Thanks for your replays to my email, it was very much appreciated. I tried
modeling the doas system with a dummy zone and OA from system. While looking
at my Air side reports I found that the DOAS system OSA equaled the sum OSA
from each zone in each system (fine that's logical). But each system has its
own OSA total which is larger than the sum of OSA requirements of its zones
(not sure why). Whether I model a doas dummy or not the individual system
still require the same amount of OSA. Therefore with the dummy air totals
added to the system air totals my building needs more OSA and consumes more
BTU's. Not sure what all this means but It would seem bad? Any insights,
does this sound right? This makes me think if I could eliminate this Dummy
Doas system and zones, and work in the components of DOAS into the other
systems I would at least find a different result, but right?

Regards,

Brian Smith, Mechanical Design Engineer