Outdoor Air Contamination

Norma, that seems like it would be extremely complex from a scientific and methodological perspective. I'm wondering what the intent of such a protocol would be. To ascribe certain contaminant levels to outdoor air, and thus hold the LEED project harmless for them? Hard to see how that would work. Could you filter the air effectively?I suppose you would do this if it were an option, but simply following the flush-out procedure would be the easiest path to earning the credit at this point.

Since you are still using the testing methodology, the flush out parameters are less restrictive as far as air temperature and humidity control than if you were using the flush out method. Would it be an option to bring in some temporary fans to expedite the flush out?

Norma, I'm confused about how your ME arrived at 9 months for the flush out. VRF systems still need to provide a minimum outside air to the space, usually this is achieved through the use of a dedicated outside air system (DOAS). Let's say you were providing 0.15 CFM of OA/SF (California T24 Ventilation Minimum for an office space), the calculation would go like this: 0.15 CF/min per SF * 60min/hr * 24hr/day = 216 CF/day per SF You can go Path 2 (phased flush out), which requires 3,500 CF/SF. At 216 CF/day it would take 16.2 days to complete. 16 days can definitely be impossible to fit in a tight schedule, but the 9 month calculation is unheard of for this credit. Even if you were providing half the CFM of OA/SF that is required in California (closer to the ASHRAE calc), you'd be at 1 month for Part 1 of Path 2. During the occupied period, I could see there being an issue with supplying the 0.30 CFM/sf of ventilation required for Path 2 with your DOAS, but that's another story.