NC v2.2 EQc5: Indoor Chemical and Pollutant Source Control

Numerous CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide responses and LEED Interpretations previously denied the credit where fan coil units recirculating room air for supplemental cooling in high load spaces were equipped with MERVMinimum efficiency reporting value. 8 filters and where the ventilation air was supplied directly to the space by central systems with MERV 13 filters. Language added to these responses now indicates that revised credit language for LEED 2009 removes the requirement to provide MERV 13 filters on return air. MERV 13 filtration is only required on outdoor air. Check out CIR #1795 and many others on this credit. The added language states that the requirement to filter return air has been eliminated for all versions of LEED. Is there any reason to expect a credit application under v2.2 with fan coil units only recirculating room air and equipped with MERV 8 filters will be denied?

Yes, I think that they would.

Stephen,
It's fine for your own staff to do the maintenance for the walk-off mats. I would recommend that you submit a cleaning schedule and narrative that confirms your in-house program for the mat maintenance and cleaning.

Correct, v2.2 still uses the 6'-0" long mat length.

Blair, sorry for the slow reply here on the forum—I hadn't seen these posts. Here is a link to an explanation of what LEED Interpretations are and where to find them.

There have been a lot of posts on our forums about exterior mats and whether they are allowed, and should be covered. The consensus has been yes allowed but must be covered. Perhaps you could convince a reviewer that due to climate that's not necessary where you are. But are there trees, wind, or other things that could clog up a mat and reduce its effectiveness?

David, the equation you are using is correct. However, doesn't make much sense unless the door is shut. LEED requires for this credit that you provide a self closing door anyway.

Also, the ASHRAE equation above is for Pressure in "Inches of water." The equation for pressure in PA would be:

Q=165.5*A*√∆P

Example:

3 foot wide closed door with a 0.5" undercut
A=0.125 ft
∆P=5 for LEED
Solve for Q (Air Flow in CFM)

Q=165.5*0.125*√5 = 46.3 CFM

In order to ensure this room has an average negative 5 PA differential pressure to an adjacent space you need to have roughly 50 CFM exhaust (Exhaust CFM - Supply CFM). Area of the room is irrelevant for the equation but not for LEED and usually local building code. You maybe also need to ensure that you have at least 0.5 CFM/SF exhaust.

Depending upon the condition following the flush-out, some or all of the filters (regardless of MERVMinimum efficiency reporting value. rating) may be ready for replacement, but this is not a condition for satisfying the credit requirement.

Hi David, thank you for your reply, but now I'm more confused.
LEED Canada NC 1.0 Addenda EQc5, the last requirement is to install new MERVMinimum efficiency reporting value. 13 filters prior to occupancy (and this is also an item on the letter template), and one of the audit submittals is a schedule of all filtration media installed prior to occupancy and the approved shop drawings for each.
I finally found the US CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide I was looking for (#5679) but see that a) it conflicts with Canada CIR#643 for MERV rating used for the flush and b) I am not sure if it is being accepted by the CaGBC for LEED Canada projects.
So much conflicting information out there, maybe it's time for a CIR request :)
Thank you very much for your help,
Shevaun

I have not worked on a LEED project in Canada; but would recommend following the guidance of the CIRs of the Canada version when working on LEED projects in Canada.

If your project includes a small number of filters I'd suggest changing them after flushout and before occupancy rather spend the time and $$$'s on the CIR process - this path would eliminate a response from the LEED project reveiw team.

If you choose not to replace the filters after the flushout and prior to occupancy include a narrative that explains how you inspected the filters to ensure they are still clean after the flushout - documenting this with pictures also helps greatly.

Good Luck!

Okay, thank you very much. I may submit this on a larger project where it will save a substantial sum, but for this one I'll recommend changing them out.
Thanks for your recommendations!

The credit only requires walk-off mats where people enter the building from an exterior or garage or vehicular condition.

Peter, that's correct.

Michelle- we routinely use walk-off carpet tiles instead of walk off mats and have not yet had any trouble getting the credit, although I know that the credit language around this issue is non existant. You will need to make sure you have a regular maintenance contract in place (or internal plan for LEED for Schools). We have used many different products, but Shaw is the manufacturer we seem to use most.

Are the carpet tiles you use for walk off mats glued down? We are looking at using Shaw carpet tiles also but I didn't know if it matter if they were glued or if it needed to mimic a walk off mat in terms of removability?

Christi, they could be glued down as long as they can be effectively cleaned.

I have not heard of anyone trying this specifically, but this type of strategy, applying a 2009 ruling to a v2.2 project has not been successful in the past. The response was that the project would need to be upgraded to the new rating system to take advantage of the new ruling.

We have had experience submitting using the new definition about return air on a NCv2.2 project, and were able to get a successful ruling. But I agree with Allison- this is not a slam dunk becasue frequently reviewers are not willing or able to review "cross-platform (their words, not mine).

Please note that return air must still be filtered - but it no longer needs to be filtered at the space level - it can be filtered back at the AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition) 2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork.. This means you can do active chilled beams, fan coil units and fan powered boxes that work effectively, while filtering the air back at the AHU.

To be sure: a fan coil unit at space level does not need to be equipped with MERV13 filters?

That is correct, under v2009. Jonathan is indicating that he has gotten this accepted on a v2.2 project, which is good. We also have one being submitted under v2.2, so we will see if our reviewer can be convinced.

Return air should still be filtered (MERVMinimum efficiency reporting value. 8 or so), no doubt, but small units like heat pumps or fan coils just do not have the ability to create the fan power needed, plus we have reviewed the additional energy, and it would not be worth the minor improvement in IEQ.

I would also agree, that once we have a DOAS, we would have the MERV 13 on both the supply and return, but this is a much smaller volume and energy burden.

Lisa- I have not actually tried this strategy, so I am not completely sure, but I would be concerned that a gypsum lay-in ceiling would not be acceptable because they are not air tight which is the purpose of the hard ceiling for this credit. Have you checked CIRs yet?

Thank you for your posts on this. Very helpful.

I found this excellent document on LEEDUser under LEED EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems.:

http://www.leeduser.com/sites/default/files/credit_docs/EBOM_EQp3__EQc3_1_EQc3_5_GreenCleaningPolicyProgram_Template[1].doc

This template is a guide for formalizing your green cleaning practices into a comprehensive policy covering the requirements of IEQp3, IEQc3.1, and IEQc3.5.

It also is applicable to LEED-NC EQ 5

Glad you found that. Here's the direct link to the LEED-EBOM IEQp3 page on LEEDuser for anyone who's looking for it.

On a semi-related topic, we have been specifying permanently installed metal grates with carpeted tops. We recently got push back from our LEED reviewers that ANY carpeted system must have a cleaning schedule attached.

It appears they are shifting from requiring specific maintenance contracts from only roll-out to ANY carpeted systems, permanent or not.

Interestingly, this is the first time we have recieved this directive from a review team in 10+ projects utilizing this system.

The EQc5 requirements don't apply to generic central printing rooms, only high-volume copy rooms specifically.

What is considered high volume?

Ted, in LEED-EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. the figure has been 40,000 copies or more per month. As far as I know that has been successfully applied in NC.

The Oil Tank outdoors does not impact any LEED credit that I am aware of!

I would consult with local environmental codes and the MEP to make sure that you're following best practices in protecting the local environment, but I don't know of any LEED requirement that would impact this issue. The containment drain requirement doesn't apply to LEED-NC v2.2 EQc5, and I think only applies indoors.

LIsa,
LEED EB defines this in EQc5.2, Isolation of High-Volume Copying /Print Rooms/Fax Stations. I've listed the language from the reference guide below:

"Have in place over the performance period structural deck-to-deck partitions with separate outside exhausting, no air re-circulation and negative pressure to contain and isolate high volume copying/print room/fax station. High volume means any copy machine, print or fax station with a monthly copy usage of more than 40,000 pages."

It's an interesting question—the credit was written from the perspective of an office building with small maintenance square footage, and you have the opposite situation.

You would just need to follow the credit requirements here, but I would substitute "office and support spaces" for "adjacent spaces" when reading them. In other words, provide negative pressure, self-closing doors, etc., with respect to the offices.

Tristan's note above is consistent with an approach we recently took on a lab project, which seems to have been well received by reviewers after initial review but we are awaiting final award of credit.

That said, if the mechanical bays consist of multiple separate spaces, each containing different types of contaminants, you would want to keep in mind any impact these "adjacent (chemical use) spaces" could have on each other in terms of cross-contamination if not fully separated from each other in accordance with EQc5 requirements.

To achieve both EQc3.1/3.2 and EQc5, would MERVMinimum efficiency reporting value. 13 filters need to be used and replaced for the construction, flushout, and before occupancy?

Say for instance the HVAC system was not operated during construction, could you use MERV 8 filters for the flushout and then replace with MERV 13 discount filters immediately prior to occupancy?