# HVAC Integration

## **Introduction**

Heating, Ventilation and Air Conditioning (HVAC) systems are among the largest energy consumers in residential, commercial, and hospitality buildings. Efficient integration of HVAC with the iNELS system brings not only **comfort and convenience** for occupants but also **substantial energy savings** for building operators.

The iNELS platform supports seamless connection with a wide range of HVAC technologies, including:

* **VRV/VRF systems** (Daikin, Mitsubishi, Toshiba, LG, Carrier, etc.)
* **Ducted split units** (via Modbus or dedicated gateways)
* **Chillers and fan coil units** (through FCU actuator or relay-based control)
* **Underfloor heating and radiators** (integrated with iNELS room thermostats)

### **Why Integrate HVAC with iNELS?**

* **Centralized Control** – unify lighting, shading, access, and HVAC in one platform.
* **Energy Efficiency** – reduce energy consumption by linking HVAC with presence detection, card switches, and window contacts.
* **Guest Comfort** – deliver personalized temperature control in hotel and residential applications.
* **Flexibility** – support for multiple communication protocols (Modbus, MQTT) allows integration with different manufacturers.
* **Monitoring & Maintenance** – real-time status, alarms, and performance data available in dashboards.

### **Integration Methods**

1. **Direct Control**
   * iNELS thermostats (RFTC, IDRT3, GRT3-70, GRT3-100, Inspinia panels) directly operate underfloor heating, radiators, or fan coils.
2. **Gateway / Translator Integration**
   * Third-party gateways (e.g., Airlink, Intesis, CoolAutomation) translate manufacturer protocols into Modbus RTU, which the CU3-10M can process.
3. **Native Modbus Devices**
   * Many HVAC controllers already support Modbus natively. These can be connected directly to the CU3-10M/Modbus. 
4. **MQTT** 
   * For modern VRF/VRV controllers or IoT-enabled HVAC equipment, integration can be performed through MQTT broker.

### **Use Cases**

* **Hospitality** – automatically switch off AC when a guest removes the card or opens balcony doors.
* **Residential** – integrate HVAC with smart scenes (e.g., “Good Night” turns off AC and adjusts heating).
* **Commercial** – monitor energy consumption of multiple zones, optimize based on occupancy.