Project
This facility , in Durban , is a distribution centre ( DC ) for a large pharmaceutical wholesaler . The project commenced in February 2019 with initial proposals and preliminary designs , and was subsequently completed in April of 2021 .
The warehouse facility itself is approximately 200m in length , 50m wide and 16m high . The temperature controlled room is constructed from 150mm thick cold room panel-type walls and ceiling . The area of this room is 125m in length , 25m in width and 14m in height .
DESIGN SPECIFICATIONS / CLIENT BRIEF OF THE PROJECT The requirements for this project were that the temperature controlled room must be kept between 22 ° C and 25 ° C , and relative humidity ( RH ) needed to be less than 55 % all year round .
The existing HVAC system , which was installed when the warehouse was built in 2016 , had been unable to meet these specified conditions . Our brief then included to design and manage the installation of a new HVAC system that could meet and maintain these conditions . The control of internal conditions is critical to ensuring optimum shelf life of stored goods and in this application the guidelines that were followed were set out by SAHPRA ( South African Health Products Regulatory Authority ).
The warehouse undergoes a temperature mapping exercise once a year to determine temperature and RH distribution and compliance .
THE HVAC SYSTEM AND INSTALLATION The system that was designed consisted of four air handling units ( AHUs ) each linked to a dedicated air-cooled condenser with compressor , controls , and so on . Each AHU has two independent refrigerant circuits . These units are stationed outside the warehouse on steel platforms just above ground level . Supply air from these units is ducted into the temperature controlled room and air is then distributed throughout the internal space .
A mezzanine floor within the warehouse with high level ducts and jet nozzle diffusers .
The AHUs were mounted on purpose built steel platforms so the fire escape was kept un-obstructed .
www . refrigerationandaircon . co . za RACA Journal I September 2022 31