Verified Projects and Demo Cases
Page Guide
1. Case Background
The HVAC demo environment of a commercial building covers the air conditioning equipment room and the terminal endpoints on several floors of a multi-story office building: the equipment room houses chillers, chilled water pumps, cooling water pumps, and motorized control valves; the floors host fresh air units, fan coil units, and temperature-humidity and CO₂ sensors; the equipment room is also equipped with a surveillance camera.
The demo aims to verify three things:
- Unified access: without modifying the property's existing HVAC controllers, use edge gateways to connect devices with different protocols to a single platform.
- Automatic control: replace fixed schedules with scene linkage so that fresh air and terminal equipment run automatically based on the indoor environment.
- Centralized operations: a large screen on duty in the monitoring center, with operations personnel handling alerts on the mobile app, reducing the frequency of on-site inspections.
2. Solution Implementation
2.1. Device Access
Devices in the building are connected in two categories by protocol: air conditioning unit controllers connect directly to the LAN over Modbus TCP, while temperature-humidity sensors, pumps, and motorized valves connect over the Modbus RTU serial bus; both converge at the edge gateway in the equipment room, and cameras are connected to the platform via GB28181. The gateway converts field protocols uniformly to MQTT for reporting. During the demo, a network outage was simulated to verify that cached retransmission and local linkage fallback work as expected.
2.2. Thing Model and Linkage Configuration
Product thing models were created on the platform for air conditioning units, fresh air units, fan coil units, pumps and valves, and sensors respectively: properties cover temperature, humidity, CO₂ concentration, operating status, and valve opening; functions cover start/stop, temperature setpoint, and fan speed adjustment; events cover fault alarms. Three types of linkage rules were then configured:
- Air quality linkage: when a zone's CO₂ concentration stays above the threshold beyond the allowed duration, the fresh air fan for the corresponding floor is automatically started and shut down with a delay after recovery.
- Temperature regulation linkage: when a zone's temperature deviates from its setpoint range, the fan coil unit fan speed in that zone is automatically adjusted.
- Fault linkage: when a device reports a fault event, an alert is pushed and the related water-circuit valves are shut down in linkage.
3. Feature Demonstration
3.1. Visualization Large Screen
The monitoring center large screen displays the temperature, humidity, and CO₂ distribution of each zone by floor; the equipment room circuits show supply and return water temperatures, pump frequencies, and valve openings, with real-time alerts scrolling on the right. On-duty personnel can grasp the operating status of the entire building's HVAC system on a single screen.
3.2. Scene Linkage and Remote Control
In the demo, the CO₂ analog value of a zone was manually raised; the zone's indicator changed color on the large screen, and a few seconds later the fresh air fan started automatically, while the mobile app received the linkage execution record in sync. Remotely modifying a fan coil unit's temperature setpoint from the Web console prompted an immediate response from the field device, and the device log shows the complete "command delivered → device acknowledged → property read-back" chain.
3.3. Mobile Operations
Operations personnel view the device list and real-time data on the mobile app, and remotely acknowledge and handle alert push notifications; during patrols, they use the phone to perform video review of camera footage in key areas. Devices are shared with different operations personnel by role, avoiding shared accounts.
4. Operating Results
Throughout the continuous operation of the demo environment, the entire chain performed stably:
- Access side: serial and Ethernet devices delivered complete data after being connected through the gateway, and cached data was automatically backfilled without loss after network recovery.
- Linkage side: the air quality and temperature linkage rules triggered as expected, replacing the original fixed all-day operating mode, with terminal equipment automatically shut down outside office hours.
- Operations side: the response from alert discovery to acknowledgment was significantly faster; inspections are now primarily spot checks on the mobile app, and the frequency of on-site patrol inspections has decreased.
- Management side: the report center has accumulated temperature and operating duration data by zone, providing a basis for subsequent energy-saving policy tuning.
5. FAQ
Can the device access approach of the demo environment be reused directly in real projects?
The access pattern can be reused directly: Modbus devices converge through gateways, cameras connect via GB28181, and the platform performs unified modeling—the same as in real projects. The differences mainly lie in device scale and field wiring; for implementation steps, refer to the Deployment and Implementation section of the Reference Solution.
What if a linkage rule triggers by mistake?
When configuring rules, it is recommended to add a duration condition (for example, the over-limit state must persist for several minutes before triggering) and a recovery hysteresis, to avoid frequent device start/stop caused by values oscillating near the threshold. New rules should first be piloted in a single zone and rolled out to the entire building only after stability is confirmed.
What is the relationship between the HVAC case and the published smart agriculture case?
Both are built on the same set of platform capabilities: gateway access, thing models, scene linkage, alerts, large screens, and the mobile app. The smart agriculture case shows the complete feature interface of a real project, which can be viewed in the Smart Agriculture Complete Case; for more industry entry points, see the Industry Cases Overview.