Dear All,
After defining AIR FLOW, TEMPERATURE and HUMIDITY as an INPUTS.
 Any ideas for calculate Building Ventilation when the building connect with mechanical air conditioning system
 (external cooling equipment)?  
I think the AIR FLOW will be supply air to building.
Supply air flow  =Total air flow = Ventilation air flow +Return air flow from building
I look forward to hearing from you soon.
Regards,
Safwan Kanan
PhD student 
University of Manchester
Manchester
M13 9PL
UK