WO2022236414A1

WO2022236414A1 - Airborne pathogen neutralization methods and systems

Info

Publication number: WO2022236414A1
Application number: PCT/CA2022/050741
Authority: WO
Inventors: Raymond Boisvert; André VILLEMAIRE
Original assignee: Technologies Grb Inc.
Priority date: 2021-05-11
Filing date: 2022-05-11
Publication date: 2022-11-17

Abstract

The present disclosure relates to the field of airborne pathogen neutralization and more particularly to improved methods and systems for the sanitization of airborne pathogens in indoors settings using germicidal UV light. There is provided a germicidal device that reduces a concentration of pathogens in a room. The germicidal device has a support assembly that is mounted in an upper portion of the room and a light emitting assembly that emits germicidal UV radiation. The germicidal device can include a protective skirt that partially defines the disinfecting area. The germicidal device cooperates with an air moving device, such as a fan, to reduce the concentration of pathogens in the air prior to the air being circulated or re-circulated in the room. The germicidal device can be used in a pathogen neutralization system or as part of a method of reducing a concentration of pathogens in a room.

Description

AIRBORNE PATHOGEN NEUTRALIZATION METHODS

AND SYSTEMS

TECHNICAL FIELD

[0001] This present disclosure relates to the field of airborne pathogen neutralization and more particularly to improved methods and systems for the sanitization of airborne pathogens in indoors settings using germicidal UV light.

BACKGROUND

[0002] Aerosol transmission is now widely accepted as the principal way that many pathogens, including those that cause COVID-19, are spread, thus signifying the importance of studying and controlling natural and mechanical forms of ventilation. However, outside of health-care facilities, mechanical ventilation is designed for comfort, not airborne infection control, and cannot achieve the 6 to 12 room air changes per hour recommended for airborne infection control. More efficient air filters have been recommended in ventilation ducts despite a lack of convincing evidence that viruses spread through ventilation systems. Most transmission appears to occur in rooms where both an infectious source and other susceptible occupants share the same air.

[0003] Only two conventional room-based technologies are available to supplement mechanical ventilation: portable room air cleaners and upper room germicidal UV (GUV) air disinfection. Portable room air cleaners can be effective; however, performance is limited by their clean air delivery rate relative to room volume.

[0004] Most pathogens, including SARS-CoV-2, are highly susceptible to GUV, a conventional technology that has been shown to produce the equivalent of 10 to 20 or more air changes per hour under real life conditions in a safe, quiet, effective and economical manner. GUV causes UV-induced mutagenic DNA lesions, primarily through

1 the formation of pyrimidine dimers, and of other secondary photoproducts of genetic materials.

[0005] One option of utilizing UV irradiation for infection control is upper room ultraviolet germicidal (UR-UVG). Conventional UR-UVG devices are specially designed fixtures normally fitted with low-pressure mercury-type UVC lamp. Three issues for the current design include: (1) mercury UVC lamps are only about 30% efficient at converting input power into ultraviolet C (UVC) radiation; (2) safety continues to be a major concern as ozone is a by-product; and (3) inflexibility in design and cannot be manufactured to emit UV over a wide range of wavelengths. Furthermore, mercury discharge lamps emit radiation in all directions, resulting in significantly lower efficiency when light needs to be directed in a particular direction. Another shortcoming of the conventional lamp-based UR-UVG fixture is a large size, and many units may be required for a large room, which may affect the aesthetics of the room.

Despite a long history of extensive evidence of the undoubtful efficacy of the conventional UR-UVG air disinfection system over many years, the paucity of convincing solutions to address the high-lighted limitations has been a major barrier to the full acceptance, development, and wider implementation of UR-UVG systems. Therefore, safe, non-toxic, economically feasible, low-cost, low-maintenance and effective method and system are still required.

SUMMARY

[0006] According to one embodiment, there is provided a germicidal device configured to reduce a concentration of pathogens in air in a room, the germicidal device comprising: a support assembly configured to be mounted in an upper portion of the room; and a light emitting assembly comprising light emitting elements electronically coupled to the support assembly and configured to emit germicidal radiation, wherein the germicidal device is configured to cooperate with an air moving device to reduce the concentration of pathogens in the air prior to the air being circulated or re-circulated in the room by the air moving device.

- 2 [0007] In some embodiments, the germicidal radiation is UVC radiation and is emitted towards the upper portion of the room and away from a lower portion of the room.

[0008] In some embodiments, the support assembly comprises a printed circuit board electronically coupled to the light emitting assembly and configured to operate the light emitting assembly.

[0009] In some embodiments, the germicidal radiation is at least one of: ultraviolet C (UVC) radiation and far UV radiation.

[0010] In some embodiments, the light emitting elements are LEDs.

[0011] In some embodiments, the air moving device is a ceiling fan and the support assembly is configured to be coupled to the ceiling fan.

[0012] In some embodiments, the support assembly is configured to be removably coupled to the ceiling fan.

[0013] In some embodiments, the support assembly comprises an aperture for receiving a shaft of the air moving device therethrough. [0014] In some embodiments, the germicidal device further comprises a mounting assembly operatively coupled to the support assembly and configured to mount the support assembly to the shaft.

[0015] In some embodiments, the mounting assembly comprises a mechanical clip configured to fit in the aperture of the support assembly to couple the support assembly to the shaft.

[0016] In some embodiments, the mechanical clip is comprised of a first clip portion and a second clip portion configured to couple to each other, wherein the first clip portion and the second clip portion define a clip aperture that is configured to fit the shaft when coupled to each other.

- 3 - [0017] In some embodiments, the coupling between the first clip portion and the second clip portion is adjustable such that the mechanical clip can be sized and shaped to fit a plurality of shafts.

[0018] In some embodiments, the mechanical clip comprises a circumferential groove configured to receive a peripheral border of the support assembly.

[0019] In some embodiments, the mechanical clip comprises protrusions in the circumferential groove that are configured to fit in a corresponding groove formed in a periphery of the aperture in the support assembly.

[0020] In some embodiments, the mounting assembly comprises a magnetic clip operatively coupled to the support assembly and configured to couple the support assembly to the shaft.

[0021] In some embodiments, the support assembly further comprises a notch extending from the aperture to an edge of the support assembly and configured to receive a portion of the shaft.

[0022] In some embodiments, the notch is one of: radial and curved.

[0023] In some embodiments, the support assembly further comprises a notch cover sized and shaped to fit within and/or couple to the notch.

[0024] In some embodiments, the support assembly comprises a first portion and a second portion pivotally coupled to each other and at least partially delimiting together the aperture, wherein when in an open configuration, the support assembly can be mounted onto the air moving device and when in a closed configuration, the shaft extends through the aperture to mount the support assembly to the air moving device.

[0025] In some embodiments, the support assembly comprises a bumper on one of the first portion and the second portion that is configured to prevent an overlap of the first portion and the second portion when in the closed configuration. 4 [0026] In some embodiments, the germicidal device further comprises a protective skirt removably coupled to the support assembly, wherein the protective skirt defines a disinfecting area with the light emitting assembly.

[0027] In some embodiments, the protective skirt is removably coupled around a periphery of the support assembly.

[0028] In some embodiments, the protective skirt comprises a first skirt portion and a second skirt portion removably coupled to at least one of: each other and the support assembly.

[0029] In some embodiments, the first skirt portion and the second skirt portion each comprise an interior groove configured to receive the periphery of the support assembly.

[0030] In some embodiments, the interior groove comprises channels dispersed between support structures configured to receive a portion of the support assembly.

[0031] In some embodiments, the first skirt portion and the second skirt portion each comprise a protrusion on a first end thereof and an aperture on a second end thereof, wherein the aperture on the first skirt portion is configured to receive the protrusion on the second skirt portion and the aperture on the second skirt portion is configured to receive the protrusion on the first skirt portion to removably couple the first skirt portion to the second skirt portion.

[0032] In some embodiments, the first skirt portion comprises a first shield on the first end that is configured to overlap with the second end of the second skirt portion when the first skirt portion and the second skirt portion are coupled to each other.

[0033] In some embodiments, the second skirt portion comprises a second shield on the first end that is configured to overlap with the second end of the first skirt portion when the first skirt portion and the second skirt portion are coupled to each other.

- 5 - [0034] In some embodiments, the protective skirt further comprises a flared section extending axially from the periphery of the support assembly and configured to block a portion of the germicidal UVC radiation.

[0035] In some embodiments, the flared section is configured to prevent the germicidal UVC radiation from being emitted in the lower portion of the room.

[0036] In some embodiments, the flared section is configured to prevent the germicidal UVC radiation from being emitted horizontally or in directions lower than the horizon.

[0037] In some embodiments, when coupled to the support assembly, the flared section curves radially outwardly from the periphery of the support assembly. [0038] In some embodiments, the protective skirt comprises a bottom wall with a skirt aperture configured to receive a shaft of the air moving device.

[0039] In some embodiments, the support assembly comprises at least one aperture and the bottom wall comprises at least one protrusion, wherein the protective skirt is removably coupled to the support assembly by the at least one protrusion coupled to the at least one aperture.

[0040] In some embodiments, the germicidal device further comprises a second skirt coupled around the protective skirt.

[0041] In some embodiments, the second skirt is concentric to the protective skirt.

[0042] In some embodiments, the protective skirt is comprised of a flexible material. [0043] In some embodiments, the protective skirt further comprises a plurality of openings, each of the plurality of openings being coupled to a tubular section at a first end thereof, the tubular sections being configured to channel the air into the disinfecting area. 6 [0044] In some embodiments, the plurality of openings extend through the protective skirt at a tangential angle such that the air channeled through the tubular sections is inserted tangentially into the disinfecting area.

[0045] In some embodiments, the plurality of openings and the tubular sections are configured to insert the air tangentially to produce a vortex or circular air motion.

[0046] In some embodiments, a second end of each of the tubular sections comprises an air filter configured to prevent particles from entering the disinfecting area.

[0047] In some embodiments, the germicidal device further comprises a protective covering configured to be removably coupled to the protective skirt or the support assembly over the light emitting assembly.

[0048] In some embodiments, the protective covering is a convex dome.

[0049] In some embodiments, the protective covering is comprised of light-permeable material.

[0050] In some embodiments, the germicidal device further comprises a baffle coupled to the protective skirt or the support assembly, the baffle comprising a plurality of holes that are configured to direct a cone of emission of the germicidal radiation.

[0051] In some embodiments, the plurality of holes have a diameter configured to allow central rays of the germicidal radiation to pass through the baffle into the disinfecting area.

[0052] In some embodiments, the plurality of holes are provided at a radial offset that increases towards a periphery of the baffle to direct the cone of emission of the germicidal radiation.

[0053] In some embodiments, the germicidal device further comprises a fan configured to create an additional air current to prevent an accumulation of particles on at least one of: the light emitting assembly and the support assembly.

- 7 - [0054] In some embodiments, at least a portion of the germicidal device is coated with a dust repellent coating.

[0055] In some embodiments, the germicidal device further comprises a mirror operatively coupled to the support assembly, wherein the mirror is configured to project an image of at least one of: the support assembly and the light emitting assembly to the lower portion of the room.

[0056] In some embodiments, the mirror is configured to reflect visible light and prevent the reflection of the germicidal radiation to the lower portion of the room.

[0057] In some embodiments, the germicidal device further comprises a dusting device comprising a dusting arm pivotably connected to the support assembly, wherein the dusting arm is configured to pivot around a central axis of the support assembly.

[0058] In some embodiments, the dusting arm comprises a dust-removing material or dust-removing fibers.

[0059] In some embodiments, the germicidal device further comprises an electric motor, wherein the dusting device is actuated by the electric motor.

[0060] In some embodiments, the dusting device is actuated at a beginning or an end of a power cycle of the germicidal device.

[0061] In some embodiments, the dusting device is actuated at pre-determ ined timed intervals. [0062] In some embodiments, the germicidal device further comprises a UVC power meter configured to monitor the germicidal radiation emitted by the germicidal device.

[0063] In some embodiments, the germicidal device further comprises a pathogen sensor configured to determine a pathogen concentration in the air in the room. 8 [0064] In some embodiments, the pathogen concentration is at least one of: a bacterial concentration and a viral concentration.

[0065] In some embodiments, the pathogen sensor is configured to capture and identify at least one pathogen type in the pathogen concentration. [0066] In some embodiments, the pathogen sensor is configured to output real-time information on the pathogen concentration.

[0067] In some embodiments, the germicidal device is configured to output geolocational data with the pathogen concentration.

[0068] In some embodiments, the germicidal device is configured to juxtapose the geolocational data with an identification of occupants in the room.

[0069] In some embodiments, the germicidal device further comprises an overtemperature protection system configured to deactivate the light emitting assembly when a temperature of the germicidal device reaches a predetermined threshold.

[0070] In some embodiments, the overtemperature protection system comprises a bi- metal switch.

[0071] In some embodiments, the germicidal device and the air moving device have the same power source such that deactivating the air moving device, deactivates the germicidal device.

[0072] In some embodiments, the germicidal device further comprises at least one of: an occupancy sensor configured to detect a number of occupants in the room and a motion detector configured to detect motion in the room.

[0073] In some embodiments, the germicidal device is configured to activate or deactivate upon at least one of: when the occupancy sensor determines that the number of occupants is greater than 0; and when the motion detector detects motion in the room.

- 9 - [0074] In some embodiments, the germicidal device is configured to activate and/or deactivate upon voice command.

[0075] In some embodiments, the germicidal device is provided with a power source, and the power source is configured to activate and/or deactivate the germicidal device at specific time intervals or on a fixed schedule.

[0076] In some embodiments, the germicidal device has a sanitation mode configured for use with at least one occupant in the room and a rapid sanitation mode configured to use with no occupants in the room.

[0077] In some embodiments, the rapid sanitation mode is activated by the occupancy sensor.

[0078] In some embodiments, the support assembly comprises a conductive material configured to conduct heat dissipated by the light emitting assembly.

[0079] In some embodiments, the conductive material comprises aluminum.

[0080] In some embodiments, the germicidal device further comprises a visible indicator configured to output real-time performance indicators based on at least one of: a pathogen concentration, air flow, and occupancy.

[0081] In some embodiments, the germicidal device further comprises a low reflectance blocker installed at a terminal end of a disinfecting area defined by the germicidal radiation, wherein the low reflectance blocker is configured to reduce the germicidal radiation that is reflected towards the lower portion of the room.

[0082] In some embodiments, the low reflectance blocker comprises a material having a low reflectance in the UVC spectral range.

[0083] In some embodiments, the germicidal device further comprises a flexible membrane configured for installation on a ceiling of the room, wherein the flexible 10 membrane is configured to minimize the germicidal radiation reflected towards the lower portion of the room.

[0084] In some embodiments, the flexible membrane comprises a UVC absorbing coating. [0085] In some embodiments, the UVC absorbing coating is zinc oxide paint.

[0086] In some embodiments, the germicidal device further comprises a cover configured to be installed above the light emitting assembly, wherein the cover is configured to minimize the UVC light reflected towards the lower portion of the room.

[0087] In some embodiments, the cover is configured to be installed on the support assembly, the air moving device, or a ceiling of the room.

[0088] In some embodiments, the cover comprises at least one of a UV resistant material and a UV absorbing material.

[0089] In some embodiments, the cover comprises polycarbonate/polybutylene

Terephthalate. [0090] In some embodiments, the cover comprises grooves configured to reduce a UV reflectance of the cover.

[0091] In some embodiments, the cover comprises a first cover portion and a second cover portion removably coupled to the first cover portion.

[0092] In some embodiments, the germicidal radiation comprises wavelengths between 100 nm and 400 nm.

[0093] In some embodiments, the germicidal UVC radiation comprises wavelengths between 200 nm and 222 nm.

[0094] In some embodiments, the germicidal UVC radiation comprises wavelengths between 260 nm and 300 nm.

- 11 [0095] In some embodiments, the germicidal device further comprises a casing operatively coupled to the support assembly on a side opposite the disinfecting area.

[0096] In some embodiments, the casing comprises casing apertures configured to allow an air flow on a bottom side of the light emitting assembly or the support assembly.

[0097] According to another embodiment, there is provided a germicidal device configured to reduce a concentration of pathogens in air in a room, the germicidal device comprising: a support assembly configured to be mounted on an upper portion of the room, the support assembly comprising a circuit board; a light emitting assembly comprising light emitting elements electronically coupled to the circuit board; and a protective skirt surrounding at least a portion of the light emitting assembly and configured to define a disinfecting area with the light emitting assembly, wherein the protective skirt comprises a plurality of openings, wherein each of the plurality of openings are configured to cooperate with an air moving device to channel the air into the disinfecting area; and wherein the light emitting elements are configured to emit germicidal radiation in the disinfecting area.

[0098] In some embodiments, of the plurality of openings are coupled to a tubular section at a first end thereof, the tubular sections being configured to channel the air into the disinfecting area.

[0099] In some embodiments, the plurality of openings extend through a side wall of the protective skirt at a tangential angle, such that the air channeled through the tubular sections is inserted tangentially into the disinfecting area.

[00100] In some embodiments, the plurality of openings and the tubular sections are configured to insert the air tangentially into the disinfecting area to produce a vortex or circular air motion.

[00101] In some embodiments, a second end of each of the tubular sections comprises an air filter configured to prevent particles from entering the disinfecting area. 12 [00102] According to another embodiment, there is provided a germicidal device configured to reduce a concentration of pathogens in air in a room, the germicidal device comprising: a light emitting assembly comprising: light emitting elements configured to emit germicidal radiation; and a circuit board configured to be mounted to an air moving device; and a mounting assembly operatively coupled to the light emitting assembly and configured to mount to a shaft of the air moving device; wherein the germicidal device is configured to cooperate with the air moving device to move the air through a disinfecting area defined by the germicidal radiation.

[00103] In some embodiments, the germicidal device further comprises a protective skirt surrounding a periphery of the light emitting assembly and configured to define a disinfecting area with the light emitting assembly.

[00104] According to another embodiment, there is provided a pathogen neutralization system configured to reduce a concentration of pathogens in air in a room, the pathogen neutralization system comprising: an air moving device; a germicidal device comprising: a circuit board assembly; and a light emitting assembly electronically coupled to the circuit board assembly; and a power source configured to power the circuit board assembly, wherein the germicidal device is configured to cooperate with the air moving device to reduce the concentration of pathogens in the air prior to the air being circulated or re circulated in the room by the air moving device.

[00105] In some embodiments, the pathogen neutralization system further comprises a UVC power meter configured to determine a UVC power level of the light emitting assembly.

[00106] In some embodiments, the pathogen neutralization system further comprises a framework configured to support the UVC power meter at a predetermined height.

[00107] In some embodiments, the framework is a tripod. 13 [00108] In some embodiments, the pathogen neutralization system further comprises a user interface and a communication link configured to communicate a status of the germicidal device to the user interface.

[00109] In some embodiments, the communication link is configured to communication via at least one of: short-range wireless technology, ethernet, WiFi, infrared light waves, and radio-frequency identification.

[00110] In some embodiments, the status comprises at least one of: an identification number of the device, geolocational data, maintenance information, operation time, a number of power cycles, and UVC power levels.

[00111] In some embodiments, the air moving device is an existing air moving device and the germicidal device is retrofitted to the existing air moving device.

[00112] In some embodiments, the existing air moving device is a ceiling fan comprising a shaft and the germicidal device is coupled to the shaft.

[00113] According to another embodiment, there is provided a method of reducing a concentration of pathogens in air in a room with an air moving device, the method comprising the steps of: i) providing a germicidal device comprising a light emitting assembly configured to emit germicidal radiation, wherein the germicidal radiation defines a disinfecting area; ii) installing the germicidal device in proximity to the air moving device such that the air is exposed to the disinfecting area prior to being circulated in the room; iii) circulating the air with the air moving device; and iv) exposing the air to the disinfecting area.

[00114] In some embodiments, the method further comprises providing the germicidal device with a protection assembly to further define the disinfecting area.

[00115] In some embodiments, the germicidal radiation comprises at least one of: germicidal UVC radiation and germicidal far UV radiation. 14 [00116] In some embodiments, the germicidal device comprises a pathogen sensor, and wherein the method further comprises determining the concentration of pathogens in the air before and/or after exposing the air to the disinfecting area.

[00117] In some embodiments, the germicidal device comprises at least one of: an occupancy detector and a motion detector, and wherein the method further comprises detecting an occupancy of the room with the occupancy detector and/or the motion detector.

[00118] In some embodiments, step iv) of exposing the air to the disinfecting area is activated and/or deactivated based on the occupancy of the room. [00119] In some embodiments, step iii) of circulating the air with the air moving device and step iv) of exposing the air to the disinfecting area are executed simultaneously.

BRIEF DESCRIPTION OF THE DRAWINGS

[00120] Reference will now be made to the accompanying drawings, showing by way of illustration an example embodiment thereof and in which: [00121] FIG. 1 is an exemplary schematic of a room with an airborne pathogen neutralization system according to one embodiment;

[00122] FIG. 2 is a graph showing the pathogen decrease over time in the presence of a prior art UVG system;

[00123] FIG. 3 is a diagram describing a conventional air exchange system, such as a room with an open window;

[00124] FIG. 4A is a front view of a support assembly according to one embodiment, showing an electronic circuit board comprising unit cells;

[00125] FIG. 4B is a workflow schematic of a unit cell in the electronic circuit board shown in FIG. 4A;

- 15 - [00126] FIG. 4C is a workflow schematic of an exemplary regulation circuit according to one embodiment;

[00127] FIG. 5A is a side perspective view of a support assembly according to one embodiment in an open configuration for being mounted to a shaft of an air moving device; [00128] FIG. 5B is a side perspective view of the support assembly shown in FIG. 5A in a semi-open configuration being mounting to the shaft;

[00129] FIG. 5C is a side perspective view of the support assembly shown in FIG. 5A in a closed configuration and mounted to the shaft;

[00130] FIG. 5D is a plan front view of a support assembly according to another embodiment;

[00131] FIG. 5E is a side perspective view of a casing according to one embodiment;

[00132] FIG. 6A is a front perspective view of a GUV device according to one embodiment mounted on a shaft of an air moving device;

[00133] FIG. 6B is an exploded view of the GUV device shown in FIG. 6A; [00134] FIG. 7A is a perspective side view of a first clip portion according to one embodiment that forms a mechanical clip with the second clip portion shown in FIG. 8A;

[00135] FIG. 7B is a front plan view of the first clip portion shown in FIG. 7A;

[00136] FIG. 7C is a top plan view of the first clip portion shown in FIG. 7A;

[00137] FIG. 7D is a front plan view of the first clip portion shown in FIG. 7A;

[00138] FIG. 8A is a perspective side view of a second clip portion according to one embodiment that forms a mechanical clip with the first clip portion shown in FIG. 7A;

[00139] FIG. 8B is a front plan view of the second clip portion shown in FIG. 8A;

- 16 - [00140] FIG. 8C is a top plan view of the second clip portion shown in FIG. 8A;

[00141] FIG. 8D is a front plan view of the second clip portion shown in FIG. 8A;

[00142] FIG. 9A is a front plan view of a skirt portion according to one embodiment, which is configured to couple to another skirt portion to form a protective skirt; [00143] FIG. 9B is a top plan view of the skirt portion shown in FIG. 9A;

[00144] FIG. 9C is a perspective front view of the skirt portion shown in FIG. 9A;

[00145] FIG. 9D is a perspective top view of the skirt portion shown in FIG. 9A;

[00146] FIG. 10A is a front view of a protective skirt according to another embodiment that is designed to prevent the accumulation of dust; [00147] FIG. 10B is a front view of a protective skirt portion according to another embodiment that is configured to facilitate the ejection of dust from the GUV device;

[00148] FIG. 10C is a perspective bottom view of the protective skirt portion shown in FIG. 10B;

[00149] FIG. 11 is an exemplary schematic of a room with an airborne pathogen neutralization system according to one embodiment;

[00150] FIG. 12 is an example workflow diagram for an exemplary installation process for a GUV device;

[00151] FIG. 13A is a perspective front view of a cover according to one embodiment in an open configuration; [00152] FIG. 13B is a perspective front view of the cover shown in FIG. 13A in a closed configuration;

[00153] FIG. 14 is a graph representing the total, diffuse, and specular reflectance (%) of germicidal UV radiation between 250 and 350 nm;

- 17 - [00154] FIG. 15A is a front perspective view of a cover according to one embodiment coupled to a shaft of an air moving device on a ceiling;

[00155] FIG. 15B is an enlarged view of the cover shown in FIG. 15A taken at section 15B showing grooves;

[00156] FIG. 16 is a graph representing the relative intensity of the light emitting elements, such as LED, at an angle from the normal (degrees);

[00157] FIG. 17 is a cross-sectional front view of a GUV device according to another embodiment with a baffle;

[00158] FIG. 18 is a top plan view of the baffle shown in FIG. 17;

[00159] FIG. 19 is a graphical representation of a baffle for use with a GUV device according to another embodiment and showing the dimensions of the openings in the baffle; and

[00160] FIG. 20 is a graphical representation of the cone of emissions of two light- emitting elements when used with a baffle.

[00161] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

DETAILED DESCRIPTION

[00162] The present description discloses multiple systems and methods for using germicidal ultraviolet (GUV) devices with the goal of reducing the concentration of pathogen in the air of a room. The germicidal devices are configured to cooperate with an air moving or air circulating device, such as a fan, to provide a germicidal dose of UV radiation to the air prior to the air being circulated or recirculated in the room. The germicidal devices are configured to emit germicidal UV radiation that defines a disinfecting area. In some embodiments, the disinfecting area is defined above a germicidal device that is installed in the upper portion of the room, such that occupants in

- 18 - the room are not exposed to the radiation. As such, one factor in reducing the concentration of pathogens in the room is the rate of upward flow (convective room air mixing) that transports the pathogens in the occupied zone (i.e., the lower portion of the room) upwards to the irradiation zone (disinfecting area) produced by the germicidal device. As described herein, cooperation with the air moving device can move the contaminated air into the disinfecting area prior to the air being circulated or re-circulated in the room.

[00163] Referring now to Figure 1 , an overall view of an embodiment of a pathogen neutralization system 101 in accordance with one embodiment for reducing the concentration of airborne pathogens in the air in a room 111 is shown. The system 101 comprises a germicidal ultraviolet (GUV) device 103 mounted to an air moving device 109 installed on a room ceiling 107. The GUV device 103 emits germicidal UV radiation 105 upwards towards the room ceiling 107.

[00164] In the exemplary embodiment, the air moving device 109 is a ceiling fan that circulates the air in the room 111 by drawing the air downward and causing an air circulation pattern. The air circulation pattern results in the central portion 113 of the air traveling downwards, while the peripheral portion 115 of the air adjacent to the room walls 117 circulates upwards. The air in the room 111 contains a certain number of pathogens 121 per liter. As the air is circulated in the room, certain volumes of air are transported to the upper portion of the room in the area between the GUV device 103 and the ceiling 107 (i.e., above the GUV device 103). The GUV device 103 is configured to emit germicidal UV radiation 105 towards the upper portion of the room and, thus, the pathogens 121 suspended in the air get irradiated by the GUV device 103. The germicidal UVC radiation 105 at least partially neutralizes the pathogens 121 by disrupting their molecular structure. Once neutralized, the pathogen molecular material can be recirculated by the air moving device 109 and the neutralized pathogens can no longer infect the occupants of the room, thus curtailing transmission between occupants in the room.

- 19 - [00165] The germicidal UV radiation 105 can be emitted by a light emitting assembly that can comprise light-emitting elements, such as mercury discharge lamps, ultraviolet C (UVC) light emitting diodes (LEDs), or other UVC emitting sources. Advantages of using UVC LEDs include their small size (for example, 1 mm), the lower voltage of operation compared with mercury discharge lamps, and the possibility to operate the LEDs at any power level below their rated maximum power; whereas mercury discharge lamps can generally only be operated at one power level.

[00166] In some embodiments, the light emitting assembly of the GUV device 103 can include light-emitting elements that emit UV radiation with wavelengths in the range of 100 to 380 nm, or UVC radiation with wavelengths in the range of 200 to 280 nm. In some embodiments, the light emitting elements can emit far UV radiation with wavelengths in the range of 200 to 222 nm to further reduce the number of pathogens in the room. One advantage of far UV radiation is that wavelengths in this spectrum do not cause harm to exposed human tissue. Consequently, far UV radiation can be safely emitted in any portion of the room without requiring the measurement or validation of exposure. Far UV radiation can be utilized in any direction including downwards toward the room occupants. In some embodiments, the GUV device 103 has a light emitting assembly that that emits germicidal UVC radiation upwards or above the horizon (i.e., away from occupants in the room) and emits far UV radiation downwards or below the horizon (i.e., towards the occupants in the room). Use of both germicidal UVC radiation and far UV radiation can achieve higher efficiency coefficients when reducing the concentration of pathogens in the room.

[00167] In some embodiments, the air moving device 109 can be an axial flow fan or centrifugal fan installed on the ceiling or an upper section of the wall. In some embodiments, the air moving device 109 can include a fan or air circulating device that forms part of a ventilation system. Depending on the type and location of the air moving device 109, the GUV device 103 can cooperate with other airflow patterns to circulate the air in the room. Consideration should be given to the type and placement of air moving device 109, whether as part of the system 101 or when retrofitting an existing air moving 20 device 109, as air flow patterns play an important role in circulating an effective amount of air room particles through the disinfecting area created by the GUV device 103, thereby neutralizing the pathogens 121 in the room.

[00168] In some embodiments, the germicidal device is a horizontal-emitting GUV device 123 that is configured to emit germicidal UV radiation 105 horizontally to neutralize the pathogens 121 in the air in the upper section of the room prior to the air being recirculated by the air moving device 109. The horizontal-emitting GUV device 123 can be installed on the ceiling 107 or an upper section of the wall 117. The horizontal-em itting GUV device 123 can be installed on one wall 117 and emit germicidal UV radiation 105 substantially horizontally from the horizontal-emitting GUV device 123 to an end of the disinfecting area (i.e., at a distance from the GUV device 123 where the germicidal UV radiation 105 is no longer effective at neutralizing the pathogens 121 ). In other embodiments, the system 101 can comprise horizontal-emitting GUV devices 123 installed on two or more interior walls 117 of the room to define the disinfecting area on more than one side. For example, the system 101 can comprise four horizontal-emitting GUV devices 123 that are configured to direct germicidal UV radiation 105 towards a center of the room to define a disinfecting area that comprises a horizontal plane in the upper portion of the room. When the germicidal UV radiation 105 is emitting horizontally, consideration should be given to the direction of the germicidal UV radiation 105 to prevent direct irradiation of occupants present in the lower section of the room. For example, the horizontal-emitting GUV device 123 can comprise a collimating element, such as lenses or concave mirrors, to ensure that the beam of germicidal UV radiation 105 is properly collimated. The collimating element is configured to divert the germicidal UV radiation 105 towards the disinfecting area and away from the lower portion of the room.

[00169] The air’s exposure to germicidal UV radiation 105 in the disinfecting area gives rise to an exponential decrease of the pathogen 121 concentration, as illustrated in graph 201 in Figure 2. The average concentration of pathogens 121 in the air C(t) can be determined by the following equation:

- 21 C(t) = Co e-f wherein b is determined by the following equation: k vPuvc b = V b is proportional to the power of GUV device 103 Puvc and the ratio of the irradiated volume v divided by the volume of the room V. The proportionality constant k is a function of the pathogen 121 in the room being calculated. The graph 201 shows three successive experimental measurements of the concentration of E. Coli (y axis) aerosolized in a test room as a function of time (x axis) (Nunayon, S., et. al. “Comparison of Disinfection Performance of UVC-LED and Conventional Upper-Room UVGI Systems.” Indoor Air, 30, 1 , 2020, 180-191 ). The graph 201 plots In as a function of time t and therefore the

slopes of the curves are simply -b as calculated by the following equation:

The average slope -b of the three experiments (/CLED) shown in graph 201 is -0.3331 ± 0.07 min ¹. [00170] A comparison of the efficacy of the GUV device 103 at decreasing the pathogen concentration can be made against other competing sanitization approaches, such as a simple exchange of air obtained by opening an exterior window or by using an air exchange system connected with outdoor air using ducts. Referring now to Figure 3, which illustrates air exchange, the air 303 in a room 305 having a volume V has a concentration of pathogens C(t) that is altered by admitting a volume u of fresh air 307 coming from outside 309, while simultaneous exhausting an equivalent volume u of air 311 over the same time period, thereby not causing any appreciable change in pressure of the room. In these calculations, an assumption was made that the concentration of pathogens C in the fresh air 307 is 0. 22 [00171] The removal of pathogens n contained in the exhausted volume u 311 while not admitting any new pathogens reduces the room pathogen concentration. The effect of dilution can be calculated by defining the concentration of pathogens C(t) in the following equation: C(t) º

Where N(t) is the number of pathogen in the room and V is the volume of the room. The number of pathogens n(t) in the exhausted volume u can be calculated by multiplying the concentration of pathogens C(t) in the room by the exhausted volume u using the following equation: n(t) = it C(t).

By determining the conservation of the total number of pathogens, the rate of change of the number of pathogens inside the room

iV(t) can be calculated with the following formula:

The rate of change of the number of pathogens inside the room

N(t) is equal to the number of pathogen n(t) inside the exhausted volume u multiplied by the ratio of the rate of flow f divided by the volume u. Accordingly, the concentration of pathogens C(t) in the room can be determined by the following equation:

«o = -_ji t which describes an exponential phenomenon with the solution expressed in the following equation:

- 23 - [00172] The exponential coefficient g can be determined by the formula g = , as the exponential coefficient g is equal to the rate of flow f divided by the room total room volume V. The exponential coefficient g can be considered as the number of “air changes” per unit time. In these calculations, an assumption was made that the newly admitted fresh air mixes with the contaminated air resulting in the concentration of pathogens C(t) being uniform in the room. With this assumption, the concentration of pathogens C(t) does not reduce to zero after one full “air change” - rather only to 37% of the initial concentration of pathogens C(t) prior to the air change. Even if non-uniform concentration was assumed, the concentration would not be reduced to zero after one full “air change”, as this would require a laminar flow system.

[00173] Both the neutralization of pathogens and the dilution of active pathogens in the air can be modeled as exponential decays. Accordingly, the efficiency of GUV devices 103 can be expressed in terms of equivalency to “air changes”, which provides a convenient figure for comparison. For example, for the particular experimental setup of the UV emitting device shown in Figure 2, which determined an average b of 0.3331 ± 0.07 min ¹, means that this method is equivalent to 0.3331 changes per minute or approximately 20 air changes per hour. This example experimental measurement illustrates how efficient the neutralization of pathogens with germicidal radiation is compared to air exchange methods. To achieve 20 air changes of air per hour using conventional air exchange technology would require massive ventilation systems that would impose uncomfortably elevated air currents for the occupants of the rooms, in addition to being noisy and cumbersome for any reasonable room sizes.

[00174] The approach of air exchange in either cold or warm climates also brings additional expenses to heat or cool the admitted air to keep the ambient air comfortable for the room’s occupants. Fleat exchangers can reduce this problem by passively thermalizing the admitted air with the exhausted air; however, because this process can only achieve essentially a mid-point equilibrium, heating and cooling is still necessary to reach comfort and introduces additional cost compared to the GUV sanitizing approach, which does not require any air exchange with the outside.

- 24 - [00175] Referring now to Figures 5A to 5C, a GUV device that can be configured to be retrofitted on an existing air moving device is shown. In the exemplary embodiment, the existing air moving device is a ceiling fan that extends from the ceiling with a shaft 509. The GUV device comprises a support assembly 507 and a light emitting assembly (not shown) coupled to the support assembly 507.

[00176] In the exemplary embodiment, the support assembly 507 includes the electronic circuitry that supports the light emitting assembly, such as a printed circuit board (PCB) that supports UVC LEDs (i.e., the light emitting assembly). In other embodiments, the support assembly 507 can comprise a physical or mechanical support for the light emitting elements and their electronic circuitry. The support assembly 507 is comprised of two half-disks defined as a first portion 503a and a second portion 503b pivotally coupled at a pivot point 505. The support assembly 507 further comprises an aperture 511 that is configured to receive the shaft 509. Accordingly, to retrofit the GUV device on an existing air moving device, the support assembly 507 can be placed in close proximity to the shaft 509 in an open configuration, as shown in Figures 5A and 5B. The support assembly 507 can be installed on the shaft 509 by pivoting the first portion 503a and the second portion 503b at the pivot point 505 so as to completely surround the shaft 509 in a closed configuration, as show in Figure 5C.

[00177] In some embodiments, the support assembly 507 can comprise multiple segments that are coupled to each other and configured to allow the support assembly 507 to have an open configuration and a closed configuration. For example, other configurations with 3, 4, 5, 6, or more segments can be used. One advantage to having a support assembly 507 with smaller segments is reducing the cost of repair in the event of a single LED failure as the segment with the failed LED can be replaced without replacing the entire support assembly 507.

[00178] In other embodiments, different configurations of the support assembly 507 can be used to allow the support assembly 507 to be installed or retrofitted on an existing air moving device without the need for disassembly. In some embodiments, the support

- 25 - assembly 507 can comprise a notch that extends from the aperture 511 to an edge of the support assembly 507 and is configured to receive a portion of the shaft 509. For example, referring now to Figure 5D, a support assembly 512 is shown. The support assembly 512 comprises a single disk with a radial notch 513 that is configured to receive the shaft 509. The radial notch 513 can have a width that is equal to the width of the shaft 509 or can include an appropriate tolerance to allow easy installation on a pre-existing air moving device. In some embodiments, the support assembly 512 can further comprise a cover that is sized and shaped to fit within and/or couple to the radial notch 513 after the support assembly 512 is installed on the shaft 509.

[00179] Referring now to Figure 5E, the GUV device can further comprise a casing 515. The casing 515 comprises a support notch 517 that is configured to receive the shaft 509 of the existing air moving device. In some embodiments, the casing 515 can further comprise a notch cover 519 that is sized and shaped to fit within and/or couple to the support notch 517 after the casing 515 is installed on the shaft 509. The notch cover 519 can prevent germicidal UV radiation from being reflected downwards towards the occupants of the room and/or for aesthetics.

[00180] In the exemplary embodiment, the casing 515 comprises spokes 523 that define apertures 525 in the bottom side of the casing 515. The apertures 525 can allow an air flow from the air moving device to remove the heat dissipated by the light-emitting assembly and/or the support assembly, thus keeping the GUV device 103 at a safe operating temperature.

[00181] In some embodiments, the casing 515 comprises protrusions 523 that can extend through apertures in the support assembly to couple the casing 515 to the support assembly, for example with fasteners or with an interference fit. In other embodiments, the casing 515 can comprise a groove that is configured to receive a support assembly.

[00182] In some embodiments, the casing 515 can have side walls that are configured to define a disinfecting area. In some embodiments, the side walls can comprise a flared

- 26 - section that is configured to prevent the germicidal radiation from being emitted horizontally or in directions lower than the horizon.

[00183] Referring now to Figure 4A, a support assembly 1201 according to one embodiment is shown. The support assembly 1201 comprises a printed circuit board that is configured to electronically couple to the light-emitting assembly. The electronic circuits shown on the support assembly 1201 are configured to comprise the top surface of the support assembly 1201 , thereby minimizing the complexity of manufacturing the support assembly 1201 and maximizing heat conductivity. Figure 4A shows an example single layer design that is comprised of 14 unit cells 1203 that are connected in parallel. In some embodiments, the support assembly can be constructed using multiple layers of printed circuit boards to increase the UVC power without increasing the lateral dimensions of the GUV device 103.

[00184] Referring now to Figure 4B, an electrical circuit 1301 is shown as an exemplary embodiment of the unit cell 1203 with three LEDs 1303 connected in series. A regulator 1305 in inserted between the second and third LED 1303 in order to set the current in the chain to a specific value, for example 40 mA. The electrical circuit 1301 can also comprise a shunt resistor 1307 to provide a voltage signal (proportional to the current) to the regulator 1305 to enable the regulator 1305 to alter its impedance and thus achieve current regulation. The electrical circuit 1301 can also include capacitors 1309 used to stabilize the operation of the regulator 1305. It is understood that other current supplying approaches and topologies are possible to operate the light-emitting assembly.

[00185] Referring now to Figure 4C, a similar regulation circuit with additional example components for overcurrent 1313, overtemperature 1315 and ESD protection 1317 is shown. Additional reverse input power polarity protection can also be used to further protect the light-emitting assembly, such as the LEDs.

[00186] Referring now to Figure 6A, a GUV device 601 according to another embodiment is shown. The GUV device 601 comprises a support assembly 605, which

- 27 - in this exemplary embodiment is a printed circuit board (PCB) that is configured to couple to and support a light emitting assembly (not shown).

[00187] The GUV device 601 can include a mounting assembly that is operatively coupled to the support assembly 605 and configured to mount the support assembly to the shaft 509 of an air moving device. In the exemplary embodiment, the mounting assembly is a mechanical clip 623 that secures the support assembly 605 to the shaft 509. However, it is understood that other mounting assemblies can be used, such as a magnetic clip that magnetically couples to the support assembly 605 and/or the shaft 509.

[00188] In some embodiments, the GUV device 601 can include a protective skirt 625 that is removably coupled to the support assembly 605. The protective skirt 625 defines a disinfecting area with the light emitting assembly and can be used to prevent the germicidal UVC radiation from being emitted horizontally or in directions lower than the horizon, therefore protecting the occupants of the room who are located below the level of the air moving device and, thus, below the GUV device 601.

[00189] It is understood that the protective skirt 625 and the mechanical clip 623 can be manufactured in various materials, colors, textures, and/or finishes, such that the GUV device 601 can blend with the fan appearance as desired.

[00190] Referring now to Figure 6B, the GUV device 601 is shown in a disassembled and open configuration. As can be seen, when disassembled, the support assembly 605, the mechanical clip 623, and the protective skirt 625 each comprise two separate portions that are removably couplable to each other.

[00191] The support assembly 605 is comprised of a first portion 603 and a second portion 604 pivotally coupled at a pivot point 606. In this exemplary embodiment, the pivot point 606 is a self-locking nylon rivet. However, it is understood that other types of pivot mechanisms can be used, such as a nut and bolt assembly. The pivot point 606 allows the support assembly 605 to move from an open configuration to a closed configuration after being installed on the shaft 509. In some embodiments, the first portion 603 and the

- 28 - second portion 604 can comprise corresponding apertures 607 that align when the GUV device 601 is in the closed configuration. The first portion 603 and the second portion 604 of the support assembly 605 can then be maintained in the closed configuration by inserting a fastener, such as a self-locking nylon rivet or nut and bolt assembly, through the corresponding apertures 607.

[00192] In some embodiments, the first portion 603 and the second portion 604 of the support assembly 605 can be identical and designed as half-circle shapes to comprise a circular support assembly 605 when in the closed configuration. However, it is understood that the support assembly 605 can comprise any shape. In some embodiments, the first portion 603 and the second portion 604 comprise a shape that provides an overlap between the first portion 603 and the second portion 604 when the support assembly 605 is assembled and in the closed configuration, thus preventing germicidal radiation from being directed downwards towards the occupants of the room. In the exemplary embodiment, when in the closed configuration, the first portion 603 slides overtop of the second portion 604 to provide the overlap. In some embodiments, the bottom portion of the support assembly 605 (in this case, the second portion 604) can comprise a bumper 615 configured to prevent the top portion (i.e., the first portion 603) from moving beyond the close configuration, thus protecting the electronic components on the bottom portion from being scraped off or damaged by the top portion. In other embodiments, the bumper 615 can be on the top or first portion 603. In the exemplary embodiment, the bumper 615 is a nylon hexagonal screw, with the head of the screw playing the role of the bumper 615. However, any other configuration that provides a protrusion on the first portion 603 or the second portion 604 can be used as a bumper 615.

[00193] When in the closed configuration, the first portion 603 and the second portion 604 of the support assembly 605 define an aperture 610 configured to receive the shaft 509 and/or a mounting assembly. In some embodiments, a periphery of the aperture 610 can include grooves 611 configured to receive the mounting assembly and angularly position the support assembly 605 with respect to the mounting assembly.

- 29 - [00194] In the exemplary embodiment, the mounting assembly is a mechanical clip 623 that is configured to fit in the aperture 610 of the support assembly 605. The mechanical clip 623 comprises two clip portions 609 that, when coupled, define an aperture that is configured to fit around the shaft 509. Each clip portion 609 comprises a protrusion that is configured to be received in one of the grooves 611 to align the mechanical clip 623 with the support assembly 605.

[00195] In some embodiments, a protective skirt 625 can be removably coupled around a periphery of the support assembly 605. In the exemplary embodiment, the protective skirt 625 comprises two skirt portions 613 that are removably coupled to each other and/or the support assembly 605.

[00196] Referring now to Figures 7A to 8D, an exemplary embodiment of a first clip portion 701 and a second clip portion 801 are shown. The first and second clip portions 701 , 801 are configured to couple to either the bottom or top portion of the support assembly 605. In some embodiments, the first clip portion 701 can be configured to receive the second portion 604 (/.e., the bottom portion) and the second clip portion 701 can be configured to receive the first portion 603 (/.e., the top portion) of the support assembly 605. The first clip portion 701 and the second clip portion 801 can each be constructed using a half cylindrical body 703, 803 that defines a concentric or near concentric inner cylindrical section 705, 805. When coupled to each other, the inner cylindrical section 705 of the first clip portion 701 and the inner cylindrical section 805 of the second clip portion 801 define an aperture that is configured to receive the shaft 509. Consideration of the shaft 509 width should be given when determining the diameter of the inner cylindrical sections 705, 805. For example, the diameter of the inner cylindrical sections 705, 805 (thus defining the diameter of the aperture that receives the shaft 509) can be chosen to fit with the shaft 509 or can be slightly larger to allow the use of a compressible intervening material to ensure good contact with the shaft 509 and to accept slight manufacturing variations of the inner cylindrical sections 705, 805 and/or the shaft 509. In other embodiments, the first clip portion 701 and/or the second clip portion 801 can comprise flexible or deformable members that are arranged in the inner cylindrical

- 30 - sections 705, 805 such that the dimensional tolerance of the inner cylindrical sections 705, 805 to the shaft 509 fit is increased. Increasing the dimensional tolerance can provide a universal mounting mechanism that allows the mechanical clip to be sized and shaped to fit a plurality of shafts 509 with varying diameters. In other embodiments, the coupling between the first clip portion 701 and the second clip portion 801 can be adjustable such that the mechanical clip can be sized and shaped to fit a plurality of shafts 509.

[00197] The first clip portion 701 can include receiving holes 707 that are configured to receive a fastener, such as screws or bolts, to couple the first clip portion 701 and the second clip portion 801. In some embodiments, the receiving holes 707 are counterbored or countersunk. Similarly, the second clip portion 801 can include receiving holes 807 that are configured to align with the receiving holes 707 on the first clip portion 701 when in the closed configuration, such that fasteners, such as of screws or bolts, can extend through the receiving holes 707, 807 and couple the first clip portion 701 and the second clip portion 801.

[00198] The first clip portion 701 can also include a protrusion 709 that is configured to be inserted inside the grooves 611 on the support assembly 605 to provide an angular constraint and correctly orientate the first clip portion 701 with respect to the first portion 603 or the second portion 604 of the support assembly 605. Similarly, the second clip portion 801 can also include a protrusion 809 that is configured to be inserted inside the grooves 611 on the support assembly 605 to provide an angular constraint and correctly orientate the second clip portion 801 with respect to the first portion 603 or the second portion 604 of the support assembly 605. This angular constraint can be used to ensure that the first portion 603 and the second portion 604 is correctly oriented with respect to the first clip portion 701 and the second clip portion 801.

[00199] In some embodiments, the first clip portion 701 and can include a flexible clamp 711 that can be used to secure a wire, such as a power cable. Similarly, the second clip

- 31 - portion 801 can include a flexible clamp 811 that can be used to secure a wire, such as a power cable.

[00200] The mounting mechanisms shown in Figures 7A to 8A are provided as an example. Several other clip designs are also possible. For example, alternate clips could be secured to the shaft 509 using magnets instead of relying on a mechanical clamping mechanism.

[00201] Referring now to Figures 9A to 9D, a skirt portion 903 of a protective skirt according to one embodiment is shown. In this exemplary embodiment, the protective skirt comprises two skirt portions 903 that are configured to removably couple to each other and/or the support assembly 605. In some embodiments, the protective skirt is coupled around a periphery of the support assembly 605. The skirt portions 903 can include an interior groove 905 that is configured to receive a peripheral border of the support assembly 605.

[00202] In some embodiments, the protective skirt defines a disinfecting area with the germicidal UV radiation emitted by the light emitting assembly. The skirt portions 903 can each include a flared section 907 that is configured to extend axially from the periphery of the support assembly 605 when coupled to the support assembly 605. In the exemplary embodiment, the flared section 907 minimizes the blocking of the germicidal UV radiation being emitted from the lights on the light-emitting assembly that are mounted on the periphery of the support assembly 605, while preventing or reducing horizontal emission. The flared section 907 can be configured to direct the germicidal UVC radiation upwards towards the ceiling and away from the occupants in the lower portion of the room. In some embodiments, the side walls of the flared section 907 can comprise mirrors or other reflective surfaces to direct the germicidal UV radiation towards the disinfecting area.

[00203] In some embodiments, the protective skirt can extend around the entire periphery of the support assembly 605, such as when the GUV device 601 is coupled to an air moving device in or near the center of the room. When used with a horizontal- emitting GUV device 123, a single skirt portion 903 can be coupled on the bottom side of

- 32 - the support assembly 605, such that the germicidal UV radiation is directed laterally in the upper portion of the room and away from the occupants in the lower portion of the room. Other configurations of a protective skirt that defines a disinfecting area and/or directs the germicidal UV radiation to a desired area, such as towards the disinfecting area and/or away from occupants in the room, are also possible.

[00204] In some embodiments, the skirt portions 903 can be removably coupled to each other for ease of retrofitting on the shaft 509 of an existing air moving device without disassembly. The skirt portions 903 can each include a tab 909 on a first end thereof with an aperture 911 and a protrusion 915 on the second end thereof that is configured to be received in the aperture 911 on the other skirt portion 903. Accordingly, the aperture 911 on a first skirt portion 903 is configured to receive the protrusion 915 on the second skirt portion 903 and the aperture 911 on the second skirt portion 903 is configured to receive the protrusion 915 on the first skirt portion 903 to removably couple the first skirt portion 903 to the second skirt portion 903. In some embodiments, the skirt portions 903 each comprise a small shield 919 on the first end thereof (i.e., the end with the tab 909) that is configured to overlap with the other mating skirt portion 903, thus preventing germicidal UV radiation from passing in between the skirt portions 903 at the area where they join.

[00205] The protective skirt can be comprised of materials that have a moderate amount of elasticity, allowing the skirt portions 903 to flex during mating in order for the protrusion 915 on the first skirt portion 903 to fit in the aperture 911 on the second skirt portion 903. Mating the first and second skirt portions 903 allow the protective skirt to be secured around the support assembly 605 during installation. In other embodiments, the protective skirt can be constructed in one piece only, using a more flexible or elastic material, by wrapping around the support assembly 605, or using one or more skirt portions 903 that do not completely surround the periphery of the support assembly 605, or could also be at least partially formed integral with the support assembly.

[00206] In some embodiments, the GUV device 103 further comprises a protective covering configured to be removably coupled to the protective skirt and/or the support

- 33 - assembly 605 over the light emitting assembly. In some embodiments, the protective covering is a convex dome. The protective covering is configured to allow the germicidal UV radiation to pass through the protective covering, while preventing the dust or other particles from reaching the support assembly 605 and the light-emitting assembly. The protective covering can be comprised of a light-permeable material and/or a UVC transmitting materials, such as fused silica.

[00207] Referring now to Figure 10A, a protective skirt 1001 according to another embodiment is shown. The protective skirt 1001 includes a plurality of openings 1003 around the body of the protective skirt 1001 that can open into the disinfecting area defined by the body of the skirt 1001 at a tangential angle. In the exemplary embodiment, each opening 1003 is coupled to a tubular section 1005 that extend outwardly from the body of the protective skirt 1001 from these openings 1003. The tubular sections 1005 are open at both ends and are configured to channel the air into the disinfecting area define by the skirt 1001 . The tubular sections 1005 are oriented in a vertical direction at the bottom, such that the upwelling air pushed by the air moving device 109 can be channeled inside the tubular sections 1005. The tubular sections 1005 can curve towards the openings 1003 that extend into the body tangentially, such that the channeled air is inserted or channeled into the disinfecting area at a tangential angle, thereby producing a circular air motion or a vortex in the disinfecting area. This circular air motion or vortex can prevent the accumulation of dust or other particles on the support assembly 605 or the light-emitting assembly, thus limiting the amount of maintenance required. The circular air motion or vortex can also increase the time that the air (and thus the contagion particles) is suspended in the disinfecting area and can increase the germicidal effect. In other embodiments, other air duct configurations can be used to control the amount and the location of the dust or particle accumulation.

[00208] In some embodiments, the GUV device 103 can comprise air filters configured to prevent dust, pollen and other particulate material from entering the disinfecting area (i.e., the area above the support assembly 605 and the light-emitting assembly). For example, one or more of the tubular sections 1005 can include an air filter at their second

- 34 - or bottom end to prevent the dust from entering the disinfecting area through the openings 1003. The air filters can also include sanitizing components, such as activated carbon, to capture or neutralize chemical pollutants, such as volatile organic chemicals (VOCs), and allow a further purification of the air in the room.

[00209] In some embodiments, a protective assembly around the support assembly can include a second concentric (outer) skirt that is larger than the protective skirt 1001 and configured to be located around the (inner) protective skirt 1001. The second skirt can be coupled to the protective skirt 1001 by narrow radial members. The radial members can be configured to catch a cross section of upwelling air around the GUV device 103 and direct it in a way to create an air motion that prevents the accumulation of dust on the support assembly 605 and the light-emitting assembly. For example, the second skirt can comprise channels that direct the upwelling air through the holes 1003 of the protective skirt to create an air flow over the support assembly 605 and/or the light-emitting assembly. The air motion can be purposely designed to feature laminar and turbulent sections to reduce the dust and/or particles that accumulate on the support assembly 605 and/or the light-emitting assembly. In other embodiments, the protective skirt can include clearance holes that are configured to allow the dust and/or particles to be removed from the support assembly 605 and/or light-emitting assembly.

[00210] Referring now to Figure 10B, a protective skirt portion 1013 according to another embodiment is shown. The protective skirt portion 1013 comprises channels 1015 around a bottom portion of the protective skirt portion 1013 where volumes of material 1015 have been removed, while leaving some support structures 1017 intact. As shown in Figure 10C, which shows the bottom side of the protective skirt portion 1013, the support structures 1017 comprise a protrusion 1021 with a groove 1019 that is configured to receive the support assembly 605 to couple two protective skirt portions 1013 to the support assembly. When an air flow is created in the disinfecting area, dust or other particles moving along the support assembly 605 or light-emitting assembly in a radial motion 1023 before hitting the outer wall of the protective skirt portion 1013 and moving in an axial direction 1025 (i.e., the downward direction) to escape through the channel

- 35 - 1015. This travel motion of the dust and/or particles can be aided by the air flow deflected by mechanical features or other mechanical means of the protective skirt portion 1013.

[00211] Other means of dust removal are possible. For example, in some embodiments, the GUV device 103 can include a fan configured to create an additional air current to prevent an accumulation of particles on the light emitting assembly and/or the support assembly. By creating an additional air current with a fan, the accumulation of dust or particles on the light-emitting assembly and/or support assembly is prevented and/or the removal of dust or particles on the support assembly and/or the light-emitting assembly is enhanced. The fan can be powered by an electrical motor, mechanical energy harvested from an air moving device fan air flow, or by any other means. In some embodiments, one or more of the GUV device 103 components can be coated with dust repellent coatings.

[00212] In some embodiments, the GUV device 103 can be equipped with a mirror positioned in such a way as to allow an observer standing on the floor (i.e., the lower portion of the room) to see if dust or other particles are present on the support assembly or the light-emitting assembly. The mirror can be operatively coupled to the support assembly and/or the protective skirt. This mirror can be configured so as to only reflect visible light and prevent the reflection of germicidal UV radiation towards the lower portion of the room (i.e., towards the observer using the mirror) for safety reasons. Alternatively, the mirror can be deployed, either manually or automatically, when the light-emitting assembly is not activated (i.e., when no germicidal UV radiation is being emitted). Alternatively, this mirror assembly can be integrated on any of the dusting accessories described herein, such as on the protective skirt.

[00213] In some embodiments, the GUV device 103 can include a dusting device comprising a dusting arm pivotally connected to the support assembly. The dusting arm can be configured to pivot around a central vertical axis of the GUV device 103. In some embodiments, the dusting arm can comprise dust-removing material or fibers. The

- 36 - dusting device can be actuated with an electric motor at the beginning or end of the GUV device 103 power cycle, or at pre-determined timed intervals.

[00214] In some embodiments, the GUV device 103 can be mounted directly on the rotating parts of the air moving device and configured such that the centrifugal force created by the rotation of the air moving device can be used to evacuate dust or other particulates from the support assembly and/or the light-emitting assembly.

[00215] In some embodiments, the GUV device 103 can include a UVC power meter that is configured to monitor the UV light reflection that is reflected off of the ceiling (i.e., monitor the strength of the germicidal UV radiation being emitted from the light-emitting assembly). In some embodiments, the power level sensed by this power meter can be used to trigger a dusting cycle as described above when the UVC power is measured below a pre-determined level that can be expressed as a percentage of the amount sensed just after a dusting cycle. In other words, the UCV power meter can be configured to determine when the germicidal UV radiation is below a pre-determined level due to accumulation of dust or other particulates on the light-emitting assembly.

[00216] In some embodiments, the GUV device 103 can include a pathogen sensor configured to determine a pathogen concentration in the air in the room. The pathogen sensor can be configured to capture and identify the pathogens, for example virus and bacteria, that are present in the air. In some embodiments, the pathogen sensor can be configured to communicate with digital networks and send real time alerts to the owners of the GUV device 103 or to public health professionals in charge of preventing the propagation of diseases in order to determine the need for preventive actions or the enactment of enhanced safety measures. The real-time information provided by the pathogen sensor can be geolocated and can be used by epidemiologists to study the propagation of contagious diseases as well as to prevent large outbreaks. In some embodiments, multiple pathogen sensors can be used to provide information on multiple pathogens. This information can be used to establish the efficiency of the GUV device 103 and the best way to deploy them. For example, to provide information on when and

- 37 - how long to activate the GUV device 103. The pathogen sensing technologies can be integrated with mobile localization applications and contact tracing applications to measure the efficiency of the GUV devices 103. For example, the GUV device 103 can be configured to juxtapose the geolocational data associated with the pathogen sensor with an identification of occupants in the room, such as via the occupant’s cellular phone or wearable devices, such as a smart watch.

[00217] Referring now to Figure 11 , a pathogen neutralization system 1101 according to one embodiment is shown. In this system 1101 , the GUV device 103 is installed on an air moving device 109, such as a ceiling fan. The GUV device 103 is powered using an external AC/DC electrical converter 1111 , which can be connected to the same AC electrical circuit 1113 that powers the air moving device. Accordingly, in this exemplary embodiment, the GUV device 103 is powered only when the air moving device is active, thereby providing air circulation directly under the GUV device 103. The air circulation is in direct proximity to the GUV device 103 and thus can be configured to remove the heat dissipated by the light-emitting assembly, thus keeping the GUV device 103 at a safe operating temperature. In some embodiments, the GUV device 103 circuit can be equipped with an overtemperature protection that is configured to shut off the light- emitting assembly if the temperature reaches a preset threshold. In some embodiments, the overtemperature protection is a bi-metal switch installed on the support assembly. In some embodiments, the support assembly is a printed circuit board that is fabricated using a conductive material such as aluminum in order to efficiently conducted the heat dissipated by the light-emitting assembly present on the support assembly, down to the bottom surface of the support assembly, where it can be convectively removed by the air circulated by the air moving device 109.

[00218] The system 1101 can include a UVC power meter 1115, optionally installed on a tripod 1117, such that the sensing surface of the UVC power meter 1115 is facing towards the ceiling 107. The tripod 1117 can be placed on the floor or on a table where occupants are likely to be located. Consideration of the height of the highest body part of the occupants, such as the head, or any height recommended in international biosecurity

- 38 - standards, should be considered when placing the UVC power meter 1115, such that the measurement is representative of the UVC dose that would be delivered to the occupant.

[00219] The UVC power meter 1115 can be operated when an irradiance measurement is required for instillation, or the UVC power meter 1115 can be operated continuously after being installed at the correct position. If the UVC power meter 1115 operates continuously, the UVC power meter 1115 can be configured to issue audible or visible alerts when the irradiance safety thresholds are exceeded.

[00220] In some embodiments, the power meter is a smart device configured to give an audible or visual command to the installer that instructs the installer as to what power adjustment is required to meet the regulations. In some embodiments, the UVC power meter 1115 is connected wirelessly 1119 to a portable electronic device 1121 that can provide visual or audible instructions to the installer regarding the power adjustment required to meet regulations.

[00221] In some embodiments, the UVC power meter 1115 is connected to the Internet 1125 either via WIFI 1123 or indirectly via a portable electronic device 1121, including a mobile phone or tablet. The information pertaining to the installation may be sent to a database 1127 for validation of the installation parameters. The information sent to the database 1127 may also include the final irradiance level, sampled irradiance levels during installation, the GPS coordinates of the GUV device 103, the installer name, and/or installation pictures. This system 1101 can also include specialized firmware or software controlling the UVC power meter 1115 and/or the portable electronic device 1121. Additional software components could also be required to access the database.

[00222] In some embodiments, the GUV device 103 can be equipped with a communication link (e.g. Bluetooth, Ethernet, WIFI, Infrared, RFID, etc.) to communicate the status of the GUV device 103 to the owners of the assets or the sanitation authorities. For example, the communication link can be configured to communicate with the database 1127 and provide information to a user via the portable device 1121. The status information communicated can include the serial number of the device, the device

- 39 - geolocation (civic address and room number), the names and means of communication for the owner and person responsible for maintenance, the total operation time, total number of power cycles, remaining useful hours, UVC power levels, excessive dust or particular matter detected, technical problems detected, etc.

[00223] In some embodiments, alerts concerning an abnormal operation of the light- emitting assembly and/or a lower than expected UVC power can be transmitted via the communication link or via an audible signal to facilitate a dusting, maintenance, and/or repair visit to be scheduled.

[00224] In some embodiments, one or more UVC dose sensors can be installed on the upper side of the ceiling fan blades to ascertain the level of reflection from the ceiling. These UVC dose sensors can be photosensitive films that change color according to the total cumulative dose of germicidal UVC radiation received. With this method, the UVC sensing can be performed periodically by maintenance personnel in an inconspicuous manner.

[00225] In some embodiments, the GUV device 103 can include an occupancy detector configured to detect a number of occupants in the room and/or a motion detector configured to detect motion in the room, and thus the presence of at least one occupant. The GUV device 103 can be configured to be activated and/or deactivated when the occupancy sensor determines that the numberof occupants is greaterthan 0 and/or when the motion detector detects motion in the room. In some embodiments, the occupancy detector and the motion detector can be used in conjunction with each other, with each acting as a fail-safe for the other.

[00226] In some embodiments, the GUV device 103 can be configured to deactivate after a pre-determ ined time period that starts when the occupancy detector indicates that the last occupant of the room has left and/or when the motion detector indicates that there has not been motion for a specific time period. The pre-determined time period can be selected to match the amount of time that the GUV device needs to adequately sanitized the room air when new contagions are not being introduced by occupants. Alternatively,

- 40 - the GUV device 103 can be programmed to activate and deactivate according to a fixed schedule, such as according to the time period where the establishments that the GUV device 103 is deployed in are open and occupants are expected to be present. For example, a GUV device 103 deployed in a school room can be programed to activate at 7h00 (i.e., slightly before occupants are expected in the room) and deactivate at 18h00 (i.e., slightly after occupants are expected to have left the room). In this example, the GUV device 103 could also be programed to take into account holidays and other school closures when the GUV device 103 can be deactivated. When the GUV device 103 comprises multiple intermittent operation modes, the GUV device 103 saves energy and the lifetime of the light-emitting assembly can be extended.

[00227] In some embodiments, the GUV device 103 can have a sanitation mode configured for use with at least one occupant in the room and a rapid sanitization mode configured for use when no occupants are present in the room. During the sanitation mode, the light-emitting assembly emits a level of germicidal UV radiation that is sufficient to reduce the pathogen concentration in the room and remain safe for the occupants in the room (i.e., the germicidal UV radiation would meet the irradiance levels set by international safety organizations). In contrast, during the rapid sanitation mode, the irradiance levels set by international safety organizations can be exceeded because no occupants will be subjected to these high levels. In some embodiments, the rapid sanitization mode can be activated manually, for example by trained operators, or automatically activated by the occupancy detector and/or motion detector. The rapid sanitization mode can also be activated if the occupants are wearing protective gear. In some embodiments, the special rapid sanitization mode can be activated when the risk of contagion is established by warning systems, such as the pathogen sensor or sensors. In some embodiments, the GUV device 103 can be activated and/or deactivated by voice command.

[00228] In some embodiments, the GUV devices 103 can be controlled by a system that communicates with multiple pathogen reduction devices and systems within the room and/or building, such as the GUV devices 103, ventilation systems, air exchange systems

- 41 - and other air purification technologies. Advanced analytical techniques including machine learning algorithm can be applied to optimize the efficiency of these systems.

[00229] In some embodiments, the GUV device 103 can comprise a light-emitting assembly that has an increased optical power, for example by comprising more germicidal UV emitting elements, such as LEDs, or more powerful germicidal UV emitting elements for a more efficient sanitation or to facilitate the rapid sanitation mode. When installing the GUV devices 103, a UVC absorbing material can be applied on the ceiling or adjacent walls, whether preexisting material or purposely applied films or coatings, or rooms with higher ceilings (e.g. warehouse, plants, airports, etc.) can accept higher optical power GUV devices for improved sanitation performance while keeping the occupants of the room safe.

[00230] In some embodiments, the optical power of the GUV device 103 can be reduced in warm climate situations when windows in the room are open and physical air exchange is used in combination with the germicidal UV radiation sanitation, achieving an equivalent overall sanitation performance. Operating at reduced optical power also results in less heat dissipation in the room, thereby avoiding heating of the ambient air and increasing the comfort of the occupants. The lower currents in the UV light-emitting elements can be achieved by several methods, including changing the resistance of the shunt resistor 1307 and changing the voltage of the supply to the LEDs.

[00231] In some embodiments, the GUV device 103 can include one or more additional indicator lights, such as LEDs, to indicate an operating mode of the GUV device 103, such as activate, deactivate, in sanitation mode, in rapid sanitation mode, normal function, maintenance required, malfunction, etc. These indicator lights can be any color, for example green to indicate normal function or blue/violet to indicate that germicidal UV radiation is being emitted. A multi-colored indicator light panel or a group of varying color indicator lights can be used to indicate the operation of the GUV device 103, including the color red, to indicate malfunction or maintenance action being required.

- 42 - [00232] In some embodiments, an indicator panel, such as a set of LED segments stacked vertically or horizontally, can be installed on the ceiling fan column. The visible indicator panel can provide information to occupants that are based on the time of powering the GUV device 103, the pathogen sensors, airflow sensors, motion detectors, and occupancy detectors. The vertical visible indicator can be used to inform the occupants of the room in real time about the level of pathogen neutralization, the effective number of air changes, a maintenance requirement, and/or other performance-related indications.

[00233] As shown in Figure 11 , the germicidal UV radiation 105 emitted by the GUV device 103 can be reflected off the ceiling 107 and thus can impinge on various objects as well as occupants present in the room. In order to keep the germicidal UV radiation 105 level below the human safety levels set by the regulation organizations, e.g. the International Electrotechnical Commission, the GUC device 103 can be installed according to the exemplary installation procedure shown in Figure 12.

[00234] During the method of installation 1401 , the installer first installs 1403 the GUV device (GUVD) 103 according to the installation manual. The installer can activate the GUV device 103 by powered on the device 1405. Next, an irradiance measurement is acquired 1407 at some representative position in the room where occupants will spend extended amounts of time. If the measurement is compliant 1409 with the established standards, for example the irradiance is less than 1 pW/cm² from IEC 62471 :2006, the installation is deemed compliant and the installation is complete 1415. On the contrary, if the measurement exceeds the irradiance limit, the GUV device 103 is deactivated by powered off 1411 the GUV device 103. The UVC power of the GUV device 103 (i.e., the level of germicidal UC radiation 105 being emitted) must be reduced 1413 and a new measurement is taken 1407 after powering the GUV device on 1403. The cycle is continued until the irradiance level is compliant with the regulation organization requirements.

- 43 - [00235] In some embodiments, measures can be taken to ensure that the germicidal UV radiation is not directed towards the occupants in the room. For example, in some embodiments, the GUV device 103 can include a level to assist in the proper installation of the GUV device 103 and prevent the GUV device 103 from being installed incorrectly (i.e., where the germicidal UV radiation is directed towards the bottom portion of the room).

[00236] In another embodiment of the installation procedure, the power level of the UVC power of the GUV device 103 is controlled remotely and thus the step 1411 is not required. Remotely control can be achieved by changing the global current set point of all the light-emitting elements, such as UVC LEDs, or by partially or completely reducing the power emitted by a subset of the light-emitting elements.

[00237] In one embodiment, the UVC power adjustment 1413 of the GUV device 103 can be performed by removing physical jumpers to break one or several unit cells 1203 of the support assembly 1201 or the electrical circuit 1301. Referring back to Figure 4A, the location of exemplary physical jumpers that can be used to remove one unit cell 1205, two unit cells 1207 and/or three unit cells 1209 is shown.

[00238] Alternatively, instead of using physical jumpers, the unit cells 1203 can be broken by opening electronic switches located at positions similar to the jumper locations indicated in Figure 4A and actuated manually or via a microcontroller or microprocessor communicating with a user interface. In other embodiments, the current circulating in each unit cell 1203 can be controlled by replacing one or many shunt resistances 1307 by a variable resistance, for example with a potentiometer, an electronically controlled potentiometer, a transistor, or another appropriate electronic component, that is controlled manually or via a microcontroller or microprocessor communicating with a user interface.

[00239] Alternatively, the UVC power meter 1115 and the power measurement performed by the UVC power meter 1115 can communicate information to a microcontroller or microprocessor within the GUV device 103 electronics, and the microcontroller or microprocessor can automatically control the global UVC power by

- 44 - either breaking open one or many units cells 1203 or by varying one or many shunt resistances 1307 as herein.

[00240] In some embodiments, the GUV device 103 can include a low reflectance blocker configured to reduce the germicidal UV radiation 105 reflected towards the lower portion of the room. The low reflectance blocker can be comprised of a material featuring a low reflectance in the UVC spectral range. The low reflectance blocker can be installed on the ceiling above the air moving device to reduce the amount of germicidal UV radiation 105 reflected towards the occupants. The low reflectance blocker can be made of a film or flexible membrane so as to allow folding or rolling for ease of packaging and transportation. The film or membrane low reflectance blocker can be installed on the ceiling using self-adhesive segments installed on the back of the low reflectance blocker or additional adhesive applied to the back of the low reflectance blocker. The low reflectance blocker can have an aperture at its center to provide a clearing for the interface between the shaft of the air moving device interface and the ceiling. The low reflectance blocker can also have a radial slit to facilitate the installation of the low reflectance blocker on an existing air moving device without requiring disassembly. The film or membrane material can comprise any geometric shape, such as a disk, a square, hexagon, octagon, etc. In some embodiments, the film or membrane can be configured as a decorative item to match the aesthetics of the air moving device, the room, and/or the GUV device 103.

[00241] In some embodiments, the portion of the ceiling that will be irradiated by the germicidal UV radiation 105 can be coated with a flexible membrane comprising paint or a coating that is configured to absorb UVC radiation. For example, zinc oxide paints are excellent absorbers and feature a UVC reflectance level around 4%. In some embodiments, the low reflectance blocker and/or the flexible membrane can be comprised of a material that can be exposed to UVC light for extended period of time while resisting material degradation. In other embodiments, the low reflectance blocker or flexible membrane applied to the ceiling can be configured to react with the contact of

- 45 - pathogens and provide a visual cue to indicate the nature of the pathogen (e.g. the type of virus or bacteria detected).

[00242] Referring now to Figure 13, the pathogen neutralization system or the GUV device 103 can further comprise a cover 1503 that is configured to be installed with the GUV device 103. The cover 1503 can be installed above the light emitting assembly and is configured to act as a low reflectance blocker and minimize the UVC light reflected towards the lower portion of the room. In some embodiments, such as with a horizontal- emitting GUV device 123, the cover 1503 can be installed across from the light emitting assembly to define the end of the disinfecting area. The cover 1503 can be installed on the support assembly 605, the air moving device 109, or the ceiling 107 of the room. In some embodiments, the cover 1503 can be used to hide the AC/DC converter 1111 required to provide DC electrical power to the light-emitting assembly. The cover 1503 can also be used to hide the electrical wires from and to the AC/DC converter 1111. In some embodiments, the cover 1503 is comprised of a UV resistant and/or UV absorbing material so as to minimize the amount of UV light reflected towards the lower section of the room where occupants are present. The cover 1503 can be comprised of moldable UV-resistant plastics, including a non-reinforced, impact modified, injection moldable grade resin such as polycarbonate/polybutylene Terephthalate (PC/PBT). Referring now to Figure 14, a PC/PBT material (Valox 357) was determined to show a very low reflectance of around 7 to 9% through both diffuse reflection and specular reflection. The total reflectance of the cover 1503 can further be lowered to approximately 2% by adding groove textures in the molded parts, as shown in Figures 15A and 15B.

[00243] The cover 1503 can be provided in multiple cover portions, so as to enable easy installation on an existing air moving device without disassembly. In the exemplary embodiment, the cover 1503 is installed on the ceiling 107 of the room, and when installed in a closed configuration, is coupled around the shaft 509 of the air moving device 109.

[00244] Referring now to Figures 15A and 15B, a cover 1603 according to another embodiment is shown. The cover 1603 is configured to be installed with the GUV device

- 46 - 103 and act as a low reflectance blocker to minimize the germicidal UV radiation that is reflected towards the lower portions of the room. The cover 1603 can comprise grooves 1605 or baffles that are configured to further deflect the germicidal UV radiation that is emitted from the light emitting assembly.

[00245] Referring now to Figure 16, a graph representing distribution of light emission of a representative UVC LED as a function of the angle from the normal of its emitting surface is shown. Most UVC emitting LEDs emit light in a cone with a relatively large angle. As can be seen, an appreciable amount of UVC power is emitted in angles beyond 50 degrees. Accordingly, when in use, the light-emitting assembly can emit germicidal UVC radiation at a larger angle than desired, such that the light rays extend beyond the intended disinfecting area and/or are not absorbed by the low reflectance blocker.

[00246] Referring now to Figure 17, a GUV device according to another embodiment is shown. The GUV device includes a baffle 1903 that is configured to limit the rays of germicidal UV radiation that would otherwise miss the cover 1503 and impinge on the ceiling. The GUV device comprises the baffle 1903 operatively coupled to a support assembly 1905 and a protective skirt 1906 operatively coupled to the support assembly 1905 and the baffle 1903. The baffle 1903 is located at a predetermined distance from the support assembly 1905 onto which the light emitting assembly comprising light- emitting elements 1907 are mounted. The baffle 1903 can be comprised of a flat, thin material that is opaque and exhibits UV absorbing attributes.

[00247] The baffle 1903 includes a plurality of holes 2003, which can be arranged in a pattern as illustrated in Figure 18 or 19. The diameter of each hole 2003 is chosen to allow the central rays 1909 to pass through unimpeded, while the rays with large angles 1911 impinge on the lower surface of the baffle 1903 and are absorbed. Note that the position of each hole 2003 can be adjusted with respect to the position of the corresponding light-emitting element 1907 so as to define the desired cone of emission that emits the germicidal UV radiation into the disinfecting area. In the exemplary embodiment shown in Figure 18, the relative hole 2003-to-light-emitting element 1907

- 47 - offset is calculated so as to direct the emission cone towards the cover 1603. Accordingly, the holes 2003 are provided at a radial offset that increases as the light emitting elements 1907 are located further away from the baffle center. For example, as shown in Figure 20, light emitting elements 1907a that are located closer the baffle center can be aligned directly or nearly directly to a corresponding hole 2003a to provide a cone of emission 1927a that is directed towards the cover 1603 or another low reflectance blocker; whereas light emitting elements 1903b that are located further away from the baffle center are offset from their corresponding hole 2003b to provide a cone of emission 1927b that is also directed towards the low reflectance blocker.

[00248] In this exemplary embodiment, the protective skirt 1906 comprises a bottom wall 1921 that is configured to couple to the support assembly 1905. The bottom wall 1921 comprises a skirt aperture 1923 that is configured to receive the shaft 509 of the air moving device 109. In this embodiment, the protective skirt 1906 also includes protrusions 1925 that extend through apertures in the support assembly 1905 and the baffle 1903 to couple the protective skirt 1906 to the support assembly 1905 and the baffle 1903 and to hold the baffle 1903 at a desired distance from the light-emitting elements 1907. Flowever, other methods of coupling the protective skirt 1906 to the support assembly and/or the baffle 1903 can be used. For example, the protective skirt 1906 can be coupled around the periphery of the support assembly 1905.

[00249] In some embodiments, the GUV device 103 can be provided with a pair of protective glasses that block UVC light while allowing to see longer wavelength light (e.g. red, yellow, green, violet or blue). The pair of glasses can be used to safely observe the light-emitting assembly and the light-emitting elements and confirm that they are functioning correctly. In the case of unexpectedly disabled light-emitting elements, the wearer of the glasses can request a maintenance or repair action.

[00250] In some embodiments, the GUV device 103 can be modified to provide aesthetic lighting and/or sound to the occupants in the room. For example, the GUV device 103 can include light-emitting elements that emit light in the visible spectrum to create special

- 48 - ambient lighting adapted to the location of the device, such as restaurants, bars, offices, etc. The variation of light intensity and color can be modulated according to the sound level in the room (chatter, music, etc.) or the presence and number of occupants. In some embodiments, the lower side of the GUV device 103 can be equipped with a visible display to show images, information, or publicity to the occupants of the room. In other embodiments, the GUV device 103 can be equipped with a projector or a holographic projector to display images or information on the ceiling or on walls. In some embodiments, the GUV device 103 can include a speaker to provide music, ambient sounds and/or audible information about the operation of the GUV device, including a start-up sound and/or alert sounds in the case of malfunction. In some embodiments, the speaker can broadcast sound therapies, such as music or sounds, that promote the general well-being or concentration of the listener, for example in a hospital or school setting.

[00251] The embodiments described above are intended to be exemplary only.

-49 -

Claims

What is claimed is:

1. A germicidal device configured to reduce a concentration of pathogens in air in a room, the germicidal device comprising: a support assembly configured to be mounted in an upper portion of the room; and a light emitting assembly comprising light emitting elements electronically coupled to the support assembly and configured to emit germicidal radiation, wherein the germicidal device is configured to cooperate with an air moving device to reduce the concentration of pathogens in the air prior to the air being circulated or re-circulated in the room by the air moving device.

2. The germicidal device of claim 1 , wherein the germicidal radiation is UVC radiation and is emitted towards the upper portion of the room and away from a lower portion of the room.

3. The germicidal device of claim 1 or 2, wherein the support assembly comprises a printed circuit board electronically coupled to the light emitting assembly and configured to operate the light emitting assembly.

4. The germicidal device of any one of claims 1 to 3, wherein the germicidal radiation is at least one of: ultraviolet C (UVC) radiation and far UV radiation.

5. The germicidal device of any one of claims 1 to 4, wherein the light emitting elements are LEDs.

50

6. The germicidal device of any one of claims 1 to 5, wherein the air moving device is a ceiling fan and the support assembly is configured to be coupled to the ceiling fan.

7. The germicidal device of claim 6, wherein the support assembly is configured to be removably coupled to the ceiling fan.

8. The germicidal device of any one of claims 1 to 7, wherein the support assembly comprises an aperture for receiving a shaft of the air moving device therethrough.

9. The germicidal device of claim 8, further comprising a mounting assembly operatively coupled to the support assembly and configured to mount the support assembly to the shaft.

10. The germicidal device of claim 9, wherein the mounting assembly comprises a mechanical clip configured to fit in the aperture of the support assembly to couple the support assembly to the shaft.

11.The germicidal device of claim 10, wherein the mechanical clip is comprised of a first clip portion and a second clip portion configured to couple to each other, wherein the first clip portion and the second clip portion define a clip aperture that is configured to fit the shaft when coupled to each other.

12. The germicidal device of claim 11, wherein the coupling between the first clip portion and the second clip portion is adjustable such that the mechanical clip can be sized and shaped to fit a plurality of shafts.

13. The germicidal device of any one of claims 10 to 12, wherein the mechanical clip comprises a circumferential groove configured to receive a peripheral border of the support assembly.

- 51 -

14. The germicidal device of claim 13, wherein the mechanical clip comprises protrusions in the circumferential groove that are configured to fit in a corresponding groove formed in a periphery of the aperture in the support assembly.

15. The germicidal device of claim 10, wherein the mounting assembly comprises a magnetic clip operatively coupled to the support assembly and configured to couple the support assembly to the shaft.

16. The germicidal device of anyone of claims 8 to 15, wherein the support assembly further comprises a notch extending from the aperture to an edge of the support assembly and configured to receive a portion of the shaft.

17. The germicidal device of claim 16, wherein the notch is one of: radial and curved.

18. The germicidal device of claim 16 or 17, wherein the support assembly further comprises a notch cover sized and shaped to fit within and/or couple to the notch.

19. The germicidal device of anyone of claims 8 to 18, wherein the support assembly comprises a first portion and a second portion pivotally coupled to each other and at least partially delimiting together the aperture, wherein when in an open configuration, the support assembly can be mounted onto the air moving device and when in a closed configuration, the shaft extends through the aperture to mount the support assembly to the air moving device.

20. The germicidal device of claim 19, wherein the support assembly comprises a bumper on one of the first portion and the second portion that is configured to prevent an overlap of the first portion and the second portion when in the closed configuration.

- 52 - The germicidal device of any one of claims 1 to 20, further comprising a protective skirt removably coupled to the support assembly, wherein the protective skirt defines a disinfecting area with the light emitting assembly. The germicidal device of claim 21 , wherein the protective skirt is removably coupled around a periphery of the support assembly. The germicidal device of claim 22, wherein the protective skirt comprises a first skirt portion and a second skirt portion removably coupled to at least one of: each other and the support assembly. The germicidal device of claim 23, wherein the first skirt portion and the second skirt portion each comprise an interior groove configured to receive the periphery of the support assembly. The germicidal device of claim 24, wherein the interior groove comprises channels dispersed between support structures configured to receive a portion of the support assembly. The germicidal device of any one of claims 23 to 25, wherein the first skirt portion and the second skirt portion each comprise a protrusion on a first end thereof and an aperture on a second end thereof, wherein the aperture on the first skirt portion is configured to receive the protrusion on the second skirt portion and the aperture on the second skirt portion is configured to receive the protrusion on the first skirt portion to removably couple the first skirt portion to the second skirt portion. The germicidal device of claim 26, wherein the first skirt portion comprises a first shield on the first end that is configured to overlap with the second end of the

- 53 - second skirt portion when the first skirt portion and the second skirt portion are coupled to each other. The germicidal device of claim 26 or 27, wherein the second skirt portion comprises a second shield on the first end that is configured to overlap with the second end of the first skirt portion when the first skirt portion and the second skirt portion are coupled to each other. The germicidal device of any one of claims 21 to 28, wherein the protective skirt further comprises a flared section extending axially from the periphery of the support assembly and configured to block a portion of the germicidal UVC radiation. The germicidal device of claim 29, wherein the flared section is configured to prevent the germicidal UVC radiation from being emitted in the lower portion of the room. The germicidal device of claim 29 or 30, wherein the flared section is configured to prevent the germicidal UVC radiation from being emitted horizontally or in directions lower than the horizon. The germicidal device of any one of claims 29 to 31 , wherein, when coupled to the support assembly, the flared section curves radially outwardly from the periphery of the support assembly. The germicidal device of claim 21 , wherein the protective skirt comprises a bottom wall with a skirt aperture configured to receive a shaft of the air moving device. The germicidal device of claim 33, wherein the support assembly comprises at least one aperture and the bottom wall comprises at least one protrusion, wherein

- 54 - the protective skirt is removably coupled to the support assembly by the at least one protrusion coupled to the at least one aperture.

35. The germicidal device of any one of claims 21 to 34, further comprising a second skirt coupled around the protective skirt.

36. The germicidal device of claim 35, wherein the second skirt is concentric to the protective skirt.

37. The germicidal device of any one of claims 21 to 36, wherein the protective skirt is comprised of a flexible material.

38. The germicidal device of any one of claims 21 to 37, wherein the protective skirt further comprises a plurality of openings, each of the plurality of openings being coupled to a tubular section at a first end thereof, the tubular sections being configured to channel the air into the disinfecting area.

39. The germicidal device of claim 38, wherein the plurality of openings extend through the protective skirt at a tangential angle such that the air channeled through the tubular sections is inserted tangentially into the disinfecting area.

40. The germicidal device of claim 38 or 39, wherein the plurality of openings and the tubular sections are configured to insert the air tangentially to produce a vortex or circular air motion.

41. The germicidal device of anyone of claims 38 to 40, wherein a second end of each of the tubular sections comprises an air filter configured to prevent particles from entering the disinfecting area.

- 55 -

42. The germicidal device of anyone of claims 21 to 41, further comprising a protective covering configured to be removably coupled to the protective skirt or the support assembly over the light emitting assembly.

43. The germicidal device of claim 42, wherein the protective covering is a convex dome.

44. The germicidal device of claim 42 or 43, wherein the protective covering is comprised of light-permeable material.

45. The germicidal device of any one of claims 21 to 44, further comprising a baffle coupled to the protective skirt or the support assembly, the baffle comprising a plurality of holes that are configured to direct a cone of emission of the germicidal radiation.

46. The germicidal device of claim 45, wherein the plurality of holes have a diameter configured to allow central rays of the germicidal radiation to pass through the baffle into the disinfecting area.

47. The germicidal device of claim 45 or 46, wherein the plurality of holes are provided at a radial offset that increases towards a periphery of the baffle to direct the cone of emission of the germicidal radiation.

48. The germicidal device of any one of claims 1 to 47, further comprising a fan configured to create an additional air current to prevent an accumulation of particles on at least one of: the light emitting assembly and the support assembly.

49. The germicidal device of any one of claims 1 to 48, wherein at least a portion of the germicidal device is coated with a dust repellent coating.

- 56 -

50. The germicidal device of any one of claims 1 to 49, further comprising a mirror operatively coupled to the support assembly, wherein the mirror is configured to project an image of at least one of: the support assembly and the light emitting assembly to the lower portion of the room.

51.The germicidal device of claim 50, wherein the mirror is configured to reflect visible light and prevent the reflection of the germicidal radiation to the lower portion of the room.

52. The germicidal device of any one of claims 1 to 51 , further comprising a dusting device comprising a dusting arm pivotably connected to the support assembly, wherein the dusting arm is configured to pivot around a central axis of the support assembly.

53. The germicidal device of claim 52, wherein the dusting arm comprises a dust- removing material or dust-removing fibers.

54. The germicidal device of claim 52 or 53, further comprising an electric motor, wherein the dusting device is actuated by the electric motor.

55. The germicidal device of any one of claims 52 to 54, wherein the dusting device is actuated at a beginning or an end of a power cycle of the germicidal device.

56. The germicidal device of any one of claims 52 to 54, wherein the dusting device is actuated at pre-determ ined timed intervals.

57. The germicidal device of any one of claims 1 to 56, further comprising a UVC power meter configured to monitor the germicidal radiation emitted by the germicidal device.

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58. The germicidal device of any one of claims 1 to 56, further comprising a pathogen sensor configured to determine a pathogen concentration in the air in the room.

59. The germicidal device of claim 58, wherein the pathogen concentration is at least one of: a bacterial concentration and a viral concentration.

60. The germicidal device of claim 58 or 59, wherein the pathogen sensor is configured to capture and identify at least one pathogen type in the pathogen concentration.

61.The germicidal device of any one of claims 58 to 60, wherein the pathogen sensor is configured to output real-time information on the pathogen concentration.

62. The germicidal device of any one of claims 58 to 61 , wherein the germicidal device is configured to output geolocational data with the pathogen concentration.

63. The germicidal device of claim 62, wherein the germicidal device is configured to juxtapose the geolocational data with an identification of occupants in the room.

64. The germicidal device of any one of claims 1 to 63, further comprising an overtemperature protection system configured to deactivate the light emitting assembly when a temperature of the germicidal device reaches a predetermined threshold.

65. The germicidal device of claim 64, wherein the overtemperature protection system comprises a bi-metal switch.

66. The germicidal device of any one of claims 1 to 65, wherein the germicidal device and the air moving device have the same power source such that deactivating the air moving device, deactivates the germicidal device.

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67. The germicidal device of any one of claims 1 to 66, further comprising at least one of: an occupancy sensor configured to detect a number of occupants in the room and a motion detector configured to detect motion in the room.

68. The germicidal device of claim 67, wherein the germicidal device is configured to activate or deactivate upon at least one of: when the occupancy sensor determines that the number of occupants is greater than 0; and when the motion detector detects motion in the room.

69. The germicidal device of any one of claims 1 to 68, wherein the germicidal device is configured to activate and/or deactivate upon voice command.

70. The germicidal device of any one of claims 1 to 69, wherein the germicidal device is provided with a power source, and the power source is configured to activate and/or deactivate the germicidal device at specific time intervals or on a fixed schedule.

71. The germicidal device of any one of claims 1 to 70, wherein the germicidal device has a sanitation mode configured for use with at least one occupant in the room and a rapid sanitation mode configured to use with no occupants in the room.

72. The germicidal device of claim 71 , wherein the rapid sanitation mode is activated by the occupancy sensor.

73. The germicidal device of any one of claims 1 to 72, wherein the support assembly comprises a conductive material configured to conduct heat dissipated by the light emitting assembly.

74. The germicidal device of claim 73, wherein the conductive material comprises aluminum.

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75. The germicidal device of any one of claims 1 to 74, further comprising a visible indicator configured to output real-time performance indicators based on at least one of: a pathogen concentration, air flow, and occupancy.

76. The germicidal device of any one of claims 1 to 75, further comprising a low reflectance blocker installed at a terminal end of a disinfecting area defined by the germicidal radiation, wherein the low reflectance blocker is configured to reduce the germicidal radiation that is reflected towards the lower portion of the room.

77. The germicidal device of claim 76, wherein the low reflectance blocker comprises a material having a low reflectance in the UVC spectral range.

78. The germicidal device of any one of claims 1 to 75, further comprising a flexible membrane configured for installation on a ceiling of the room, wherein the flexible membrane is configured to minimize the germicidal radiation reflected towards the lower portion of the room.

79. The germicidal device of claim 78, wherein the flexible membrane comprises a UVC absorbing coating.

80. The germicidal device of claim 79, wherein the UVC absorbing coating is zinc oxide paint.

81. The germicidal device of any one of claims 1 to 80, further comprising a cover configured to be installed above the light emitting assembly, wherein the cover is configured to minimize the UVC light reflected towards the lower portion of the room.

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82. The germicidal device of claim 81 , wherein the cover is configured to be installed on the support assembly, the air moving device, or a ceiling of the room.

83. The germicidal device of claim 81 or 82, wherein the cover comprises at least one of a UV resistant material and a UV absorbing material.

84. The germicidal device of claim 83, wherein the cover comprises polycarbonate/polybutylene Terephthalate.

85. The germicidal device of any one of claims 81 to 84, wherein the cover comprises grooves configured to reduce a UV reflectance of the cover.

86. The germicidal device of any one of claims 81 to 85, wherein the cover comprises a first cover portion and a second cover portion removably coupled to the first cover portion.

87. The germicidal device of any one of claims 1 to 86, wherein the germicidal radiation comprises wavelengths between 100 nm and 400 nm.

88. The germicidal device of any one of claims 1 to 87, wherein the germicidal UVC radiation comprises wavelengths between 200 nm and 222 nm.

89. The germicidal device of any one of claims 1 to 87, wherein the germicidal UVC radiation comprises wavelengths between 260 nm and 300 nm.

90. The germicidal device of any one of claims 1 to 20, further comprising a casing operatively coupled to the support assembly on a side opposite the disinfecting area.

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91. The germicidal device of claim 90, wherein the casing comprises casing apertures configured to allow an air flow on a bottom side of the light emitting assembly or the support assembly.

92. A germicidal device configured to reduce a concentration of pathogens in air in a room, the germicidal device comprising: a support assembly configured to be mounted on an upper portion of the room, the support assembly comprising a circuit board; a light emitting assembly comprising light emitting elements electronically coupled to the circuit board; and a protective skirt surrounding at least a portion of the light emitting assembly and configured to define a disinfecting area with the light emitting assembly, wherein the protective skirt comprises a plurality of openings, wherein each of the plurality of openings are configured to cooperate with an air moving device to channel the air into the disinfecting area; wherein the light emitting elements are configured to emit germicidal radiation in the disinfecting area.

93. The germicidal device of claim 92, wherein each of the plurality of openings are coupled to a tubular section at a first end thereof, the tubular sections being configured to channel the air into the disinfecting area.

94. The germicidal device of claim 92 or 93, wherein the plurality of openings extend through a side wall of the protective skirt at a tangential angle, such that the air channeled through the tubular sections is inserted tangentially into the disinfecting area.

95. The germicidal device of claim 93 or 94, wherein the plurality of openings and the tubular sections are configured to insert the air tangentially into the disinfecting area to produce a vortex or circular air motion.

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96. The germicidal device of anyone of claims 93 to 95, wherein a second end of each of the tubular sections comprises an air filter configured to prevent particles from entering the disinfecting area.

97. A germicidal device configured to reduce a concentration of pathogens in air in a room, the germicidal device comprising: a light emitting assembly comprising: light emitting elements configured to emit germicidal radiation; and a circuit board configured to be mounted to an air moving device; and a mounting assembly operatively coupled to the light emitting assembly and configured to mount to a shaft of the air moving device; wherein the germicidal device is configured to cooperate with the air moving device to move the air through a disinfecting area defined by the germicidal radiation.

98. The germicidal device of claim 97, further comprising a protective skirt surrounding a periphery of the light emitting assembly and configured to define a disinfecting area with the light emitting assembly.

99. A pathogen neutralization system configured to reduce a concentration of pathogens in air in a room, the pathogen neutralization system comprising: an air moving device; a germicidal device comprising: a circuit board assembly; and a light emitting assembly electronically coupled to the circuit board assembly; and a power source configured to power the circuit board assembly, wherein the germicidal device is configured to cooperate with the air moving device to reduce the concentration of pathogens in the air prior to the air being circulated or re-circulated in the room by the air moving device.

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. The pathogen neutralization system of claim 99, further comprising a UVC power meter configured to determine a UVC power level of the light emitting assembly. . The pathogen neutralization system of claim 100, further comprising a framework configured to support the UVC power meter at a predetermined height. . The pathogen neutralization system of claim 101, wherein the framework is a tripod. . The pathogen neutralization system of any one of claims 99 to 102, further comprising a user interface and a communication link configured to communicate a status of the germicidal device to the user interface. . The pathogen neutralization system of claim 103, wherein the communication link is configured to communication via at least one of: short-range wireless technology, ethernet, WiFi, infrared light waves, and radio-frequency identification. . The pathogen neutralization system of claim 103 or 104, wherein the status comprises at least one of: an identification number of the device, geolocational data, maintenance information, operation time, a number of power cycles, and UVC power levels. . The pathogen neutralization system of any one of claims 99 to 105, wherein the air moving device is an existing air moving device and the germicidal device is retrofitted to the existing air moving device.

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107. The pathogen neutralization system of claim 106, wherein the existing air moving device is a ceiling fan comprising a shaft and the germicidal device is coupled to the shaft.

108. A method of reducing a concentration of pathogens in air in a room with an air moving device, the method comprising the steps of: i) providing a germicidal device comprising a light emitting assembly configured to emit germicidal radiation, wherein the germicidal radiation defines a disinfecting area; ii) installing the germicidal device in proximity to the air moving device such that the air is exposed to the disinfecting area prior to being circulated in the room; iii) circulating the air with the air moving device; and iv) exposing the air to the disinfecting area.

109. The method of claim 108, further comprising providing the germicidal device with a protection assembly to further define the disinfecting area.

110. The method of claim 108 or 109, wherein the germicidal radiation comprises at least one of: germicidal UVC radiation and germicidal far UV radiation.

111. The method of any one of claims 108 to 110, wherein the germicidal device comprises a pathogen sensor, and wherein the method further comprises determining the concentration of pathogens in the air before and/or after exposing the air to the disinfecting area.

112. The method of any one of claims 108 to 111 , wherein the germicidal device comprises at least one of: an occupancy detector and a motion detector, and wherein the method further comprises detecting an occupancy of the room with the occupancy detector and/or the motion detector.

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. The method of claim 112, wherein step iv) of exposing the air to the disinfecting area is activated and/or deactivated based on the occupancy of the room. . The method of any one of claims 108 to 113, wherein step iii) of circulating the air with the air moving device and step iv) of exposing the air to the disinfecting area are executed simultaneously. 66