Feature replace a filter . What happens is that the filter is full of dust , which is loaded with active bacteria and virusus may colonise on the filter . It makes sense that handling a filter jam-packed with contamination will contaminate the system , air channel , and the circulation air in general ,” says Michael Smorenburg , managing director of GermZero South Africa .
“ Another very important thing to mention is that you cannot tell if a filter needs to be changed by simply looking at it – so you have to check differential pressures ,” adds Verster .
NEW TECHNOLOGY There are various new mobile filter systems or air purifying units with integrated HEPA filters that come in sizes to cater for small rooms to large industrial workshops . These units will become particularly important for existing buildings .
There is a new coating available for filters in South Africa called ‘ Germagic ’. It is an antimicrobial coating which gives contact-killing , release-killing and anti-adhesion abilities to HEPA filters . Unlike conventional antimicrobial technologies which solely rely on contact-killing , the coating releases reactive oxygen species in a controlled-manner , allowing for a germicidal effect in the coating ’ s proximal area . This product can be applied to any filter including new installations , retrofits , and existing filters in an HVAC system .
“ The polymer nano-technology in Germagic was developed over a decade ago as a longterm / slow-release disinfectant response to the SARS and MERS outbreaks . The coating in spray form can actually be added to any surface . There is also a filter range that aready comes impregnated with the active ingredients . The filter comes in a pouch and folds out to size of 600mm x 400mm . It can be cut to fit any size of HVAC / filter or grill . Where the spray application is used , we recommend standard PPE and the use of an electrostatic spray system ,” says Smorenburg .
LOOKING TO THE FUTURE “ Existing buildings can ’ t easily be retrofited with any type of HEPA system because HEPA filters take up a lot of the fan pressure , so current systems would need upgrades through additional or replacement fans or adapted AHUs . Offices with splits or non-ducted casettes will have to rely on mobile air purifyers if air quality is a key requirement . Everything is gong to change in future and the engineer will hopefully rethink designs of big offices and open areas in terms of the HVAC system for future alterations . Currently the regulation in place dictates a certain amount of air changes per hour per space , where every room is different and this needs to be evaluated for HEPA inclusion . I believe HEPA will be a definite need as is seen in overseas countries who have very strict air quality policies . With the addition of HEPA and possibly UV-C lighting this will significantly increase general health for building occupants ,” notes van Wyk .
Ulpatek
Various types of AHU filters for the HVAC sector . These come in different dimensions and qualities .
“ What I see for the future is that better filtration is going to be dictated by the end users and multiple filter scenarios will need to be implemented . Different designs have implications , so if you previously had a small filter , and introduce all of these pressure drops with additional filters , you have to overcome this . Coil designs will change and fan designs will change . Because the design changes it ’ s easier to add UV-C lights and so on . AHUs will have to change to match the pressure requirements too . Everyone now wants clean air and trends will have to move towards better filters and removing finer particles out of the air ,” says Verster . RACA
www . hvacronline . co . za RACA Journal I November 2020 19