International. The existing R404A refrigeration system of a supermarket called Waitrose located in Holsworthy (UK) has been refurbished with R449A refrigerant (HFO/HFC mixture of R32, R125, R134a and R1234yf).
R449A has a fairly high GWP (1397) but significantly lower than R404A's GWP (3922) and meets the requirements of the EU Gas Regulation. The cooling system consists of two high-temperature packages and a low-temperature package connected to 27 showcases and four cold rooms. No components or oil changes were required, which made adaptation very quick and easy.
During the follow-up period – two weeks before adaptation and then three weeks after adaptation – the energy consumption of high-temperature systems was reduced by 8.7%. For the low-temperature system, energy consumption was reduced by 3%. For the total cooling system, this equates to a reduction in energy consumption of 6.6%.
In addition, a paper recently published in the International Journal of Refrigeration presents measurements of a lightweight retrofit replacement of R404A using R449A in a medium temperature indirect cooling system (secondary fluid temperature at evaporator outlet between -9 and -4°C). It shows that with a slight adjustment of the expansion device and a 4% increase in the refrigerant charge, R449A can be used in this cooling system designed for R404A due to its suitable thermodynamic properties and maximum acceptable discharge temperature. At a secondary fluid temperature at the condenser inlet of 30°C, the COP of R449A almost matches that of R404A (both were between 1.9 and 2.2), despite having an approximately 13% lower cooling capacity.
The refrigerants used to carry out the project in the supermarket chain were supplied by Chemours.
Source: International Institute of Refrigeration.
