Question-and-Answer Resource for the Building Energy Modeling Community
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Maximum Fraction of Outdoor Air Schedule doesn't change airflow in the loop, it just applies desired fraction of OA. As per docs indicates, "The current schedule value is multiplied by the current system mixed air flow rate to set the maximum outdoor air flow rate. This schedule is applied after all other limits (except EMS and demand-limiting overrides)." If you want a 100% OA system it should be 1 all the time. But where the mixed air flow is specified should be modified. I cannot tell without more details of how you model it. The least case is that you can modify the airflow by actuate fan air flow rate via EMS, where you can read in your schedule (via sensors) and multiply it by maximum/full air flow rate then assign the desired air flow rate to fan actuator. I haven't tried it but it looks reasonable in theory.
Good luck.
