The development of new technologies such as modulating ejectors is helping to improve the efficiency of CO2 transcritical refrigeration systems in warmer climates and consolidating their position as market-ready alternatives to HFCs, especially for supermarket refrigeration, heard participants at ATMOsphere Ibérica conference on natural refrigerants in Madrid on 18 September.
“CO2 has demonstrated efficiency and security: Goodbye to the psychological barrier of the ‘CO2 equator’!,” said Julio Minguillón from Carrier.
“Carrier has installed more than 7,500 transcritical CO2 systems in Europe, and 94 systems in the Iberian Peninsula, for 16 different clients,” Minguillón added.
Boundary conditions like the warm climate of southern Europe had long been seen as a barrier to wider adoption of CO2, limiting the efficiency of these systems.
But Minguillón argued that energy-efficiency solutions such as ejectors are now more available and that prices are falling. To him, “CO2 growth is unstoppable”.
The EU F-Gas Regulation bans the use of certain HFCs with GWPs above 150 in centralised and plug-in commercial refrigeration equipment from 2022. As a result, rising prices of R404A and R507 (which are commonly used in supermarkets) are now driving companies to look for sustainable alternatives.
Diego Ortega from EPTA showed during his presentation the field results of the Full Transcritical Efficiency solution to boost the efficiency for CO 2 transcritical systems. Ortega presented the results obtained in a CO2-based commercial refrigeration installation of 139.5 kW (-10°C) on the medium-temperature side and 34 kW (-35°C) on the low-temperature side in Bologna, Italy.
“The FTE solution has proven higher efficiency compared to a traditional system, even in warm ambient climates,”said Ortega.