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© Gree Airconditioning South Africa
it makes sense that replacement of one component rather than two is more cost-effective .
VRF , as a flexible solution , can meet any realistic budget and because of its modular nature , is easy to roll out in portions which allows for installing particular sections at pre-planned times . This is a useful benefit , especially in today ’ s time where owners are squeezed , by allowing them to build according to their finances .
That being said , VRF systems can be complicated and are in fact delicate systems that require contractors that have had sufficient training , as every supplier will tell you . Each VRF system will have many pipe runs and this can get extremely confusing . Obviously , systems won ’ t work correctly if pipes are connected incorrectly and a further complication is that these problems would typically only be discovered at the commissioning stage .
Scott notes some of the cons in VRF systems that should be taken under consideration in his view ,” Technician ’ s must be properly trained to install and diagnose VRF systems and thus training needs to be manufacturer-specific . In theory , the level of technician that works on these system-types should be at a higher level , but the reality is , your average property owner can ’ t tell the difference between a capable technician and an incapable one . Skill availability is particularly worse in remote or outlying areas . Technology has also advanced so rapidly in recent times , we find our VRF systems may soon contain obsolete technology . Most of the major players have good support , but it ’ s a concern that spares may not be available when you need them in future . Further , as large amounts of electronics are used , they can be susceptible to power spikes as has been mentioned , while this is true for all electrical equipment .”
All suppliers have the strategy of regular site visits in support of the installation teams to ensure the system is installed correctly . Not all suppliers perform the actual commissioning themselves and leave it up to their contractor base . The installation in VRF systems requires many Ref-Net joins and if these joins are not levelled correctly they will create ‘ dead legs ’ in the system and cause functionality issues which is one element we have seen a number of times in
The latest addition to the Gree VRF system is the ability to have up to 100 % solar PV power supply . the installation process . The ease of the installation really all comes down to the technical expertise of the technicians and can also be perceived as a negative for this solution because we have unfortunately seen some terrible work out in the field , and this damages the overall reputation of VRF as a solution ,” notes Ferdinandi .
VRF systems also demand flushing with nitrogen during installation welding , and taking short cuts in this particular function were noted by several companies that can cause system failures and must be avoided . “ We have seen that this step was left out on only the last two welds of the last pipe run of an installation , but resulted in one of the control boxes needing to be replaced – therefore stressing the need to follow best practices ,” says Ndelu .
“ With regards to the installation training for our VRF technology , we don ' t schedule training sessions for numerous contractors , we do contract-specific training at their premises . The reason for this is we have noticed that this method offers a better outcome because sometimes you will find technicians won ’ t participate with other companies being involved ( for various reasons ) thus not giving them the answers they need to suitably understand installation requirements . Naturally , this is more time consuming at the end of the day because we do the same training over and over for numerous contractors , but the results prove beneficial for our approach . We have also included near field communication ( NFC ) on all our outdoor units . This allows the technician to connect to these units with an Android phone , giving access to all the operating data on the system that can be analysed for performance and troubleshooting . Reports can be shared directly with our technical team via email and so we can also see exactly what the system is currently doing while the contractors are on site to provide further guidance ,” adds Bester .
LOOKING TO THE FUTURE As technology transitions to more environmentally friendly refrigerants , the shift is going to require significant training initiatives , and in South Africa this will be a particular challenge to regulate as many of the lower GWP refrigerants are mildly flammable and thus perceived hazardous . The reality is that we don ’ t have the same enforced regulatory or environmental compliance like for example the US or Europe , while even these leading economies have shown that training for new low GWP refrigerants is lacking .
“ The future will definitely include technologydriven aspects . Today we already have apps and digital means to monitor , diagnose and control systems and this can be done on your smart phone .
Further , the future really depends on refrigerant
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RACA Journal I July 2021 www . hvacronline . co . za