Projects
Jared Nel, IT Specialist of Mainstream Refrigeration explains the
PMS to delegates of the Kigali Amendment (KA) Workshop.
Each CO 2 rack has six Frascold semi-hermetic compressors
– four medium temperature/parallel and the smaller two
on low temperature.
JOURNEY TO GREEN COOLING
The conversion to CO 2 refrigeration plant is in line with the policy
of Woolworths to have all new supermarket refrigeration systems
charged with CO 2 and have the lowest energy usage.
The refrigeration plant has two similar trans-critical parallel
booster racks designed, manufactured and installed by Mainstream
Refrigeration. The swing to CO 2 from HFCs started at a slow pace
in 2008 with cascade subcritical systems. Although not the first
in Woolworths, Mainstream Refrigeration installed a sub-critical
CO 2 /R134a plant at the new Woolworths store in Palmyra Junction
in 2010. The plant is still operational and in 2013, Mainstream
Refrigeration installed a trans-critical plant at the new Waterstone
store in Somerset West. To reduce energy usage further, a trans-
critical parallel booster CO 2 plant was installed in 2016 at the
Woolworths Cascades store in Pietermaritzburg.
Mainstream Refrigeration have installed in excess of 42 trans-
critical CO 2 sites for Woolworths in Richards Bay, Bloemfontein,
Pietermaritzburg, Durban and Cape Town. Commercial
Refrigeration have installed the many trans-critical plants at all
the new Woolworths stores in the densely populated Gauteng and
Northern regions.
Low Temperature cabinets have double glazed glass doors
with heaters.
Alex Kuzma, head of engineering services, Woolworths Real
Estate Department guided KA delegates during the site visit
Natasha Kochova from UNIDO alongside back up cylinders of CO 2 .
With the very low incidence of leaks, not much back up supply of
CO 2 is kept on site.
www.hvacronline.co.za
Each of the racks at the V&A can handle 75% of the
refrigeration load of the 37 medium temperature (MT)
(2 to 4 o C),display cabinets, 5 low temperature (LT)
(-25 o C) cabinets, three back up cold stores (2 to 4 o C), two
freezer stores (-25 o C) and a holding store (2 to 4 o C) at the
receiving bay on the ground floor.
RACA Journal I March 2020
53