I am editing my original answer based don't know OS, so I can't comment on realizing some more things and reading comments added how to the orginal question.... In short, do this in that UI, but I still have the same suggestion that think what you should try assigning need is to assign your schedule to the "maximum fractionmaximum outdoor air schedule field. Not: minimum as you stated in your question.... Actually, I just now looked more closely at the screenshots you posted and I see the input field is there for "maximum fraction of outside air schedule".

The schedule". ...oh yeah, furthermore, I see now that the schedule you used applied as you applied it should act work as a multiplier on the minimum outside air requirement. ...so, you also asked in your comment: "why do I still design osa rate to force osa flow to zero at night. Might be worth trying the other schedule to see outdoor air at night even though I have this schedule at the space/zone level?"if that helps!

I don't know OS, so I can't comment on how to do this in that UI, but I think what you need is to assign your schedule to the maximum outdoor air schedule field. Not: minimum as you stated in your question.... Actually, I just now looked more closely at the screenshots you posted and I see the input field is there for "maximum fraction of outside air schedule". ...oh yeah, furthermore, I see now that the schedule you used should work as a multiplier on the design osa rate to force osa flow to zero at night. Might be worth trying the other schedule to see if that helps!schedule".

I don't know OS, so I can't comment on how to do this in that UI, but I think what you need is to assign your schedule to the maximum outdoor air schedule field. Not: minimum as you stated in your question.... Actually, I just now looked more closely at the screenshots you posted and I see the input field is there for "maximum fraction of outside air schedule".question.