Flush for Residential Multifamily several stories

As a laboratory that does the IAQ testing for all the LEED parameters I can tell you that gas vapors have no barriers. In other words if you flush out one floor and later flush out another, the VOC's potentially can be pushed back to the flushed floor. We did a 35 story high rise and they wanted to test each floor within 2 weeks after a quick flush out.  The problem was they were still working on one floor down and they kept failing TVOC's. What we did find out is if they put a 2-3 floor buffer the retesting wasn't fully clean but they it pass the 500ug/m3 criteria. Sue feel free to give me a call if you like 315-431-9730 Centek Labs. We do the IAQ work for the LEED 3.2, V4 and V4.1 criteria.

Russ, Have you ever done pre and post flush out air testing to evaluate its effectiveness?

Yes, some of our clients before they sample go in and to get a baseline of where the building sits before they do the actual air test. They won't do all locations but they will do a pre and post test.  For example, a client has to deploy 20 locations, however the GC may have just finished doing the work less than a week ago. Our laboratory always issues a couple of extra 1L canisters for backup, we tell our client to grab a sample that they feel is the highest in VOC's (it is the #1 item that fails) and rush it back to the lab for a quick turn around. This serves 2 purposes: 1 did they meet the 500ug/m3 criteria and 2 what are the compounds that caused me to fail, which you can't get that information from a handheld.  Many times their instincts are correct they fail the 500ug criteria and from the compounds we can get an idea that it came from paints, adhesives or the worst gluing of PVC pipe. Also, while they are waiting for the results our clients will do some additional running of the HVAC systems to prepare for the air sampling. When they go back they will sample all of their location and usually pass with no problems. What we have done is save our clients and their clients a lot of time and money. It is better to RUSH 1-2 samples then sample 20 and have to go back and re-sample as much as 60% of the work.  On a further note: One of the big problems that we have seen in the LEED V4 and 4.1 is that all furnishings has to be in place before testing is done. Many items have formaldehyde in them that will cause them to exceed the 27ppb criteria. We have seen a lot of this especially in schools, dorms, healthcare facilities due to the shelving that is used. They are made of press board that is held with glue that yes contains formaldehyde. However, we can check the concentration using the same canister that was submitted with the RUSH turnaround sample. (Yes I know formaldehyde has to be done with a tube but it is an approved TO-15 and ISO certified method...but that's a another discussion). I hope this gives you some answers to you question but feel free to contact me at 315-431-9730 or just email me at Russ@CentekLabs.com for any further questions. Enjoy the Holidays...Russ