Spool Compressor Advances Toward Near-Zero GWP Air-Conditioning
Cumming, Georgia — January 10, 2019
The spool compressor is advancing rapidly toward an R410A-free future. Torad Engineering is working diligently to introduce its technology optimized on “future-proof” refrigerant Solstice® ze (HFO-1234ze). “R410A replacements such as R32, R466A and R452B ignore the ultimate reality, mandated near-zero GWP air conditioning. Planet earth does not negotiate, and neither will global regulations. Near-zero GWP will be the mandate,” said Greg Kemp, TORAD Engineering CEO.
As building owners realize that R410A replacements are simply medium-term products, they will reward the AC packager offering them a future-proof, ultra-low GWP solution. Taking into account toxicity, ODP, GWP, flammability, cycle efficiency, operating pressures and cost, TORAD believes the spool compressor utilizing Solstice® ze (HFO-1234ze) from Honeywell is the future-proof solution.
TORAD’s spool compressor with Solstice® ze (HFO-1234ze) has achieved EERs within 2.5% of a similarly operating R410A scroll. TORAD president and COO, Joe Orosz commented “TORAD’s Solstice® ze spool compressor will surpass the EER of similar R410A scroll compressors. Equally important, the Solstice® ze spool compressor can be delivered with a cost structure comparable to the R410A scroll while delivering more than twice the volumetric flow.”
1234ze is a low pressure/low density refrigerant. Thus, to achieve the same cooling capacity of an R410A based compressor the 1234ze based compressor flow rate must be increased 2.5 times. For the compressor manufacturer this means their current R410A, 40 tonR (140 kW) scroll mechanism becomes an 18 tonR (62 kW) scroll mechanism using 1234ze. This also results in decreased compressor efficiency and an obvious increase in cost per unit of cooling capacity.
Over the past two years, Torad Engineering has been developing its Spool Compressor technology specifically for applications using low pressure/low density refrigerants. The spool compressor’s architecture is exceptionally well suited for applications utilizing low density gas due to its high displacement density and low cost to manufacture.
Torad is now testing HFO-1234ze with a 30 Ton (105kW) prototype spool compressor originally designed for use with R134a. No modifications have been made to this R134a prototype to optimize for 1234ze. Test results show the expected reduction in capacity of 22% (based on the lower density of the gas), but a reduction in overall isentropic efficiency of only 1.8% at typical air-cooled chiller conditions. TORAD’s technical analysis projects its next generation semi-hermetic compressor designed specifically for Solstice® ze will surpass the EER of competitive products.
To learn more about the future of air-conditioning and to see semi-hermetic and fully hermetic spool compressor technology designed for use with Solstice® ze, stop by the Torad booth location B2809 at the 2019 AHR Expo
