Air Sampling

Farah, this is a tricky question. The last FAQ under the Bird's Eye View section covers this in detail. I would recommend reviewing that guidance.

One part of the LEED 2009 Reference Guide states "For each portion of the building served by a separate ventilation system, the number of sampling points must not be less than 1 per 25,000 square feet or for each contiguous floor area, whichever is larger." Another part states "Take at least one sample per 25,000 square feet in each portion of the building served by a separate ventilation system." LEED 2009 states "The number of sampling locations will depend on the size of the building and number of ventilation systems. The number of sampling locations must include the entire building and all representative situations. Include areas with the least ventilation and greatest presumed source strength."

Clear as mud, right? The approach I have taken starts with the number of contiguous floors in the building. Each floor is going to get at least one sample. Then I find out the square footage (sf) of each floor. If <25K sf then one sample set on the floor. If >25K and <50K, then two sample sets per floor and so on in 25K increments. Then I find out how many ventilation units serve each floor. I define a ventilation unit as an outdoor intake air location. VAV boxes are not counted. If two ventilation units serve a <25K sf floor then two sample sets are collected on that floor. If multiple floors are served by one ventilation unit then the square footage takes precedence. For example, a ten story building with the top eight stories having a square footage of 20K sf each, the second story having a square footage of 40K sf and the first story (ground floor) being 80K sf would have fourteen (14) sample sets collected. This assumes no more than one ventilation unit per each of the top 8 floors, no more than two units for the 2nd floor and no more than 4 for the ground floor. If the ground floor had 5 separate ventilation units (i.e., outdoor air intake locations), then the total sample sets would be fifteen (15) (one for each of the top 8 floors, 2 on the 2nd floor, and 5 for the 1st floor).

I hope this helps.

Farah, again I recommend reviewing the guidance above to understand how USGBC will review documentation for this credit.

Tristan,

I clicked on the Birds Eye View and I didn't see any FAQs. When I clicked it didn't seem to do anything. How can I review the guidance you are speaking of above? Thank you.

Dale, it looks like you are not a LEEDuser member. You will need to sign up in order to see that guidance. Our basic membership costs $9.95/month, and you should also see an offer for a free trial at the top of this page.

Farah,
If you have 65,000 sf and on ventilation zone for the entire 65 this would require 3 IAQ test areas. This assumes all 65 is on one floor.