Hyper U in Porto Vecchio chooses R-455A to optimise the total cost of ownership of its refrigeration system

We head to the beautiful island to discover this first hypermarket installation built using R-455A entirely, a refrigerant with a very low GWP (146) distributed by Climalife and produced by Honeywell.

With a surface area of 4,200 m², the Porto Vecchio hypermarket is located close to the coast, attracting 3,000 customers a day, rising to more than 5,000 during the summer months. The shop has undergone a number of renovations over the past twenty years, with extensions and changes in configuration depending on the retailer, while retaining its R-404A direct expansion refrigeration units.

Faced with the F-Gas III regulations and restrictions on the marketing of equipment and products, the issue of replacing the refrigeration systems came up very quickly when the Hyper U chain bought the shop in 2023. The new owner, Eric Cascio, and his manager Franck Marrot, advised by their installer Mecafroid, were well aware of this problem when drawing up the specifications for the refurbishment of this superstore.

Renovation work on the hypermarket’s layout would also be carried out to bring it into line with the U concept and current consumer trends.

The “market” style had to be reflected in the fresh produce area, with the fruit and vegetables, butcher’s, delicatessen, pre-prepared meals and cheese areas enlarged to improve circulation in the space. In order to meet regulatory requirements, and, above all, reduce the hypermarket’s electricity consumption which amounts to more than €200k a year, the enclosing of units with doors was also a key part of the refurbishment.

The Nîmes-based consultancy Garcia was asked to study the possibility of changing the refrigeration system and to propose a new alternative to R-404A.

The choice of technology

Choosing a refrigeration system has become a strategic decision in terms of environmental and financial impact for supermarket chains. Different architectures are being considered to cover refrigeration needs.  A transcritical CO₂ system option was quickly ruled out by the parties involved, even though they were already used to using R-744 on other projects.

« Given the shop’s location in southern Corsica, the energy performance of the CO₂ system could be compromised » points out Paul Trojani, head of Mecafroid. « Indeed, installing a CO₂ system in a hypermarket where summer temperatures can be very high is still complicated today, and has not been fully understood when you look at the feedback from existing similar installations, » explains Eric Cascio, who already owns a Super U in Sainte Lucie and a Marché U in Sagonne.

And when it comes to emergency maintenance, the island’s specific conditions don’t really lend themselves to it, not to mention the increased energy requirements during the summer months with the influx of tourists.

The alternative is to use synthetic refrigerants with a very low environmental impact, while keeping investment (CAPEX) and operating (OPEX) costs under control and ensuring the reliability and safety of the refrigeration system.

R-455A: the winning combination against CO₂

Ultimately, the choice fell to a 61 kW direct expansion plant equipped with 5 Bitzer compressors for low-temperature cooling and a chilled water loop for medium-temperature cooling with two AF-Energy chillers of 150 kW per unit, all using Solstice® L40X, a mildly flammable refrigerant (A2L) designed for new low- and medium-temperature installations. With a very low GWP, R-455A is an F-Gas III-approved long-term solution. And its refrigeration capacity close to R-404A, high energy efficiency, high critical temperature and low critical pressure make it an ideal choice for this commercial refrigeration application. What’s more, Solstice® L40X is easy to install and maintain, making it accessible to all technicians, a significant advantage when it comes to responding to emergencies.

An ambitious project in a very short space of time

At the end of December, the order was signed and the work had to be completed in seven weeks, with a mandatory reopening date of 26 February 2024 to meet the owner’s wishes. The entire installation was designed by Savoie-based refrigeration equipment manufacturer AF Energy, which also specialises in regulation and supervision for supermarkets.

The two chillers, each containing 108 kg of R-455A, produce continuous cooling for greater reliability and supply a common 2,000-litre storage tank with two secondary pumps per circuit, one for the medium temperature cold rooms and the other for the Exkal medium-temperature display cabinets, all with a common return. The glycol water network is charged with 9m3 of Friogel® Neo -18°C, a refrigerant produced by Climalife for a -4°C / -8°C operation. The choice of the water loop offers the advantage of being able to modulate the layout of the shop if necessary and, above all, to reduce and confine the refrigerant charge in the machine room, which simplifies the search for leaks, points out Stéphane Chapuis, the Mecafroid technician in charge of managing this project. Danfoss three-way valves have been installed on each piece of equipment for greater flexibility in the event of a line failure. This also means that the display cabinets can be converted into dry sales units during the winter, when there is less need.

The low temperature plant operates at -32°C / +45°C with a charge of 215 kg of R-455A and supplies Carrier display cabinets and low temperature cold rooms.

A fixed detector has been installed in the machine room to comply with regulations. The plant’s noise level has been reduced by limiting the roof-mounted condensers to 80% and by fitting the machine room with a sound trap to protect the neighbourhood. Heat recovery from the refrigeration units has not been implemented, as recent roof top units provide heating and air conditioning for the hypermarket.

All those involved in the project are very pleased with the choice of architecture.

Even with high outside temperatures, the coefficient of performance remains good, the risk of goods being lost is minimised and the water loop solution has no impact on energy consumption compared with a CO^₂ system, concludes Mohammed Youbi Idrissi, Technical Leader EMEA at Honeywell, who explains that secondary refrigeration generally offers two advantages: even distribution of the refrigerant in the refrigeration exchangers and much lower energy consumption for defrosting.

Eco-efficiency simulation for Hyper U in Porto Vecchio

Eco-efficiency modelling confirms choice of new Hyper U architecture and Solstice® L40X refrigerant

Assuming a refrigeration system lifetime of 10 years and an annual leakage rate of 15% for the different architectures, the total cost of ownership (CAPEX + OPEX) is lower than for a CO₂ transcritical system. The financial gain is close to €200k. The environmental impact is also reduced. Solstice® L40X is a durable, high-performance F-Gas III-approved refrigerant.

From left to right: Stéphane Chapuis, Technician at Mecafroid, Mohammed Youbi-Idrissi, Technical Leader EMEA at Honeywell, Eric Cascio, Owner and Franck Marrot, Manager of Hyper U in Porto Vecchio, Paul Trojani, Director of Mecafroid, Daniel Dias, Business Development Manager at Climalife.

Description of the new installation with Solstice® L40X (R-455A)