United States. In follow-up to the document Tecumseh issued in October 2014 regarding recommended refrigerants, the company reported that it has not stopped testing several low-GWP refrigerants with the goal of determining suitable replacements for R404A (globally) and R134a (primarily for North America).
For standalone commercial refrigeration equipment with a capacity of less than 1/2 HP, Tecumseh continues to support HC R290 refrigerant (propane) as the preferred option. Based on its testing and experience, the R290 offers a 10% to 45% improvement in efficiency compared to the R134a. However, because R290 is classified as "A3" (highly flammable), its limitations and safety requirements must be taken into consideration.
With the exception of the United States, where EPA has issued a proposed standard for the early phase-out of R134a, medium temperature applications with capacities up to 30 HP can use R134a refrigerant as a medium-term solution.
The company also indicates that HFO refrigerant R1234yf is also a viable alternative to R134a. However, the compensation comes in the form of reduced capacity (approx. -5%) and lower efficiency (approx. -10%) compared to R134a. With lower condensation temperatures, the R1234yf exhibits better performance than the R134a. It is also important to note that R1234yf is classified as an "A2L" which means that the refrigerant is slightly flammable and therefore subject to charge limitations.
For medium and low temperature applications ranging in the capacity of 1/2 HP and up to 30 HP, HFO refrigerant R452A (GWP 2140) is an interim solution for R404A. The R452A offers a 45% reduction in GWP vs. R404A (GWP 3922), is classified as an "A1" refrigerant (non-flammable and no charge limitations) and uses the same lubricating oil (i.e. POE oil) as R404A.
Finally, tests have confirmed that R452A refrigerant offers almost the same capacity and efficiency as R404A across an evaporation temperature range of -25C to -10C (-13F to +14F). However, for evaporation temperatures below -25C (-13F), the R452A exhibits a slight capacity reduction (up to 9% capacity drop to -35C/-31F). At a high evaporation temperature (-10C/14F+), the R452A shows an efficiency increase of up to +5% compared to the R404A.
