Liquid Cooling for Data Centers: 4 Types, Benefits & AI Data Center Applications
Why Data Centers Need Liquid Cooling
Liquid cooling is becoming a core infrastructure for next-generation high-performance data centers. With AI model training, cloud computing, and high-performance computing (HPC) driving increasing compute density, data centers now demand unprecedented thermal control precision and energy efficiency. Compared to air-based cooling, liquid cooling uses the high heat capacity and thermal conductivity of coolant to efficiently transfer heat directly from the source, achieving lower PUE, more stable operating temperatures, and more compact compute unit designs.
4 Types of Liquid Cooling
RDHX (Rear Door Heat Exchanger)
RDHX:Supports both Chilled Water (CW) and Direct Expansion (DX) cooling systems.
RDHX is a rack-level liquid cooling solution that installs a liquid heat exchanger on the rear door of a server cabinet. Exhaust heat is removed via chilled water circulation. This solution is easy to deploy, suitable for medium-density environments and retrofit projects. RDHX provides localized liquid cooling without modifying the internal rack structure, reducing air conditioning load and energy consumption while supporting incremental upgrades without affecting existing equipment operations.
D2C (Direct-to-Chip) Cooling
D2C Liquid Cooling:Up to 50kW cooling capacity in 6U space saving dimension.
D2C cooling delivers coolant directly to CPUs, GPUs, or other high-heat-density chips via cold plates for precise thermal conduction. This method provides extremely high cooling efficiency, capable of handling HPC, AI training, and high-density cloud computing nodes under sustained full load. D2C systems typically include modular cold plates, liquid distribution networks, and temperature sensors that adjust flow in real time to ensure temperature balance and equipment stability. Compared to rack-level liquid cooling, D2C is better suited for compute-intensive applications, allowing higher compute density per unit area.
Immersion Cooling
ATTOM OceanCool:Liquid cooling cabinet + CDU distribution unit integrated as one for plug and play
Immersion cooling submerges entire servers or compute nodes in dielectric coolant to remove heat directly. Immersion systems can be single-phase or dual-phase: single-phase cooling circulates the heated liquid to a heat exchanger, while dual-phase cooling uses liquid evaporation for heat absorption and condensation for heat release. This approach excels in ultra-high-density HPC clusters, reducing fan energy consumption and data center noise while minimizing hotspots. Immersion cooling also enables more compact rack layouts and is a key cooling solution for future supercomputing centers and AI clusters.
Liquid-to-Air Hybrid Cooling
Liquid-to-air hybrid cooling combines liquid and air heat transfer methods. The liquid absorbs heat from devices and then transfers it to the air via a heat exchanger. This solution is widely used in medium-density data centers or edge computing environments. It provides good compatibility with existing air-cooled infrastructure, enabling smooth upgrades. Liquid-to-air hybrid systems ensure effective heat removal while offering flexible deployment options and moderate energy savings, making them ideal for transitional or retrofit data centers.
Liquid Cooling vs Air Cooling
Traditional air cooling has been widely used in data centers for decades, using airflow management, cooling units, and containment systems to remove heat from IT equipment. However, as AI workloads and high-performance computing increase rack power density, air cooling faces challenges in efficiently managing higher thermal loads.
Liquid cooling provides a more efficient approach by transferring heat directly through liquid coolant, which has a much higher heat transfer capability than air. This makes liquid cooling particularly suitable for AI data centers, GPU clusters, and other high-density computing environments.
| Air Cooling | Liquid Cooling | |
|---|---|---|
| Cooling Method | Uses air circulation and HVAC systems to remove heat | Uses liquid coolant to capture heat directly from components |
| Best For | Traditional enterprise workloads and moderate-density racks | AI, HPC, and high-density computing environments |
| Rack Density | Limited by airflow and cooling capacity | Supports significantly higher rack power density |
| Energy Efficiency | Requires more airflow and cooling infrastructure | Can reduce cooling energy requirements in high-density deployments |
| Typical Applications | Enterprise data centers, general IT workloads | AI data centers, GPU clusters, HPC systems |
For modern AI infrastructure, liquid cooling does not completely replace air cooling. Instead, many data centers adopt hybrid cooling strategies, combining air cooling and liquid cooling technologies to achieve optimal performance, efficiency, and scalability.
Commercial Benefits of Liquid Cooling
Liquid cooling not only improves heat dissipation but also delivers significant commercial value. By reducing cooling energy consumption, liquid cooling lowers PUE and operational costs. Stable thermal conditions extend the lifespan of servers, GPUs, and other equipment, reduce fan and mechanical maintenance, and minimize downtime risks. Liquid cooling allows higher density deployments, increasing compute output per unit area, which benefits HPC, AI model training, and cloud services economically. Additionally, liquid cooling supports green data center initiatives, reduces carbon emissions, and aligns with ESG and sustainability goals. Despite higher initial investment, energy savings, reduced maintenance, and increased compute density usually yield ROI within 2–3 years.
Liquid Cooling for AI Data Centers
AI data centers require significantly higher rack densities and thermal management capabilities compared with traditional computing environments. Liquid cooling enables efficient heat removal from high-performance GPUs and processors, helping data centers support advanced AI workloads while maintaining reliability and energy efficiency.
Related Resources
Data Center Liquid Cooling: Efficiency, Evolution, and Deployment Considerations
Explore how liquid cooling is transforming modern data center thermal management, including liquid cooling technologies, efficiency benefits, deployment considerations, and its role in supporting high-density computing and AI infrastructure.
Liquid Cooling in Modern Data Centers: Unlocking ROI in High-Density Computing
Explore how liquid cooling helps modern data centers support high-density computing workloads by improving thermal efficiency, increasing rack density, and enabling scalable AI infrastructure deployments.
Related Terms
- Direct-to-Chip Cooling
- Immersion Cooling
- Rear Door Heat Exchanger
- Thermal Management
- High-Density Computing
- AI Data Center
- GPU Data Center
ATTOM Liquid Cooling Solutions
ATTOM provides advanced liquid cooling solutions designed for high-density computing environments, including AI data centers, HPC deployments, and next-generation modular infrastructure.
- Modular Design & Flexible Deployment
Provides modular liquid cooling components for different rack sizes and power densities.
Supports rapid deployment and expansion of RDHX, D2C, immersion, and liquid-to-air hybrid cooling. - Hardware Compatibility & Custom Solutions
Offers compatibility verification and custom cold plate solutions for servers, GPUs, and accelerator cards.
Adapts to existing infrastructure to reduce retrofit risks. - Operations & Lifecycle Management
Provides long-term operational guidance and technical support to ensure stable system operation.
Includes leak protection, coolant management, and inspection strategies to maintain a safe and reliable liquid cooling environment.
Contact our cooling experts to explore customized liquid cooling solutions.
Questions About Data Center Liquid Cooling
What is liquid cooling in a data center?
Liquid cooling is a thermal management technology that uses liquid to remove heat from high-performance IT equipment. It enables more efficient cooling for data centers with increasing power density and demanding workloads such as AI and high-performance computing.
What are the main types of liquid cooling?
The main types of data center liquid cooling include direct-to-chip cooling, immersion cooling, and rear door heat exchanger (RDHx) solutions. Each approach provides different methods for managing heat in high-density computing environments.
Is liquid cooling better than air cooling for AI data centers?
For AI data centers with high-density GPU workloads, liquid cooling can provide more efficient heat removal than traditional air cooling. It supports higher rack densities, improved thermal management, and more effective operation of advanced computing systems.
Does liquid cooling improve data center efficiency?
Liquid cooling can improve data center efficiency by reducing cooling energy consumption and enabling better thermal performance. When combined with optimized infrastructure design, it can help support lower energy usage and improved overall efficiency.
What is direct-to-chip liquid cooling?
Direct-to-chip liquid cooling is a cooling method where liquid coolant is delivered directly to heat-generating components such as CPUs and GPUs. This approach provides efficient heat removal for high-performance computing and AI infrastructure applications.
