Taylor Robinson
Managing Director · 2026-03-10
Variable Refrigerant Flow, commonly known as VRF, is the dominant air conditioning technology for commercial buildings over 500 square metres. Originally developed by Daikin as VRV, the technology has been adopted by every major manufacturer including Mitsubishi, Toshiba, and Samsung. If you are bidding on commercial fit-outs, office developments, or retail chains, you need to understand how these systems work.
At its core, VRF uses a single outdoor condensing unit connected to multiple indoor units via refrigerant pipework. The outdoor unit modulates the flow of refrigerant to each indoor unit based on real-time demand. This means one condenser can serve twenty or more cassettes, wall units, or ducted fan coils, each operating independently.
The two main configurations are two-pipe heat pump systems and three-pipe heat recovery systems. Heat pump systems can either cool or heat the entire building at any given time, making them suitable for spaces with consistent seasonal loads. Heat recovery systems can cool one zone while heating another simultaneously, which is essential for buildings with mixed-use spaces, large glazing, or varying occupancy patterns.
For contractors, VRF installations demand a higher skill level than split systems. The pipework is larger diameter, the brazing must be done with nitrogen purging to prevent oxidation, and the refrigerant charge must be calculated precisely based on total pipework length and indoor unit capacity. Get any of these wrong and the system will fault repeatedly.
Electrical design is another critical factor. VRF outdoor units draw significant power on start-up. The inrush current can be three to four times the running current, which means standard MCBs will trip unless they are correctly rated. We always recommend a dedicated supply with adequate cable sizing and appropriate circuit protection.
Commissioning is where VRF systems differ most from conventional AC. Each indoor unit must be addressed on the central controller, capacity tables must be programmed, and the system needs a full performance test across all modes before handover. A proper commissioning report is essential for warranty validation with manufacturers.
Aboveboard Group specialises in VRF and VRV installations across London and Surrey. Our in-house engineers are experienced with all major brands and we handle everything from first fix pipework to final commissioning. Whether you need a pair for a two-week install or a full team for a multi-phase project, we have the qualified labour to deliver.