22 www. refrigerationandaircon. co. za RACA Journal I June 2026
CONTROLS feature
Supplied by AES
Beyond conventional BMS connectivity, integration with digital platforms such as OpenBlue from Johnson Controls enables advanced analytics, remote diagnostics and predictive maintenance strategies.
Through cloud-connected monitoring, operators can access:
• Automated performance reports
• Fault detection and diagnostics
• Predictive maintenance alerts
• AI-assisted optimisation recommendations
In high-availability environments, predictive maintenance is particularly valuable. By identifying subtle changes in vibration, temperature, electrical characteristics or load response, potential failures can be addressed before impacting operations.
An often-overlooked aspect of HVAC controls in data centres is electrical quality. The YVAM’ s variable speed drive( VSD), equipped with active front end technology, plays a critical role in safeguarding power quality within the data centre environment. By delivering zero inrush current during start-up and ensuring compliance with IEEE- 519 harmonic standards, the system minimises electrical distortion and reduces the risk of interference with sensitive IT infrastructure. In facilities housing high-density computing equipment, maintaining clean, stable power is just as essential as maintaining precise temperature control. Electrical disturbances can be as disruptive as thermal fluctuations, and the chiller’ s power management capabilities are designed with this reality in mind.
Resilience is further enhanced through integrated UPS functionality and Quick Start capability, which allow the YVAM to return to full load within minutes following a power disruption. From a controls perspective, this rapid restart capacity strengthens facility-level redundancy strategies and supports overall business continuity planning. Cooling recovery time is a critical factor in mission-critical environments, and the ability to restore full operational capacity quickly helps ensure that thermal stability is maintained even after unexpected power events.
In the modern data centre landscape, HVAC controls have evolved far beyond basic operational management. They now function as strategic enablers, directly influencing energy efficiency, carbon reduction initiatives, system reliability and uptime, plant optimisation, and long-term lifecycle cost management. As cooling technologies adapt to higher chilled water temperatures and ever-increasing rack densities, it is the sophistication of the control layer – integrating power quality management, intelligent monitoring and rapid recovery capabilities – that ultimately defines overall plant performance.
Centralised operations using a remote monitoring system( RMS).
SMART DIFFUSER CONTROLS DRIVE PRECISION AND EFFICIENCY Control at diffuser level is emerging as a powerful lever for energy efficiency and indoor comfort, according to Raphael Smith, sales director of Rickard Air Diffusion. Rather than relying solely on central plant responses, modern systems increasingly push intelligence to the edge of the HVAC network – directly into the air distribution devices themselves.
“ At its core, our system combines the variable air volume( VAV) body, electronic controls and actuator into a single solution. We’ re not just moving air – we’ re controlling it precisely at the point of delivery and feeding that information back to the building management system( BMS),” Smith explains.
A defining feature of Rickard’ s approach is the integration between diffuser-level control and central plant operation. Each VAV diffuser continuously reports its operating status, enabling demand-driven control strategies.
“ We output information to the BMS so it can respond to real demand. For example, if a large percentage of diffusers exceed a certain actuator position, say 80 %, the system can bring additional chillers online. Conversely, at lower demand levels, it can optimise for heating or energy recovery,” says Smith.
This feedback loop allows the HVAC system to operate dynamically, reducing unnecessary energy use while maintaining tight comfort conditions.
Central to this capability is the actuator control logic embedded within the diffusers.“ Our patented actuator logic as sent to the BMS is highly accurate and reliable. That accuracy is critical, because the entire plant response depends on what’ s happening out in the field,” Smith notes. In large installations, aggregated data – sometimes referred to as‘ pointless’ or mapped points – provides a system-wide view of demand. This enables more sophisticated control algorithms at plant level, particularly in complex buildings.
Rickard has also extended its control philosophy to traditionally problematic applications, such as fan coil systems serving multiple zones.
“ In a typical setup, you’ ve got one wall thermostat trying to control several zones. That leads to hot spots in one area and overcooling in another,” Smith explains. The company’ s solution integrates VAV diffusers with a fan coil controller, allowing each zone to influence system operation.
“ The diffusers provide feedback on their damper position, and that feeds into the controller. The result is proper temperature control across all zones – no more overcooling or underheating,” he says.
The control technology is developed in South Africa through a long-standing partnership with a Stellenboschbased electronics specialist, in which Rickard holds a stake.
“ All our controls are developed locally, and we’ ve been refining them for nearly two decades. We also have a lab in Cape Town based on ASHRAE standards, which allows us to design and test new solutions for specific project requirements,” says Smith.
Recent innovations include Bluetooth-enabled diffusers, allowing occupants to adjust setpoints via a mobile app – further decentralising control and enhancing user interaction.
For Smith, the broader trend is for intelligence to move closer to the conditioned space.“ The diffuser is often overlooked, but it’ s where comfort is actually delivered,” he says.“ By making it smarter and integrating it properly with the BMS, you unlock both energy savings and a much higher level of control.” RACA
22 www. refrigerationandaircon. co. za RACA Journal I June 2026