Part 1: Exploring Purifii™ Upper Air UVGI


Blending Form, Function, and Health — Beautifully

How well is COVID-19 transmitted through the air? How long does it remain airborne? What are the best ways to provide healthier air in my business so I can keep my doors open?

Over the last year, there have been countless postulates and theories about the behavior of COVID-19 (SARS-CoV-2) particles in the air and on surfaces. Yet there is a growing body of evidence detailing the potential for airborne transmission as the ongoing major factor in the spread of COVID-19.

Last year, more than 200 scientists agreed “beyond any reasonable doubt” that microdroplets released during exhalation, talking, and coughing can stay in the air and pose an infection risk at distances beyond four to seven feet from infected individuals. It was also noted that droplets can remain suspended in the air like smoke — for seconds to hours — and accumulate in poorly ventilated indoor air. Not a novel mode of transmission, airborne transmission has played a part in other pathogens, including the flu.

How, then, do we gain control of airborne disease transmission moving forward to battle a variety of infectious diseases?

Clearing the Air — The Answer To Transmission

Ultraviolet germicidal irradiation (UVGI) has a long history of use and is proven to kill or inactivate a wide range of pathogens including E. coli, mycobacterium tuberculosis, staphylococcus aureus, salmonella typhimurium, adenoviruses, Hepatitis, HIV-1, measles, mumps, cold viruses, influenza and varicella zoster (chickenpox).

More recently, studies including Luminii’s own testing, have proven that UVGI is highly effective at inactivating COVID-19. Upper air UVGI is a proven technique for applying UV to the control of airborne pathogens. So much so, the CDC recently recommended the use of upper air UVGI to inactivate COVID-19 within occupied spaces. 

Upper Air UVGI vs. In-Duct UVGI

How does upper air UVGI work? The system creates a concentrated plane of light in the upper part of a room, above the heads of occupants — applying high levels of germicidal UV in the upper room, while keeping levels in the lower room below established safety thresholds. Vertical air mixing in the space created by HVAC systems, fans and/or natural convection moves air up through the germicidal zone and then back down into the lower room, providing continuous disinfection in the occupied space. 

Compare that to in-duct UVGI that disinfects recirculated air but does little to prevent infection between two people sharing the same air in the same space. 

Solutions with Limited Applications

Currently, there are several upper air UVGI solutions on the market, but most have two main limitations. 

Typically, form factors are large (5” x 6” in cross section or similar) and are unsightly, mainly driven by the light source. Large reflectors focus the light emitted from a low-pressure mercury lamp and, even then, the beam is not shaped precisely enough to sufficiently limit UV in the lower room. For that, deep, matte black louvers are used, creating an even larger, somewhat industrial, profile.

In addition, most existing solutions use potentially hazardous, low-pressure mercury lamps as their light source. Mercury from disposed lighting devices is considered a serious environmental issue. It is why 128 countries signed the Minamata Convention on Mercury, which aims to protect humans and the environment from mercury’s adverse effects. 

While some users may look past these limitations during unconventional times, aesthetically minded and environmentally conscious users often take a pass on these options. 

Enter Luminii — A New Approach to Upper Air UVGI

Luminii’s solution, Purifii™, is decidedly different. Luminii created the Purifii upper-air UVGI platform around a UV-C LED light engine rather than the more traditional mercury sources in the market — creating a fixture that aligns well with the missions and policies of environmentally conscious users. As for size, the small source made a minimalistic fixture form factor possible, allowing for seamless architectural integration and use in environments where existing solutions would be too intrusive. 

One of the major challenges of any upper air UVGI system is beam shaping. While current solutions achieve this with large reflectors and louvers, Luminii’s solution utilizes multiple convex quartz lenses over the LEDs, optically coupling them with a custom PVD-coated linear aluminum reflector to precisely re-construct the ray path. Leveraging the help of this refract-reflect system, Luminii can precisely control the ray path to deliver an intense ≈10 degree beam, without a large system of bulky and unsightly louvres.

Aesthetic, slim, and safe, Luminii’s upper air UVGI fixture answers the challenge of airborne viruses for a wider array of  applications and environments today — and well into the future.