Tesco calls for the use of R744 now

Given its technological, economic and environmental advantages there is no reason to delay the use of CO₂ Technology in supermarket refrigeration, finds the global retailer with sales of US $ 82.4 billion that employs more than 450.000 people worldwide.

The natural refrigerant CO₂ (R744) offers a long-term solution for commercial refrigeration being "future proof" in terms of energy and cost efficiency, environmental performance and safety.

This is the key message from Tesco's latest study presented by Andy Campbell, Head of Refrigeration, on 5 April before the Institute of Refrigeration. Tests with one subcritical cascade and one transcritical system working under real-life conditions in frozen food cabinets demonstrated that both systems have been working efficiently without any failure over the one year test period.

Subcritical cascade systems using R744 in combination with other primary refrigerants lead not only to energy savings of up to 15% compared to conventional R404a cooling cycles, but also reduced the total global warming impact by nearly 60%.

More specifically, the study proved the following:

Energy efficiency: One year tests have demonstrated a higher Coefficient of Performance (COP) for R744 cascade systems compared to systems running with HFCs (hydrofluorocarbons), such as R404a. Due to an improved heat transfer within the heat exchanger and reduced system pressure drop this will significantly reduce indirect global warming emissions.

Cost efficiency: Tesco expects no significant difference in system cost between R744 and R404a technology once serial production has started. On the contrary: The leading retailer foresees a further reduction of running costs if inspections under the upcoming F-gases regulation in the European Union could be avoided by using R744.

Material reduction: Due to its higher cooling capacity in a given volume compressors for CO₂ Technology are 6-8 times smaller than those of R22 systems. In addition, more compact pipe works, valves and heat exchangers will also reduce the material use compared to R404a systems.

Emissions reduction: Due to its higher energy efficiency and its partly use of the low global warming refrigerant R744, Tesco's cascade system lead to a total reduction of 774.2 tons of CO₂ emissions compared to a conventional R404a system within only one year.

Safety: The excellent safety properties of the non-toxic and non-flammable fluid R744 makes it the preferred choice for large refrigeration systems whose pipes run through the customer area.

In view of these encouraging results, Tesco will now expand its range of R744 refrigeration systems to complete the largest supermarket natural refrigerant solution installed in the UK to date. To enable a wide-spread use of CO₂ Technology the company calls on system suppliers and service staff to get familiar with its design and maintenance as soon as possible.