Dan,

[I copied the equest-users instead of bldg-sim.]

You need to enter zone-level OA as OA-FLOW/PER and/or OA-FLOW/AREA. The
OA flow/per (person) is what will vary the OA on an hourly basis, based
on your occupancy schedule(s). (Hourly OA = (# of people) * OA-FLOW/PER
* (% occupancy in schedule)). In order to turn OA off during unoccupied
hours, I create a MIN-AIR-SCH, coinciding with the fan schedule, set to
zero when fan is off (or night cycling) and -999 when fan is on. The
hourly OA can be verified by creating a new hourly report for the system
to track total system supply air flow rate and ratio of outside air to
total supply air.

Regards,
Bill

William Bishop, EIT, BEMP, LEED(r) AP