See all forum discussions about EBOM-2009 IEQp1
 Subscribe to new posts about EBOM-2009 IEQp1 Post a new question aboutEBOM-2009 IEQp1
See LEEDuser’s guidance on EBOM-2009 IEQp1»
FAQs about IEQp1 :

What if after our Preliminary Review we have to re-work the ventilation rate procedure calculations and find that we need to make corrections to the system in order to meet the prerequisite? Can we redo the outside air testing after making corrections? Wo

What if our systems do not meet the required outside air when systems are tested at worst-case conditions?

Our building has a single fan that supplies outside air to multiple AHU’s. Do we need to perform outside air testing at the supply fan or at all AHUs?

We have a VAV system where single AHUs serve multiple zones. Do we need to take outside air measurements at each VAV box?

View answers »

Forum discussion

EBOM-2009 IEQp1:Minimum IAQ Performance

Critcal Zone 100% Out Door Air System

Default Avatar
Natascha Altensen
Project Partner
Drees & Sommer Advanced Building Technologies
LEEDuser Basic Member
2 thumbs up

We are currently confusion regarding a review we received. Our building is a multizone building that is supplied with 100% outdoor air. From the review team it is required to perform critical zone calculations even though spaces are supplied with 100% outdoor air. From my understanding critical zone calculations are required for recirculation systems to determine the Primary Outdoor air Fraction (Zp) and System Ventilation Efficiency (Ev). How can i determine the critical zone for systems with 100% outdoor air supply? Shall I use instead the occupant density and zone distribution configuration (Ez) as the critical figures? Thanks

1
Post a reply

You rely on LEEDuser. Can we rely on you?

LEEDuser is supported by our premium members, not by advertisers.

Go premium for $15.95  »

Profile picture for user samantha_2
Samantha Harrell
LEED Project Reviewer certificate holder
LEEDuser Basic Member
76 thumbs up

Mon, 03/26/2012 - 12:30

You are correct, the critical zone is not an applicable calculation factor when the system supplies 100% outdoor air. A quick way to test this is to download the latest IEQp1 Sample Form (v04, active version) from LOv3 and indicate that the project is 100% outdoor air. The form will only allow inputs for applicable calculation factors.

Mon, 11/26/2012 - 16:31

We saw this discussion regarding IEQp1 you had in March 2012. In our project, our building is also supplied with 100% outdoor air. Is it correct that we can not use calculations with critical zones according to 62MZ? Instead, we must use the VRP Compliance Calculator? If we shall use the VRP Compliance Calculator, must all occupiable areas be included for these calculations (and not only the critical zones). Is this correct? Thank you in advance.

Mon, 11/26/2012 - 17:01

Yes, as stated, the concept of "critical zones" does not apply to a 100% OA system. Provide the calculation for all the spaces.

Add new comment

To post a comment, you need to register for a LEEDuser Basic membership (free) or login to your existing profile.