In follow-up to the document that Tecumseh issued in October 2014 regarding recommended refrigerants, the company has continued to test various low GWP refrigerants with the objective of determining suitable replacements for R404A (globally) and R134a (primarily for North America). The effect that HFO refrigerants have on compressor reliability is of extreme importance to Tecumseh. As previously reported, some HFO blends have been ruled out due to the higher discharge temperatures and negative impact on compressor reliability and life.
Tecumseh Updated Recommendations
For self-contained commercial refrigeration equipment with capacities less than ½ HP, Tecumseh continues to support HC refrigerant R290 (Propane) as the preferred choice. Based on our testing and experience, R290 delivers anywhere from a 10% to a 45% improvement in efficiency when compared to R134a. However, because R290 is classified as an “A3” (highly flammable) refrigerant, charge limitations and safety requirements must be taken into consideration. Typical applications for R290 include beverage coolers, reach-ins, vending equipment and, commercial refrigerators and freezers.
With the exception of the United States, where the U.S. EPA has issued a proposed rule for the early phase-out of R134a, medium temperature applications with capacities up to 30 HP can utilize refrigerant R134a as a mid-term solution. In fact, Tecumseh currently offers a wide range of compressors and condensing units that are optimized for R134a.
HFO refrigerant R1234yf is also a viable alternative for R134a. However, the trade-off comes in the form of reduced capacity (approx. -5%) and lower efficiencies (approx. -10%) in comparison to R134a. With lower condensing temperatures, R1234yf does exhibit better performance than R134a. It is also important to note that R1234yf is classified as an “A2L” refrigerant meaning that it is mildly flammable and therefore subject to charge limitations.
For medium and low temperature applications ranging in capacity from ½ HP and up to 30 HP, HFO refrigerant R452A (GWP 2140) is an interim solution for R404A. R452A offers a 45% reduction in GWP vs. R404A (GWP 3922), is classified as an “A1” refrigerant (not flammable and no charge limitations) and, uses the same lubricating oil (I.e., POE oil) as R404A. Testing has confirmed that refrigerant R452A provides nearly the same capacity and efficiency as R404A across an evaporating temperature range of -25C to -10C (-13F to +14F). However, for evaporating temperatures below -25C (-13F), R452A exhibits a slight reduction in capacity (up to 9% capacity drop at -35C / -31F). At a high evaporating temperature (-10C / +14F), R452A shows an efficiency increase of up to +5% in comparison to R404A.
With reference to the above mentioned performance test data and in conjunction with the low discharge temperatures, Tecumseh recommends the use of refrigerant R452A as a mid-term solution in medium and low temperature commercial refrigeration applications. The low discharge temperatures exhibited by refrigerant R452A are extremely important to Tecumseh mainly due to our experience with hermetic compressor reliability.
OEM customers interested in obtaining R452A compatible compressors for performance and/or field test samples should contact their Tecumseh sales representative. In parallel, Tecumseh is evaluating the availability of R452A compatible compressors and condensing units via our network of authorized wholesaler distributors with a tentative launch date of early 2016.
Tecumseh is continuing to devote resources in evaluating its products for use with low GWP refrigerants including, the determination of a sustainable long-term solution. We are also continuing to evaluate other interim solutions for R404A where there are opportunities to deliver higher compressor efficiencies without sacrificing product reliability.
Tecumseh’s new AE² and AJ² series commercial refrigeration compressors are optimized for use with eco-friendly R290 (Propane) refrigerant. Some AE² models and the new AJ² range are optimized for use with HFO refrigerant R1234yf. The entire range of Tecumseh fractional HP compressors is compatible R134a. All “Next Generation” Tecumseh commercial refrigeration compressors, including the AEX, TC and AK2 series are being designed for use with the best available eco-friendly refrigerants.
Tecumseh sources say the company has the interest of its customers and the environment in mind, as evidenced by its promotion of eco-friendly refrigerants that don’t have an adverse effect on product reliability. Another key stated company objective is to limit the number of medium term refrigerants that can work across its product range and within commercial refrigeration operating temperatures. In addition, Tecumseh sources say it continues to work in conjunction with industry associations AHRI and ASERCOM and affiliated member companies in the evaluation and testing of Low GWP refrigerants.