Feature
Freudenberg Filtration
A large-scale application of pocket filters .
especially when the AHU is feeding a line , section or space where clean air is essential . Depending on the particular conditions , filters may become full of moulds or other pathogens on top of the the regular dusts and particles , and the AHU itself can also be neglected to the point where it is falling apart – rendering it useless ,” says van Wyk .
Poor or no maintenance can lead to production shutdowns or decontaminations being required and this can be an
extremely challenging and a costly excersise when an office building or hotel needs to be taken care of and income is affected . This is the same for industrial processes where equipment ’ s lifecyle is shortened by excessive corrosive particles being present in the space .
Primary filters , as a first defence also experience the same challenges and need to be well maintained to prevent damage and reduced lifespan of secondary and HEPA filters .
Another challenge is that many clients do maintain the filters , but the whole AHU has been there for 20 years so its like a sieve anyway – it sucks from all of the areas of wear and not through the filters allowing pathogens and bacteria into the space .
Poorly maintained filters also make the other components have to work that much harder – fans work harder , chillers work harder – and this increases operational and replacement costs . Filters should also no be touched when maintenance is being done because they may be contaminated and need to be incinerated .
“ Microbial growth on filter media may cause damage to filters and become a secondary contamination source . Moreover , backdraft during filter replacement also posts health and safety concerns to maintenance workers . Backdraft refers to the threat of secondary contamination to technicians and the environment / site faces once airflow through a duct is suspended in order to
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RACA Journal I November 2020 www . hvacronline . co . za