The AHR Expo, the largest showcase for HVACR technology in North America, serves as a focal point for both established and emerging trends. The market is moving toward higher-efficiency systems, reduced environmental impact, and more compact equipment. Engineers, manufacturers, and system designers are aligning around new performance priorities: Refrigerant optimization, thermal efficiency, and intelligent system control.
Several themes stood out across the exhibition floor:
Within these technological changes, small-diameter copper tubing has served as an important design element. Systems that use 5 mm and 7 mm copper tubes now define many of the most advanced HVACR platforms on display.
Manufacturers are moving away from traditional 9.35mm (3/8-inch) and larger tubing toward 7 mm and 5 mm copper tubes across a range of applications. These include larger-scale variable refrigerant flow (VRF) systems, residential split systems, dedicated heat pumps, and commercial refrigeration equipment.
Small-diameter copper tubes deliver several measurable performance benefits:
Several manufacturers demonstrated these advantages in real systems at the expo:
Across the expo floor, 7 mm copper tubing appeared consistently in heat pumps, residential split systems, and VRF platforms. Growing in popularity, using 7 mm copper tubing provides a balance between efficiency, manageable pressure drop, and manufacturing compatibility.
By adopting 7 mm tubing, manufacturers achieve lower refrigerant charges and improved thermal performance, while also enabling more compact outdoor units that are easier to install and better suited for limited spaces.
Additionally, 7 mm systems consistently deliver better performance in cold climates, ensuring reliable heat pump operation even in challenging conditions. The growing use of this format reflects a strong industry consensus on its versatility and effectiveness.
Some examples seen at AHR 2026 included:
While 7 mm copper tubing is now standard in many HVAC applications, 5 mm copper tubing is used widely in refrigeration and compact cooling systems. Manufacturers use 5 mm tubing in commercial refrigeration, display cases, and compact evaporators to achieve multiple system benefits.
The smaller diameter allows for a significant reduction in refrigerant charge, often by 20-40 percent compared to larger tubing, supporting environmental goals and reducing operating costs. In addition, 5 mm tubes reduce airside pressure drop, thereby improving airflow efficiency. As a result, design engineers can specify lower power fans, further improving energy savings and overall system performance.
Some examples seen at AHR 2026 included:
These developments highlight how 5 mm tubing supports both performance and sustainability objectives.
The modern uprising of artificial intelligence is placing high demands on data center cooling systems. With modern AI chips generating thermal loads of several kilowatts each, traditional air cooling methods can’t keep pace with the intense heat output. To manage such heat loads, manufacturers are advancing liquid-cooling methods to maximize performance and efficiency.
Direct-to-chip cooling solutions use cold plates, coolant distribution units, and precisely engineered liquid circuits to remove heat directly at the source, enabling higher computing density and more reliable operation.
Copper is essential in these designs, for a number of reasons, most importantly its proven reliability under extreme heat flux. Engineers incorporate copper into cold plates, heat exchangers, and high-density coils, ensuring optimal heat transfer and long-term performance.
Some examples seen at AHR 2026:
Both showcased the industry’s commitment to copper-based components.
Global regulatory frameworks continue to push the industry toward refrigerants with lower environmental impact. R32, R290, and R744 are now central to system design strategies.
These refrigerants introduce new engineering requirements. Some systems, like R744, must operate at higher pressures, achieve greater heat exchanger efficiency, and some need to minimize refrigerant charge.
Small-diameter copper tubing directly supports all these requirements. It enables compact heat exchanger designs that improve efficiency while reducing refrigerant volume. It also provides the strength needed to handle higher operating pressures.
Manufacturers are equipping HVAC systems with advanced AI to enable predictive energy management, real-time optimization, and more accurate load forecasting. These intelligent controls help maximize efficiency, reduce energy consumption, and support proactive maintenance.
Some examples seen at AHR 2026:
At the same time, the industry is adopting modular system design, enabling scalable VRF platforms, modular chillers, and integrated heat pump solutions that better adapt to varying building needs.
The ongoing shift toward electrification is also accelerating, with air-to-water heat pumps gaining momentum as a cleaner, more efficient alternative to traditional combustion-based heating systems.
The move toward small-diameter copper tubing is transforming HVACR engineering and manufacturing. Engineers are creating more compact heat exchangers and optimizing fin and tube layouts, while manufacturers improve tube-bending precision and brazing for smaller diameters. Installers and technicians are adjusting to systems that require updated handling and service methods.
Next-generation developments are already underway, including 4 mm copper tube designs for ultra-compact systems and improved internal geometries for better heat transfer. Hybrid heat exchangers that combine multiple materials are also being explored. Companies like Indus Coils are working on 4 mm tubing concepts, and KRN is expanding microgroove technology to boost efficiency.
These innovations will further cut refrigerant charge, reduce equipment size, and enhance overall system performance.
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