Cold Link Africa May/June 2016 Vol 1 No 5 | Page 20

EVENTS AND EXHIBITIONS
INCORPORATING COLD CHAIN

as a regulation. During the last study tour
to Europe the group noted that several
signatories of the ATP agreement did not
enforce the requirements.
As a case study Michael Schuster
made available a report on the adoption
of ATP in Serbia, as South Africa could
be considered being in a similar position
when the thermal testing of vehicles is
first introduced. A wider acceptance in
South Africa of the benefits of the thermal
testing of refrigerated vehicles and a higher
usage of the chamber needed extensive
publicity, wider channels of communication
and ongoing industry workshop forums.
Insulated vehicle body manufacture
European body builders and Igor Croiset,
a GIZ-appointed specialist, have visited
local body builders to advise on changes
in manufacturing processes and design
techniques to improve the thermal
performance of refrigerated vehicles.
Based on observations of manufacturing
standards in South Africa, GIZ has estimated
that improved thermal efficiencies resulting
from changes in manufacturing processes
could, as an example, reduce the annual
diesel consumption of a refrigeration unit on
a large rigid vehicle by 3 500ℓ to only 5 000ℓ.
Based on GIZ recommendations, the
participating body builders will each build a
pilot body to be tested in the SABS thermal
chamber to quantify the improvements
gained.

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Natural Refrigerants
Transport refrigeration units are mostly
changed with R404A and R134a, both
having a global warming impact. A pilot
project in co-operation with Transfrig
(South Africa’s only local manufacturer
of transport refrigeration units), together
with technical expertise by Dr Daniel
Colbourne (a GIZ-appointed consultant
from Europe), on the feasibility of using
a hydrocarbon (R290) in a transport
application has been researched.
A self-contained Transfrig 450 unit
with a diesel-driven compressor and a
cooling capacity of 7.95kW at 0°C was
used for the pilot project. The 450 unit
was redesigned for with a much lower
refrigerant charge of only 0.65kg of R290
and the model number changed to 480
(the 450 unit has a charge of 3.5kg of
R404A). Both units have similar cooling
capacities as tested by the Tshwane
University of Technology. Another benefit
of the R290 model include being more
‘green’ as its direct carbon emissions
only equate to 0.001t C02 equivalent
compared to 6.9t C02 equivalent of the
R404A model. However, there are safety
concerns with regards to the flammability
of R290 and a possible explosion if
concentration levels of leaked gas rise
above the safety limit.
To mention a few of the design changes,
pipe jointing was changed to reduce
possible leakage of R290, an open drive

compressor was changed to a semi-hermetic
and changes were made to the diesel
exhaust outlet and electrical connections
changed to reduce risk of sparks.
The design of the 480 is compliant with
seven different EN standards to reduce
leakages and the ATEX directive (from
the French name Appareils destinés à
être utilisés en ATmosphères EXplosibles)
to reduce possible explosions. The field
tests of the 480 should be completed by
October 2016.

GIZ has estimated that improved
thermal efficiencies resultant
from changes in manufacturing
processes, could as an example,
reduce the annual diesel
consumption of a refrigeration
unit on a large rigid vehicle by
3 500ℓ to only 5 000ℓ.
At the meeting, Bill Wilson of Transfrig was
upbeat about the experience gained
from the pilot project and saw a possibility
of acceptance by the market but only
after extensive field trials and confidence
gained by service technicians.
Training of technicians
Hydrocarbon charged units also poise
safety risks to service technicians. As a

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further element of the GIZ Project, Dennis
Huehrer of Proklima, Germany spent time
in Johannesburg to train technicians of
transport refrigeration service providers in
the safe handling of R290 at Transfrig.
Further training courses in refrigerated
transport technologies were conducted
at OTTC in Springs. Isolde Döblin reported
that participants from GEA/Thermoking,
PECSSER/Carrier, Twister Trans/Mitsubishi
and Transfrig were optimistic about the
training presented by Dennis Huehren.
His training models included the design
of leak tight systems, leakage detection,
commissioning and reporting after servicing
of equipment.
Way forward
The meeting ended on a positive note but
with a general concern about the continuity
of the GIZ initiatives and sustainability of
the test chamber after the project team
returned to Germany.
An option for continuity would be the
formation of a technical commission
of government, SABS and industry
representation to meet on a regular basis
and address challenges as they occur.
At the close of the meeting, the GIZ
was thanked for their investment in the
development of refrigerated logistics in
South Africa. Without the involvement of
GIZ, a thermal test chamber in South Africa
might never have gone beyond the stage
of talking about it. CLA

COLD LINK AFRICA • May | June 2016