Coolblock X-520: Smarter Cooling for the Digital World
SYNAPSECOM blog post
Non-Technical Overview
Coolblock is bringing the future of cooling to today's technology. Their latest product, the X-520 immersion cooling tank, is designed to keep IT equipment cool in a much more efficient and sustainable way than traditional air-cooling systems.
Instead of blowing air over hot devices, the X-520 gently submerges the IT equipment in a special cooling liquid. This liquid absorbs the heat quietly and effectively, helping systems run more smoothly while using far less energy. The design is compact, stackable, and nearly silent. It’s ideal for environments where space, efficiency, and reliability are important.
The X-520 is also part of a larger European initiative called MODERATOR, which focuses on making data centers more sustainable. MODERATOR captures heat produced during operation and stores it so it can be reused later. This heat, which would normally be wasted, is instead turned into renewable energy to heat buildings, factories, or other systems.
Here’s how it works: The X-520 cools IT equipment using its special liquid. The heat is then transferred to water and stored in advanced containers designed to hold energy at stable temperatures. The stored energy can be used even months later, helping reduce waste and improve energy efficiency across various industries.
The X-520 includes built-in smart monitoring that allows operators to check on temperatures, performance, and system alerts remotely. A web-based dashboard makes it easy to understand how the system is performing and whether any action is needed, without requiring technical knowledge.
In summary, the Coolblock X-520 is not just a new way to cool IT equipment—it’s part of a bigger shift toward cleaner, more responsible energy use in the digital world.
The Technology Behind Coolblock X-520
COOLBLOCK delivers the latest liquid immersion cooling solutions in the IT industry, bringing emerging cooling technology of tomorrow, today. The latest immersion cooling product is the X-520 single-phase, open-bath, indoor immersion cooling tank.
The X-520 is a high-performance, fully modular immersion cooling tank designed to support dense IT workloads, from AI and high-performance computing to cloud and enterprise applications. It replaces traditional air cooling by submerging servers in a special dielectric fluid that absorbs and removes heat silently and efficiently. The tank has a heat dissipation capacity of up to 50 kW. Its stackable, space-saving design can store 22 OU of IT equipment. It operates nearly silently without fans, offers up to 50% energy savings over air cooling, and includes remote monitoring and sustainable operation features.
The X-520 is connected to the MODERATOR Project. MODERATOR is a European innovation project dedicated to making data centers more sustainable. It focuses on capturing waste heat—normally lost during cooling—and turning it into a renewable energy source. By combining advanced immersion cooling, like the X-520, with smart thermal storage, MODERATOR enables greener digital infrastructure. The project tackles two main challenges: improving the quality of recovered heat and making it available when needed, even months later. MODERATOR uses immersion cooling, thermal storage with special Phase Change Materials (PCM), and ultra-efficient insulation to store energy and deliver it on demand.
The X-520 tank plays a critical role in this system by capturing heat directly at the server level, starting the energy recovery process. Instead of wasting energy, MODERATOR repurposes it for heating buildings, factories, or storage systems.
How it works: First, servers are submerged in dielectric fluid, efficiently capturing heat. Then, heat moves from the fluid into a closed water loop via a heat exchanger. The heated water is stored in PCM modules, keeping energy at stable temperatures. Extra heat is stored in insulated tanks, ready for later use. Finally, stored energy is delivered to buildings and industries through smart thermal networks. With X-520 as the starting point, MODERATOR turns today’s waste heat into tomorrow’s clean energy—smarter, cleaner, and more sustainable.
The X-520 includes an immersion tank with Shell dielectric liquid that cools the immersed IT equipment. It comes with an external CDU featuring 1+1 redundant Grundfos pumps. An integrated Alfa Laval Heat Exchanger handles heat dissipation. A Siemens S7-1200 PLC works as the main control unit of the system, and IFM controllers and sensors monitor performance. The system is operated via an Advatech Industrial Panel PC that hosts the software stack.
Real-time monitoring of the tank is handled through communication via high-speed PROFINET protocol between the PLC and the software in the embedded panel PC. Metrics tracked include coolant and water temperature (in and out), flow rates, coolant electrical conductivity (for leak detection), point level detection, power consumption, working load, and current pump status. Historical metrics are also recorded.
Real-time control is also handled through PROFINET communication between the PLC and pumps. The Siemens S7-1200 PLC allows dynamic parameter control and supports four automation routines: performance, adaptive, continuous, and manual. The system has a threshold-based alarm system for temperature and flow and allows remote control of the CDU pumps.
The external CDU circulates the coolant through the system, ensuring efficient heat dissipation from the IT equipment. It delivers balanced flow and pressure across the entire tank, maintaining optimal thermal performance regardless of server placement.
Power and cable management options include top-mounted PDUs and bottom OCP v3 PSUs with 48V BusBar integration.
A web dashboard provides real-time system statistics, alerts for flow, temperature, and system events, and historical analytics for performance tuning. The Coolblock Monitoring Dashboard is accessible at my.coolblock.com.
Technical Specifications:
Power input: 3 Phase, 16A
Tank power consumption: 80–2500 W
Heat dissipation capacity: 50 kW
Coolant flow rate: 4–12 m³/h
Water flow rate: 1–4 m³/h
IT gear capacity: 22 OU
Coolant volume: 535 L
Operating temperature: -5°C to 55°C (indoor)
Dimensions: 2350 × 1250 × 1220 mm
Built-in redundancy: 2N pump