Torad Engineering has tested a new 40-tonne spool compressor designed specifically for medium-pressure refrigerants such as R134a, as well as low and ultra-low GWP refrigerants such as R513A and HFO-1234yf. The US firm’s new spool compressor has demonstrated improved efficiency and performance characteristics compared to scroll, screw and magnetic bearing centrifugal compressors. The technology is targeted toward commercial chillers with compressor capacities under 100 tonnes, where the spool compressor has a cost advantage over legacy compressors. Financial support for the project came from five leading global manufacturers of commercial compressors and air conditioning chillers.

“Closed cycle testing of the prototype spool compressor proves the technology is an attractive alternative to legacy compressors utilising medium-pressure refrigerants,” said Joe Orosz, Torad’s chief operating officer.

“The spool compressor’s excellent performance at both full-load and part-load chiller conditions combined with its low manufacturing cost provides a viable path to affordable, high-efficiency chillers.”

According to Greg Kemp, Torad’s founder and chief executive officer, “worldwide regulatory groups have made it pretty clear that ultra-low GWP refrigerants (GWP < 10) will be mandated in the future, the only real question is how soon. The air conditioning industry is facing a genuine challenge regarding the delivery of ultra-low GWP air conditioning products that are more energy efficient while at the same time being affordable. Torad’s spool compressor has the potential to help meet these challenges.”

“With only four key components that are easily manufactured on cost-effective machine tools, the spool compressor is positioned to dramatically change the air conditioning and refrigeration compressor marketplace by delivering significant cost savings to OEMs. The spool compressor’s unique design enables it to scale and be easily configured across a broad range of compression applications. Compared to most legacy compressor technologies, the spool compressor is smaller in size, lower in weight, and easier to manufacture, yielding a significantly lower overall cost,” the company said.

Torad’s spool machine technology holds the promise of breakthrough cost and efficiency advantages for energy conversion applications that are ubiquitous to modern society.