Our project has 4 basements with fresh air, exhaust and circulation fans. The logic of exhaust fan functioning is designed such that during normal mode only few fans operate, during pollution mode few more fans additionally switches on. CO sensors are installed to monitor and control the fan operation. Can we take benefit for this logic in exceptional calculations as per the guidelines outlined in advanced energy modelling guide appendix (Like a dual speed fan)?
If yes, the baseline has to be defined for 0.75 Cfm/sft and 0.3W/cfm as per ASHRAE. But these values are only for the exhaust fans in normal mode alone. (Please correct if the understanding is wrong). Then how to take benefit of the logic defined to save energy?. Also how to do the exceptional calculations for the fresh air and circulation fans running in dual speed mode?

Thank you !