I'm working on a system with heat pumps and VAV boxes, filing for LEED 2009. How can I present a Diversity factor to demonstrate an outdoor air requirement that is less than the uncorrected O/A requirement that the Table calculates for me?
Also, does LEED require supplementary documentation for this prerequesite, beyond plans and O/A schedules?
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Roger Chang
Principal, Energy and Engineering LeaderDLR Group | Westlake Reed Leskosky
LEEDuser Expert
398 thumbs up
August 17, 2010 - 9:43 am
You can claim a credit for diversity in two ways: one is short-term averaging (applicable to spaces like conference rooms or multi-purpose rooms that have intermittent occupancy); the other approach is the account for occupant diversity using the same factor used for sizing the block airflow for your VAV system (80% is typical). Plans and schedules are base submission requirements. You typically want to submit a spreadsheet showing ASHRAE 62 calculations in detail, especially if you don't have a decoupled ventilation system. Consider using the ASHRAE 62 calculation spreadsheet (available on LEED online).
Bob Richardson
11 thumbs up
August 18, 2010 - 8:14 am
Thanks, Roger.
I couldn't find a way to show the short term averaging or the diversity factor on the Table at LEED online so I must submit my calculations in another form. We use HAP 4.5 from Carrier. Does it seem like they would accept that?
Roger Chang
Principal, Energy and Engineering LeaderDLR Group | Westlake Reed Leskosky
LEEDuser Expert
398 thumbs up
August 23, 2010 - 9:20 am
Bob, I would submit the HAP output, but also include a separate narrative clearly describing the calculation approach with references to relevant sections of ASHRAE 62. Did you have a look at the formal ASHRAE calculation spreadsheet? This is a separate thing from the LEED online letter template. The ASHRAE spreadsheet allows you to enter in factors for diversity.