Freezer with Variable-Speed R290 Compressor Found to Use 41% Less Energy than Fixed-Speed Unit

In a study conducted by Brazilian manufacturer Embraco (a brand of Nidec Global Appliance) and Italian OEM EPTA Refrigeration, a vertical ice cream freezer using a prototype variable-speed propane (R290) compressor was found to use 41% less energy than a reference cabinet using a fixed-speed (on/off) R290 compressor. 

The study was described at the ATMOsphere Europe conference held online September 28-29. The conference was organized by ATMOsphere (formerly shecco), publisher of Hydrocarbons21.com.

The freezers in the study were supplied by EPTA, while the compressors were provided by Embraco, including an FMFD413U variable-speed “Smart Drop-in” unit. The Smart Drop-in compressor, which uses an on-off thermostat, is an “easy replacement of an on-off compressor,” and can be customized for an appliance, said Marino Bassi, Key Account Senior Advisor at Nidec Global Appliance, in his presentation at ATMOsphere Europe. 

Embraco’s FMFD compressors can achieve a maximum displacement of 15cc,  equivalent to 21cc due to the high-speed feature. They are also bivolt, operating at 110V or 220V 

While the efficiency of retail display cases can be improved with e-glass, insulation and other measures, the biggest contribution comes from the compressor,” said Bassi.

The 41% energy reduction would allow the vertical freezer to upgrade from a C to a B label in the European energy-efficiency labelling system. 

“This result shows that the commercial refrigeration industry can deliver great energy savings to retailers and, consequently, a better total cost of ownership, with the migration from fixed-speed compressors to variable speed,” said Bassi.  ”We believe that variable speed adoption is inevitable in order to cope with upcoming efficiency requirements.”

“We see an increasing customers awareness regarding energy label ratings, added Marco Solimeo, EPTA Research & Development laboratory manager, who shared the presentation with Bassi. 

Study of horizontal freezer with R600a

In the same presentation, Embraco and EPTA discussed another study with horizontal ice-cream freezer/merchandisers, comparing a unit with a fixed-speed isobutane (R600a) compressor with units using a variable-speed R600a compressor. The best result achieved was a 24% energy savings, using Embraco’s prototype FMX compressor. 

“In merchandisers, the adoption of variable-speed technology is still at a very low level,” said Bassi. “We wanted to show with this case study the excellent results in terms of energy efficiency using Embraco variable speed ‘entry-level’ compressors, which can pave the way for the adoption of variable-speed technology as a standard solution for merchandisers.” explains Bassi.

According to Bassi, hydrocarbons are used in 72% of all plug-in commercial cabinets in 2021, with a projected increase to 82% in 2025 and 95% in 2030. In addition, among hydrocarbon compressors used in plug-in cabinets, variable-speed units have a 15% share in 2021, with a projected rise to 30% in 2025 and 50% by 2030.

In June, Nidec Global Appliance  announced that it will invest US$70 million in new production lines for its Embraco brand compressors and condensing units, including propane (R290) and isobutane (R600a) models. 

Want to find out more, or have something to say about this story? Join the ATMO Connect network to meet and engage with like-minded stakeholders in the clean cooling and natural refrigerant arena.