The term “smaller-footprint chiller” is more than a marketing phrase.

“As far as building owners go, they’ve always valued small footprint,” said Greg Shirk, an associate product manager at Johnson Controls who specializes in water-cooled chillers. “So at Johnson Controls, we’ve valued the same.”

Chiller manufacturing experts say there are multiple factors behind the demand for smaller chillers. In addition to allowing building owners and managers to use building space more effectively, especially in plants with multiple chillers, smaller chillers can be more easily installed, weigh less — which may be especially important when installed on a rooftop — and pose fewer shipping, rigging, and building-construction challenges, experts say.

“It has always been a key facet of our chillers to try and pack in as much capacity into as small a package as possible,” Shirk said. “It’s consistently in demand.”

“There’s a lot of value in reducing footprint, and a lot of different drivers for continuing to push us to find ways to do that,” said Andrew Graybill, director of product management for air-cooled chillers at Johnson Controls.

Generational Differences

Johnson Controls’ newest York YVAA air-cooled, variable-speed drive screw chillers, Graybill said, can achieve the same range of capacities as the models in the last generation, but with a footprint that’s 15% to 30% smaller, and at sometimes higher efficiency, depending on the model. The YVAA chillers, with models ranging from 150 to 575 tons of refrigeration, are recommended for a variety of applications, including data centers.

NEW GENERATION: The newest York YVAA air-cooled, variable-speed drive screw chillers have the same range of capacities as the models in the last generation, but with a footprint that’s 15% to 30% smaller, depending on the model. (Courtesy of Johnson Controls)

OIL-FREE OPERATION: The new York YVAM air-cooled, magnetic-bearing centrifugal chiller has a cooling capacity of about 40% greater, in a data center application, than its forerunner in the previous generation, Graybill said, even with a footprint that’s about 3% smaller. The magnetic bearings mean there’s no oil, and the YVAM uses a low-GWP refrigerant. (Courtesy of Johnson Controls)

Another new chiller from Johnson Controls, the York YVAM air-cooled, magnetic-bearing centrifugal chiller has a cooling capacity of about 40% greater, in a data center application, than its forerunner in the previous generation, Graybill said, even with a footprint that’s about 3% smaller. The YVAM uses the refrigerant R-1234ze, which has a low GWP, and the magnetic bearings mean an oil-free operation. It’s available in models ranging from 250 to 500 tons.

“You get a lot more cooling capacity out of it, and we were even able to shrink the footprint,” Graybill said.

Shirk mentioned the York YMC², a water-cooled, centrifugal chiller with magnetic bearings. The YMC² primarily uses a medium-pressure refrigerant that “allows us to fit a good amount of capacity in a small package,” he said. The YMC² is available in capacities ranging from 165 to 1,000 tons.

At Carrier Corp., the newest AquaEdge 19MV 600-ton water-cooled centrifugal chiller can fit through a 72- by 80-inch doorway without disassembly and has a footprint that’s 15% smaller and a height that’s 24% lower than the model it replaced, said Tom Franaszek, director of global product management for water-cooled chillers at Carrier.

“This makes shipping, rigging, and installation significantly easier and more cost-effective,” Franaszek said. (AquaEdge 19MV chillers are available with capacities between 300 and 700 tons.)

IT’S A SNAP: Carrier’s AquaSnap 30RC air-cooled scroll chiller was also designed with space savings in mind, said Tom Franaszek, a director of global product management at Carrier. (Courtesy of Carrier Corp.)

Carrier’s AquaSnap 30RC air-cooled scroll chiller was also designed with space savings in mind, Franaszek said. The AquaSnap 30C is available in capacities ranging from 60 to 250 tons.

“The design, with a physical footprint less than standard chillers, enables it to be deployed where space is tight without compromising performance,” Franaszek said. “With the high cost of real estate, Carrier developed the smaller footprint for a range of applications where optimum space utilization is crucial.”

Evolving Technology

Manufacturers say advances in the design of a number of chiller components have enabled them to develop smaller chillers, and that smaller chiller sizes go hand-in-hand with increases in energy efficiency. That’s because as components that transfer heat or consume power become more efficient, the surface area needed to transfer heat can be made smaller while still achieving desired results, Graybill said.

“That helps you to reduce the size or the footprint of the chiller,” he said. “If you don’t need as much heat-transfer surface to achieve your target cooling capacity and target efficiency, then you can reduce the size.”

Advances in evaporator technology and condensers, high-efficiency compressors and, in air-cooled chillers, fans with efficient blade designs and high-efficiency, electronically commutated motors have all contributed to both energy savings and smaller chiller sizes, Graybill said.

“The shells on a heat exchanger often will get smaller by way of improving the efficiency of those other components,” said Shirk. Developments that allow the amount of refrigerant in a chiller to be reduced, without compromising efficiency, are also factors, Shirk said.

Carrier’s Franaszek said compressor design is the key to the AquaEdge 19MV’s smaller size.

“If you want to build a better chiller, start with a better compressor,” he said. The AquaEdge 19MV employs dual two-stage compressors that “enable a smaller chiller footprint while providing the operating range and efficiency modern buildings require,” Franaszek said.

Ensuring Servicability

Manufacturers say they aren’t letting the drive for smaller chillers get in the way of ensuring that they are easy to access and service.

“Our product teams are very closely linked to our service teams as well, so that is kept in mind throughout the development process,” said Johnson Controls’ Shirk.

“We give instructions to our team of engineers designing the product to place certain components near the perimeter of the of the chiller package so that a person servicing it can get to that part quickly,” Graybill said. “We also have to set clearance requirements between certain components, or around certain components, so that there’s enough space to use the necessary tools, and to allow a person access it properly and safely.” Chillers with magnetic bearings, such as the York YVAM, have no oil or oil system components that need to be serviced.

“Carrier fully integrates the concept of service into our new product development,” said Franaszek. “Placement and access for service technicians and tools are a key part of design.”

Oftentimes, Franaszek added, reducing a chiller’s size increases serviceability because the height and weight of components are reduced, and a technician doesn’t have to reach as far to access them.