I am running a model for an operating room. My goal is to show the system savings for a night set back. I am using a VAV system that is currently running 24/7 at 100% flow. My goal is to show the benefit of running this system at different maximum airflow levels while maintaining constant flow during unoccupied times.

If my OR schedule is 5am to 5pm, I would like the fan to run at 20 ACH during occupied time, 10 ACH during the first 3 hours of unoccupied time, and 6 ACH for the remaining unoccupied time.

Can I achieve this by adjusting fan schedules, or fan parameters for different occupancy settings? Any advice that may point me in the right direction would be helpful.

If three different levels of fan speed are too much to ask, I would be happy with being able to run at 20 ACH during occ. And 6 ACH during unocc.

Crina Bosch