R744 exclusive interview with Alan Walker, Masstores Makro SA
Following Masstores recent completion of two new Makro stores using CO2, R744.com held an exclusive interview with Alan Walker, Store Development Manager for Masstores - Makro South Africa.
Mr. Walker answered questions regarding Makro’s preference for CO2, refrigerant performance in extreme temperature ranges (40 degrees Celsius in summer to around 0 degrees in winter), design and use challenges, as well as insightful technical data on the new units.
R744: Masstores has recently implemented the use of CO2 refrigeration in its new Makro store builds. What was the driving force behind the implementation of CO2 technology?
Masstores has always been acutely aware of the long-term damage caused by HFC/HCFC use. During the last eight years, by using all the most modern electronic controls, variable speed compressors, high efficiency evaporators and floating condensing we have taken traditional refrigeration systems to a high level of efficiencies.
R744: How many stores does Masstores operate currently using CO2 technology? Are there plans for continued application in either refurbishment projects or new builds?
Makro has 2 stores that are using CO2 technology at the moment. We are planning on using CO2 in our future stores. When a total refurbishment takes place, CO2 will be the preferred refrigerant.
We do not believe it is viable to refurbish an existing plant without replacing all the components associated with the system and will only change our existing systems when they have run their normal lifespan. This is especially valid if you only want to use natural refrigerants. One could obviously use some of the existing multiplex systems for the high stage, but what are you really achieving?
R744: What challenges were encountered and lessons learned from the first CO2 installation?
The main challenges were obtaining components which generally have long deliveries and not as readily available as one is lead to believe when visiting trade shows and advertising leaflets. R744: What performance differences have you observed between the old refrigeration units and the new CO2 based solutions? COP? Cost? Maintenance?
Theoretically, the plant should be in the region of 13% more efficient and this is mainly due to the excellent properties of CO2. The plants have only been running for three and a half months and will take at least a year to totally evaluate the system.
R744: Are there specific suppliers/partners you worked with on the CO2 projects?
The basic components are Bitzer compressors, Danfoss controls and Swep heat exchangers.
95% of the piping is stainless steel - which should go a long way to preventing leaks - which is normally one of the biggest disadvantages of a normal system in which copper piping is used. Our main aim will be to use 99% stainless steel when fittings etc become readily available.
We work very closely with Commercial Refrigeration Services with regards to development, design, and installation.
READ THE FULL INTERVIEW HERE
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