The best HEPA UVC air purifiers to remove Covid-19 virus particles use UVC lamps, paired with hospital grade HEPA filters, to trap and deactivate viral particles. We use the term (deactivate) because viral particles are not considered to be "living" things. The tiny pieces of RNA that comprise a virus are more like seeds than living organisms. The best HEPA UVC Air Purifiers trap particles as small as .3 microns and impede the movement of viral particles that are even smaller. The viral particles (SARS-CoV-2) that cause Covid-19 are smaller than .3 microns. Some of these particles pass right through the HEPA filters. Others are trapped and later become dislodged and re-circulated. UVC lamps, positioned adjacent to the HEPA filters, project UVC ultraviolet light on impeded particles and deactivate any trapped particles.

 

CDC guidelines require a filtration system to capture particles as small as .3 microns to qualify as HEPA (High Efficiency Particle Absorbing) filters. Viral particles are much smaller than .3 microns, so a HEPA filter alone is not sufficient. 

 

HEPA filters use three different methods to trap

particles in a woven network of fibers. Diffusion

impedes the travel of particles, and in some cases

the particle may stick to the fibers. Interception

uses a curved weave to help channel and grab       

larger particles. Impaction uses a special weave

to channel the flow of particles into dead ends.  

These barriers are very good traps for particles

like pollen, dust, fungus spores and bacteria;

however, virus particles are small enough to

travel through HEPA filters. 

 

 

 

Very small particles such as the Coronavirus are measured in nanometers. The SARS-CoV-2 virus that causes Covid-19 is approximately 125 nanometers in diameter. A micron is 1000 nanometers. HEPA filters are designed to a trap particles as small as 330 nanometers.  

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Our Guardian Angel systems combine the best HEPA UVC air purification methods to disinfect interior atmospheres. Viral particles are more like seeds, than living organisms, as we previously stated. They must come in contact with a living host and invade the cell by penetrating its outer cellular membrane. Once inside the virus can reproduce. These viral particles called virions are strands of RNA (genetic material). Their lifespan can exceed 4 hours on some surfaces. HEPA filtration will catch or impede the travel of some virions, but because of the size limitations, HEPA filter manufacturers cannot honestly claim these units will remove viral particulate. Air flow through the system could dislodge virions, that do become trapped, and send them back out into the environment. The addition of a UVC lamps exposes these trapped particles, so they are no longer dangerous, if dislodged and blown back into the room.

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Some filtration units combine the HEPA system with charcoal enhanced filters, but charcoal only removes certain gases like chlorine. While this is a desirable feature, charcoal filtration is not effective against pathogens like the Coronavirus that causes Covid-19.

 

Other systems use an electrically charged metal filter, that is supposed to attract negatively charged particles like a magnet. There is very little,  peer reviewed research to prove the efficiency of these systems, but they probably do deactivate some particulate. We use an electrically charged screen to attract particles, but our multi-level system is not dependent on this single method to remove deadly pathogens.

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Guardian Angel MTB-800 units combine the above systems with UVC light exposure. UVC is a proven, recognized sanitizer that damages reproductive genes in pathogens like bacteria, fungus, and viral particles like SARS-CoV-2, the virus that causes Covid-19. The EPA and CDC recognize the effect of UVC ultraviolet light, and they have compiled research data that list how much exposure to UVC is required to deactivate certain pathogens. In general, in order to deactivate moving viral particles or other pathogens, a powerful UVC light source, located very close to the target, is required. 

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The HEPA UVC light air purifier in our Guardian Angel line of UVC light disinfection equipment uses industrial quality versions of all of the above mentioned systems.  The HEPA UVC light air purifier will capture and deactivate pathogens (germs) and the smallest viral particles. As its name implies, our HEPA UVC light air purifier combination leaves nothing to "chance". A multi-stage air purification process is the Best HEPA air purifier available.