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FAQs about IEQc3.2 :

Should we install furniture and furnishings before IAQ testing or flushout?

The air temperature and/or relative humidity went out of the credit requirement specifications for a portion of the flush-out. What do we do? Can we extend the flush-out for the equivalent amount of time to make up for it?

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NC-2009 IEQc3.2:Construction IAQ Management Plan—Before Occupancy

Option 1 Path 2

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shaun Andriano
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C2 Design Architecture
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Hello. We have a building looking to meet the requirements for Option 1 Path 2. In the credit language it states that the flush is to stop at the end of occupancy for that day. The operating hours are from 9am-6pm. Seeing there's a 3 hour minimum in which we start the ventilating, are we allowed to just ventilate 24 hours a day until we reach 14,000?

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Dylan Connelly
Mechanical Engineer
Integral Group
LEEDuser Expert
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Wed, 02/29/2012 - 16:25

Yes. You can run the ventilation 24 hours a day during the post occupancy part of "Option 1 Path 2." However, you will need to supply 0.3 CFM/SF of OSA during that time if that is more than your IEQp1 OSA minimum (it usually is). Some systems can't handle the load of that much OSA during certain times of the year. Your sequence of operations may need to be altered to ensure comfort during the occupied periods. Another thing to consider is that if you have a 100% OSA system and it is only sized for the minimum OSA requirements then you may not be able to meet the 0.3 CFM/SF OSA requirements.
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shaun Andriano
Project Manager
C2 Design Architecture
LEEDuser Basic Member
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Wed, 02/29/2012 - 16:30

Thank you for your quick response. You're correct. The .3 is more than our design value. We have one RTU that is OSA only and it doesn't supply enough to ventilate at that rate. However, we plan to have the TAB consultant provide documentation that opening the dampers x% on the other 3 units will contribute an assumed value to the ventilation. We are hoping this will satisfy any questions GBCI may have. Would you say that is a reasonable approach? Thank you for the additional information on the sequence of operations, that is one thing we had left out.
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Dylan Connelly
Mechanical Engineer
Integral Group
LEEDuser Expert
342 thumbs up

Wed, 02/29/2012 - 17:15

That sounds good. I would also recommend having your CxA or GC install temporary temperature and humidity sensors in the space. These sensors can trend data during the flushout to ensure/prove you are meeting the temperature and humidity requirements of the credit.
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shaun Andriano
Project Manager
C2 Design Architecture
LEEDuser Basic Member
23 thumbs up

Wed, 02/29/2012 - 17:21

Ok Great. The one unit that is OSA only, has sensors and has been programmed to trend the date at given intervals. This is the only system that will operate for the initial 3500 flushout to ensure the 60/60 requirements. Will we need to provide trending data for the assumed value units? Or can we just supply the trending date for the OSA unit? Again, thanks for taking the time to address my questions.
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Dylan Connelly
Mechanical Engineer
Integral Group
LEEDuser Expert
342 thumbs up

Wed, 02/29/2012 - 18:26

The temporary sensors would be in the space to ensure that the space is maintaining the 60/60 requirement, not just that the unit is supplying 60/60. Currently the LEED form does not require that you upload any data for "proof" that your ran the units for the required amount of time and that you maintained the 60/60 requirement. However, the reviewer may question how you "could" prove it if you didn't install temporary temperature and humidity sensors if you don't already have permanent sensors. I recommend you describe your method to measure the OSA quantities and maintain 60/60 in the narrative to avoid questioning.

Tue, 04/17/2012 - 13:43

What sort of methods have people used to measure the OSA quantities? Would it have to be readings from an OA CFM meter? Or would it be acceptable if you calculated it from fan speeds, damper positions, etc?
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Dylan Connelly
Mechanical Engineer
Integral Group
LEEDuser Expert
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Tue, 04/17/2012 - 14:54

Daniel, There is a NC2.2 CIR (ID#2099) that clarifies that you can use a current transducer (CT) to check fan status on an 100% OSA system. However, it states you cannot use a CT if the system is not 100% outside air or constant volume. So damper position and fan speed will not work. The basic reason is that air flow quantities may still vary based on different pressure situation.

Tue, 04/17/2012 - 16:22

Where can you look up these CIRs? usgbc.org? My question really is will they accept methods for measuring the OA flow for flush out other than using a flow meter?
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Dylan Connelly
Mechanical Engineer
Integral Group
LEEDuser Expert
342 thumbs up

Tue, 04/17/2012 - 16:41

https://www.usgbc.org/leedinterpretations/lilanding.aspx They would likely accept using a CT for flush out if you are running the system 100% OA or at a constant volume.

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