The Refrigerant Revolution, Part I: Hydrocarbons Get Hot

On the heels of the European Union's (EU’s) F-gas regulation, the recent EPA proposal for new climate-friendly refrigerants, first and foremost, reinforces the importance of and need for a planned, orderly global phasedown of HFC refrigerants. The proposal also harbors performance and efficiency benefits for equipment, but identifies a need for the acceleration and adoption of revised fire and building codes. 

Commercial Applications
For commercial refrigeration applications and, specifically, self-contained equipment, EPA’s proposal will essentially push the market toward the broad use of hydrocarbons – and there are performance gains. Moving to R290 (propane) in these applications has proven to result in increased equipment performance. For example, when the compressor, thermostatic expansion valve, and heat exchanger are developed for R290, the system can see a 10 to 25% improvement in energy efficiency. As a flammable refrigerant, the safety challenge of R290 is more prominent in retail standalone display cases that use larger internal volume heat exchangers, such as oversized evaporators or condensers, to meet the 150g charge limit. Smaller self-contained systems — such as equipment used in restaurants and small household systems — that use R290 and meet the 150g charge limit do not pose any significant concerns during installation; however, care should still be taken when servicing and designing this equipment.

Residential Applications
In room air-conditioning units, R32 and R32/R1234yf blends are viable future refrigerant solutions. As the high-pressure, high-capacity portion of R410A, R32 typically can result in a modest 3 to 5% capacity improvement and similar efficiencies without any major system modifications. The benefit of switching to R32 from R410A is further increased if the compressor and heat exchangers are designed for using R32. The design concern in switching to R32 over R410A is its flammability and the discharge temperatures; however, some of the R32/R1234yf blends could help reduce the discharge temperatures. 

For the industry, the effect of the proposal should be, in part, two-fold. First, there needs to be an acceleration and adoption of revised fire and building codes to ensure safety in applications using mildly flammable and flammable refrigerants. Second, by de-listing some of the current higher-GWP HFCs for the direct R22 retrofit market, it could mean a simplified R22 retrofit refrigerant choice for equipment owners and contractors, as the number of potential HFC refrigerant alternatives is significantly reduced in supermarket applications.

Broadly, the proposal dictates an urgent need for industry’s proven solutions for hydrocarbons, revised natural refrigerants, and other low-GWP refrigerants to be made commercially viable.

Jeff Staub is application engineering manager for Danfoss. He can be reached at [email protected].