Energy and exergy evaluation of R404A and R290 in a shelf-cooled commercial vertical deep freezer

The European Union F-Gas regulation has accelerated the transition from high-GWP refrigerants to environmentally friendly alternatives in commercial vertical refrigeration systems. This study experimentally investigates the use of R290-propane as a replacement for R404A-hydrofluorocarbon in a shelf-cooled commercial vertical deep freezer without modifying external components. While previous studies primarily focused on energy analyses, this research uniquely integrates both energy and exergy evaluations. Experimental results show that the R290 system demonstrated a 7 % higher coefficient of performance and a 17 % increase in exergy efficiency compared to the R404A system, confirming its superior thermodynamic behavior. The total exergy losses in the R290 system were approximately 0.043 kW lower, primarily influenced by enhanced compressor performance, which contributed the most to system irreversibilities. Additionally, the system’s equivalent carbon emissions were reduced by 99.92 %, highlighting its significant environmental advantages. These findings demonstrate that R290 is a highly efficient and sustainable alternative to R404A for commercial vertical refrigeration, offering improved thermodynamic performance, lower energy consumption, and a substantially reduced carbon footprint.