Forum discussion
NC-2009 IEQp1: Minimum IAQ Performance
This may be nothing, but should I still count for zones that are served by a multizone unit but the ventilated air is not recirculated back to the unit? The air is pretty much exhausted through their own exhaust fans.
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Is outdoor air quality testing required in a space using natural ventilation?
What options are available to projects outside the US to meet this prerequisite?
Can LEED 2009 projects elect to follow ASHRAE 62.1-2010 for this prerequisite?
Which units should be included in the calculations for this prerequisite?
Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
532 thumbs up
November 16, 2019 - 8:13 am
Regularly and non-regularly occupied rooms must be provided with outdoor air.
Unoccupied rooms are not required to be provided with outdoor air.
If the rooms served by the multizone unit are regularly and/or non-regularly occupied, then they will need to be included within the vent calcs.
Edgar Arevalo
Associate19 thumbs up
November 18, 2019 - 2:15 pm
Well that depends on the space type category provided in the drop down list of the calculator. But what I'm asking is if these spaces, that are considered regularly occupied, receive outdoor air but the the ventilated air is directly exhausted instead of a portion of it recirculated back to the unit, should I still include those spaces in the calculator?
Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
532 thumbs up
November 18, 2019 - 3:50 pm
Yes, regularly occupied spaces must be included within the ventilation calculator.
Edgar Arevalo
Associate19 thumbs up
November 18, 2019 - 4:46 pm
Understood, thank you. Perhaps you could help me with a follow-up question, David. The LEED project in question is a museum building. Would you happen to know what the occupancy category would be for an Etching Room and Polymer Film Room (both are part of a Printmaking/Non-silver Room, which I believe would be considered an art classroom), and a Hammer Room, Dirty Room, and Chemical Room (all three part of a Jewelry Room, which I believe would be considered a gallery space)?
Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
532 thumbs up
November 19, 2019 - 10:03 am
I think I have a better understanding of your project specifics, and now understand why you are questioning that regularly occupied rooms should be entered into the ventilation calculator if all outdoor air that is provided will be exhausted rather than returned to the air handling unit.
If the room type more closely aligns with a room type listed in 'Table 6-4 Minimum Exhaust Rates' of ASHRAE 62.1 then you do not need to include it within the ventilation calculator - even if it is considered to be regularly occupied.
For such scenarios we provide the following narrative with our LEED application: "Project includes rooms that are regularly occupied however they have been excluded from the ventilation calculator. The ventilation of such room adheres to the exhaust requirements listed in Table 6-4 of ASHRAE 62.1"
HOWEVER....."Art Classroom" and "woodwork/metal shop" space types are listed in both the ventilation table: Table 6-1 and the exhaust table : Table 6-4. My opinion would be to include them in the ventilation calculator since 'art classroom' and 'wood//metal shop' are selections. Since they are being exhausted per Table 6-4, they should not create problems within the ventilation calculator...in other words, I would not expect that you would need to provide more outdoor air when compared to the exhaust rate listed in Table 6-4.
Hope this provides better direction.
Great Question!!