
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Jenny Carney
Vice PresidentWSP
LEEDuser Expert
657 thumbs up
November 13, 2009 - 6:41 pm
Ultimately, in our experience project teams are expected to use the 2007UM_62MZCalc.xls (downloaded directly from LEED Online) to show the required OA rate. This involves first reporting total floor area and population served by the system (cells I7 and I8 in the spreadsheet), and then listing out potentially critical zones (columns J and on). Some teams choose to list out every space type within the system separately as a potentially critical zone in these columns, but as far as I can tell they do this mostly because it helps them know they've got all spaces accounted for. A different copy of the spreadsheet is submitted for each ventilation system.
From there, the required OA from the spreadsheets is transferred over to the submittal form in LEED online under "Table. Ventilation Air Flow Summary".
Hope this gets at the question. I wasn't sure exactly what you meant by the "abbreviated one", so definitely let me know if the above doesn't quite clear things up.
Alice Cook
76 thumbs up
January 8, 2011 - 6:24 pm
Jenny,
When you fill 2007UM_62MZCalc.xls , if you only input the critical zones cfm , the total System output Vou (line i43 ) > Vps output (line i42) , this last value being calculated by only the critical zones
This give a Xs value ( uncorrected req OA as a fraction of primary supply airflow ) > 1 !!!
In my example , let say your AHU is 43762 cfm , population Ps is 700 , Ras is 0.06, Rps is 11.4 and the total cfm of the critical zones you're analyzing is 5000 cfm . The exel sheet will calculate a Vou of 9477 and Vps is 5000 ...
Correct me if i'm wrong but you absolutely need to input all zones in exel sheet otherwise results will be wrong?
Thanks in advance
Julia Weatherby
PresidentWeatherby Design & Co. Engineers
94 thumbs up
March 18, 2011 - 12:59 am
When you fill 2007UM_62MZCalc.xls, if you have not included all zones, then you will need to override the calculated values for total square feet served and for total system supply air.
If you look at the Directions tab in 2007UM_62MZCalc.xls under "Design primary supply fan airflow rate" and "Floor area served by system", this is mentioned there.