01
Sensors and room units
Temperature, humidity, pressure, air quality and occupancy information supports HVAC operation and comfort.
Field devices are the foundation of accurate control
A controller cannot perform well if sensors provide misleading measurements or if an actuator is incorrectly sized. Field devices should be robust, easy to install and serviceable under the actual operating conditions.
Sensors and measuring devices
- Room, duct, immersion, strap-on and outdoor temperature sensors.
- Humidity, CO₂, air-quality and differential-pressure measurement.
- Flow and energy measurement for water and other utilities.
- Room operation units, thermostats and suitable occupancy interfaces.
Valves, damper actuators and room control
Two-way and three-way valves control or mix hydronic flows; pressure-independent designs suit applications where varying differential pressure would affect conventional control. Damper actuators regulate air paths in HVAC equipment, while specialised models meet defined fire- or safety-related requirements. The correct torque, stroke, signal type and fail-safe behaviour are application-specific.
Examples from the historical Siemens portfolio
| Equipment category | Product-family examples |
|---|---|
| Temperature sensors | QAA, QAM, QAE, QAD, QAP, QAC |
| Two- and three-way valves | VVF, VVG, VXG, VXF |
| Magnetic control valves | MXF461, MXG461 |
| Valve and damper actuators | SAX, SAS, SAL, GBB, GCA, GDB, GEB |
| Room controllers and units | RDF, RDG and earlier RCC/RAB families |
| Utility and heat meters | WFW, WFC, WFM, WFN and UH50 families |
These are examples from archived product documentation, not a current availability or compatibility guarantee. Always verify the exact model, revision, electrical connection, communication interface and replacement options against current manufacturer documentation.
Digital interfaces at the field level
Where supported, KNX or Modbus-capable devices can reduce the need for separate analogue signals and provide additional diagnostic values. However, bus topology, power supply, addressing and commissioning procedures must be considered from the beginning.