RACA Journal February 2026 RACA_Feb_2026 | Page 25

FEATURE

Meanwhile, the integration of advanced monitoring, leak detection and safety shutoffs ensures that VRF systems are easier to manage, more reliable and safer for occupants than ever before.

VRF and VRV systems represent a mature, adaptable and forward-looking solution for modern HVAC needs. From simultaneous heating and cooling to advanced safety measures and globally informed standards, the technology offers a unique combination of flexibility, efficiency and reliability.

DESIGN, INSTALLATION AND MAINTENANCE: INSIGHTS FROM ASHRAE JOURNAL PODCAST 29

While VRF systems offer flexibility and efficiency, real-world performance depends heavily on proper design, installation and maintenance. In Episode 29, Kelly Cramm, P. E., Life Member ASHRAE and mechanical engineer with Henderson Engineers, highlighted recurring issues such as premature compressor failures and system underperformance. Her decades of HVAC experience underscore that VRF’ s benefits are only fully realised when engineered and maintained correctly.

COMMON PITFALLS Cramm identified improper installation and insufficient maintenance as the leading causes of system failures. In multizone buildings, indoor fan coil unit filters must be changed regularly, yet maintenance staff are often stretched thin. Outdoor condenser coils, typically microfin designs, require at least biannual cleaning to prevent airflow restrictions and system overheating. Unlike traditional DX systems, VRF heat pumps operate year-round, increasing exposure to contaminants and operational wear.

Installation best practices are equally critical:

• Purge refrigerant piping with inert gas( nitrogen or argon) during brazing to prevent slag formation and ensure clean joints

• Require factory-trained, certified installers, as even experienced pipefitters can introduce debris that damages compressors

• Recalculate refrigerant charge if field modifications alter piping length or layout. Overcharging is a common cause of premature compressor failure

• Install suction line side-stream filters with isolation valves to capture residual debris from brazing; these can be valved off after startup

• Ensure compliance with ASHRAE Standard 15 and the International Mechanical Code, particularly regarding refrigerant piping in egress paths

During the design phase, engineers must decouple ventilation from VRF units. VRF fan coils are generally ill-suited to handle latent loads, particularly in humid climates. Using a Dedicated Outdoor Air System( DOAS) ensures proper dehumidification and allows VRF units to operate as sensible-only devices, simplifying operation and eliminating condensate issues.

Contractors also play a crucial role, ensuring that qualified personnel handle critical installation tasks. Integration into building management systems( BMS) remains a challenge due to proprietary controls, though interoperability is gradually

improving. Additionally, in cold climates heating capacity declines as outdoor temperatures drop, necessitating backup heat and consideration of wind effects on outdoor units.

Cramm concluded:“ VRF systems can deliver outstanding performance, but only when designed, installed and maintained properly. With the right practices, they can be among the most flexible and efficient HVAC options available today.”

DHLAMINI JUNCTION MALL CHOOSES VRF FOR FLEXIBLE, EFFICIENT HVAC

The recently completed 17 000m ² Dhlamini Junction mall in Soweto( see RACA Journal July 2025 issue for full project coverage) highlights the advantages of modern, adaptable VRF solutions. Central to the mall’ s heating and cooling strategy was a VRF system from LG, selected for its energy efficiency, flexibility and ease of operation.

Given the mall’ s dynamic retail environment – where only half of the units had tenants secured at the start – flexibility was a key design requirement. The VRF system allowed each store to operate independently with dedicated condensing units and ducted hideaway indoor units of standardised sizes, enabling rapid adjustments to shop layouts and tenant-specific requirements. This adaptability simplified installation, reduced co-ordination complexity and ensured consistent HVAC performance across the development.

The VRF system also delivered significant energy savings. Its variable-speed compressors ramp capacity gradually, matching demand rather than operating at full power continuously. This load-matching reduces energy consumption, extends equipment lifespan and supports compliance with SANS 10400-XA energy efficiency standards. Integration with LG’ s AC Smart BMS provides real-time monitoring, remote control and an automated generator mode that limits condenser operation during power outages, further optimising energy use.

Overall, the VRF solution offered a scalable, cost-effective, and energy-efficient HVAC approach. It met the operational needs of diverse retail tenants, facilitated rapid changes during construction, and contributed to long-term sustainability goals for the mall. RACA

LG Multi V5 at Dhlamini Junction Mall.

© RACA Journal feature