As part of its plans to refurbish its stores and mindful of the European F-gas regulations, Mega Image through its technical manager, Vasile Casian, contacted Climalife to develop a range of thermodynamic models to compare R404A with various lower GWP refrigerants. R407F, R448A and R449A – all in different types of configurations – were considered.
The company’s aim was clearly defined: to find a fluid with a lower GWP, reduce electricity consumption and optimise the efficiency of its equipment.
Founded in 1995, Mega Image is Romania’s leading supermarket chain, with a network of 410 local stores across the country, bearing the trade names of Mega Image, Shop & Go and AB Cool Food. It is part of the Belgian Delhaize Group.
Bogdan Toma, Climalife’s development manager in Romania, worked alongside Mega Image to aid its initiative, and called upon Climalife’s technical support to deliver the most appropriate solution.
The refrigerant R448A, sold by Honeywell as Solstice N40, was subsequently chosen as the best option for low temperature systems.
Within the operating range covered using R404A, and compared to the alternatives, the discharge temperature measured with R448A proved to be lower for low-temperature applications, thus reducing operating costs and the amount of energy consumed.
A small supermarket of 200m² in Obor, close to the centre of Bucharest, was chosen for the first conversion, which was carried out by Bucharest-based contractor Frigotehnics. The R404A refrigeration unit was mainly supplying the frozen food cabinets in the store and the frozen storage facility in the back room.
To avoid disrupting the company’s sales activity, the conversion was performed one evening after the shop had closed. The frozen products were placed in refrigerated cabinets before the work began on a mild June evening. For food safety reasons, the team had to work very quickly. The first step involved removing the 45kg of R404A from the system. The filters and used oil were then replaced and the Solstice N40 was charged into the system.
The entire conversion was completed in four hours without disruption to the stores opening hours.
The system with R448A is now said to be operating more efficiently than when using R404A.
“The advantage of R448A is that it can be used directly as a drop-in replacement for R404A, without changing any equipment,” said Pierre-Emmanuel Danet, technical support manager at Climalife.
“R448A has similar pressure requirements to those of R404A (equivalent LP and slightly higher HP (+1b)), but its cooling capacity is 10% higher on average, and its coefficient of performance is 6% better in comparison,” he added.
Switching to a refrigerant with a lower GWP (1,387 in the case of R448A) means that Mega Image can continue to operate R404A equipment and still comply with F-gas requirements prohibiting solutions with a GWP greater than 2,500 and reduce global energy consumption to lessen the impact on global warming.