Makro South Africa chooses CO2 and Ammonia for its new stores

By team, Nov 24, 2010, 13:12 2 minute reading

Citing the efficiencies of CO2 and ammonia based refrigeration, Doug Jones, Financial Director of Makro SA, announced the development of the Makro Polokwane, a 15,000sqm store slated for opening in the latter half of 2011, which will employ an advanced CO2 and ammonia refrigeration plant.

Makro Polokwane will be the 15th Makro store in South Africa and like its recent peers, will employ efficient refrigeration solutions, utilising a CO2 and ammonia refrigeration plant instead of ozone-depleting refrigerant gasses.

"While this increases our installation costs, it is an investment in the environment and the gasses used are 100% natural with zero ozone-depleting and global warming potential," says Mr. Jones. Regarding the choice of natural refrigerants, he added, “The chain purchased the most efficient refrigeration solutions possible.”

CO2 the refrigerant of choice for South African stores

In addition to the Makro Polokwane store, new Makro stores at Vaal (Vanderbijlpark) and Silver Lakes have utilized advanced refrigeration solutions.

Makro Vaal will use CO2 and ammonia in its refrigeration plant instead of ozone-depleting refrigerant gasses. This will not only consume just half of the energy required by traditional refrigeration processes, but will also use sophisticated technology to reclaim all heat generated by the refrigeration units to heat hot water geysers.

Refrigeration specialists Dave Spence and Mike Holt are working on Makro Vaal’s refrigeration plant. Holt says, “Makro has chosen CO2 and ammonia even though the total installation is 21% more expensive when compared to a traditional installation. The refrigeration gasses used are 100% natural and have a zero ozone-depleting (ODP) and global warming potential (GWP) rating.

“What’s more,” says Holt, “gasses like R134A have a coefficient of performance (COP) of 2.16. Makro Vaal’s CO2 and ammonia refrigerants have a COP of 2.48. This means we’ll get more energy out of these gasses.”

Refrigeration plant to also provide heat

Hot water for the store’s washrooms and the canteen kitchen is produced without the use of electricity. Heat from the refrigeration plant is reclaimed and used to heat water, saving the store another 15 kW of electricity.

The store’s trading floor will also be heated via hot water that is warmed by heat reclaimed from the refrigeration system. This will have an electricity savings of 385 kW.

For Makro Silver Lakes, by using Danfoss electronic expansion valves throughout the system they were able to achieve extra efficiency by incorporating a floating condensing control. Due to noise restrictions all the condensers are speed controlled and selected at a maximum of 660rpm and based on an ambient of 36 degrees.

The overall refrigeration efficiency has been increased by approximately 25% when compared with the normal refrigeration system using standard expansion valves.

Among the suppliers for the Makro Silver Lakes store were Danfoss (electronic control system) and Bitzer (compressors).


By team (@r744)

Nov 24, 2010, 13:12

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