Belgian retailer Delhaize, part of the Ahold Delhaize group, has installed an evaporative cooling system on existing air-cooled gas coolers serving transcritical CO2 systems at more than 100 corporate stores, effectively turning the gas coolers into energy-saving adiabatic systems.

The evaporative cooling system, called the chillBooster, from Italian component manufacturer Carel, consists of a cabinet with a pressurizing pump (10bar/145psi) and a system of nozzles mounted onto steel manifolds around the condensing unit.

Delhaize installed the chillBooster retrofits in response to a series of heat waves during the summer of 2019, which caused refrigeration performance issues at some Delhaize stores. “In addition to an overall decline in the performance of cold rooms and refrigerated showcases, the higher temperatures caused several units to shut down, with a consequent loss of the goods on display and, in some cases, forcing the stores to close for a few days,” said Carel in a statement.

By installing the Carel units, Delhaize sought to “limit the heat peaks during the heat wave,” said Marc Verleyen, Delhaize’s Manager for Technics & Equipment.

Adiabatic condensers are designed to spray water to cool the air when ambient temperatures run high, thereby improving the efficiency and performance of transcritical CO2 systems at those times. In the summer the chillBooster can bring reductions of around 10-15°C (18-27°F) in condensing unit air inflow temperature, Carel said.

The chillBooster system was installed on 120 gas coolers in supermarkets throughout Belgium, said Carel, adding that the flexibility of the system made it possible to adapt it to the  different needs of more than 100 systems. The retrofits enabled the existing units to “meet the original design requirements again, saving energy and bringing an immediate benefit in terms of efficiency,” said Carel.

According to Verleyen, an adiabatic system is now a standard option in all Delhaize stores.

Delhaize Belgium has around 900 stores, of which 140 are operated by the company itself, and the rest by affiliates who invest their own money in the stores (as opposed to franchisees). In the stores operated by Delhaize, 75% are now converted to CO2 refrigeration. The converted stores have, on average, experienced a 15% drop in energy consumption.

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