FEATURE
INCORPORATING COLD CHAIN
Consider installing mobile racking to ensure that the size of the cold
store is minimised for the pallet holding capacity with the subsequent
reduced running costs associated with a smaller cold store.
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Updated and correct qualifications
are a must.
Ensure that the correct design is done
for what is required to be output of
plant.
No shortcuts.
Make sure you account for more than
enough capacity.
Don’t compromise on insulation.
Understand the mandate.
Always maintain a clear space between the rack frames and the
loaded pallets as well as between the pallets themselves.
owner must do their homework on the
contractor’s track record and their client
base – not simply consider the price for
the installation.”
“Energy savings vs price is a major
challenge,” Ford says as well. People
generally want the most efficient plant but
have a very tight budget, and the more
expensive units are cheaper to run and
have a high return on investment. “The
cheaper system may not offer long-term
running and energy savings. Clients want
a Rolls Royce for the price of a Citi Golf.”
La Grange adds that often good
solutions aren’t considered because it
cannot be done in the short time frame
allocated.
The electrical supply available on the
planned site is becoming more relevant
too, according to La Grange. Expanding
the electrical distribution network requires
long-term planning in most cases. Existing
industrial sites often have a very big supply
connection, without the need to upgrade
to a very costly new distribution network. In
some cases customers pay for transformer
upgrades at huge cost before considering
a more energy efficient system. “Good
empirical evidence can help many a
customer not make that mistake. Electrical
upgrades are very costly,” he says, and
can cause major delays.
Another challenge is designing a
system that can match the part load
conditions closely as well as the full load
conditions required, says La Grange,
“the goal being to match the cooling
demand closely with what the system
can supply”. The variables are the cooling
load as well as the ambient conditions
where the facility would be built. Ambient
conditions influence the heat load
calculations and the system’s condensing
conditions. Should the selected solution
use an evaporative condenser, the
relative Humidity RH and Wet WB across
the seasons needs to be factored in
thoroughly, he advises.
Ford adds that it can be tricky satisfying
customer needs and incorporating
those needs into a practical design.
“Sometimes the customer wants one thing
but the product being stored has other
requirements.”
But the challenges aren’t just the cold
store’s refrigeration equipment – but also
the operation, explains Merrick Smith of
Pro Active Refrigeration. “Typical cold
storage rooms are high and workers are
required to work at height with lifting
equipment and relevant safety gear.”
“The greatest challenge is making sure
that the fruit is on temperature and all
procedures are being followed, and the
safety of all people on site,” explains
These are Smith’s tips:
• Make sure that piping and equipment
are kept dry and clean when being
stored while waiting for installation.
• Ensure that pipe insulation is glued
and joined correctly.
• Ensure that free air movement is
allowed for around all insulated
piping.
• Ensure piping is installed so that
effective oil return to the plant occurs.
It’s never quite as easy as it looks – every
project has its challenge. The budget
definitely has a big influence on much of
the decision-making, so that is often a big
challenge, explains La Grange.
Van der Merwe agrees. “Low pricing
combined with marginal equipment
selections and non-compliance with
current legislation will always offer a
favourable price to the owner. This will
often result in a system not achieving the
desired operating conditions.” The owner
cannot see the final product, they can
only see a price on a quotation and must
make a decision without understanding
the effect of their decisions. “The
CHALLENGES
With the dock leveller outside the building which is closed by a properly insulated and sealed sectional door, the amount of air exchange that
takes place during loading is limited.
COLD LINK AFRICA • July/August 2019
www.coldlinkafrica.co.za
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