The Belimo 22RTH-5U00A is a wall-mount active room sensor measuring Relative Humidity, Dew Point, and Temperature with native Modbus RTU and BACnet MS/TP communication for direct integration with any modern building automation system, plus an MP-Bus channel for Belimo network applications. Occupants view current values and adjust setpoints by tapping a smartphone to the device's NFC zone via the Belimo Display App. An onboard LED provides at-a-glance indoor air quality status when CO2 measurement is enabled. The sleek white (RAL 9003) housing matches commercial interior finishes and mounts to a single-gang box or flat to drywall.
Key Features
Native BACnet MS/TP + Modbus RTU
Direct integration with any major BAS — no gateway, no protocol converter. The room sensor exposes all measured values, setpoints, and configuration parameters as standard BACnet objects or Modbus registers. MP-Bus is also available for Belimo damper actuator networks.
Belimo Display App + LED
Smartphone-based occupant interface — tap the phone to the sensor and the app shows live readings and lets the occupant adjust the temperature setpoint within BAS-defined limits. Optional 4-digit access code prevents unauthorized changes. The onboard LED also provides traffic-light indication of CO2 levels when measurement is enabled (configurable via Belimo Assistant 2).
Capacitive Humidity Sensor
Long-term-stable capacitive RH element with ±2% accuracy between 0-90% RH at 25°C and ±0.25% RH/year drift. Dew point is calculated and provided as an additional measured value.
Configurable Setpoint Range
Define how far the occupant can shift the setpoint above or below the BAS schedule. All limits, scaling, and offsets are configurable via the Belimo Assistant App or BAS object writes — no DIP switches, no jumpers.
Technical Specifications
| Specification | |
|---|---|
| Measured Values | Relative Humidity, Dew Point, Temperature |
| Output Signal | Modbus RTU + BACnet MS/TP digital + 1x Digital Input |
| Communication | MP-Bus + Modbus RTU + BACnet MS/TP |
| Temperature Range | 32...122°F [0...50°C] (default, configurable) |
| Temperature Accuracy | ±0.3°C @ 25°C [±0.5°F @ 77°F] |
| Humidity Range | 0...100% RH (default, configurable) |
| Humidity Accuracy | ±2% between 0...90% RH @ 77°F [25°C] |
| Humidity Long-Term Stability | ±0.25% RH per year |
| Dew Point Range | -58...122°F [-50...50°C] |
| Display | Belimo Display App + LED |
| Setpoint Adjustment | Yes (via Display App / NFC) |
| Nominal Voltage | AC/DC 24 V |
| Voltage Range | 19.2...28.8 V (AC or DC) |
| Power Consumption | 1 VA AC / 0.5 W DC |
| Electrical Connection | Spring-loaded terminal 0.25-1.5 mm² |
| Cable Entry | Back, top, and bottom side |
| Housing | PC, white, RAL 9003 |
| Protection | IP30 / NEMA 1 |
| Ambient Temperature | 32...122°F [0...50°C] |
| Ambient Humidity | Max 95% RH, non-condensing |
| Storage Temperature | -40...160°F [-40...70°C] |
| Certifications | UL/cULus per UL60730-1, IEC/EN 60730-1, CE, ISO 9001 |
| Warranty | 5 Years |
Documentation
Frequently Asked Questions
What does the 22RTH-5U00A actually measure?
The 22RTH-5U00A measures relative humidity, dew point, temperature (calculated). All values are available simultaneously over mp-bus + modbus rtu + bacnet ms/tp.
Does the BACnet/Modbus version still need analog wiring?
No. The 5U00 series provides all measured values and accepts setpoint writes over Modbus RTU or BACnet MS/TP — only power (24 V) and the digital network conductors are required at the wall sensor. A digital input is also provided on-board for window-open, occupancy, or override contacts.
How does the occupant change the setpoint without a physical dial?
Occupants download the free Belimo Display App, tap their phone to the sensor's NFC zone, and view current readings or adjust the temperature setpoint. An optional 4-digit access code prevents unauthorized adjustments. For occupants without smartphones, the BAS or a wall thermostat can also drive the setpoint.
What's the power requirement?
AC/DC 24 V nominal (19.2-28.8 V tolerance). Power consumption is 1 VA AC or 0.5 W DC. Use Class 2 supply per UL60730-1; cable type CL2 or higher for USA/Canada installations.
How does this mount?
PC housing in white RAL 9003 mounts directly to a single-gang electrical box (back-side cable entry) or flat to drywall (top or bottom cable entry). Spring-loaded terminals accept 0.25-1.5 mm² conductors — no screws to overtighten.
- Sensor Type:
- Wall Mount
- Temperature Element:
- BACnet/Modbus
- Supported Protocols:
- BACnet/Modbus
- Humidity Element:
- 2%
- CO2 Element:
- None
- Setpoint:
- Setpoint
- Override:
- No Override
- Display:
- No Display
- Material:
- Plastic
