Despite power and supply constraints, the demand for high-capacity data centers is soaring. The drivers behind the increased demand include AI applications, high-performance computing, and next-gen workloads that rely on technologies such as cloud computing and the Internet of Things (IoT). Advances in semiconductor technology have led to more powerful GPUs and higher rack densities. Can conventional, air-based cooling systems handle modern data centers?

Although air cooling is still widely used, many data center developers are turning to more efficient options. When air cooling is inadequate alone, it can become part of a smarter, hybrid strategy rather than being completely replaced. Airedale by Modine is helping to lead that transition.

The Chip Power Density Boom

Increasingly powerful CPUs and GPUs are pushing 500W to 700W per unit. This leads to entire server racks that can exceed 800kW. According to Schneider Electric, AI workloads could rise from 4.3 GW to 13.5 GW over the next five years. This represents a growth in AI workloads from the current level of 8 percent to 15 to 20 percent. CyrusOne recently announced an AI-specific data center with rack densities up to 300 KW.

AI applications rely on machine learning models that use complex processes and tremendous computing power for training. This requires more powerful chips, in addition to more chips that are packed together tightly on boards.

Additionally, accelerated computing in hyperscale and edge environments is another driving force behind greater chip densities. Companies are deploying specialized systems at scale to handle real-time analytics in extremely large data centers. At the same time, companies are using smaller, stand-alone data centers in constrained locations for use cases such as factories and smart cities.

All of these high-performance computing applications use miniaturized components, such as transistors, which allow for more performance per unit but increase the power draw. For data center operators, this means clients are demanding faster performance that creates more heat in less space. The tighter workflows mean less airflow, which in turn means that air cooling systems are less effective.

What Air Cooling Can and Can’t Do

When your rack density reaches around 30kW to 40kW per rack, air cooling struggles to disperse the heat build-up. It can’t transfer as much heat as alternatives, such as liquid.

As racks become denser, there are hot spots that make it even harder for air systems to balance the airflow needed in different areas. This is a particular concern in data centers that have mixed-density environments. When you add denser racks, your fans have to work harder, which leads to a higher mechanical power usage effectiveness (PUE).

However, despite the limits of air cooling, it’s still viable in many situations. It works well in most colocation and enterprise facilities, which are typically optimized for 5W to 20W racks. They’re cost-effective and easily deployed in many situations. Air-based systems are also easy to maintain.

Airedale by Modine is pushing the capabilities of air cooling further by integrating technology such as intelligent airflow optimization. High-efficiency chillers give you optimal performance in a range of environments. Modern CRAHs are built on free-cooling systems that deliver maximum uptime and redundancy at the lowest cost. In-row air cooling units deliver cooling where you need it most and offer 83% more cooling than conventional units.

In most instances, the issue isn’t that conventional air cooling doesn’t work. Instead, it’s that it isn’t enough on its own for high-density environments.

Airedale by Modine’s Position: Modern Conventional Cooling Is Evolving

Conventional cooling is a bit of a misnomer. Today’s air-cooling systems are far more advanced than they were even five or ten years ago. Airedale by Modine has developed the following air cooling innovations:

Variable Capacity Components

Elements such as pumps, fans, and compressors can dynamically adjust in real time to meet load demands without wasting energy. This provides you with better temperature and humidity control in partial loads or mixed-density centers.

Smarter Control Algorithms and Automation

Airedale by Modine’s systems include advanced sensors and predictive controls that optimize performance based on variables such as usage patterns and seasonal changes. These systems work without manual intervention and reduce your carbon footprint.

Modular and Scalable Designs for Future Expansion

At Airedale by Modine, we build systems that are designed to allow you to meet future demands without completely retrofitting your entire data center. With modular components, you can add racks or cool high-density zones while maintaining your existing cooling structure.

These improvements let you stay competitive and relevant with conventional cooling systems. For most facilities, traditional air cooling is cost-effective and has fewer operational risks, so it will remain the primary option for years to come. However, Airedale by Modine products also allow you to transition to hybrid or liquid cooling systems when you’re ready.

Where Conventional Cooling Starts to Fall Short

In data centers that are optimized for the most demanding loads, air cooling likely won’t be up to the job. Some current use cases that are beyond conventional cooling’s ability to support include AI and machine learning clusters that run 24/7 and servers that primarily run GPUs.

Air coolers will also fall short in dense hyperscale and research data centers. Because of these limitations, liquid cooling is often used in modern greenfield data centers that are built specifically to support demanding workloads.

If you’re gradually upgrading your data center to provide more servers for HPC use cases, you should be aware of warning signs that your facility may be approaching the limits of air cooling capacity, including:

● Continued hot spots even after you’ve optimized airflow
● CRAC/CRAH systems that are constantly running at 100% capacity continuously
● Disproportionate energy costs that are outpacing your load growth

In these situations, hybridization is a necessity rather than an option. Implementing products such as direct-to-chip liquid cooling and rear-door heat exchangers can make your system more efficient and effective.

Enter the Hybrid Cooling Strategy

Hybrid cooling combines air and liquid cooling systems that are specifically designed to meet your workload and rack density. It approaches cooling as a customized process rather than a one-size-fits-all.

Airedale by Modine is playing an active role in facilitating hybrid cooling design. We’ve developed CDUs that enable direct-to-chip cooling in specific zones. This allows you to cool specific AI or HPC zones without a complete system overhaul.

We also offer rear-door heat exchanges that you can pair with chilled water systems and mount at the back of high-density racks. They intercept and absorb heat at the source before it can enter the room. Airedale by Modine systems use intelligent controls to help optimize your cooling infrastructure.

With a hybrid cooling strategy, you can modernize your data center in phases. You can continue to use your existing equipment in areas where it’s effective, reducing the need for capital expenditures. Hybrid systems deliver targeted cooling to the racks that need it, eliminating energy waste through overcooling.

One example of this strategy in action is that of a colocation operator with mixed tenants. This operator uses air-cooled CRAHs for their 5 kW to 10 kW general-purpose racks and CDUs for AI tenant clusters with 50 kW GPU racks, providing optimal thermal performance throughout the entire data center.

Planning for the Next Generation of Thermal Management

The demand for high-performance data centers is only expected to increase in the future. If you don’t plan ahead, your facility won’t be able to handle the thermal loads required. As a result, you’ll risk running into capacity constraints and an increased risk of equipment failure. Starting to plan now for rising power densities means you won’t find yourself in unexpected trouble later.

Here are some questions every operator needs to ask:

● What is our current thermal ceiling?
● Can we support higher-density zones without doing a full retrofit?
● Is our cooling system set up to grow along with increasing workloads?

Airedale by Modine takes a consultative approach to thermal planning. We perform site-specific analysis of your current system to find opportunities and bottlenecks. We’ll help you create a phased, cost-effective transition plan that includes controls integration and future-ready system design.

The Future Is Flexible, Not Binary

Cooling is often framed as air vs. liquid. However, that’s not the reality in most cases. Instead, it’s air and liquid, with your choice based on rack density and efficiency, as well as uptime goals.

Air cooling won’t be replaced completely anytime soon. It will continue to become more efficient and will be supplemented by liquid cooling where needed for the foreseeable future. Although liquid cooling adoption will grow, not every rack or facility will need it. In the next decade, you can expect to see the hybrid model in widespread use. Airedale by Modine’s portfolio reflects this approach through products that enable advanced air cooling, high-efficiency CDUs, immersion cooling readiness, and unified control software.

Not the End, But a New Chapter

Rising chip power densities are creating a demand for more powerful data centers. However, this demand won’t eliminate conventional cooling systems. Instead, it will motivate operators to rethink how and where they use both conventional and liquid cooling systems.

Airedale by Modine continues to evolve air-cooled technologies to improve their efficiency while also developing hybrid and liquid strategies so you can meet and stay ahead of demand. Reach out today to our engineering team to discuss your density roadmap and learn how we can help you develop a cooling strategy that scales with your performance and sustainability goals.