User Manual

Page 30 Unrestricted 0 – Siemens Smart infrastructure
Product Bundle (C): VAV control via KNX thermostat
Operation
Operating modes
Comfort
The operating mode when the room is occupied must be Comfort.
Economy
Economy must be the operating mode in a room that is unoccupied for a longer period (e.g.
planned night setback).
Protection
The operating mode when the building is unoccupied (for example, during holiday periods)
for any extended period of time must be Protection. The operating mode Protection must
protect the building against overheating or cooling down too much.
Determine the operating mode
Local
Presence detector: The room thermostat switches to Comfort mode when the presence
detector is active (room occupied).
Combined central and local
Room occupancy time schedule: The room operating mode is determined by a time schedule
and is commanded via the communication bus. The scheduler must be used on the
automation or management level and specifies the operating mode. The room temperature
must be controlled to the setpoint defined for these states.
Presence detector: If presence is detected, the room operating mode determined by the time
schedule is overridden and the Comfort mode is activated.
Room equipment
Room thermostat
The thermostat must be able to:
• Measure the room temperature and maintain the setpoint
• Receive a combined CO
2 and VOC reading from an Air Quality Sensor and control the air
damper position according to the higher of the two (CO
2 and VOC) measurements
• Receive a signal from a presence detector and switch the thermostat into Comfort mode
• Provide the user with the following:
• Local operation to change the temperature setpoint
• Manual selection of room operating mode/occupancy
• LCD display for room/outside temperature, air quality, operating modes