Siemens has introduced the Series 2200 range of CO2 room units. Designed to work with Siemens’ APOGEE Building Automation System and BACnet programmable terminal equipment controllers (PTEC), the units include sensing-only and fully interactive models. The units offer numerous options for zone level CO2, and temperature- and humidity-sensing. On display models, a 96 × 64 pixel graphical organic light-emitting-diode display alternately indicates zone CO2, temperature, humidity, and/or day-and-night operation status. A convenient plug-in human machine interface (HMI) port is standard. The maintenance-free, compact, low-profile units connect to the BACnet PTEC controller via the controller’s RJ-11 port. Ventilation slots in the room unit housing optimize airflow through the cover for fast measurement response and superior control. —Siemens