For air conditioning in commercial buildings and in tenant space (tenant improvement), the space will be divided in separate zones (occupancy zones). For zonings, each group of the 3 exterior offices, exterior open office (maximum up to 800 square ft), the group of interior offices or open offices (maximum up to 12,00 square ft) and each conference room by itself would be an individual zone. Each zone will be equipped with a dedicated thermostat for temperature control and an optional occupancy sensor for the ventilation (outside air). The occupancy sensor (CO2 sensor) can be adjusted for the 700 ppm to provide a required ventilation per ASHRAE 62 (see question for the required outside air). As the outside air pollution is considered about the 300 ppm (by EPA), the additional 400 ppm for interior air quality is acceptable (total 700 ppm) to provide required ventilation for indoor air quality. For the projects which apply for a LEED certification, any space over 1,000 sq.ft need to be equipped with the occupancy sensor.