Most contractors will never see the inside of a hyperscale data center, but the design standards being written for them right now will eventually show up in the bid sets of any commercial mechanical contractor adjacent to that world. On May 5, 2026, Johnson Controls released its second Johnson Controls AI Factory Reference Design Guide, this one focused on air-cooled chillers for gigawatt-scale AI data center cooling, following the company's first guide on water-cooled chillers released in February. Together, the two documents are meant to become what Johnson Controls calls the industry's most comprehensive global mapping of AI factory cooling design.

What the Guide Actually Specifies

Reference design guides are not products. They are standardized blueprints, full system layouts, temperature and flow data, and integration best practices, intended to be applied repeatedly across hyperscale projects worldwide rather than describing a single piece of equipment. The new air-cooled chiller guide centers on raising chilled-water temperatures to support warm-water cooling loops, an approach Johnson Controls says delivers a 30 percent improvement in coefficient of performance and requires 27 percent fewer chillers than a conventional design. The company also says the configuration can support zero-water cooling, eliminating cooling towers entirely and saving more than 12 million gallons of water per day at scale, while returning as much as 50 megawatts of capacity back to the data center for actual compute use and improving annual energy consumption by 32 percent.

Johnson Controls' data center solutions president described the guide as part of a strategy to help customers plan integrated systems that scale predictably as AI infrastructure technology continues to evolve, framing it explicitly as a planning tool for design teams rather than a one-off product announcement.

This Fits a Pattern Across the Entire OEM Landscape

Johnson Controls is far from the only major HVAC manufacturer racing to formalize data-center design standards this year. Daikin Applied has built a dedicated global data center business unit, opened new manufacturing capacity specifically for large-tonnage and custom air-handling equipment, and acquired modular white-space cooling capability through DDC Solutions. AAON's BASX segment has reported backlog growth in the triple digits as data-center demand accelerates. Every signal points the same direction: data center cooling has become enough of a strategic priority that major OEMs are now investing in standardized design frameworks, not just selling individual pieces of equipment into a market they expect to keep growing.

That formalization matters because reference design guides like this one shape what mechanical engineers actually specify on real projects long before a contractor ever sees the drawings. Warm-water cooling loops and raised chilled-water setpoints are quickly becoming the default assumption baked into new builds, which means a contractor unfamiliar with that baseline is starting a bid behind competitors who already understand the design logic.

Why Air-Cooled Chiller Work Is a More Realistic Entry Point Than Liquid Cooling

Direct-to-chip liquid cooling and immersion cooling, the technologies getting the most attention in data center coverage generally, require specialized skills that most established commercial contractors do not currently have and would need significant retraining to acquire. Air-cooled chiller work is a different story. It sits much closer to traditional commercial HVAC skill sets, chillers, piping, and controls that established mechanical contractors already understand, making it a far more accessible entry point into the data-center cooling boom for firms that have never bid mission-critical work before.

For contractors with existing commercial chiller capability who want a piece of this growth without retraining an entire crew on liquid cooling technology, studying reference designs like Johnson Controls' new guide now, before it shows up in a competitor's bid, is essentially free continuing education on where the fastest-growing segment of commercial HVAC is headed.

What This Means for Contractors

•       If your firm does commercial chiller work, study Johnson Controls' and competing OEMs' AI Factory reference designs now. Warm-water loop and raised chilled-water-temperature configurations are becoming the default spec on new data center builds.

•       Treat air-cooled chiller work as the more accessible entry point into data-center mechanical work compared to liquid or immersion cooling, which requires specialized retraining most commercial contractors have not yet undertaken.

•       Expect more OEMs to publish similar reference guides this year as the data-center cooling buildout continues. Reading them early is a low-cost way to understand where bid specifications are heading before competitors do.