What’s the best solution for your business or home?
We often receive questions about the difference between Micro-Filtration and HEPA filtration. As the industry’s leading supplier of Janitized® brand “commercial grade” vacuum cleaner filter bags, we have extensive experience on this subject.
It seems that many consumers believe these are similar technologies. While their ultimate function is similar – the collection of microscopic particles – the technology used is actually quite different.
Micro – means “small” and used to indicate a smaller than average scale (microscopic scale), as opposed to prefixes like mega and macro, used to indicate a larger than average scale. Specific to vacuum cleaner filter bags, microfiltration is specific to the filtration level or filter efficiency of the filter bag.
Standard vacuum filter bags are made using a 1 ply outer layer of cellulose filter media, Micro-Filtration filter bags incorporate an additional 2nd ply layer typically comprised of a polypropylene melt-blown filter media. This additional 2nd ply increases the filter efficiency, reducing the amount of micro particulates being blown through the filter bag and exhaust air into your office or home. Traditional 1 ply or lower quality filter bags pick up and trap large pieces of dirt and debris, but cannot stop fine dust molecules or allergens from being released into the air. Micro-Filtration filter bags vary in filter efficiency and may have more than 2 ply’s.
A 2009 study by the University of Virginia Asthma and Allergic Diseases Center, entitled “Micro-Filtration Vacuum Bags May Ease Allergies” found that microfiltration bags can have a positive effect on reducing allergens in the air. These findings pointed to the positive effect on removing cat dander, one of the most common, and aggravating, sources of allergy suffering. ASTM standards provide consumers with confidence in the things they buy and use, including vacuum cleaner bags.
Because single layer vacuum cleaner filter bags do not trap allergens and small particles, vacuums can actually reintroduce these particulates back into the breathing zone in your office or home. A vacuum fitted with a Micro-Filtration filter bag can significantly increase the filtration of submicron particles and improve indoor air quality.
HEPA (High-Efficiency Particulate Air) filters provide much higher filter efficiencies vs Micro-Filtration filters. Glass fibers, typically used in HEPA media’s, are microscopic fiber diameters randomly layered and arranged. The spaces between the fibres are larger than the sub-micron particles they capture.
As air and debris pass through the filter, the glass fibres trap small particles in three ways. Some particles catch the side of the fibres and stick to them – called “interception” – while others impact directly into the fibre, embedding themselves – called “impaction.” The third process is called “diffusion.” These particles collide with gases in the filter, causing them to slow down or stop, and then get caught up in the fibres.
Interestingly, HEPA filters become more efficient as they capture more particles. As particles build up on the fibres, their electrostatic charge becomes stronger, improving their ability to attract particles.
Micro-Filtration vs. HEPA Filtration – Which is the best investment?
There is no simple answer to this question as each end use varies. For example, contract cleaners, hotel & hospital operations, and government buildings have fixed cleaning budgets. The replacement cost of filter bags vs HEPA filters needs to be carefully examined to determine total appliance maintenance costs. Often forgotten is the cost of lost productivity due to sick leave, which could be a result of reintroducing allergens into the working environment. This should be factored into this equation.
Other factors include the quality build of the vacuum cleaner. Commercial vacuum cleaners are typically better constructed for more abuse vs household vacuums.
Ultimately, it depends on what trade offs you are willing to sacrifice for high air purity.
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APC has the knowledge, tools and expertise to provide the custom filter you need. With over 34 years of filter design, engineering, manufacturing, testing and prototyping capabilities, our client retention of 98% speaks volumes.