Located in Mumbai, this project was for a pioneering Tier IV data center with a total power capacity of 8.2MW, owned by one of India’s leading collocation providers. The facility offers world-class, carrier-neutral connectivity to a wide choice of carriers, and cloud and network service providers to help its customers build optimum high-speed, high-performance communication networks. 

The Challenge
To meet the business needs of its clients and play its part in building a hyper dense data ecosystem for India, the client collaborated with a global Graphic Processing Unit maker to enhance its facility’s capacity and capability to handle AI workloads.  

This was a bold investment which enabled the client to provide services like indigenous hyperscale cloud platforms and most importantly, India’s first and fastest artificial intelligence supercomputer. 

With greater computational capacity came increased heat loads generated for the data center. CPU-based servers in traditional data centers may average 5 to 10kW, but GPU clusters could easily reach 20 to 50kW in an AI-capable rack. 

Additionally, these GPUs could be running at high utilization rates for long periods of time for intensive tasks, such as training AI models.  

This can add up into a significant increase in sustained heat loads, and would require continuous, reliable cooling which conventional cooling systems would struggle to handle. 

The data center needed a scalable cooling solution that could handle higher heat loads with minimum impact on the infrastructure, while at the same time achieving an energy-efficient PUE. 

The Solution
This is where the ColdLogik Rear Door Heat Exchanger (RDHx) by USystems, a brand of Legrand, comes into play. 

ColdLogik RDHx's compact design and easy installation made it a flexible retrofit solution for data centers that face space constraints or need to work with legacy systems.

In the client’s data center, we installed 192 units of the CL20 Active RDHx: 138 units of the 42U with a net sensible capacity of 50kW, 24 units of the 42U with a net sensible capacity of 30kW and, 30 units of the 48U with a net sensible capacity of 20 kW. 

The Coldlogik technology in these units were based on ‘Air Assisted Liquid Cooling'. As ambient air is drawn into the rack by equipment fans, hot exhaust air is drawn over the heat exchange coils by fans mounted in the RDHx chassis. 

After heat from the air has been transferred to the water within the coils, and then the newly chilled air is released into the room at, or just below, the predetermined room ambient temperature of22°C, with the water in the exchange coils at maintained at 15°C. ColdLogik adaptive intelligent controllers, built into all RDHX units, manage these processes and monitor the temperatures of the inlet and return water, ensuring consistent conditions for effective heat exchange. 

The Impact
The client was able to achieve a PUE of 1.35 on the racks with the ColdLogik RDHx units installed, well within the range that qualifies a data center as energy efficient.  

With sustained, consistent cooling by the CL20 Active RDHx units, the data center is now capable of running racks with 40kW loads in N+1 from day one, with headroom to scale up to 59kW.  

As a result of ColdLogik RDHx's low footprint, heat removal could be done at the rack level without the need for additional ducting and other airflow management devices, maximizing white space and reducing installation and maintenance costs. 

Also, the cooling mechanisms prevented hot air from mixing with cooler ambient air in the facility, reducing hot spots and airflow problems usually associated with higher density racks. This will in turn increase hardware lifespan and future costs savings for the client.