The template requires data be entered for both Ez and Ev. From what I read in ASHRAE 62.1-2007 Ez is not related to your Vot if you have a multi-zone system. In additional unless your population density varies then Vot is basically the sum of Vbz (Vou) divided by Ev so you end up with Vou/Ev.
The problem I'm having is that the template is calculating Voz by dividing Vbz by Ez (Vbz/Ez = Voz) and then calculating Voz by dividing Voz by Ev (Voz/Ev = Vot) to obtain Vot for the zone. From what I read in ASHRAE 62.1-2007 and calculated using the 62MzCalc.xls spreadsheet, the second equation is not correct.
Has anyone else had this issue? I've tried contacting the USGBC, but have not been able to talk with anyone that understands the actual equations from ASHRAE 62.1-2007.
Roger Chang
Principal, Energy and Engineering LeaderDLR Group | Westlake Reed Leskosky
LEEDuser Expert
398 thumbs up
May 27, 2010 - 8:56 am
We recently ran into this issue also and had difficulty getting anyone at USGBC to understand this. Ez does still factor into the equation at the zone level. I would fill out the template the best you can and then include a note describing the issues with consistent terminology for this letter template. The second equation you mentioned isn't completely incorrect, unless you are claiming some sort of credit for diversity or short-term conditions.
Kimberly Frith
323 thumbs up
July 22, 2010 - 4:24 pm
I just discovered this issue also and sent a feedback request to GBCI asking if there is a way for us to provide our ASHRAE 62MZ Calc spreadsheets instead of filling in their jumbled template calculator. I'll post if I get a relevant response.
Scott Yager
Energy AnalystE&C Engineers & Consultants Inc.
6 thumbs up
August 31, 2010 - 11:27 am
I would like someone to explain to me where you find Vot as a zone level calculation in ASHRAE Std 62.1-2007? Wouldn't the zone level calculation be Voz? Also, if you actually add up the "Vot" calculations provided by the new IEQp1 form and compare to the ASHRAE 62MZ Calc spreadsheets, you will find your outside air is over-sized by almost 15% from what is actually required. This can be further compounded if you are seeking IEQc2 for your project.
Roger Chang
Principal, Energy and Engineering LeaderDLR Group | Westlake Reed Leskosky
LEEDuser Expert
398 thumbs up
September 2, 2010 - 9:33 am
Scott, what version form are you using? I recommend all users check to see whether a form is still in BETA or not. You can request upgrades to individual forms by emailing USGBC through the feedback button on LEED online. The zone level ventilation should be Voz. If you're dealing with a multi-zone recirculating system, Vot will be the sum of Voz divided by Ev, the system ventilation efficiency. What are you entering in for Ev in the form? The form doesn't do the Ev calculation for you, so you can enter the Ev from the ASHRAE 62 calculator to match up results.
Scott Yager
Energy AnalystE&C Engineers & Consultants Inc.
6 thumbs up
September 2, 2010 - 12:07 pm
Roger, your suspicion about an incorrect Ev value was true. We had the wrong Ev entered on the form which increased the Vot totals. I think one of the issues with saying Vot=Voz/Ev instead of Vot=Vou/Ev is this makes it seem like you can actually control the exact amount of outside air that ends up in each ventilation zone when in reality you cannot do this for a Multiple-zone system. I can understand the logic for using Vot like a zone level calculation in the IEQp1 form since Voz=Vbz/Ev and Vbz=Vou as long as you understand this does not mean you will be getting that amount of outside air at that ventilation zone and that outside air calculations are done for the air handling systems and the areas they serve. Hopefully this makes sense.
Scott Yager
Energy AnalystE&C Engineers & Consultants Inc.
6 thumbs up
September 2, 2010 - 2:10 pm
Actually, there is still a problem with the IEQp1 form.
The form is calculating Vot =Voz/Ev
This is wrong since Voz=Vbz/Ev and already includes the System Ventilation Efficiency (Ev).
By applying the Ev twice to the same ventilation zone you are increasing the total system Vot unnecessarily.
Has this been corrected in a updated form?
jack snow
sr. project managermep associates
2 thumbs up
October 25, 2010 - 5:14 pm
Kimberly - did you get a response from the USGBC to your question regarding submittal of ASHRAE 62.1 EZ calculator in lieu of filling out the error-prone LEED template?
Stephanie Guy
8 thumbs up
October 27, 2010 - 10:49 am
I am having problems with this IEQ prerequisite form as well. It doesn't match up with the 62.1 spreadsheet that I used for the design. Has anyone heard back on submitting the 62.1 spreadsheet in lieu of filling out the form?
Tristan Roberts
RepresentativeVermont House of Representatives
LEEDuser Expert
11478 thumbs up
November 11, 2010 - 10:28 pm
Has anyone gotten a response from GBCI on form? Check, of course, if you're using a BETA form if you're having trouble. I would recommend trying to get the form to work rather than submitting an alternative form.
Kirk Simoneaux
8 thumbs up
March 2, 2011 - 12:52 pm
Having the same issues. No response from GBCI since originally submitted in October 2010?