Feature
AIR FILTRATION :
NEVER TO BE ( DE ) PLEATED
By Benjamin Brits
As we see the world turn to masks as one of the solutions to a global pandemic , it is compelling to think that this was in fact the first recorded method of air filtration .
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Ulpatek ( Airbox )
Ulpatek ( Airbox )
It was in the late 1840s when the first air-filtering mask was invented and patented . The design incorporated moistened wool and one-way clapper valves and was able to filter dust particles . Subsequently , the original patent for the gas mask was also lodged in 1849 by the same inventor .
In the 1900s , large-scale air filtration went through the most significant developments as complete HVAC systems were developed , incorporating various methods of air-cleansing .
It was also the period where the high efficiency particulate air ( HEPA ) filter was first invented – one of this year ’ s hottest
An example of a galvanised sheet metal primary filter .
An example of a v-compact type activated carbon filter typically used in a public building , airports , workshops , hospitals , food and pharmacetutical industry , industrial and civil air conditioning systems .
RACA Journal I November 2020
components . HEPA filters were originated by the United States defence force between the two World Wars as a protection mechanism against radioactive chemicals used to build the first atomic bomb . The technology was released commercially after World War II .
Today , having a look at any filter company ’ s brochure , their range of products really opens up a very large door to how and where filters are used , as well as the development that has occurred in filtration over the years .
For the HVAC sector , air quality has become a much bigger commercial concern than what has been required before as building occupants have developed heightened awareness of air quality in relation to pathogens and pollution , and sick building syndrome and social distancing at workplaces are in the spotlight for design reviews .
On the industrial applications side , processing and manufacturing produce various fumes or gases that need to be collected because this cannot just to go into the atmosphere , so extraction systems are also designed that take processed air to a collection point to be filtered before being released .
So , air filtration can be applied to air into a space , or air out of a space and is therefore intended to contain particulate either in or out , ensuring a healthy environment for the occupants and environment .
FILTERS AND HVAC DESIGN Air filtration naturally depends on the type of HVAC system design and the particular application . The most common commercial , industrial ( and medical installations ) incorporate air handling units ( AHUs ) and configurations vary between what the desired outcome will be . This could be as simple as the reduction of dust , to ensuring a complete contamination-free zone .
“ The legislation in South Africa regarding filtration requirements is covered in the SANS 0400-1900 , and is grouped together with plumbing and electrical . Interestingly , the standard doesn ’ t indicate a particular value ( micron size or particle size ) when talking about air quality with in applications , but rather it specifies requirements around tobacco smoke or no tobacco smoke , with x-many air changes required . One question
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