Central Plants and LEEDv4 Enhanced IAQ Management Strategies

Allison Wilson

Sustainability Director

Ayers Saint Gross

LEEDuser Basic Member

5 thumbs up

April 5, 2024

Hey there hive mind,

We went looking through LEEDuser to try and find some direction and didn't find much so I thought I'd bring my team's question here to all of you smart people. We're working on a non-combustion central plant tied to a geothermal field and grid electricity. The project has cooling towers and their associated chemical treatment tanks are in the basement of the central plant, but not in their own little enclosed space. The treatment tanks are aggregated into a small zone amidst the much broader array of equipment that's part of the plant.

Have any of you ever had a similar circumstance, and if so, how has USGBC understood such infrastructure in context of the Enhanced Indoor Air Quality Strategies credit? Our Ayers Saint Gross team is assuming the chemical tanks count as "hazardous gases or chemical storage" and we therefore need to show the area as being exhaust only somehow and the project's MEP thinks it falls outside the scope of the credit because mechanical rooms are not part of the sample list of spaces (such as garages, housekeeping and laundry areas, copying and printing rooms) that USGBC identifies in this credit.

If you've ever had a similar project experience, I'd love to learn more about what you encountered with USGBC and this credit - thanks in advance!

Aley

awilson@ayerssaintgross.com

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Sara Goenner Curlee

Sustainability Manager and Architect

Pope Design Group

LEEDuser Basic Member

47 thumbs up

Fri, 04/05/2024 - 18:10

I've done a number of campus projects on district systems. It is interesting what LEED decides to pull in and what it does not for these projects. In the context of the Enhanced Indoor Air Quality Strategies, I have not had to account for the infastructure or its support spaces if they fall outside the LEED boundary for the project. So if these chemical tanks are outside the LEED Boundary for your project, I'd say they are outside the scope of the credit.

Sarah Gudeman

Principal | Practice Lead

BranchPattern

LEEDuser Premium Member

6 thumbs up

Sat, 04/06/2024 - 12:43

Agree with Sara that the project boundary is important, here. And also will second that I haven't personally encountered an instance where a LEED review questioned HVAC chemical storage. My opinion would be that if it's not a regularly occupied space, it wouldn't fall under the consideration of the credit and might not get triggered in a review.
Aside from the Enhanced IAQ credit, though, complying with minimum IAQ prerequisite, of course, dictates compliance with ASHRAE standard 62.1, which requires exhaust from chemical storage rooms. Not to mention compliance with mechanical code, NFPA and Fire code requirements for chemical storage and dispensing. And if the client organization has design guidelines to comply with.
So for the context of the LEED credit, I don't think it's necessairily going to be flagged, but the room should definitely be exhausted and then probably would comply with credit requirements anyway. ;)

Allison Wilson

Sustainability Director

Ayers Saint Gross

LEEDuser Basic Member

5 thumbs up

Tue, 04/09/2024 - 15:31

Thanks for the insights, team! I honestly can't remember if I've ever certified a central plant or not and it's got some definite oddities to it. This space that includes the cooling tower makeup water chemicals is literally like 1/3 of the footprint of the building because it's where most of the other central plant equipment is living too. To Sarah's point, this room has all manner of other requirements it has to meet because of all that equipment anyway so while USGBC might not flag it for this particular IAQ strategies credit, it's got other hoops to jump through for code compliance. I'll stop worrying about it now =) Aley