POV: Tecumseh on the HVACR Refrigerant Transition

Oct. 17, 2014
A number of HFO low temperature alternatives to R404A are showing promise with respect to capacity and efficiency. However, some of the blends have been ruled out due to the higher discharge temperatures and negative impact on compressor reliability and life.        

The refrigerant sector of the HVACR industry is operating in an accelerated state of change. This has been driven primarily by government mandates in the U.S. and Europe, due to concerns related to global warming and ozone layer protection. Original equipment manufacturers — whose many customers have many questions related to refrigerant regulations — have at various times stated their positions on refrigerant preferences. Here is a position paper has received from Tecumseh. —Terry McIver, executive editor

Europe: R-404A Threatened
F-Gas Regulations which were finalized in April 2014, require the phase-out of high GWP refrigerants, starting first with R404A and secondly, R134a.  Production of these refrigerants will be limited before their complete scheduled ban in 2030.

The European Union Ecodesign Directive provides rules for reducing the energy consumption and environmental impact of energy related products (ERPs) and will have a strong impact on system components and their applications.

Consequently manufacturers are faced with two challenges: 1) future refrigerant alternatives and 2) energy efficient product designs.  Both of these challenges will have a significant impact on industry standards and safety agency approvals, as well as qualification of the complete system.

Refrigerant R404A, the industry standard for self-contained commercial refrigeration equipment with capacities >1 HP, is threatened by the F-Gas regulation.  The phase-out of R404A will not only affect new equipment designs but also existing installations where equipment may need to be retrofitted, adapted and/or replaced.

North America: R290 the Preferred Choice
The recent Notice of Proposed Rule (NOPR) issued by the U.S. EPA Significant New Alternatives Policy (SNAP) also calls for the accelerated phase-out of refrigerants R404A and R134a for new and retrofit refrigerated food equipment.  This includes self-contained refrigerated food equipment, as well as remote condensing units.

While the above mentioned rule has not been finalized, there is a good chance that the U.S. will closely follow European F-Gas regulations.

Low GWP Refrigerant Evaluation
Tecumseh has been actively involved in AHRI’s Alternative Refrigerant Evolution Program (AREP), an industry-wide cooperative research program to test and evaluate Low GWP refrigerants.

Tecumseh and other AHRI member companies have spent considerable resources in testing alternative refrigerants.  Results of the first phase of testing were shared in Jan. 2014 at AHRI’s Low GWP conference.  We are now conducting the second phase of testing with the focus being solely on alternatives for R404A.

In addition to benchmarking for capacity and efficiency, the effect that the various alternative refrigerants have on compressor reliability is of extreme importance to Tecumseh. A number of HFO low temperature alternatives to R404A are showing promise with respect to capacity and efficiency. However, some of the blends have been ruled out due to the higher discharge temperatures and negative impact on compressor reliability and life.    

Tecumseh's Recommendations
For self-contained commercial refrigeration equipment with capacities less than ½ HP, most of which are utilizing R134a today, HC refrigerant R290 (Propane) is 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.

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.

For medium and high temperature capacities ranging in capacity from ½ HP and up to 10 HP, HFC refrigerants R407A (GWP 2107) and R407F (GWP 1825) are interim solutions for R404A.  Their moderately high GWP levels and reduction in capacity (-12% to -14% vs. R404A, depending on the amount of superheat) rule them out as long term solutions.  Tecumseh does NOT recommend the use of R407A and/or R407F for low temperature applications primarily because of their negative impact on compressor reliability.

As mentioned earlier, Tecumseh is continuing to test various HFO blends as an alternative for refrigerant R404A.  We are optimistic that one or more of these blends will be within acceptable limits with respect to capacity, efficiency and compressor reliability.  Tecumseh will keep the industry informed or our findings and recommendations.

Tecumseh’s new generation AE² and AJ² compressors are optimized for use with R290.  Some AE² models and the new AJ² range are optimized for use with refrigerant R1234yf.  The entire range of Tecumseh fractional HP compressors is compatible with R134a.

Tecumseh Product Energy Efficiency and Eco-Friendly Refrigerants
“As we mark Tecumseh’s 80th Anniversary in 2014, it’s fitting that we’re again on the forefront of the global refrigerant transition. Tecumseh will continue to invest in the research technology and engineering resources necessary to help all of our customers manage industry change and advances in efficiency and energy use reduction,” says Bill Merritt, Tecumseh global vice president of sales and marketing.