20 www. refrigerationandaircon. co. za RACA Journal I March 2026
ENERGY EFFICIENCY FEATURE SERIES
Energy efficiency
MBS Engineers, appointed as the client’ s mechanical consulting engineers, were responsible for the HVAC design and for overseeing construction and cost management. With energy efficiency embedded as a core design philosophy, the team selected an LG Multi V5 variable refrigerant flow( VRF) system for the project.
The Multi V5 platform has demonstrated consistent efficiency improvements of 40 – 50 % compared to conventional constant-speed compressor systems. Beyond reduced energy consumption, the system offers heat recovery capability, simultaneous heating and cooling, individual zone control and reduced installation and space requirements – attributes well suited to an energy-constrained, off-grid environment.
The De Deur project reflects a broader shift in thinking around renewables. Rather than simply adding solar panels to a conventional building design, the project demonstrates how efficiency-led system selection determines whether renewable energy solutions are viable in the first place.
“ There’ s a misconception that you can solve energy problems by just throwing solar at them. Our view is the opposite – efficiency must come before renewables. If your loads aren’ t optimised, no amount of solar will save you,” says Bekker.
That principle was put to the test at De Deur. Engineers worked closely with an energy-literate client who owns multiple properties and understood the long-term implications of energy decisions. Selecting inverter-driven VRF technology was not optional; it was fundamental to making a fully off-grid building possible.
That early efficiency-first mindset ultimately determined whether going off-grid was feasible at all.
WHICH BUILDINGS CAN GO OFF-GRID? From LG’ s perspective, not all building types are equally suited to off-grid or solar-dominant HVAC solutions. Load profile remains the defining factor.
Standard office buildings operating on an 8 – 5 daily schedule are among the most suitable candidates. In these environments, HVAC demand aligns closely with peak solar generation, allowing systems to operate directly from solar power during the day with minimal reliance on batteries.“ At De Deur, the office building can run entirely on solar during daylight hours. The batteries are there, but they’ re not carrying the full load,” Bekker explains.
Warehouses, however, present a more complex challenge. Many operate on a 24-hour cycle, shifting a significant portion of energy demand into night-time operation. While solar-assisted HVAC is still possible, it becomes a hybrid scenario where battery capacity – and cost – becomes critical.“ You can do it,
20 www. refrigerationandaircon. co. za RACA Journal I March 2026