HEPA is the short form of High Efficiency Particulate Air, hence HEPA filter refers to the High Efficiency Particulate Air filter. Filters, used either for an air purifier or any other implementation, are developed with a range of benefits. This article focuses the HEPA filters, what they are and how they work, to throw some light on its ecosystem.
What makes HEPA filters different from the rest is that they are more than just filters. This is because to be a true HEPA filter, it must first clear the test to be approved. The Institute of Environmental Sciences and Technology says that the HEPA filter must capture 99.97% of particulates 0.3 microns or bigger. This does not imply that the filter is unable to capture particles that are smaller than 0.3 microns, as many HEPA filters can; it is only the threshold that must be reached to qualify for HEPA name.
The HEPA Filtration Processes
In simple words, the HEPA filters capture air contaminants in a wide web of fibers. Based on the size of the particle, this can occur in four diverse ways:
- Inertial Impaction
Bigger particles are trapped through inertial impaction as well as sieving. The particles either hit with the fibers and get captured or are trapped while trying to travel through the fibers. Medium sized contaminants when flow through the filter, are trapped by the fibers through interception. Smaller particles are dissolute as they travel through a filter and finally collide with a fiber and then trapped.
Not All Filters are HEPA Filters
As perceived mistakenly, not all HEPA filters are the same. There are differences in terms of their composition as well as utilization. The air first flows through an ionizer that charges the incoming particles with a negative electrostatic charge.