Designing for AI-Scale: The Engineering Architecture Behind Techno Digital’s Chennai Data Center

Powering India’s AI Future — From Chennai 

India’s data center landscape is expanding beyond traditional metro concentration. As AI adoption accelerates and inference workloads become more distributed, infrastructure must move closer to both data sources and end users. In this shift, Chennai has emerged as one of the country’s most strategically positioned destinations for AI-scale infrastructure.

The city brings together several structural advantages. It offers a mature and industrial-grade power backbone capable of supporting sustained high-density loads. It sits in close proximity to major submarine cable landing stations, enabling low-latency connectivity across Asia Pacific markets. Tamil Nadu’s policy acceleration has further streamlined approvals and strengthened infrastructure readiness.

Chennai is not a secondary market. It is an AI-scale infrastructure corridor.

For us at Techno Digital, this required a fundamentally different design approach. AI workloads are not simply larger versions of traditional enterprise compute. They introduce higher density, sharper load volatility, higher floor strength, and sustained thermal intensity. Designing for this environment requires rethinking power and cooling from first principles.

That thinking shaped every layer of the Chennai campus.

The AI Density Shift: Why Legacy Designs Fall Short

One of the most significant shifts in our industry today is the acceleration in rack density. Traditional enterprise environments typically operated at 6 to 10 kW per rack. AI and GPU clusters now operate consistently in the 30 to 100 kW range and, in many cases, even higher.

This shift is not incremental. It changes the physics of infrastructure.

GPU-driven workloads introduce transient load behaviour, sharper ramp rates, and sustained high thermal output. Electrical systems become more sensitive to instability, and cooling systems must operate within tighter tolerance bands.

Higher density introduces several interrelated engineering challenges:

  • Increased conductor ampacity and sensitivity to voltage drop in conventional longer low-voltage distribution paths
  • Higher I²R losses when power is transmitted over longer internal distances
  • Thermal management complexity due to concentrated and continuous heat loads 
  • Sustainability is becoming a board-level performance metric, where inefficiency directly impacts both cost and environmental reporting

At AI-scale density, inefficiencies compound rapidly. Small electrical losses translate into significant operational impact. Minor airflow imbalance can reduce performance headroom. Thermal instability can affect GPU utilization.

AI infrastructure is fundamentally an electrical and thermal engineering challenge.

When we began designing the Chennai facility, the objective was not to retrofit for higher loads later. It was to engineer the campus ground-up for this density curve over the next decade.
At AI scale, inefficiency is no longer operational overhead, it is performance loss.

Utility-Level Power Reception: 110 kV Architecture Built for Uptime

Once we aligned on the density curve, the next question was clear: how do we ensure that upstream power integrity can support sustained AI-scale loads?

. At Techno Digital Chennai, the facility is powered through dual independent 110 kV power feeds sourced from two separate substations of TNEB and TANGEDCO  located within 500 meters from the campus. This close proximity improves response reliability and reduces transmission exposure.

Both 110 kV paths are routed through underground, shielded, and physically segregated transmission lines, enhancing resilience against environmental disruptions and minimizing the risk of simultaneous path failure.

At the intake level, the system integrates 132 kV-rated Gas Insulated Switchgear configured in a double-bus architecture. This enables real-time monitoring, remote switching, controlled load management, and maintenance without operational interruption.
By engineering power intake at utility scale and maintaining control at every layer, this ensures consistent electrical behaviour even under sustained high-density load conditions.

11kV Intelligent Power Distribution: Engineering Stability Closer to Load

Once utility-grade power is received, the next engineering responsibility is how that power is distributed internally. In high-density AI environments, distribution strategy directly influences performance stability.

At Chennai, we implemented physically segregated 11 kV A and B power feeds routed through dedicated duct banks across the campus. This physical separation ensures complete physical isolation and eliminates single points of failure at the distribution layer.

Transformers are strategically positioned near low-voltage panels to shorten electrical paths further and simplify maintenance access. This arrangement improves electrical efficiency while maintaining operational clarity during service activities.

In AI-driven environments, where rack densities are elevated and power behavior is more dynamic, these refinements matter. High-voltage distribution closer to the load enhances voltage stability at rack level and strengthens readiness for sustained AI-scale deployments. Stability at rack level is engineered, not assumed.

Backup and Energy Storage Architecture: Stability Beyond Redundancy

As workloads become more compute-intensive, resilience must evolve beyond traditional redundancy definitions. In AI environments, continuity is not only about backup capacity. It is about how seamlessly systems behave during disturbance.

At the Chennai campus, backup and energy storage were designed as an integrated stability architecture rather than independent subsystems, enabling:

  • Controlled and instantaneous changeover during grid disturbances
  • Stable load transfer with minimized transition shock
  • Reduced fault current levels during switching events
  • Coordinated load sharing across DG sets
  • Optimized generator utilization under variable load conditions

Smooth transition behaviour is critical for GPU environments, where abrupt electrical shifts can impact performance.

BESS and DG Yard Strategy

Energy storage placement was approached with equal deliberation. Instead of locating battery systems within the main facility envelope, we adopted an external BESS strategy integrated with the DG yard layout.

Lithium-ion battery systems are housed in two-hour fire-rated containers outside the primary building structure. This design provides:

  • Thermal and fire isolation
  • Risk containment away from data halls
  • Improved safety compliance
  • Optimized utilization of internal white space

By physically separating high-energy storage systems from server environments, we strengthen containment without compromising accessibility.

Cooling Architecture Designed for AI Thermal Realities

Electrical stability alone does not sustain AI infrastructure. Thermal behavior determines whether high-density systems operate at their intended capacity.

As GPU clusters push rack densities upward, heat becomes more concentrated and continuous. Cooling systems must therefore be designed for thermal intensity rather than moderate enterprise loads.

At Chennai, our mechanical architecture was developed specifically for high-density AI environments.

Centralized Water-Cooled Chiller Plant

The facility uses a centralized water-cooled chiller plant with dual headers across data halls and engineered as an energy-efficient base cooling layer. It provides stable and scalable thermal capacity capable of supporting sustained high-density loads.

This automated central plant management system ensures consistent cooling performance under varying operational conditions.

Adiabatic Cooling Towers

To complement the chiller system, we implemented adiabatic cooling towers. These towers achieve approximately 75 to 80% water savings compared to conventional cooling towers while maintaining peak performance during high ambient temperature conditions.

This reduces long-term water dependency and enhances thermal stability during seasonal fluctuations. Efficiency and water stewardship operate together within the same system.

Fan Wall Units Instead of CRAC/PAHU

Within the data halls, we adopted Fan Wall Units in place of traditional CRAC/PAHU systems. 

This architecture provides:

  • Improved airflow uniformity across large spaces
  • Higher EC fan efficiency
  • Lower aerodynamic loss
  • A smaller mechanical footprint with higher output
  • Modular scalability buffers for future density increases

This approach ensures predictable airflow under concentrated thermal loads. This becomes critical as rack densities scale and thermal margins narrow.

Quantified Efficiency Outcomes: PUE, CUE and Water Stewardship

Sustainability is embedded into the engineering design of the campus. 

The facility is optimized for low PUE performance under AI-density conditions. Its Carbon Usage Effectiveness (CUE) stands at 0.02 kg CO₂ per kWh, contributing to the prevention of approximately 170,000 tonnes of CO₂ annually.

Water savings are equally significant, with approximately 65 million litres of water saved annually through efficient cooling strategies. Greywater recycling mechanisms are integrated into operations, and a 750kL rainwater harvesting tank supplements water management. Additionally, 25% of the campus area is dedicated to native plantations, supporting long-term ecological balance.

Efficiency is not treated as an offset-driven exercise. It is a direct outcome of mechanical and electrical engineering decisions.

Spatial Engineering and Floor-to-Floor Intelligence

Infrastructure performance is influenced not only by equipment, but by how it is arranged.

At Chennai, spatial decisions were approached as engineering variables. DG yard positioning, external BESS containment, server hall stacking strategy, UPS room configuration, and meet-me room placement were aligned with airflow logic, risk isolation, and operational accessibility.

Containment alignment was calibrated to support thermal predictability, while maintenance corridors were designed to enable safe and efficient intervention without disrupting adjacent systems.

Every spatial decision impact airflow behavior, density scalability, uptime reliability and scaling to AI requirement. 

Multi-Layered Security Architecture

Physical security supports digital continuity.

Techno Digital’s Chennai campus incorporates a nine-layer physical security framework, including perimeter intrusion detection systems, crash-rated bollards, biometric mantraps, controlled access points, and continuous 24/7 Security Operations Center monitoring.

This layered model aligns with hyperscale-grade and regulated enterprise compliance expectations, ensuring that infrastructure integrity is protected at every boundary.

Chennai as a Node in a Nationwide AI Fabric

The Chennai facility operates within a broader distributed infrastructure network that includes 102 edge data centers nationwide, along with hyperscale campuses in Chennai, Noida, and Kolkata.

This distributed AI-ready model supports low-latency inference, geographic redundancy, and scalable deployment across regions.

Chennai is not an isolated installation. It is a critical node within a national digital backbone designed to support AI growth across India.

Closing Perspective: Engineering From Grid to GPU

Techno Digital Chennai represents a system engineered from the utility grid to the GPU rack. Each layer, from 110 kV power reception to distribution, backup management, cooling architecture, spatial logic, and sustainability metrics, operates as part of a unified framework.

The campus MEP systems were not adapted for AI. They were engineered for it.

Density, resilience, and sustainability are not treated as separate objectives. They are outcomes of deliberate engineering choices made across every layer of the infrastructure.

Experience the Chennai Facility

We invite infrastructure leaders, architects, and technology teams to experience how these engineering decisions translate into production environments.

  • Explore how utility-grade power engineering influences GPU stability.
  • See how thermal architecture protects high-density workloads.
  • Understand how integrated design supports scalable AI deployment.

Schedule your Chennai Data Center site visit and experience AI-scale infrastructure in action.

RAKESH MISHRA

Vice President – Design & Engineering