Academic Engagement

New applications of UVC light and Far UVC light to reduce the airborne transmission of Covid-19

This idea concerns Covid-19. Since the Covid-19 campaign no longer exists here, I have no recourse but to post this idea, and many others, in the five current campaigns which still exist here.

It appears that DHS no longer reviews ideas that are submitted on this site. I hope they will disprove this assumption by communicating with me on each of my ideas and directly address any potential which they may have.

My idea follows.

By now, many who have been following the development of Covid-19 have become aware that UVC light (or Germicidal UV) can kill it, both on surfaces and in the air. Since UVC light is harmful to humans, it is difficult to see it having a role in settings where people can easily be exposed to it. Thus, I will not be discussing any attempts to clean person-level surfaces by UVC light while people may be in the vicinity. However, its role in cleaning the air will be discussed in depth. An alternative and safer option, Far UVC, will be brought up in later text.

UVC light has been used for many years to eradicate microorganisms from the air of buildings. Units are usually installed within ductwork, or on walls at least seven feet from the ground with shielding to prevent eye damage to people nearby (this is termed "upper air irradiation"). The wall unit lights point outward at an angle and upward, often towards a ceiling air vent. The following describes these type of arrangements: .

If a building has units as described above, it is already having an effect on the airborne transmission of Covid-19. Perhaps the effectiveness of what a building has established can be verified by testing. However, there may be ways to improve the quality of their respective installations even further. In addition, in buildings where no such systems are in place, possibly due to costs, there may be ways to bring them into the fold through other approaches. I will be proposing approaches to address these two situations (increasing current UVC measures or starting UVC measures) that will not only attain the respective goals, but also have the added benefit of being publicly visible. The visibility of UVC efforts (evident in the preceding only in upper air irradiation) is extremely important, for it will give the public greater confidence that various settings are indeed safe from the perspective of airborne transmission. This, in turn, will have a tremendous effect on the economy. I cannot stress this point enough.

It is reasonable to assume that if the owners of a building wanted to install the above mentioned systems, they would do so. However, they may be deterred by the costs. The main high level expenses would likely involve expensive wiring. I therefore propose that manufacturers be urged to create UVC options which could adapt to existing light fixture or wall outlet placements.

Let us first consider ceiling light fixtures. They would generally fall into the following categories: (1) recessed bulbs; (2) bubs in fixtures that are close to the ceiling; (3) hanging light fixtures; and (4) recessed, long bulb fluorescent light fixtures. There might be a few more types, but this should suffice for our discussion. The height of ceilings should also be taken into account and will be touched upon, below.

You can't simply replace the current bulbs involved in #1 - #4, above, used for lighting, and install a UVC bulb or fixture. Such a replacement would, of course, have to be pointed upwards and to the sides (with shielding against downward projection). Yes, it would provide protection, but the inhabitants of the room below would have lost a good amount of their needed illumination. The solution would be to create hybrid fixtures which would piggyback onto the existing fixtures. For example, with #1, a screw in connection to the existing bulb receptacle would hang down and feed power into a new fixture, below, which would have been attached to the ceiling. This new fixture would have a UVC component, shining upwards and laterally in a manner which cannot be seen by people below. On the bottom side would be the bulb for illumination. This whole fixture would be stabilized by non-obtrusive struts connecting onto the lower surface of the ceiling. If the ceiling had fire prevention tiles, a way to attach to the visible tile holders would need to be devised, without having a negative impact on the integrity of the tile system. Whatever is designed would need to meet fire code standards. As for #2 fixtures, they would be addressed in a manner similar to #1. With #3, the hanging fixtures would remain at the same level, but a UVC fixture would be added higher up. There would need to be some assurance that the UVC light would not tilt if it is not attached directly to the ceiling. As for #4, a new fixture would need to be suspended from the ceiling just below it. UVC bulbs (with proper shielding) would be installed in the already existing recessed fixture. The wiring would need to be fixed so that both lamps would be powered.

Note that the following device which is on the market is similar to the preceding approaches, but it uses Far UVC light:

Assuming all of the original fixtures were reasonably spaced from one another, the suggested alterations would provide good UVC coverage close to the ceiling. That is good for that part of the room (the upper few feet), but the protective effect for the entire room, at all levels, would be much better if the "dirty" air from below circulated up to the ceiling area for cleaning by the UVC light. Any intake vents already in the ceiling near these proposed fixtures would help effect this. So would any existing ceiling fans. If neither of these air movers are nearby, or existing ones are insufficient in number, additional fans will need to be installed in tandem with the above mentioned dual-purpose fixtures. In fact, if you had a room in which the ceiling was covered with UVC light fixtures, but no means to draw the air upward (vents or fans), the addition of fans to the above-discussed fixture adaptations would be essential. They would need to be of a very efficient design: ; . This bladeless fan is compelling: The problem with having to add fans is that the cost of room alterations would increase significantly. But it would work.

The preceding suggestions for light fixture alterations would probably not be an insurmountable problem in low-ceiling rooms. However, if the involved room had a very high ceiling and a broad expanse, this would be difficult to imagine happening. One thing which could help in high ceiling situations would be long pipes extending downward from the ceiling and terminating in light fixtures. These pipes could have openings on the lower end designed to suck air upwards and dispel it in the ceiling area to be hit by the UVC. Although conceivably workable, the cost would likely be excessive.

Thus far we have spoken about ceiling fixtures (reasonably addressable in low-ceiling rooms). And we are already aware of conventional upper air irradiation. If a room had a very high ceiling and electrical outlets were available on the wall, it might be possible to create an artfully disguised stacking of traditional upper air irradiation devices, from a height of seven feet on the wall on up. Then, in order to get air fed into these UVC units, we would have built into this array a long "pipe" suction system behind the lights. This would suck in a high volume of air for cleaning. It would ideally exit at the top. Or, if it is possible, piping from a major design component or sculpture at ground level in the center of the room could circulate air from that site, beneath the floor and then upward into the stacked array either along the walls or rising straight up from the ground in the center of the room. This would likely cost a bit. This wall / "design component" approach could perhaps be approached using the technology of bladeless fans.

So far, I have presented options involving open areas with high or low ceilings. I will now discuss how the air could be further cleaned by a different type of light, Far UVC, to the benefit of people sitting at tables, desks or standing at counters. If added to the above discussed options, a building would appear to be capable of making the airborne transmission of Covid-19 virtually impossible. This soon-to-be-discussed Far UVC option would also go far in reinforcing in the public mind that the risk of contracting Covid-19 where such units are placed would be extremely low.

Now, a little background on Far UVC light. I will be borrowing a bit from what I had written elsewhere for another idea.

First, UVC light as discussed above is harmful to humans. It is not safe to look into such a light. There is however, an alternative : Far UVC. It has the same very rapid killing effect, but research so far suggests that it will not harm the human body. The following provides insights on UVC: ; ; ; .

This suggests the Far-UVC can be emitted by LED: ; ; If Far UVC can be made with LED, then the design of what follows will be greatly augmented.

This has more information on Far UVC: ;

Although Far UVC light is said to not harm eyes, out of an abundance of caution I am proposing options that will not involve a steady shining of the light into people's faces.

I propose the following: (1) Far UVC lamps could be designed for placement in the center of tables, as a fixture. They would be angled downward so that the light would terminate at the table's edge. This would have a direct effect on the air in the immediate vicinity of diners or office meeting attendees. Such lamps may need to be battery powered. (2) Far UVC lamps could also be designed for placement on counters, such as at banks and the indoor pick-up window in a restaurant. These would be angled downward in a manner similar to #1 and also only shine to the left and right (if direct face-to-face contact was involved). (3) If there was a guarantee that a setting would not allow children, such as bars and nightclubs, Far UVC could shine directly outward, with no angling, from walls, columns and barriers from the ground up to about four feet. (4) Salad bars could have lights which shine away from the customer, at an angle, along the entire length of the salad bar (at waist level). This could also be done with conference tables. (5) Upward pointed, horizontal Far UVC lamps could be affixed along the upper borders of office cubicles. (6) Far UVC lamps could outline the entrance to an office door, effectively cleaning any air which drifts in or out. There is at least one manufacturer of the preceding type of arrangement, as shown here: (7) Since stays in elevators are relatively short, consideration could be given to downward pointed Far UVC lights in elevator ceilings, as well as in the walls as mentioned in #3, above.

In prior text an existing application involving Far UVC light in a ceiling fixture was mentioned: In this approach, an existing fixture in the ceiling was replaced by one which shined Far UVC light downward, along with light for illumination. That product would be suitable when encountering, in the ceiling (1) recessed bulbs; and (2) bubs in fixtures that are close to the ceiling. I propose that the approach be expanded to include: (3) hanging light fixtures; and (4) recessed, long bulb fluorescent light fixtures. In all of these four approaches with Far UVC light, air circulation should also be taken into account.

In all of the preceding Far UVC options, consideration should be given to promoting the circulation of air into the lights, as discussed with regards to UVC light fixtures in prior text.

In evaluating UVC and Far UVC, special consideration would need to be given to any applications in airplanes, buses, subway & train cars, etc.

We would likely need to develop some type of formula which could be used to determine how a room could be covered the best. This would likely spawn a new industry of inspectors or evaluators.

All of the above mentioned UVC and Far UVC options would clean the air immensely and, of great importance, would be so visible that the public would feel more assured. The public could continue wearing masks, but there would be less fear in these settings.

Since manufacturers are already making UVC and Far UVC components, as well as air circulation systems, they do not need any encouragement in their development of particular fixtures. However, what is needed is a high-level request from the government to consider making the types of devices as described above. Such a request would be magnified even further if all of the industries that have been severely affected by Covid-19 were to clamor for the production of such options. They would know that if these systems were in place their employees would be safer and the public would feel far safer in patronizing them.

Unfortunately, the cost of placing any of the above systems in offices, schools, restaurants, etc. to a degree to where they would be truly effective would be sky high. That is where the Federal government may need to use the Defense Production Act, offer tax deductions, etc. Mass installations could effectively serve as a infrastructure measure.



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Idea No. 1194