FGaz, commercial refrigeration, low GWP, HFO blends, CO2, transcritical condensing units, drop in tests, Seasonal energy perfromance
The European regulation has set a series of limitation to reach the objective of reducing the Global Warming Potential (GWP) emissions. Among these limits, the ban of Hydrofluorocarbons (HFC) refrigerants having a GWP higher than 2500 starting 2020. To replace these refrigerants, a new family of refrigerants was invented: hydro-fluoro-olefins (HFOs), also new systems were developed using CO2. In this paper, we present the outcome of a testing campaign aiming to compare the performance, operating range and cost of two condensing units of a rated capacity of 8kW cooling a secondary glycol loop. One of these machines, initially operated with R-404A, is operated with low GWP blends containing HFO while the other is using CO2. The comparison includes traditional HFC refrigerant (R-404A), 3 different commercial HFOs containing blends and transcritical CO2. The comparison is made using different ambient temperatures to have a fair comparison. A special focus is done analysing the glide impact on the condensing unit behaviour and performance. The glide matching blend (R-454C) shows an increased performance while the other refrigerants are penalized. Finally, HFOs containing blends were found more efficient and capable of operating at a wider temperature range compared to CO2.