UK: A Waitrose supermarket is said to be achieving refrigeration energy savings of nearly 7% following the replacement of R404A with a new HFO-based blend.
The results have been achieved at one of the British supermarket chain’s store in Holsworthy, Devon, using Opteon XP40, Chemours brand name for R449A. This HFO/HFC blend of R32, R125, R134a and R1234yf has a GWP of 1397, which is significantly lower than R404A, the refrigerant it is designed to replace.
As well as needing to comply with the requirements of the European F-gas regulations and forthcoming bans on high GWP refrigerants, Waitrose has been looking for ways to decrease its carbon footprint across all its 336 sites.
Waitrose’s Carbon Plan, published in 2010, identifies the indirect and direct emissions from the refrigeration systems in its shops as a very significant contributor, making this area a prime target for improvement.
Under the European F-gas phase-down, refrigerants with a GWP of 2500 or more will be banned from use in all new equipment and for service in systems with a charge >40T CO2e from 2020. This particularly affects popular supermarket refrigerants R404A and R507A.
Many major compressor manufacturers have now approved R449A for use as an R404A replacement and can be found in their compressor selection software.
The refrigeration system at the Holsworthy store consisted of two high temperature packs and one low temperature pack all of which were manufactured by Space Cooling Systems in 2004. All packs use Copeland Scroll compressors.
The low temperature pack was connected to six in-store cabinets and one cold store. The high temperature packs were connected to a total of 18 cabinets and three refrigerated counters in the store and three cold rooms for storage.
The energy consumption of the refrigeration systems was measured for two weeks before the retrofit and then for three weeks after the retrofit had been completed. ColdService performed the first retrofit overnight on July 12 last year, with the other two packs retrofitted on consecutive nights. No disruption was caused during the store’s trading hours.
The retrofit guidelines provided by Chemours for Opteon XP40 were followed and no components or oil changes were required, making the retrofit very fast and straightforward.
Analysis of the energy consumption data was performed by Emerson Climate Technologies, Retail Solutions, which revealed that at equivalent ambient temperatures during the monitoring period, the high temperature systems energy consumption was reduced by 8.7%. For the low temperature system, the energy consumption was reduced by 3%. For the total refrigeration system, this equates to a reduction in energy consumption of 6.6%.
“No component changes, no oil changes and similar system operating parameters made the retrofit very straightforward and fast once the R404A had been recovered,” commented Paul Blanch, Emerson Climate Technologies, Retail Solutions’ senior manager.
The reduction in energy consumption and the 64% reduction in the GWP by using R449A compared to R404A are seen as providing Waitrose with a significant opportunity to lower its CO2e emissions and help to achieve the target set out in its Carbon Plan.
Danny Ryan, Waitrose’s refrigeration manager, who is leading the overall project, commented: “Reducing our CO2e emissions is a key target and so retrofitting existing R404A systems with a lower GWP refrigerant is a key part of our strategy. Opteon XP40 has helped achieve this by not only reducing the direct emissions of the refrigerant, but also by reducing the energy consumption of the systems.”