Hi All,

I am trying to model a fan coil units serving each zone and a fresh air
air handling unit serving all these zones.

While looking in the archive I conclude that we can?t assign 2 systems for
one zone, and for this reason we have to create a DOAS with a dummy zone.
But I didn?t understand the concept. Is that what should be applied in my
case?

Plz can you explain me the idea of DOAS, and how can I model my HVAC system.

Any help will be appreciated. Thanks