Feature
VRF : NEW TECHNOLOGY
CREATES NEW POSSIBILITIES
By Benjamin Brits
Variable refrigerant flow ( VRF ) has been around for a long time , as with most HVAC technology , and continues to evolve .
Today ’ s technology in this category needs to address so many elements in meeting client demands and so all manufacturers continually invest significant amounts of money in research and development to bring to market their latest ideas in addressing those various needs .
The VRF concept , pioneered by Daikin in the 80s ( patented as VRV ), initiated the simultaneous ability of cooling and heating functions – whereas in the past either one or the other mode could be delivered at a time to individual indoor units . Each brand today is referenced by a particular model name while their branch controllers would follow a similar convention and are the ‘ junctions ’ where heat recovery control takes place and essentially enables dual mode function . All the brands currently work on a three-pipe system , with the exception of Mitsubishi , who uses their exclusive patented two-pipe system .
“ In simple terms , VRF systems , through the use of MCU ( Mode Change Units ), allow users on a single circuit to individually change between heating and cooling mode . The system is able to adjust the speed of the inverter compressor to meet the required capacity need of the system ,” says Tinus du Plessis , project engineer at Fourways Air South Africa .
System performance , energy efficiency , reliability and capacity will be the words you read on any supplier ’ s marketing sheets as these elements are the talking points around the world . For the most part , we see a significant mindset shift in end users ’ awareness of environmental impacts . These factors also open more doors to participate in the now highly competitive business environment .
This , for example , can be linked to a commercial office space where significant savings can be achieved through reduced HVAC operating costs , addressing limited plant room space offering more ‘ lettable area ’, a retrofitted building ’ s structural capacity not needing to be reviewed , meeting an aesthetic requirement , or overall lifespan-operational-costs .
So , from monitoring and control technology , to new smaller chassis , to increased horsepower and the latest compressor capacities , each of the brands available in South Africa , have their own benefits and sometimes niche sectors that they are able to be best utilised in .
© AHI Carrier Toshiba © RACA Journal | Benjamin Brits
The Toshiba SMMS-u , released into South Africa , comes with options of a new triple-rotary compressor design and an improved twin rotary compressor design .
The Mitsubishi Electric Airconditioners hybrid chilled water VRF system eliminates the need for room leak detection sensors .
VRF function today enables an assortment of flexible solutions that can incorporate all indoor units – wall units , ducted units , cassette units , fan-coil units , and standing units . Systems can also be linked into air handlers , and packaged units . Further , any mix of units is also possible .
www . hvacronline . co . za RACA Journal I July 2021 19