Home HVAC System: Slave Actuator

The slave actuator unit(s) control a fan or HVAC in one room or section of a home or building by following instructions from the master actuator. This can be one or all of the following fan controls:​

• RPM of a brushless DC (BLDC) fan motor​
• Direction of flow, i.e., in/out (and optionally swipe up/down, left/right) ​
• Flow sensor (Liter/min) ​
• Electrical heater 0% - 100%​

If the actuator controls an HVAC rather than a simple fan, it may have additional sensors and outputs of its own to better control the HVAC, such as:​

• RPM of BLDC compressor motor​
• Compressor pressure sensor (bar)​

An additional GUI using capacitive touch or simple push button(s) and/or an LCD can be used to display local values and enter data.​ A more sophisticated GUI may also be achieved via a master actuator, IP gateway or smartphone. A real-time clock (RTC) could easily be added to switch between different operation modes, depending on the day, time, holiday, etc. All RTCs could also be synchronized within the system. ​

System Benefits​:

• Bluetooth^® 5 Mesh communication enables communication with other sensors and actuators. Advantages of Bluetooth 5 include:​
  • Secure bidirectional packet data flow​
  • Low power (can go down to µA average while being connected)​
  • Additional wiring is not required​
  • Automatic routing (with no setup for the routing itself)​
  • Scalable speed vs. range (i.e., for four times range or a double speed option, depending on the location)​
• For the power supply, usually, mains will be needed (e.g., 230Vac or 110Vac, or 24Vdc) from the building control system. Renesas has a comprehensive set of solutions available, depending on the exact use case.​