It replaced an R22 system at an old facility with an ultra-low-charge ammonia packaged system at a new facility.
NXTCOLD units atop KPAC General's warehouse in South Gate, Calif.
Like many small businesses, cold-storage operator KPAC General started modestly.
In the late 1980s, it leased a building in Bell Gardens, Calif., and installed a patchwork refrigeration system that was a “Heinz 57 of different used components,” said Ronnie Ceballos, vice president and general manager.
Upon that foundation, Ceballos, a CPA, and his late brother John, who had previously run a trucking concern, provided 50°F storage for a Chino, Calif., cheese company. They later took in grapes and stone fruits from a Chilean importer. From that point, the business grew significantly.
In 2007, the Ceballos brothers sold their company, then called General Cold Storage, to KPAC (Konoike-Pacific), a Japanese operator that today also owns two cold-storage facilities in Wilmington, Calif., near the Port of Long Beach.
Inevitably, the Bell Gardens facility, with its 14-package refrigeration system that used R22, “started to deteriorate and was not efficient,” said Ceballos. “We decided to build our own facility from the ground up,” buying property in 2014.
That building, a state-of-the-art cold-storage warehouse located close to Bell Gardens in South Gate, Calif. (south of downtown Los Angeles), had its grand opening in July 2017, though it did not start full operation till January of this year. It stores a variety of protein products, cheese and frozen foods. The Bell Gardens warehouse has been shuttered.
Of course, in opening a new cold-storage facility, Ceballos had to answer the $64,000 (actually much more than that) question: what refrigeration system should we install?
The answer turned out to be ultra-low-charge ammonia packaged units from NXTCOLD, a Los Angeles based start-up that is now made and distributed in the U.S. by Conyers, Ga.-based OEM Hillphoenix.
The 84,000-sq-ft (3.86 million-cu-ft) South Gate warehouse consists of five rooms – one large freezer room (-10°F) and four convertible rooms (two at 32°F to 34°F, one at 48°F, and one at 55°F to 60°F), as well as a 45°F to 50°F dock area.
Eight rooftop (“penthouse”) NXTCOLD units were installed, two above the freezer, one above each of the convertible rooms and two above the dock area. With all of the components packaged in the units, cool air is ducted down into each storage area.
The total capacity of the eight units ranges from 320 TR to 360 TR, with a total ammonia charge from 150 lbs to 240 lbs. This translates to an ultra-low charge ratio of between .47 to .67 lb/TR.
Why did Ceballos select NXTCOLD for this critical piece of his business? For a number of reasons, but, importantly, because he sees it as “the way of the future.”
“There’s a move to get rid of man-made refrigerants. So why not take a look at natural refrigerants?”
– Ronnie Ceballos, KPAC General
While there were several other companies marketing low-charge packaged ammonia systems, including Evapco, Azane, Mayekawa and Stellar), Ceballos personally knows NXTCOLD’s inventor and chief technology officer, John Scherer. Scherer is also manager of engineering at Los Angeles Cold Storage, where NXTCOLD units have been installed for several years. That helped Ceballos get acquainted with the technology.
“We saw the NXTCOLD units operate at LA Cold Storage,” said Ceballos. “And we knew the [Baker Cold Storage] in Long Beach was going to use them exclusively.”
Having used R22 at its Bell Gardens warehouse, Ceballos was intent on moving away from not only R22 (which is being phased out as an ozone-depleting gas) but other man-made high-GWP refrigerants like HFCs.
While the U.S. Environmental Protection Agency is currently restrained from regulating HFCs, California is planning an aggressive phase-down program in line with that prescribed by the global Kigali Amendment. “There’s a move to get rid of man-made refrigerants,” noted Ceballos. “So why not take a look at natural refrigerants?”
The two other KPAC facilities in Wilmington, Calif., employ a natural refrigerant – ammonia – in a traditional engine-room, large-charge overfeed design. But Ceballos was attracted to the idea of using packaged low-charge units located on the rooftop rather than in an engine room.
“Not requiring an engine room in itself was huge,” he said. “You don’t need all the piping through the warehouse, and all the ammonia pushed through by large compressors.” He also liked using the area that would have gone to an engine room for “revenue-producing storage space.”
The relative simplicity of the NXTCOLD units – and the fact that the refrigeration is distributed among eight units – was also a plus for Ceballos. “If you have an issue with one, you don’t have to be concerned about the whole facility.”
Moreover, the NXTCOLD units have redundant features to provide an operational cushion. The four units in the convertible rooms each have two compressors, though they can operate with just one if the other is not working. The freezer and dock areas are each served by two units, though one can handle the load if necessary.
The distributed nature of the NXTCOLD system makes it easy to add additional units in the event of an expansion. Ceballos compared it to “going to Home Depot and buying a window air conditioner for a room.”
Each rooftop NXTCOLD unit at the South Gate facility was installed with an accompanying mini water tower. Ceballos considered a central water tower but decided it was better to customize each unit with its own water tower.
Ceballos was also impressed by the minimal amount of ammonia used in the packaged units. “At KPAC’s other two facilities, there’s probably 1,000 to 1,200 gallons of ammonia,” he said. At South Gate, the total charge ranges from 30 to 47 gallons. “We’re talking a huge reduction in the amount of ammonia, so we fly under the radar for regulatory compliance.” In California, 500 lbs of ammonia triggers a high-level of government scrutiny, compared to 10,000 lbs at the federal level.
To reduce its ammonia charge to under one lb/TR, the NXTCOLD unit dispenses with many of the refrigerant-holding components typically found in ammonia systems, such as receivers and accumulators. Instead, the refrigerant travels directly from the condenser to the evaporator to the compressor.
In addition, the system is able to control the refrigerant mass within the evaporator by “keeping the quality level at the level it needs to be,” NXTCOLD’s Scherer told Accelerate America magazine in 2016. It does that by means of an electronic refrigerant injection control (ERIC) mechanism, which uses multiple-point liquid-ammonia injection with varying tube diameters. “We inject it [into the evaporator circuits] when we need it, not when we don’t need it,” he said.
In transitioning from R22 to ammonia, Ceballos acknowledged he was a “little leery” about the toxicity of ammonia. But he was reassured by the small amount of charge in the NXTCOLD units, which limits the liability from ammonia leakage. Even in the event of a leak of the entire charge in one of the eight units – a simultaneous leak from multiple units being highly unlikely – “you wouldn’t harm anybody or products.” He expects to pay lower insurance premiums as a result.
KPAC General’s NXTCOLD units are the subject of a study sponsored by Southern California Edison (SCE) examining their energy efficiency and demand-response opportunities, compared to that of its previous system.
According to Paul Delaney, senior engineer for SCE, the utility is spending $230,000 on this analysis, which is being done by Cypress, Ltd., an energy consulting firm based in Coto de Caza, Calif. SCE will use the results of the study to justify paying KPAC General an incentive to defray the cost of the system. The incentive for the NXTCOLD units is projected to be about $82,000, said Delaney.
Refrigerated warehouses offer a “prime-time opportunity for demand-response/load management” using precisely controlled low-charge-ammonia packaged units, said Delaney. He also sees food processing, walk-in coolers in supermarkets, industrial air conditioning and data centers as other applications for low-charge ammonia packages.
The NXTCOLD units, added Delaney, are designed to handle demand response. “You just tell the PLC [controller ] what to do. It uses open ADR 2.0 protocol.” SCE is determining the optimal hours to shift demand.
Ceballos credited NXTCOLD with “providing value-added services regarding utility rebates and incentives.”
Based on his own inspection of current utility bills, Ceballos estimated that the energy costs of the South Gate facility are about 20% less than those at the old building, even though the new building holds 50% more space.
The cost of the NXTCOLD system, he said, was comparable to – and maybe a little less than – that of a conventional flooded ammonia system with a central engine room.
One additional cost in installing penthouse NXTCOLD units is the engineering and steel required to secure the roof.
Ceballos expects the maintenance cost of the NXTCOLD units to be less than that of a conventional system because of the absence of extensive piping. “If you have a leak, you’re not running through the gamut of lines to figure out where the leak is,” he said.
Ceballos acknowledged that being one of the first companies to invest in a relatively new technology is “a bit of a gamble.” But he was reassured that OEM Hillphoenix has partnered with NXTCOLD to manufacture and distribute the units. “It’s a positive for NXTCOLD and Hillphoenix as well,” he said.
Ceballos visited Hillphoenix’s production facilities in Conyers, Ga., and found that “they run a class A operation.” He also went to Bitzer’s facility to see how its compressors – used in six of his eight NXTCOLD units – were made, and also came away impressed.
For Ceballos, one challenge presented by the NXTCOLD units was a two-month delay in receiving them while NXTCOLD made design enhancements. (Installation of the units, though, is typically a one-day affair.) Since their installation, NXTCOLD has been on-site fine-tuning the units “to make sure they are running optimally,” he said. Mericle Mechanical, a local contractor, has participated in fine-tuning and maintaining the units.
He added he has been satisfied with their performance to date and would select the NXTCOLD units in any future cold-storage development.
Ceballos was supported in exploring and ultimately purchasing a relatively new refrigeration system by KPAC’s management team, including its president, Richard Burke, who took over in 2014. “[Burke] has brought a fresh, aggressive, pioneering management style and was willing to take a chance on this new technology,” he said.
Ceballos invoked two California icons in describing KPAC’s approach. “I kind of liken us to the old Western style, Ronald Reagan thing,” he said, and added, quoting John Wayne, “Courage is being scared to death and saddling up anyway.”
Another motivation was not wanting to fall behind the times. “We didn’t want to have a plaque that says, ‘The last conventional refrigeration system in California,’” he said. “We wanted to go in a new direction, and [low-charge ammonia] looked like the way to go – the way of the future.”
The original version of this article, in the March 2018 issue of Accelerate America, can be found here