In follow-up to a document that Tecumseh issued in October 2014 regarding recommended refrigerants, the company said it has continued to test various low global warming potential (GWP) refrigerants with the objective of determining suitable replacements for R-404A (globally) and R-134a (primarily for North America).

“The effect that HFO refrigerants have on compressor reliability is of extreme importance to Tecumseh,” the company said in a press release. “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’s updated refrigerant recommendations are as follows:

“For self-contained commercial refrigeration equipment with capacities less than ½ hp, Tecumseh continues to support HC refrigerant R-290 (Propane) as the preferred choice. Based on our testing and experience, R-290 delivers anywhere from a 10 percent to a 45 percent improvement in efficiency when compared to R-134a. However, because R-290 is classified as an “A3” (highly flammable) refrigerant, charge limitations and safety requirements must be taken into consideration. Typical applications for R-290 include beverage coolers, reach-ins, vending equipment, and commercial refrigerators and freezers.

“With the exception of the United States, medium-temperature applications with capacities up to 30 hp can utilize refrigerant R-134a as a mid-term solution. In fact, Tecumseh currently offers a wide range of compressors and condensing units that are optimized for R-134a.

“HFO refrigerant R-1234yf is also a viable alternative for R134a. However, the trade-off comes in the form of reduced capacity (approximately -5 percent) and lower efficiencies (approximately -10 percent) in comparison to R-134a. With lower condensing temperatures, R1234yf does exhibit better performance than R-134a. 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 R-452A (GWP 2,140) is an interim solution for R-404A. R-452A offers a 45 percent reduction in GWP vs. R-404A (GWP 3,922), is classified as an “A1” refrigerant (not flammable and no charge limitations) and, uses the same lubricating oil (i.e., POE oil) as R-404A. Testing has confirmed that refrigerant R-452A provides nearly the same capacity and efficiency as R-404A across an evaporating temperature range of -25°C to -10°C (-13°F to 14°F). However, for evaporating temperatures below -25°C (-13°F), R-452A exhibits a slight reduction in capacity (up to 9 percent capacity drop at -35°C / -31°F). At a high evaporating temperature (-10°C / 14°F), R-452A shows an efficiency increase of up to 5 percent in comparison to R-404A.¬¬

“With reference to the above mentioned performance test data and in conjunction with the low discharge temperatures, Tecumseh recommends the use of refrigerant R-452A as a mid-term solution in medium- and low-temperature commercial refrigeration applications. The low discharge temperatures exhibited by refrigerant R-452A are extremely important to Tecumseh mainly due to our experience with hermetic compressor reliability.

“OEM customers interested in obtaining R-452A compatible compressors for performance and/or field test samples should contact their Tecumseh sales representative. In parallel, Tecumseh is evaluating the availability of R-452A 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 R-404A 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 R-290 (Propane) refrigerant. Some AE² models and the new AJ² range are optimized for use with HFO refrigerant R-1234yf. The entire range of Tecumseh fractional horsepower compressors is compatible with R-134a. 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 has the interest of its customers and the environment in mind by promoting eco-friendly refrigerants that don’t have an adverse effect on product reliability. Another key objective is to limit the number of medium-term refrigerants that can work across our product range and within commercial refrigeration operating temperatures. In addition, Tecumseh continues to work in conjunction with industry associations AHRI and ASERCOM and affiliated member companies in the evaluation and testing of low GWP refrigerants.”

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