Designing for the future

Modern AI clusters are driving the scale and thermal management requirements of data centers inevitably upwards. Rack densities are growing exponentially year on year. Data center operators are having to meet rapid deployment demands, diverse workloads and faster time to value.

To help data center operators and facility managers rise to the technical challenge, Johnson Controls has expanded its series of reference design guides with the addition of a first-of-its-kind air-cooled chiller plant reference design for gigawatt-scale AI Factories.

The series outlines how to build high-performance, scalable facilities from a thermal management perspective. Each reference design guide acts as a blueprint that is intended to increase standardization, enable globalization and accelerate scalability to reduce time to revenue. Together, they will be the industry's most comprehensive set of global design guides mapping the full data center thermal chain. 

Air-cooled reference design guide for gigawatt-scale AI Factory

The latest reference design guide from Johnson Controls focuses on how to plan and design an air-cooled chiller plant capable of serving a full 1 gigawatt AI Factory.

Operators are facing mounting challenges including the power needed for cooling systems, rising cooling loop temperatures, efficiency losses from heat islands and limited water availability. Reference Design Guide 401 outlines a comprehensive thermal cooling architecture that manages both air-cooled and liquid-cooled IT loads. It also outlines how to achieve industry-leading energy and water efficiency while minimizing noise impact on surrounding communities.

The globally repeatable blueprint includes the following primary thermal chain elements:

• Fan coil walls (FCWs)
• Computer room air handlers (CRAHs)
• Air-cooled centrifugal chillers (including YDAM and YVAM chillers)
• Coolant distribution units (CDUs)
• Thermal controls

The guide also provides sizing references for 220MW compute clusters, including recommended design temperatures and operating conditions across each stage of the thermal chain – from chip-level heat capture to final ambient rejection.

Critical outcomes for gigawatt-scale AI Factories

Building on the previously released water-cooled chiller guide (Reference Design Guide 402), the new blueprint supports the scalable design of data centers utilizing air-cooled chillers.

The approach outlined in the reference design guide delivers the following critical outcomes:

• 50MW returned to the AI Factory through the implementation of bifurcated loops for air- and liquid- cooling systems
• 32% improvement in annual energy consumption through the intelligent utilization of redundant chillers
• 20MW peak power savings by quantifying and mitigating heat island effects of air-cooled chiller plants
• Zero water usage saves over 12 million gallons daily by eliminating the need for cooling towers to produce facility water
• 30% Coefficient of Performance (COP) improvement and 27% fewer chillers from raising the chilled water temperature to support warm-water Technology Cooling System (TCS) loops

Speaking at the launch of Reference Design Guide 401, Austin Domenici, President, Johnson Controls Global Data Center Solutions, said:

“The future requires designing integrated systems that can scale predictably, perform efficiently and adapt as technology evolves. This guide reflects how Johnson Controls helps customers plan holistically for AI growth, from design to operations, anywhere in the world."

Download the new air-cooled reference design guide

AI Factories must be future-ready, built for evolution, and maximized for operational and physical capacity. Reference Design Guide 401 provides a scalable air-based cooling architecture that delivers operational flexibility in a compact physical footprint, across a range of ambient conditions.

Frequently asked questions

What is the YORK® YDAM?
The YORK® YDAM is an air-cooled magnetic bearing centrifugal chiller that is designed for high-density data centers applications. With up to 3.5MW of cooling, the YORK® YDAM delivers up to 20% increased capacity density* than other available solutions.

What are Silent-Aire® CRAH units?
Silent-Aire CRAH (Computer Room Air Handler) units are high-performance cooling solutions that are purpose-built for hyperscale facilities and mission critical data center environments. The Silent Aire CRAH units offers a range of cooling capacities and supports various cooling methods such as chilled water for higher rack densities.

What is the Silent-Aire CDU?
The Silent-Aire CDU (Coolant Distribution Unit) is a versatile alternative to traditional air conditioning systems that is specifically designed to meet the high-performance demands of hyperscalers and data center operators. By enabling placement near the equipment that requires cooling, the Silent-Aire CDU conserves energy and eliminates the need to circulate coolant over a large area.

*Performance results, including higher capacity density, are based on several factors, including but not limited to system configurations, operating temperatures, site conditions and maintenance routines. Actual outcomes may vary and are not guaranteed.