A propane (R290)-based variable-speed compressor from U.S. manufacturer Tecumseh meets the requirements of the U.S. Environmental Protection Agency’s (EPA) Energy Star “Emerging Technology” award, according to a recent study conducted by the company.

The findings of the study were presented by Tim Collins, Application Engineer at Tecumseh, during a refrigeration case studies session at the ATMOsphere (ATMO) America Summit 2022 on natural refrigerants. The conference, which took place June 7–8 in Alexandria, Virginia, was organized by ATMOsphere, publisher of Hydrocarbons21.com.

Energy Star presents its Emerging Technology Award (ETA) to “innovative technologies that meet rigorous performance criteria to reduce energy use and lower greenhouse gas emissions.” In 2022, the program added “Adaptive Commercial Refrigeration Equipment” as a new category of equipment that would receive the ETA award. The award goes to a refrigerator unit.

To be eligible, a unit must be self-contained, use variable-speed technology and a refrigerant with a GWP of less than 15, be approved for use in the U.S and outperform the U.S. Department of Energy’s (DOE) measured annual energy consumption standard by 25%. According to Tecumseh, its R290 VCT variable-speed compressor would enable a self-contained unit to meet those criteria.

For the study, Tecumseh analyzed the performance of a 24.1ft3 (0.7m3) single-door bottle cooler using one of its VCT compressors.

With the unit meeting four out of Energy Star’s five requirements – self-contained, variable-speed, refrigerant GWP less than 15 and U.S. approved – the study sought to establish the cooler’s energy consumption when using the VCT compressor.

After conducting the product test, which was done in line with DOE standards as required by Energy Star, Tecumseh showed that its VCT variable-speed compressor outperformed the DOE’s minimum standard for annual energy consumption by 32.3% – 2.21kWh/day vs. 3.27kWh/day, exceeding the 25% threshold. The Energy Star 4.0 limit value is 2.32kWh/day.

Tecumseh’s VCT variable-speed compressor “definitely [meets] the requirements for the new Energy Star award,” said Collins.

The study also compared the performance of the VCT compressor to one of Tecumseh’s fixed-speed model with similar specifications. During the same test with the same bottle cooler unit, Tecumseh’s fixed-speed compressor achieved results of 2.37kWh/day.

In this instance, Tecumseh’s variable-speed compressor reduced the energy consumption of the bottle cooler by 6.8% compared to a fixed-speed compressor.

According to Energy Star, if all self-contained commercial refrigeration equipment sold in the U.S. used an advanced adaptive compressor system – i.e., a variable speed compressor with a sensor-driven control system – and met the initiative’s criteria, the energy cost savings would grow to approximately $31 million each year.

“We are doing more testing, and we plan to get a better result,” explained Collins. “We’re looking [to outperform the DOE standards by] around 40% using different compressor changes and maybe some other configurations. I’m comfortable we’re going to be a lot better results.”

Energy Star’s Emerging Technology Award 2022

The winner of the 2022 Energy Star Emerging Technology Award for Adaptive Commercial Refrigeration Equipment was Beverage-Air/Victory Refrigeration (Ali Group North America – Refrigeration Division). The winning Victory RS-2D-S1-EW-HC refrigerator is driven by a Secop DLV compressor, which uses R290.

“As a recipient of the 2022 ENERGY STAR Emerging Technology Award, the above model is recognized as promising technology that has the potential to significantly reduce greenhouse gas emissions,” said Ann Bailey, Director of Product Labeling Climate Protection Partnerships Division at Energy Star.

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