It’s hard to fault the new Johnson Controls’ YORK YZ Magnetic Bearing Centrifugal Chiller. Released globally in September 2018 and now available in South Africa. it brings together ground-breaking YORK innovations refined over decades of real-world use to deliver the world’s first chiller fully optimised to use the next-generation low-global warming potential (GWP) refrigerant—R-1233zd(E) and rated ‘the world’s most efficient chiller’—a claim you don’t make without strong proof.

“Johnson Controls has pulled out all the stops to achieve this accolade. The York YZ, which provides cooling capacities of between 800kW and 3.5MW, is truly the most advanced and energy efficient solution in its class. I believe it will achieve a strong uptake among organisations that are focused on energy efficiency and greener refrigerants, driving down operating and lifetime costs, and maximising their investments,” says Johnson Controls’ Russell Hattingh.

Annual energy savings: 35% 

Johnson Controls used a holistic approach to the system’s design and engineering, optimising every component around the low GWP refrigerant for ultimate performance. The chiller uses an integral, variable speed drive and advanced magnetic bearing technology that features a single moving assembly suspended in a magnetic field that does not require lubrication. This technology requires significantly fewer moving parts than traditional oil- or refrigerant-lubricated drivelines. 

“The result is enhanced reliability, reduced maintenance and improved efficiency,” notes Hattingh. “And if you want to quantify that, compared to traditional fixed-speed oil-bearing chillers, the YZ delivers up to 35 percent annual energy savings. That’s a huge saving when you consider that the initial cost of the chiller is only a small fraction of the life cycle operating energy cost.” 

The energy savings and lower operating costs the YZ chiller delivers are achieved by taking advantage of the off-design conditions where chillers operate 99 percent of the time. The YZ operates with entering condenser water temperature as low as 4.5°C, providing enhanced performance in every operating condition and the widest operating envelope in the industry. 

The chiller can also operate with condenser temperatures below the evaporator temperatures, eliminating the need for a water-side economiser, which simplifies the system, requires less mechanical room space and saves money on components, piping, controls and maintenance.

The YZ’s magnetic bearing technology deserves some attention—it delivers extraordinary reliability and radically simplified maintenance, which translates into massive cost savings.

Magnetic savings: 

With just a single moving assembly levitating in a magnetic field, the driveline in the York YZ doesn’t require any lubrication and has 80% less moving parts. The non-contact design of the driveline delivers dramatically reduced maintenance costs over the life of the chiller.