FEATURE
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ventilation. The final aspect of pipe design is
ensuring proper pipe size selection, reduced
risers, oil traps, and pipe run gradient to ensure
that effective oil return to the plant is taking
place, says Smith.
“Commissioning of the system is sometimes
a problem, too,” says Robinson. A system
often gets switched on without being properly
commissioned. “Sometimes there simply
isn’t any time for adequate commissioning
in the construction programme. Proper
commissioning takes a few days and needs to
be done right.”
Kriel agrees that a big problem is not
providing enough time to complete the
process properly and allowing the delays of
other trades to compress the commissioning
period. Problems include not performing an
adequate audit after commissioning and
then making the corrections. Nor ensuring
that the plant performance data gets to the
maintenance supervisor.
MAINTENANCE MATTERS
But it’s not just about the installation;
maintenance is vital, too. Sometimes people
sell a store design that is highly efficient initially,
explains Robinson. But then the different
service companies/technicians change the
system set-up/settings, changing things (often
not making informed decisions). And soon the
system is no longer running efficiently at all.
Sometimes the client doesn’t renew the
service level agreement and gets an in-
house technician to do the maintenance
who isn’t skilled or knowledgeable enough
to do it properly, explains Robinson. Or they
simply hire someone who isn’t necessarily
qualified to work on the system. “You don’t
know what people don’t know. They might
not be keeping up with new technology or
practises. Systems have gotten quite a lot
more complex over the years.”
Repairs, maintenance, leakages, and
managing the human factor is key, says
Breckle. “You need to have a lot of data to
see where the faults are happening and how
to improve this.” But, instead of recording
the data and fixing the problem, sometimes
retailers just push up the price of the goods to
compensate for this. “You need to manage
the basics and get proper data to make
proper plans.”
There is often a problem with not using the
refrigeration system to its full potential, says
Breckle. Even going back to original set points.
“Sticking to design criteria is an issue.”
“Most refrigeration guys don’t do
preventative maintenance; they just put out
fires all the time and fix breakdowns,” says
Breckle. “There is no real servicing, just a lot
of ‘firefighting’. There are no preventative
maintenance plans.”
Sometimes there is a problem with there
not even being a plant room in the design at
all, explains Breckle. Design is very important
and you need the right professional team.
Having an open forum before even starting
construction, adds a lot of value. “Good
planning creates good systems and good
installation and good maintenance. Even
putting the plant room in the wrong place
can be a problem. Sometimes, technicians
cannot get to it easily. Architects don’t always
think about the serviceability of the system.”
“It’s important to build a trust relationship
with the client and installers and assist in
after-sales service and maintenance,” advises
Hanssen.
CONSIDERATIONS FOR SYSTEM
SELECTION
So, which factors should be considered
before designing a specific supermarket
refrigeration system?
“Design should be based around
minimising life-cycle costs and ‘future-
proofing’ the system,” advises Kuzma.
“Running costs must be minimised by
incorporating all the latest energy-saving
technologies and using a natural gas that is
not subject to phase outs and shortages.”
Who your client is will determine what
kind of system you advise, explains Hadfield.
INCORPORATING COLD CHAIN
There is often a problem with store owners focusing more on the inside of their store than on
the plant — sometimes not even leaving space for a plant room at all.
Smaller chains tend to want returns on
investments quicker and won’t go for such
expensive, top-of-the-range installations.
Middle-range to high-end clients can afford
more sophisticated installations and they are
looking for efficiency that will look good on
their balance sheets.
It’s important to ask these three questions,
according to Hadfield:
1. Who is your client?
2. What is the size of the store?
3. Where is the location of your installation?
Kriel agrees with these but adds that one
should also consider the availability of
service and repair contractors. As well as the
availability of spares and refrigerant.
If the location is too remote, there won’t
be the necessary resources to look after a
sophisticated system. Especially for some
installations in remote locations in Africa, it’s
better to keep it basic and simple.
Other than these, Naidoo suggests taking
into account local and international trends
as well as also taking a holistic approach
COLD LINK AFRICA • March/April 2019
and not just focusing on the refrigeration
systems alone.
Here are some very useful tips from Smith
when selecting the refrigeration system: “The
plant area layout is of critical importance,”
he advises. The equipment used in the
design, like compressors, refrigerant, and
components, must be accessible to
the market. “Don’t design using some
specialised gadget that takes eight weeks
to come from the other side of the planet
and without which they cannot trade.”
Design the system so that regular
maintenance and repairs can be done
effectively and speedily, says Smith.
“Don’t for example install your rack in
such a way where you cannot get a
compressor out again if you need to
change it or repair it.” The location of
condensers must ensure that recirculation
of hot air does not occur, and whether
corrosion or noise will play a factor in
the selection, type, and location of
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