The Only Protocol Data Centers Will Need in 2026: Redfish

[Cengiz Özemli]

### Data Centers Are Reaching Thermal Limits
With the rise of AI workloads, hyperscale expansion, and liquid-cooled architectures, data centers have reached a point where thermal density, energy consumption, and operational complexity overwhelm legacy control systems. According to Goldman Sachs, data centers in the US will consume approximately 8% of the national electricity by 2030. Frost & Sullivan predicts that the data center cooling market will exceed $18.5 billion by 2030.

### Cooling Is No Longer Just a Facilities Issue
Cooling accounts for approximately 40% of total data center energy expenditure, and with rack densities exceeding 30-60 kW, there is no room for error. Today, the best-performing data centers are those that integrate cooling control systems with IT management on a common DCIM management platform. This eliminates delays and protocol conversion issues.

### Cooling Is Now an IT Responsibility
Previously, cooling systems were managed locally with PLCs, providing limited visibility to the IT side. This model worked in environments where demand was predictable but fails under dynamic conditions such as increasing workloads and liquid cooling. In modern data centers, cooling systems must:

• Provide real-time visibility
• Integrate directly with DCIM and IT platforms
• Support redundancy and rapid fault detection
• Scale consistently across all facilities

### A Common Management Language Is Needed
IT systems, servers, and power equipment are managed by DCIM in a standardized format. However, cooling systems lack this common language. Consequently, cooling remains disconnected from the systems that govern organization, optimization, and operational decisions. This gap becomes a critical problem as facilities grow.

### What Is Redfish and Why Is It Becoming Mandatory?
Redfish is a REST-based, JSON-formatted modern data center management standard developed by the Distributed Management Task Force (DMTF). It provides data such as system health, power usage, thermal zones, fans, pumps, and alarms in a consistent model. Redfish is web-enabled and integrated with IPv6 and hyperscale structures. It is widely used in server and power system management.

### Why Is Redfish Inside the Controller Important?
Cooling systems require real-time and critical control. If Redfish is behind protocol conversion and translation layers, its impact is diminished. Unitronics integrates Redfish into its UniStream PLCs, providing management data along with deterministic control, real-time processing, and industrial communication.

### Unitronics UniStream PLC Features

• Redfish protocol built-in and native
• Real-time deterministic control
• Directly provides health and status information to DCIM platforms
• Instant alarm and fault notifications
• Simpler and more robust system architecture

### Practical Example for CDUs: Liquid Cooling
For high-density AI racks, a liquid cooling CDU must provide flow, pressure, and temperature control while accurately and quickly communicating its status to DCIM. Previously, PLC control plus gateways for data conversion were required. With the UniStream and Redfish combination:

• Real-time control continues
• System status becomes directly visible via Redfish
• Integration complexity is reduced
• Points of failure and delays decrease

### 2026 Is a Turning Point
As data centers grow, it is unsustainable for cooling systems to operate outside the management layer. Cooling must speak the same language as the IT infrastructure. By the end of 2026, Redfish usage will become mandatory. This is an architectural shift.

Unitronics UniStream Data Center controllers bridge the gap between IT and OT with PLC + HMI, built-in Redfish, IPv6, and protocols like BACnet, Modbus, REST API, and OPC UA.

### Conclusion
In an era where Redfish is the common language of data centers, embedding it directly into the controller is the most logical step. This is not a simple PLC feature but a new paradigm in the control and management of data center infrastructure. As 2026 approaches, Redfish will be everywhere. The question is, which platforms are ready for it.

Unitronics provides unified control solutions for data centers, offering control, visualization, OT communication protocols, and native IT integration in a single device.