Researchers at Jaume I University experimentally evaluated propylene (R1270) as a drop-in replacement for propane (R290) in a plug-in chest freezer. Pull-down and 24-hour static tests used four fixed-speed compressors and one variable-speed compressor designed for R290, with the study focusing on pull-down time and electrical energy consumption. ssrn-7441888
Tests were conducted at 25°C and 60% relative humidity. The optimized refrigerant charges were 130 g for R290 and 140 g for R1270. Both refrigerants are classified A3, and the paper reports GWP100 values of <<1 and zero ODP for both.
With the variable-speed compressor, R1270 reduced pull-down time and energy consumption by 50.4% and 42.1%, respectively, when the criterion was reaching the inner-air temperature associated with ON/OFF regulation. When the criterion was an average product temperature of −22°C, however, R1270 required 11.5% more time and 9.6% more electrical energy than R290. Its 24-hour energy consumption was 1.72% higher.
For equal-displacement fixed-speed compressors, R1270 reduced pull-down time and energy consumption to the air-temperature criterion by 40.8% and 33.6%, respectively. At the −22°C average product-temperature criterion, improvements were obtained only with the comparable lower-displacement compressor, reducing time by 10.4% and energy consumption by 4.7%. Average 24-hour energy consumption was 2.13% higher with R1270 for the fixed-speed compressors that met the test conditions.
The researchers also compared an R290 fixed-speed compressor with an R1270 compressor one displacement step lower. In this configuration, R1270 reduced pull-down time by 15.3% under the ON/OFF criterion and 11.9% under the product-temperature criterion, while energy consumption fell by 16.0% and 12.5%, respectively. During the 24-hour static test, electrical energy consumption decreased by 3.6%. The authors conclude that R1270 can provide performance benefits when compressor displacement is appropriately selected for the operating conditions and system design.
