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Project
Image by Zuber Suleman / S Projects
However, for larger stores, installing multiple roof ventilators was not economically viable and presented maintenance challenges. Instead, mechanical smoke extraction was implemented for larger stores, using dedicated extract fans and makeup air movers. The HVAC contractor managed these installations, ensuring coordination with the fire detection and suppression systems.
For instance, in Shoprite, smoke extract fans were integrated with smoke makeup louvres, which automatically open when additional
air intake is required. Activation Aerial view of Shoprite Plant Area showing packaged rooftop unit with supply and return double skin methods varied: on the main floor, ducting, economizer bank, smoke extract fans and portion of refrigeration plant area. smoke fans were triggered by a prevent excessive power draw while maintaining fresh air double-knock smoke detection system, while in back-of-shop intake and indoor air circulation. areas, activation was linked to a sprinkler flow switch. This These design choices collectively enhance system sequencing ensures that sprinklers are activated before smoke performance, energy efficiency and adaptability, ensuring that extraction began, preventing premature removal of smoke that the mall’ s HVAC & R infrastructure meet both operational needs could delay fire suppression. and long-term sustainability goals.
Kitchen extract canopies were also connected to the Recognising the impact of frequent power outages, the fire safety system, shutting off automatically upon smoke HVAC & R system at Dhlamini Junction was designed with a detection. The detailed integration of fire safety measures comprehensive standby operational mode. The mall is equipped played a crucial role in meeting regulatory requirements and with a generator, necessitating a control philosophy that ensuring occupant safety. optimises energy consumption during backup power operation. Since air conditioning loads— especially compressor operations—
CHALLENGES FACED DURING INSTALLATION consume significant power, the system was programmed to
One of the primary challenges faced during the project was the transition into an energy-efficient mode during generator use. lack of power at the site during the early construction phase. Instead of physically disconnecting outdoor units, which
The absence of electricity required the contractor to work under would have been costly and complex, the BMS was configured spotlights, making detailed work such as painting and precise to automatically disable outdoor compressors when a generator installations more difficult. Despite these conditions, the team signal is detected. This allows indoor units to operate in fan adhered to specifications, ensuring a high-quality finish. mode only, reducing power consumption while maintaining air
Additionally, the fast-track nature of the project required circulation and regulatory compliance. When municipal power constant adaptation. Shopping centres are dynamic is restored, the system seamlessly transitions back to normal environments, and last-minute modifications— such as merging operation through a simple contact point, which signals all units or subdividing retail spaces depending on changing tenant to resume full functionality. This automated process ensures requirements— necessitated rapid adjustments to the HVAC & R efficiency and reliability in power transition scenarios. design. The flexibility of the ducted system allowed for relatively Fire safety was a crucial consideration in the HVAC & R straightforward modifications, such as adding diffusers where strategy at Dhlamini Junction. Stores larger than 500m2 needed to accommodate layout changes. require specialised smoke ventilation systems. Smaller stores
The team had to react swiftly to challenges that arose utilise conventional fusible link roof smoke ventilators that throughout the project. For instance, a shortage of stainless automatically open when a preset temperature is reached. steel across the country delayed the production of certain
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RACA Journal I July 2025 www. refrigerationandaircon. co. za