Projects
side of the room was fitted with perforated stainless steel
plates to allow for the equal distribution of air from one side
of the room to the other. This is critically important to ensure
that the product dries evenly and consistently across the
entire room and thus ensure a superior product.
SAVINGS FROM THE SYSTEM
Minnaar
Rigging the
AHU into
position with
limited space.
On 17 November the first load of biltong was placed in the
room to trial its performance. This was owed to the fact
that, during all commissioning phases, there was some fine
tuning and fault finding to be done on the system once it
was operating under load. By 28 November most of the
commissioning niggles were resolved and the first batch of
high-quality product was dried in the room.
DEALING WITH CHALLENGES
One of the most challenging aspects of this project was the
timeline and the fact that this precluded the utilisation of any
desiccant dehumidification equipment due to equipment
lead times. The dehumidification and room conditioning were
achieved purely by mechanical dehumidification and reheat.
In order to achieve the correct amount of airflow over the
product a false ceiling plenum was constructed and either
Due to the significant time constraints on the project there was
not sufficient time to optimise and look at all possible energy
optimisation strategies. AMC did however perform a review of
future potential optimisation and have allowed for these in the
design at minimal initial cost.
Some of these strategies include the use of waste heat
from the ammonia plant for primary reheat of the dry off
coil air as well as the utilisation of external ambient air under
specific conditions to reduce the dehumidification load on the
AHU. In some instances that ambient air absolute humidity
content is low enough to be utilised directly under 100% fresh
air conditions.
Although no ducting or coils were installed for the above
potential modifications, space was left for these in future in the
form of a fresh air damper and physical space in and around
the AHU.
ONE OF A KIND SYSTEM
What made this project special is that it was completed
under stringent time constraints; the contractors and
equipment suppliers worked extremely well as a team;
and the client in the end had a well-designed and installed
system that operates as required and optimally. It was a
great sense of achievement to hear from the client that
their customer was happy with the quality of the final
product and that internally they were pleased by the
performance of the room as a whole.
There was a significant improvement in the final product
due to the correct drying regime and room conditions. RACA
ABOUT THE AUTHORS
•
•
The loading bay for loading once the biltong is dried, stored and
packed ready for delivery, nationwide.
52
RACA Journal I April 2020
Andrew Minnaar, director at AMC Engineers, is
a qualified professionally registered, mechanical
engineer, and a member of ASHRAE and the South
African Refrigerated Distribution Association
(SARDA).
Michael Barbosa is a director of abattoirs, food
processing and private clients at SCIP Engineering
Group. Qualified as a civil engineer and registered
as a Professional Engineer with the Engineering
Council of South Africa (ECSA). He is also a director
at Matbar, who developed the project.
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