We are working on a project that is a manufacturing facility with a small percentage of office space. The manufacturing area is using direct evaporative cooling and drawing in OA through this sytem, and there is no issue there. There are two distinct office areas on opposite sides of the building (it is about 200m long), each area of offices has a fresh air intake unit capable of supplying about 1800 CFM of OA. Is it necessary for us to monitor every individual room (office, meeting room, storage room), or could we just monitor the main OA supply?