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Vehicle thermal tests at SABS
– will it succeed?
BACKGROUND
Many role players attended meetings
and forums where the construction of a
chamber to test the thermal efficiency
of road vehicles and refrigerated marine
containers was discussed. The project
was funded by GIZ of Germany and
at their insistence, the planning was to
include the Department of Trade and
Industry (dti), Department of Transport,
vehicle body builders, transport operators,
suppliers of transport refrigeration
units, transport trade associations, the
Department of Environmental Affairs
(DEA), supermarket chain groups, and
so on. GIZ wanted the project to be
transparent and encompassing of all
parties that could benefit. The overall
purpose was to reduce the carbon
footprint of the distribution of perishables
in South Africa.
The process started in 2013. After a
call for quotations for the construction
of the chamber and another for the
operation of the chamber, the chamber
was constructed and completed at the
South African Bureau of Standards (SABS) in
Pretoria in May 2017.
During the planning, the parties
involved required that the test be done in
accordance with a South African drafted
standard. Similar to the procedure laid
down by ATP in Europe, SANS 1744 was
drafted and titled “Insulation and special
equipment used in refrigerated transport —
requirements and test methods”.
SANS 1744 defines all the technical detail
and methods for K-type testing, pull-down
test, type approval, classification, and the
plating of vehicles based on the outcome
of the thermal tests done.
Industry indicated that, based on the
annual national production of insulated
and refrigerated trailers, approximately 50
tests on trailers would be required each
year. Each test would require three to four
days and if including tests done on vehicles
that have already been in service for some
years, the chamber could be fully utilised
for at least three years, just testing trailers.
With the high capital cost of trailers, the
estimated R40 000 for a type approval
would not be too excessive. Rigid vehicles
could also be tested if operators or body
builders required same.
The interior dimensions of the chamber
can accommodate the maximum legal size
of a road vehicle, including a Hi Cube ISO
marine container on a skeletal trailer.
fitted for the testing of those vehicles to
be plated FND (mechanically refrigerated
equipment with normal insulation k=/<
0.7) or .0 FRC (mechanically refrigerated
equipment with heavy insulation k=/< 0.4),
was at the centre of much debate.
When the first vehicle was sent for
testing, it also became evident that
according to the operating procedures
of the SABS, only the entire test could be
done as laid down in SANS 10744 and not
portions thereof. The fact that on the first
trailer, the fitted mechanical refrigeration
unit would not be operated so as not to
impact on the manufacturer’s warranty,
was not acceptable to the SABS.
Here it is worth mentioning that the
refrigeration unit is not required to operate
during the test to verify the thermal
efficiency (K value). For a type approval,
the capacity of the refrigeration unit must
be at least 1.75 times the heat leakage
at which the vehicle will operate. It is
acceptable that the cooling capacity
of the unit be certified by a recognised
independent authority.
After the teething problems with
the first test, it was mooted to redraft
SANS 1744 and to split it into two
standards to accommodate pull-down
tests, which can be performed off the site
of the SABS chamber.
The standard was redrafted and has
since remained merely in draft form.
Sadly, the outcome of all the debate
and different views has been a very low
utilisation of the chamber. A total of 11
tests since May 2017 have been done and
of these, eight were on in-use vehicles.
LATEST UPDATE
At a meeting held in November 2018,
the drafting committee and SABS
accepted that SANS 1744 would remain
unchanged and that the SABS would be
prepared to undertake parts of the test
in accordance with the requirements of
the client, for example only a K valve test,
a pull-down test or naturally, a complete
type approval. No matter which test was
done, the technical detail and method
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Ackermann
S
adly, so far only 11 tests have been
done at the thermal test chamber in
Pretoria since its completion in 2017
— what is the problem?
By John Ackermann
of testing would be strictly in accordance
with SANS 1744.
It was also accepted that
mechanically refrigerated vehicles
could be sent for testing with a plug
of heat leakage similar to that of a
refrigeration unit in the aperture of the
unit. Alternatively, a ‘dummy’ used unit
supplied by industry could be fitted at the
SABS for the test.
The test chamber is an asset for South
Africa’s body builders to verify that their
products match international standards,
and body builders should be keen to
have their products tested. All too often
it is claimed by local body builders that
their products match that of European
standards. Testing in the SABS chamber
will certainly dispel any doubts.
Operators who are committed to food
safety standards, fuel usage, and global
warming, will surely also want to have
their in-service vehicles tested to gauge
when it becomes uneconomical to
operate aged vehicles.
The outcome of the November 2018
discussions paved the way towards a
beneficial utilisation of the chamber. What
remains is a close partnership between
the SABS and industry role players.
Unless there is a willingness for both
industry and the SABS to foster a
partnership, the chamber could
become defunct.
If South Africa is to adopt
international food safety standards,
it should be a strict requirement of
operators (supermarket groups, food
processors, cold chain distributors,
refrigerated logistics operators) that
at least all new refrigerated trailers be
subjected to a thermal test or type
approval in the SABS chamber. There is
no need to wait for legislation; surely the
industry still has leaders who are willing
to set the pace. CLA
1. The official opening of the SABS thermal
test chamber in May 2017.
2. The ammonia refrigeration plant that
maintains the required temperatures in
the SABS test chamber.
3. Refrigerated vehicles in Europe are
plated to indicate thermal rating,
for example FRAX — mechanical
refrigeration with heavy insulation
(k < 0.4) operating temperature 0–12°C
— and the refrigeration compressor is
driven by the engine of the vehicle.
Certification expires in May 2019.
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REGULATION ISSUES
In the drafting of SANS 1744, the
requirement of having a refrigeration unit
COLD LINK AFRICA • March/April 2019
www.coldlinkafrica.co.za
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