RACA Journal January 2020 | Page 63

Projects 1 few indoor units which were no longer working properly), and just switch over to the new outdoor units. They didn’t have to enter the building at all, which meant very few disturbances to the office. 2 Continued on page 63 www.hvacronline.co.za TURNING OLD INTO NEW 3 After putting in the new units, they simply had to flush the system, and they were good to go. As the system was designed to run on lower pressures, it wasn’t difficult to switch over to R410a from the R22 gas. Which is why there was no need to replace the piping. Once started, the system ran in recovery mode to recover the old oil. It is equipped with scrubbers to clean up the oil. The automatic cleaning of the refrigerant piping ensures clean piping network, even if a breakdown occurs. So, they recovered the gas, flushed the system, welded the condensers on, pulled a vacuum, and started up – it was that simple. Additionally, the VRV offers one point of contact that provides accurate temperature control, fresh air provision, air handling units and Biddle air curtains all integrated in a single system. The VRV IV is equipped with bigger accumulators to avoid liquid slugging on the compressors. This is already an upgrade on power saving. Also, they could use fewer condensers, replacing three systems with two – another saving in space, money, and energy. The old systems only had one inverter compressor, while the new condensers have all inverters, saving even more energy. It is estimated that efficiency gains of over 70% can be realised by virtue of 1. 2. 3. The old condensers that were scrapped had reached the end of their useable life. The replacement VRV IV condensers on the roof. The old R22 system was replaced effortlessly by an R410a system. RACA Journal I January 2020 61