RACA Journal June 2023 | Page 27

www . refrigerationandaircon . co . za RACA Journal I June 2023 25
Feature system . This is due to the lower installation costs in some cases , as well as the lower ongoing maintenance costs associated with VRF systems ,” he explains .
FLEXIBLE DESIGN VRF systems are designed to be flexible , which makes them ideal for retrofitting into existing buildings . Taylor explains that the individual AHUs can be installed in various locations , such as the roof or plant room , and ducting can be installed throughout the building to provide heating and cooling to different areas . This means that the VRF system can be tailored to meet the specific needs of the building , without requiring major changes to the existing structure .
“ VRF systems provide a comfortable environment for building occupants , as each area can be individually controlled . This means that temperature can be adjusted to suit the needs of the occupants , which can have a positive impact on their health and wellbeing . In addition , VRF systems operate quietly , which makes them ideal for use in areas where noise levels need to be kept to a minimum .”
When retrofitting a building with a VRF system , it is important to consider the system design , says Taylor . “ The size and layout of the building will need to be taken into account , as well as the number of AHUs that will be required . The VRF system will also need to be designed to ensure that it is compatible with the existing electrical and mechanical systems in the building .
“ The installation of a VRF system can be complex , and it is important to work with a qualified and experienced installer . The installation process may involve making changes to the existing structure , such as installing ducting or upgrading electrical systems . It is important to ensure that the installation is carried out safely and that all relevant regulations and standards are followed ,” he says .
Like any air-conditioning system , VRF systems require ongoing maintenance to ensure that they continue to operate efficiently and effectively . It is important to schedule regular maintenance checks to identify and address any issues before they become major problems . This can help to extend the lifespan of the system and ensure that it continues to provide optimal heating and cooling to the building .
“ With multiple VRF Hybrid systems , you are able to provide heating and cooling to different areas of a building at the same time , with each area controlled individually .”
AHI Carriers
Numerous VRF and Light Commercial outdoor units connected to FAUs for fresh air treatment to the chemical labs .
REFRIGERANT CONSIDERATIONS Trane is a Eurovent compliant system wherein R22 has been phased out . “ Trane International is spending huge funds on research and development to find new , greener and better refrigerants which will in time be introduced here in South Africa . While in Europe they are introducing new refrigerants as we speak , locally it may take some years still to go completely ‘ green ’ with regard to gas refrigerants .”
In small applications , VRF may be more efficient as well as easier to install and to control . “ Although the initial capex might be higher , the payback period is usually within three years to four years depending . On the other hand , if the building is located along the coastline , where it ’ s exposed
to harsher elements , a water-cooled chiller might be a more logical choice for the greater longevity of the equipment . Each application has its unique needs and requires careful consideration before deciding on the type of cooling system to use ,” says Byron .
“ Moreover , we have found that there are some skills required to install VRF systems which are still lacking in the industry . Many contractors treat it like a straightforward DX application , compromising on commissioning integrity , which can result in compressor failures and callbacks . Therefore , upskilling installers and strict commissioning protocols are necessary to ensure proper installations .
“ The HVAC industry is highly competitive , especially for small business owners , as they compete against household names like Samsung and LG . The industry is in many cases price-driven on the DX and VRF side , and having the right stock at the right time is crucial for success ,” he says .
In conclusion , Byron summarises that VRF technology offers many benefits , including energy efficiency , flexibility and ease of control . However , it is essential to consider the specific needs of each application before deciding on the type of HVAC system to use . It is also crucial to upskill installers and have strict commissioning protocols to ensure proper installations .

www . refrigerationandaircon . co . za RACA Journal I June 2023 25