Start with the system
Before choosing a thermostat, identify what it must control: a single split unit, a fan coil, an underfloor heating loop, or a central plant. Voltage, switching type (on/off versus 0 to 10V, PWM, or Modbus), and load decide compatibility.
Three families of thermostats
Mechanical thermostats are cheap and reliable but offer no scheduling. Programmable thermostats add time schedules and setback temperatures. Smart thermostats add Wi-Fi, apps, occupancy sensing, and BMS integration — ideal for offices and hotels.
Wiring and protocols
Check whether you need a simple two-wire control or a bus protocol such as Modbus RTU or BACnet MS/TP. A thermostat with open protocols is far easier to integrate and future-proof.
What we recommend
For most commercial retrofits, a programmable or smart Modbus or BACnet thermostat gives the best balance of cost and capability. anRens thermostats support both on/off and bus control, with a clear wiring label for fast installation.
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