Know Your Enemy
The SARS (sudden acute respiratory syndrome) CoV-2 virus that causes Covid-19 infections is a large, lipophilic, encapsulated virus from the Coronaviridae family. The lipophilic outer membrane makes it very vulnerable. Almost any cleaner, including dishwashing liquid can dissolve this "fatty" exterior membrane.
Important Facts About High Efficiency Particulate Arresting (HEPA) Air Purifiers
The versatility of these portable units allows them to be placed in critical locations.
Portable disinfection equipment is effective against all pathogens. The use of air purification systems in schools, health and office facilities can lower infection rates and improve user safety.
*Center for Disease Control (CDC) recommends the use of portable High Efficiency Particulate Arresting (HEPA) air purifiers and Ultraviolet light to prevent the airborne transmission of Covid-19 in classrooms.
CDC guidelines call for a minimum of 3 to 6 Air Changes per Hour (ACH) to lower the potential for airborne transmission of the Coronavirus. The ACH for the average classroom is 1.4 per hour.
The average size of classrooms in the US is about 1000 sq. ft. with a 10 foot ceiling height. Our UVC-800 unit will exchange the atmosphere 6 times per hour in a classroom with those dimensions. Our high efficiency units can exchange the air in a 10 X 12 room with a 10 foot ceiling 40 times an hour.
CDC/EPA guidelines recommend using portable HEPA units capable of filtering 200 to 800 cubic feet per minute (CFM) and ultraviolet light to help prevent the airborne transmission of the Coronavirus. Our 800 CFM units take room atmosphere in from two sides instead of one. This helps to overcome the reduction of air flow caused by the HEPA filters. This design allows a faster exchange of room air.
The coronavirus and many bacterial pathogens are small enough to pass through most HEPA filters. If you could place 500 coronaviruses in a line, they would measure about the same width as a human hair. A coronavirus is between 80 and 120 nanometers in diameter. It takes 1000 nanometers to equal 1 micron. A human hair is about 50 microns or 50,000 nanometers in diameter.
Genuine HEPA filters (many filters marketed as HEPA are not approved by tests) attempt to trap or divert particles as small as 333 nanometers (one third of a micron). Air flow may dislodge particles temporarily trapped by a HEPA filter, which are then spread throughout the service area of the unit.
Our hospital grade air purifiers (UVC-800 and UVC-1200) use ultraviolet light exposure in combination with several filters, including two, genuine (HEPA) filters. Two powerful ultraviolet lamps are located safely inside the unit. Any pathogens trapped in the HEPA filters are exposed to the UVC C-band light. The UVC light renders the virus incapable of reproducing, which results in the death of the virus. The close proximity of the UVC lamps to the air flow pattern results in the de-activation of any dislodged or escaping viral pathogens.
Cheap HEPA filtered units without UVC lamps actually may pose a threat to room occupants. It is important to use UVC disinfection in conjunction with HEPA exhaust fans. The foundation of HEPA filtration design is based on “luck”. The Brownian Motion Theory supposes a particle traveling through a maze assumes a random path. The theory predicts that at some point the particle will become entrapped in the maze; unfortunately, the theory does not work with particles as small as a Coronavirus.
It is possible for extremely small viral pathogens to move through the fiber maze of the HEPA filter without being trapped.
This electron microscope image of a HEPA filter shows expansive gaps between fibers. The particle visible in the lower center of the image is approximately 3000 nanometers in diameter. The smaller particle next to it is about 1000 nanometers in diameter. The Coronavirus that causes Covid-19 is 100 nanometers in diameter...a tenth the size of the smaller particle.
This image of an N95 mask, taken with an electron microscope, shows how far apart the fibers are. The scale in the lower right corner is 10 microns. A micron is 1000 nanometers. A Coronavirus is about 100 nanometers wide. A line of 100 Coronavirus particles side by side could pass easily between these fibers.
