Belimo
Swiss HVAC actuators — the standard for air damper and valve control in commercial KNX and BACnet buildings.
Belimo (Hinwil, Switzerland — founded 1975) is the global market leader in actuators for HVAC applications — air damper actuators, control ball valves, butterfly valves, and zone valve actuators. Used in virtually every commercial and high-specification residential HVAC installation across Europe. In KNX and BMS projects, Belimo actuators integrate at multiple levels: (1) 24V analog control (0-10V or 2-10V) from KNX analog output modules; (2) KNX native: Belimo offers KNX room controllers and KNX damper actuators; (3) Modbus RTU/TCP: Belimo Energy Valve with Modbus for flow measurement and balancing; (4) BACnet MS/TP and BACnet IP for commercial BMS integration. The most common KNX use case: KNX 0-10V analog output → Belimo spring-return damper actuator for ventilation zone control.
Role in our panels
How we use Belimo
Belimo integrates with KNX primarily through analog control: KNX analog output module (MDT, Hager, ABB) outputs 0-10V or 2-10V signal → Belimo actuator accepts 0-10V/2-10V as position setpoint → actuator opens to proportional position. For spring-return dampers: 0V = spring return (fail-safe closed), 10V = fully open. For modulating control valve: 2V = fully closed, 10V = fully open. The KNX-Belimo interface is simple and reliable — no protocol gateway required, just an analog output module in the panel. Belimo Energy Valve (R-series) with Modbus TCP adds flow measurement (l/h), power calculation (kW), energy counting (kWh) — valuable for KNX energy monitoring projects via a Modbus gateway.
In PanelCraft panels for commercial HVAC projects, Belimo actuators connect to: (1) KNX 0-10V analog output modules (MDT 07B8.02 8-channel, Hager TXA412A) — one channel per Belimo actuator; (2) 24V SELV transformer for Belimo 24V actuator power supply (separate from KNX 29V bus); (3) Optional Modbus gateway for Belimo Energy Valve data. Panel wiring: 24V AC/DC from transformer → Belimo COM terminal; 0-10V signal wire → Belimo Y (control input) terminal; end-switch feedback wire → KNX binary input (for valve position feedback). The fail-safe position (spring return to closed on power loss) is a safety feature — Belimo handles this mechanically, independent of KNX.
Used in these project types
Belimo products
Key components we install
Belimo LMX24-3 Air Damper Actuator
6Nm spring-return air damper actuator, 24V AC/DC, 2-10V control input. Fail-safe to closed on power loss. For HVAC supply air and extract air dampers in commercial fan coil units, VAV boxes and AHUs. KNX analog output (0-10V) → actuator position (0–90° rotation). Position feedback via potentiometer output (2-10V). EN 60730 certified.
Belimo LF24 Damper Actuator (No Spring)
10Nm non-spring-return damper actuator, 24V AC/DC, 0-10V control. Stays at position on power loss. For HVAC zone control dampers where fail-open is preferable (e.g., toilet exhaust — should stay open on fault). More compact than spring-return — for tight duct installations.
Belimo Energy Valve 1" (Modbus)
Pressure-independent characterised control valve (PICCV) with integrated ultrasonic flow meter. 1" (DN25). Modbus TCP + BACnet. Measures actual flow (l/h), differential pressure, power (kW) and energy (kWh). For KNX energy monitoring: Modbus gateway reads Belimo → KNX group address → visualisation. For hydronic balancing: valve self-balances — no commissioning with flow meter required.
Belimo Ball Valve 0.5" 24V
2-way stainless steel ball valve with 24V actuator. Spring-return (fail-closed). Flow coefficient Kvs 0.8–4.0. For fan coil heating coil control, underfloor heating manifold, and domestic hot water circuits. KNX binary output (ON/OFF) or analog (0-10V for modulating control). Most common Belimo product in residential HVAC.
Belimo Actuator with KNX Interface
KNX-native modulating damper actuator (10Nm, 24V). Direct KNX TP bus connection — no analog converter needed. Group objects: position setpoint (DPT 5.001), position feedback (DPT 5.001), run time (DPT 7.001), alarm output. ETS6 application available. For high-specification commercial projects where Belimo+KNX native interface is preferred over analog.
Belimo FAQ
How do KNX analog outputs connect to Belimo actuators?
KNX analog output module provides 0-10V DC signal. Wiring: KNX module output terminal (+) → Belimo Y terminal; KNX module 0V reference → Belimo COM terminal; 24V AC/DC supply → Belimo 24V terminal; 24V GND → Belimo COM terminal. The Belimo actuator treats the 0-10V KNX signal as a position setpoint: 0V = 0% open (or spring return), 10V = 100% open. Configure the KNX analog module DPT 9.001 output and scaling in ETS6.
What is the Belimo Energy Valve and why is it relevant for KNX?
The Belimo Energy Valve (R-series) is a PICCV valve with built-in ultrasonic flow measurement and Modbus TCP. It measures actual thermal power (kW = flow × ΔT) and cumulative energy (kWh) — more accurate than calculating from flow and temperature sensors separately. For KNX energy monitoring: Modbus gateway reads Energy Valve data every 60 seconds → KNX group addresses updated → Gira X1 displays live power per zone. For large commercial projects: Energy Valve replaces manual hydronic balancing (the valve self-regulates flow to setpoint).
Is Belimo compatible with BACnet for commercial BMS integration?
Yes — Belimo Energy Valve and many commercial actuators support BACnet MS/TP (RS-485) and BACnet IP. For KNX+BMS hybrid projects: Belimo actuators controlled via BACnet from the central BMS (Siemens Desigo, Honeywell Niagara, Schneider EcoStruxure); KNX provides room-level control (thermostat, presence) and sends setpoints to the BMS via a KNX-BACnet gateway (Intesis, Loytec). This split is common in European commercial buildings: BACnet for HVAC infrastructure, KNX for room control and lighting.
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