Daikin Applied’s Pathfinder AWV features a first-of-its-kind integrated water-side economizer (WSE) that brings the benefits of free cooling to an air-cooled screw chiller with (Variable Volume Ratio) VVR® compression technology and total unit configurability. It was this feature, along with the packaged unit’s ability to offer significant reductions in energy use and cost savings, that led our panel of judges to select it as the 2021 Commercial Comfort Product of the Year in the Cooling Equipment category.

The integrated WSE is a novel approach that adds a fluid-to-air heat exchanger coil in series with the chiller refrigerant condenser coil. The heat rejection airflow moves across both sets of coils, allowing fluid to cool without the need for vapor compression when outdoor air temperatures are sufficiently lower than the cooling fluid temperature. Even on mild days, when temperatures are not cold enough to achieve 100% cooling without vapor compression, the Pathfinder can partially precool the fluid to reduce the load on the compressors, reducing energy use.

Integrating the coils into the chiller instead of using a separate dry cooler allows for economizing without the need for additional footprint. It also uses the same fans and motors already on the chiller, saving cost and space.

“For engineers and contractors, combining two pieces of equipment into one reduces the number of equipment pads, electrical feeds, and pipe runs by 50%, speeding up design and installation and reducing first cost,” said Rob Landes, product manager, positive displacement chillers, Daikin Applied. “Bundling the mechanicals and controls also helps ensure plug-and-play operation, reduces field control issues, and maximizes performance and efficiency.

Daikin Applied’s Pathfinder offers numerous features, including:

•  Three modes of operation (mechanical, hybrid, and free cooling) to optimize efficiency in all weather conditions with the ability to meet 100% capacity in any mode.

•  Its free-cooling solution uses multilayer, faser-composite polypropylene header pipes instead of carbon steel, eliminating the potential for rust and contaminant issues. And because the material is smooth with low friction, Daikin’s header pipe design lowers pressure drop compared to steel, which can trim pump energy use and size as well as reduce both first cost and longer-term operational costs.

• VVR compressor technology adjusts the chiller compression ratio and RPM using a variable frequency drive (VFD) to meet partial load demands and varying outdoor ambient conditions at optimized efficiency levels. This ensures optimal efficiency, even when not running in free cooling or hybrid mode.

•  With fast compressor start and loading times, Daikin air-cooled chillers with RapidRestore® technology give building owners and facility managers peace of mind during a critical power loss. RapidRestore restarts the chiller in as little as 35 seconds after power is restored and features a fast time to 100% load operation for an air-cooled screw chiller with integrated WSE solution. This can substantially reduce the need for expensive and bulky water storage tanks traditionally needed for slower-starting chillers, reducing first cost and maximizing site real estate.

•  Intelligent Equipment® technology provides remote monitoring and enhanced visibility to more than 300 chiller data points. Plug-and-play capability eliminates the need for programming or wiring, reducing overall engineering and installation costs. Controls are preconfigured at the factory and ready for commissioning/startup. Energy analytics and service diagnostics help manage operation and enhance serviceability.

“The Pathfinder platform is the culmination of more than 20 years of designing award-winning solutions for the air-cooled chiller market,” Landes said. “Rather than a stand-alone development, it is an evolution based on a steadfast policy of continuous improvement and an obsession for innovation that can transform a product platform into a tactical solution to solve customer problems. For the last five years, we have studied how integrated free cooling could be a solution while listening to and learning from the comments of our customers who have tried implementing free-cooling solutions. This process allowed us to design a solution that solves those problems effectively and intelligently.”

The Judges’ Decision

For several of our judges, the integrated WSE and VAV compression helped the Pathfinder chiller stand out from its peers.

“As a main piece of cooling equipment, the energy-saving potential with this innovation is attractive,” said one judge. “We have worked with Daikin’s chillers locally, and they offer excellent technical support as well as Revit BIM [building information models] that is up to date with the industry.”

The addition of economization coils to an air-cooled chiller provides a new, easy-to-operate efficiency option to a wide variety of project types and facility operators, said another judge. “By integrating the complex controls typically required for water-side economization into the chiller package, Daikin has made water-side economization and the associated efficiency gains more approachable to a wider audience.”