Contaminants of Concern & Green Globes

John Chyz

Commissioning Authority

The Cross Creek Initiative, Inc.

LEEDuser Basic Member

11 thumbs up

June 13, 2012

As a certified Green Globes Assessor, I could not help but take issue with the comment that Green Globes has "stronger ties to mainstream industries and lobbyists". I believe that BuildingGreen owe us a little further elaboration and proof of this assertion. On a different note, while the efforts regarding avoidance of chemicals of concern in the new version of the LEED rating system are laudable, I do believe that there is an irony here which should come to light. The LEED prerequisite for indoor air quality mandates usage of the ASHRAE 62.2010 Ventilation Rate Procedure. Oddly enough as stated in the current draft: "The Indoor Air Quality Procedure as defined in ASHRAE Standard 62.1-2010 shall not be used to comply with this prerequisite." For those that are unfamiliar with the Indoor Air Quality Procedure, its primary focus is to identify the contaminants of concern and design the mechanical systems accordingly. The Green Globes rating system incidentally allows both ASHRAE 62.1 Procedures. For those that are interested, I believe that it would be worth viewing the Subcommittee on Investigations & Oversight Hearing-Green Building Rating Systems: http://science.house.gov/hearing/subcommittee-investigations-and-oversight-hearing-green-building-rating-systems Interesting that the USGBC's decision to postpone release of the next rating system follows shortly after this investigations and oversight hearing. In short, as with all fact checking endeavors for the sake of transparency and accountability.... please take a moment to verify the facts.

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Hernando Miranda

Owner

Soltierra LLC

LEEDuser Basic Member

231 thumbs up

Tue, 07/24/2012 - 15:19

I am one of the people who helped decide the "contaminates of concern" option for ASHRAE 62.1 should not be used to document LEED NC projects. There is no reason an engineer cannot design a new or major renovation project to meet the design requirements for the ventilation rate procedure. Our group had the smartest IAQ experts in the country, including ASHRAE 62.1 developers. The IAQ procedure was considered a "if you cannot do anything else" alternative. It would only apply to extreme hardship cases: EBOM and only after the ventilation and OA rates were maximized to the extent possible. In other words, don't use this for LEED NC, but make a hard case for why you have to for LEED EBOM.

John Chyz

Commissioning Authority

The Cross Creek Initiative, Inc.

LEEDuser Basic Member

11 thumbs up

Fri, 07/27/2012 - 02:21

As with most standards, ASHRAE 62.1 has evolved over time in an effort to keep pace with changing design assumptions of the engineering community at large. For those that have actually performed these outdoor air calculations, it becomes evident that the VRP is a brute-force method. In other words, rather than assessing and addressing the contaminants of concern in the air stream, the ventilation rate procedure mandates delivering enough outdoor air to essentially dilute these contaminants. While an effective strategy for many climate zones, the ventilation rate procedure offers a high energy penalty for those in hot, humid climates. In some instances, total cooling capacity can be reduced up to 1/3 using the IAQ procedure. Not only does this make economic sense, there is also the obvious carbon reduction. I believe that it is part of our mission as green building practitioners to continually search for and adapt practical solutions that strive for a more sustainable future.

Hernando Miranda

Owner

Soltierra LLC

LEEDuser Basic Member

231 thumbs up

Fri, 07/27/2012 - 03:01

VRP is not brute force. You could say that but then filtration would be brute force as well. Even with VRP, if you read ASHRAE 62.1, Section 4, is Outdoor Air Quality. You are requires to asses regional and local air quality and bounce them against EPA's National Primary Ambient Air Quality Standards. If the standards are not met you should add a treatment to the HVAC.