CA3092226A1 - System, components thereof, and methods for reducing risk of transmission of airborne infectious disease in enclosed spaces - Google Patents

Abstract

A system and methods for reducing a risk of transmission of airborne infectious disease in an enclosed space based on use data and airflow data related to the space. The system comprises at least one fan-filter unit, at least one multi-directional UV light fixture, and/or combinations of both. Each unit/fixture and the deployment/configuration of each unit within the space may be customized based on the use data and airflow data, to provide a space-specific airflow pattern.
Further, an exterior surface of each unit/fixture comprise at least one removable panel(s) may be customized to suit a space's decor and/or a user's taste. Additionally, removable exterior panel(s) may be used to direct and/or restrict a UV irradiation pattern. A
ceiling-mounted fan-filter unit and a multi-directional UV light source are also disclosed in this document.

Description

Attorney Docket No. 1512P001CA01 SYSTEM, COMPONENTS THEREOF, AND METHODS FOR REDUCING RISK OF
TRANSMISSION OF AIRBORNE INFECTIOUS DISEASE IN ENCLOSED
SPACES
TECHNICAL FIELD
The present invention relates to reducing a risk of transmission of airborne infectious disease in enclosed spaces. More specifically, the present invention relates to reducing a risk of transmission of airborne infectious disease in enclosed spaces by reducing concentrations and/or activity of airborne, aerosolised and/or surface-borne infectious disease agents using systems that filter and/or inactivate the disease agents.
BACKGROUND
The COVID-19 pandemic has had a profound impact on businesses that depend on consumer traffic and will have significant long-term implications for the safety concerns of staff, customers and patrons. Similarly, the pandemic has had a serious effect on cultural and educational activities, such as theatre, concerts, schools and universities. Much of the concern is based on the risk of virus transmission when people gather in enclosed spaces.
It was initially believed that COVID-19 (also known as SARS-Cov-2 and "the novel coronavirus") was spread only by inhalation of large respiratory droplets, or by direct touch and contact transmission from hand to face, so that transmission mainly happened at close proximity to an infected person (i.e., within 2 m). However, the WHO and CDC now accept that the virus is airborne, and that it can be carried in "aerosols" over large distances of 6 ¨ 8 m or more and remain viable in air for 3 hours or more. Such aerosols are very small nasal and respiratory fluid droplets that are expelled by an infected carrier (see Fig. 1) and that contain live virus particles/agents.
In poorly ventilated spaces, the virus can be transmitted in aerosols over large distances, and the risk of transmission increases as the number of people in the room and the time spent in the room Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 increase. If droplets and aerosols are not quickly cleared from the air they can be breathed in by other people in the room, or by people who enter the room at a later time, which is called airborne transmission. If droplets and aerosols are not quickly cleared, they can also settle on exposed surfaces, depositing live viral particles called "fomites," that can transmit infection by touch and contact, which is called contact transmission.
Unfortunately, most indoor and/or enclosed spaces are not currently configured for rapid air exchange or for removal, reduction, or inactivation of viral particles.
Typically, indoor ventilation has been concerned with general comfort, noise control, and reducing heating /
cooling costs, as will be described below, rather than with preventing the spread of infectious disease via aerosolized particles. Accordingly, most community / business /
indoor spaces are not optimized for protecting their occupants from the spread of infectious diseases such as COVID-19. Further, although some tools and devices may be used to clean the space, these tools can be expensive and are not typically configured based on the requirements of a specific space.
Fan-filter Units Enclosed spaces such as offices, meeting rooms, classrooms, lecture halls, retail stores, elevators, restaurants, bars and cafes present an increased risk of transmission of airborne infectious diseases between occupants. This risk is particularly high during a pandemic, when the infectious agent is prevalent in the population or has a high infectivity rate. There is therefore a need for optimized environmental controls that can reduce the risk to occupants.
Airborne infectious disease can be caused by bacteria (such as S. pneumonia, H. influenza and M. Tuberculosis) and viruses (such as SARS-Cov-2), and less commonly fungi and molds. The infectious agent is typically present in the respiratory tract of the infected individual, which includes the lungs, lower airways, pharynx (throat), and the nasal and oral cavities. Breathing, talking, singing, coughing and sneezing release droplets of respiratory secretions from the lungs, respiratory tract, and nasal and oral cavities, and these droplets can carry the infectious agent out of the body and into the air surrounding the infected individual. When these droplets are breathed in by a healthy person sharing the same room, the infectious agent can gain entry to their respiratory tract and cause infection. Alternatively, when said droplets settle on an exposed

- 2 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 surface in the room, the infectious agent can be picked up through contact when another person touches the contaminated surface and then uses the same hand to touch parts of their face.
Some droplets generated by talking, breathing, coughing and sneezing are large and visible (especially when coughing or sneezing), but many more droplets are less than 0.5 mm in diameter and are invisible. Large clouds of microscopic droplets, typically under 10 [tm in diameter, are called aerosols. After being expelled, larger droplets can travel distances of a few meters before falling to the ground or settling on exposed surfaces, while aerosols can remain suspended in air for hours. Aerosols can thus easily disseminate throughout even a large room, exposing all room occupants to potential infection. This is especially problematic in spaces where there is inadequate air circulation and fresh air exchange, which, unfortunately, is the case in almost all existing buildings.
The risk of exposure to airborne infection is therefore greater the longer people stay in the room, the greater the number of people in the room, and the less frequently fresh air is circulated into the air to exchange the stale air.
Airborne contaminants, including infectious organisms and aerosol droplets containing infectious organisms, are cleared from the room when the air in the room is removed and replaced with fresh, clean air, typically from outside the building. This can sometimes be achieved by opening as many windows as possible in different wind directions to create an exchange of air in the room. More often than not, as is often the case in hot or cold climates, in sealed office buildings, in cases of heavy outdoor noise or pollution, or spaces without exterior windows, this function must instead be performed by the building's HVAC (Heating, Ventilation & Air Conditioning) system. The HVAC system's job is to, over time, remove the stale air from the room and replace it with fresh outdoor air, and often also heat or cool the air to maintain a comfortable climate for the occupants. Simple recirculation of air (i.e., returning the same air back into the room without .. cleaning) is not effective at reducing the amount of airborne contaminants or infectious agents in the room and does not reduce the risk of airborne disease transmission.
Recirculating room air through an effective filter system, however, can be a very effective method of removing airborne contaminants. The High Efficiency Particulate Air (HEPA) air filter standard requires that filters remove at least 99.97% (U.S. DOE standard) of airborne particles of 0.3 [tm diameter (larger and

- 3 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 smaller size particles are removed with greater efficiency.) Thus, passing room air through a HEPA filter can be a very effective method of removing aerosol droplets and reducing the risk of transmission of airborne infection in situations where direct outdoor exchange or upgrades to the existing HVAC system are not practical.
The rate at which room air is replaced with fresh air is known as the Air Changes per Hour (ACH) rate, and refers to how many times per hour the entire volume of air in a given room is replaced with fresh (not recirculated) air. Similarly, the number of times per hour that the entire volume of air in the room is passed through a HEPA filter is knowns as the equivalent Air Changes per Hour (eACH, or sometimes just ACH).
Most commercial and public buildings and their HVAC systems have been designed for climate control and energy conservation, and not to offer occupants protection from the spread of airborne infectious diseases. Many older office and public buildings lack air vents in individual rooms, and therefore have very poor air circulation. Newer commercial and public buildings have an ACH rate of 6, and often much less than that. At a rate of 6 ACH, it takes 15 minutes to remove 90% of airborne contaminants from a closed room, and 46 minutes to remove 99% of contaminants. Typical HVAC systems in North America only bring in 15% - 20%
fresh air with each cycle, so that the true fresh-air ACH, which is the important parameter for reducing the risk of disease transmission, is only 15% - 20% of the given ACH. The risk of exposure and transmission of airborne infectious diseases in these spaces is, therefore, much higher than in well-ventilated or outdoor environments.
A second and very important consideration in the control of aerosol spread is the pattern and direction of airflow. Slow, random or turbulent airflow encourages the uniform mixing and dissemination of aerosols throughout the room, as does airflow that pulls air horizontally across a room, exposing more of the room's occupants to other people's expelled infectious agents. A
preferable stable airflow pattern would draw the air and aerosols up as soon as they are expelled, toward the ceiling and away from room occupants, and would return fresh or cleaned air back to the room in an orthogonal or opposite direction. An air circulation pattern set up this way would reduce the amount of time droplets and aerosols remain suspended in air, the distance they spread across the room and, therefore, the exposure risk to the occupants.

- 4 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 Currently, when replacement with fresh air is not possible, the air can be recirculated through a fan-filter unit (FFU). FFUs draw in the air around them, pass the air through at least one filter such as a HEPA filter, and then expel the filtered air back into the space.
However, most typical FFUs are floor-standing, portable units that have two major shortcomings:
They fail to create a proper airflow pattern to protect occupants; and They do not have sufficient true airflow capacity for the size of the room.
In particular (see Figure 2), most typical floor-standing FFUs draw air &
aerosolized particles horizontally, across the room's occupants and across exposed surfaces &
equipment. Thus, the aerosols disseminate across the room, potentially infecting occupants and creating formites, before they are cleared by the HEPA filter. This is an undesirable and often dangerous situation.
Additionally, typical FFUs are often fairly expensive, and deploying FFUs in sufficient numbers to mitigate the above airflow problem would likely be prohibitively expensive for most businesses / cultural centers. Furthermore, none of the existing devices are designed to be deployed in or permanently installed as an array of units in multiple positions and orientations, based on Computational Fluid Dynamics (CFD) simulations of airflow, for the purpose of creating an airflow pattern for the removal of infectious agents customized to that specific enclosed space.
Ultraviolet (UV) Germicidal Irradiation Exposure to UV energy ("light") in the range of 200 ¨ 280 nm wavelength (UV-C) has been a reliable and long-established method to inactivate infectious biological agents such as viruses, bacteria, molds and fungus, and is used in many industrial and healthcare applications.
However, unprotected exposure of human skin to UV-C light energy above an established threshold of exposure (approx. 6mJ/cm^2 for UVC light at 254nm), can cause an inflammatory reaction of the exposed skin (i.e., "sunburn") or of the cornea of the eye.
Existing UV fixtures typically house one or multiple UV-C-generating elements ("UV light sources" or "bulbs"), and the necessary electronic controllers for those bulbs (generally "ballasts" but sometimes constructed on a circuit board). The fixture housing of existing fixtures is designed to direct the UV energy in a single, defined direction.

- 5 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 There are currently two main types of UV Germicidal Irradiation (UVGI) strategies implemented in commercial devices that are in use in healthcare facilities and some public spaces: (1) Upper Room UV, and (2) Lower Room UV.
In Upper Room UV, a UV light generator or bulb is housed in a fixture that is typically fixed to a wall in the upper 1/3 of the room, which confines and directs the UV light to a specified upper zone of the room (typically above 7 feet from the floor), in order to minimize exposure of room occupants to UV-C energy. Upper Room UV is used to inactivate micro-organisms present in the air in the upper part of the room, thereby disinfecting the air of infectious pathogens, as long as a sufficient dose of UV-C energy is delivered. Upper Room UV is typically used when the room is occupied, and does not require the occupants to use protective equipment. However, to achieve this level of safety, essentially all Upper Room UV fixtures operate at approximately 5%
efficiency (i.e., the fixture internally absorbs about 95% of the UVC energy emitted by the internal bulb).
There are several designs of Lower Room UV fixtures, including ceiling-mounted or suspended fixtures, wall-mounted, and floor-based fixed and mobile units. These fixtures use one or multiple UV bulbs to primarily irradiate exposed surfaces in a room, such as floors, countertops, desks, beds, chairs, door handles & toilet seats, which may be contaminated by infectious organisms. Lower Room UV devices typically use multiple generators to achieve high UV-C
energy levels and are, therefore, typically used only when the room is unoccupied, or if occupants are wearing protective equipment. There are also other variations of UVGI devices, including low-energy hand-held wands and small, enclosed devices used to disinfect personal items, that would be known to the person skilled in the art.
In general, UVGI products available today fall into either the Upper Room or Lower Room UV
categories. There is no product on the market today that incorporates both an Upper Room and Lower Room UV device in one fixture, and that allows for the independent control and operation of either the Upper Room UV and Lower Room UV components, or both simultaneously.
Based on the above, there is evidently a need for FFUs that do not drag aerosols across a room, as well as for UVGI products that are not limited to a single direction.
Further, for most public and semi-public spaces, there is a serious need for systems and methods for reducing

- 6 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 concentrations of aerosols within those spaces while accounting for the space's particular requirements, both in terms of pre-existing physical structure and in terms of human use.
Further, although there are existing products that combine UVGI and FFUs (for instance, some devices feature a number of internal UVGI sources housed within the cavity of the FFU, and are designed to contain the UV light entirely within the interior of the device), these units still have significant drawbacks. In particular, the difficulty with this type of design is that, most often, even in units with low airflow rates, air velocity internally within the device is too high to deliver a lethal dose of UVGI to the airborne infectious agents. These internal UVGI
light sources do inactivate trapped infectious agents on the surface of the filter itself but contribute little to reducing the risk of infection to occupants of the enclosed space. In a similar fashion, powerful UVGI lights are sometimes used in large, commercial and industrial air handling and air conditioning systems to prevent the build up of mold and fungus due to moisture condensation on the cooling components. However, such systems do not scale well.
Accordingly, there is thus a need for devices, systems, and methods that overcome the deficiencies of the prior art.
SUMMARY
This document discloses a system and methods for reducing a risk of transmission of airborne infectious disease in an enclosed space based on use data and airflow data related to the enclosed space. The system comprises at least one fan-filter unit, at least one multi-directional UV light fixture, and/or combinations of both. Each unit/fixture and the deployment/configuration of each unit within the space may be customized based on the use data and airflow data, to provide a space-specific airflow pattern. Further, an exterior surface of each unit/fixture comprises at least one removable panel(s) that may be customized to suit a space's decor.
Additionally, removable exterior panel(s) may be used to direct and/or restrict a UV irradiation pattern. A ceiling-mounted fan-filter unit and a multi-directional UV light source are also disclosed in this document.

- 7 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 In a first aspect, this document discloses a system for reducing a risk of transmission of airborne infectious disease within a space, the system comprising: at least one aerosolized particle neutralization device; and at least one controller for controlling said at least one aerosolized particle neutralization device, wherein said at least one aerosolized particle neutralization device is selected from a group comprising ceiling-mounted fan-filter units and multi-directional ultraviolet (UV) light sources, and wherein a number of said at least one aerosolized particle neutralization device and a configuration of said system are based on airflow data related to said space and on use data related to said space, said use data relating to how said space is used and said airflow data relating to an airflow in said space.
In a second aspect, this document discloses a fan-filter unit for reducing a concentration of airborne infectious disease in a space, said fan-filter unit comprising: a housing having an intake vent and an exhaust vent, said housing containing: an intake fan; a motor for powering said intake fan; and at least one filter, wherein, when said intake fan is in operation, air surrounding said fan-filter unit is drawn in through said intake vent and filtered through said at least one filter before being directed back into the space by way of said exhaust vent, and wherein said fan-filter unit is located adjacent a ceiling of said space.
In a third aspect, this document discloses a multi-directional ultraviolet (UV) light fixture for inactivating airborne infectious disease particles in a space, the fixture comprising: at least one UV light source; at least one electronic controller for controlling said at least one UV light source; and a casing for containing said at least one controller and said at least one UV light source, wherein said fixture is located adjacent a ceiling of said space, and wherein said UV light source is positioned in said fixture to emit UV light into an area external to said fixture in a first direction orthogonal to a longitudinal axis of said fixture and in at least one second direction, said at least one second direction being selected from a group comprising:
directly opposite to said first direction and orthogonal to said first direction, and wherein said at least one second direction is also orthogonal to said longitudinal axis.
In a fourth aspect, this document discloses a method for reducing a risk of transmission of airborne infectious disease within a space, said method comprising the steps of: obtaining use data related to said space, said use data relating to how said space is used;
obtaining airflow data

- 8 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 related to said space, said airflow data relating to an airflow in said space;
determining a configuration for a system for reducing said risk, wherein said system comprises at least one aerosolized particle neutralization device and wherein said configuration is based on said use data and said airflow data, such that said system is customized for said space; and installing said system in said space, wherein said airborne infectious disease comprises aerosolized particles, wherein said at least one aerosolized particle neutralization device is selected from a group comprising ceiling-mounted fan-filter units and multi-directional ultraviolet (UV) light sources.
In a fifth aspect, this document discloses a multi-directional ultraviolet (UV) light fixture for inactivating airborne infectious disease particles in a space, said UV light fixture comprising: at least one UV light source; at least one controller for controlling said at least one UV light source;
and a casing for containing said at least one controller and said at least one UV light source, wherein said casing comprises at least one removable panel and wherein said at least one removable panel is used to direct an irradiation pattern from said UV light fixture.
In a sixth aspect, this document discloses a multi-directional ultraviolet (UV) light fixture for inactivating airborne infectious disease particles in a space, said UV light fixture comprising: at least one UV light source; at least one controller for controlling said at least one UV light source;
and a casing for containing said at least one controller and said at least one UV light source, wherein said casing comprises at least one removable panel and wherein said at least one removable panel is customizable.
In a seventh aspect, this document discloses a fan-filter unit for reducing a concentration of airborne infectious disease in a space, said fan-filter unit comprising: a housing having an intake vent and an exhaust vent, said housing containing: an intake fan; a motor for powering said intake fan; and at least one filter, wherein, when said intake fan is in operation, air surrounding said fan-filter unit is drawn in through said intake vent and filtered through said at least one filter before being directed back into the space by way of said exhaust vent, wherein said fan-filter unit is adjacent a ceiling of said space, wherein said housing comprises at least one removable panel, and wherein said at least one removable panel is customizable.

- 9 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described by reference to the following figures, in which identical reference numerals refer to identical elements and in which:
Figure 1 is a schematic showing the spread of respiratory droplets of various sizes;
Figure 2 is a schematic showing an airflow pattern resulting from the use of a floor-standing FFU;
Figure 3 is an illustration of a fan-filter unit according to an embodiment of the invention;
Figure 4 is a schematic showing an airflow pattern resulting from the use of FFUs according to an embodiment of the invention;
Figure 5 is an illustration of a multi-directional ultraviolet (UV) light fixture according to an embodiment of the invention;
Figure 6A is a schematic showing Lower Room UVGI using a system according to an embodiment of the invention; and Figure 6B is a schematic showing Upper Room UVGI using a system according to the embodiment of Figure 6A.
DETAILED DESCRIPTION
The present invention provides a system for reducing a risk of transmission of airborne infectious disease due to aerosols (i.e., aerosolized disease particles) or airborne disease particles in an enclosed space. The system comprises at least one aerosolized particle neutralization device:
that is, one or more ceiling-mounted fan-filter unit(s), one or more multi-direction UV light fixture(s), and/or a combination of both. Configuration details of the system are chosen based on use data and airflow data of the space, to allow for customization.

- 10 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 Fan-Filter Units The present invention comprises a device that uses a motor and fan to draw air in through one end or surface of the device (the intake or intake vent), move air through one or more replaceable filter layers that trap and remove airborne contaminants, and then exhaust the filtered air out through a different end or surface of the device (the return.) The device houses a circuit board that supplies electrical power to the motor, controls the operation of the motor, motor speed, duration of operation through a timer mechanism, and a switch for manual operation. The device includes an option for remote operation via a hand-held or wall-mounted control unit. Figure 3 shows a fan-filter unit according to an embodiment of the present invention.
The device is designed to be suspended from, mounted on, and/or adjacent to the ceiling, in such a way as to draw contaminated room air up and away from room occupants, filter the air and then return the filtered air back to the room. The device has multiple, repositionable mounting brackets, and multiple, predetermined mounting points that allow the device to be deployed in a vertical or horizontal orientation with respect to the direction of airflow within the device, and at any yaw angle around its central axis, for the purpose of generating an optimal airflow pattern for the space. The device includes an optional extension duct that can be mounted at either the intake or return end of the device, for the purpose of directing the flow of air in a direction orthogonal to the long axis of the device.
The device comprises a rigid casing that houses a circuit board, a cavity containing an electric motor and fan, and a plurality of replaceable filters.
The device employs a first opening on one end of the rigid casing that functions as an inlet to allow air to be drawn into the cavity of the device (the inlet opening.) The device employs a second opening on a separate surface of the casing that is different from the inlet opening and functions as an exhaust opening through which air is expelled from the device (the outlet opening.) The casing houses a compartment designed to hold one or more removable filter cassettes (the filter compartment.) The casing further has a third opening in its exterior that provides access to the replaceable filters held within the device.
The filter compartment is permanently fixed to the casing in a position and orientation that constrains all the air pulled through the inlet to pass through the filters before reaching the cavity

- 11 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 that contains the motor and fan. The filter compartment has a first opening that allows air to be pulled into the compartment and through the filter cassettes, a second opening that is opposite the first opening that allows air to exit the compartment and enter the cavity containing the motor and fan, and a third opening that allows access to replace the filter cassettes. The filter compartment is further fitted with multiple, parallel tracks on one or more of its internal surfaces that function to secure each filter cassette in place and allow air to pass through the filter cassettes during the operation of the device. Said tracks further allow the filter cassettes to be pulled out of the tracks for disposal, and new filter cassettes to be pushed into the compartment and to remain securely held in position.
The rigid casing of the device has an opening, separate from the inlet and return, that allows access to the filter compartment for the purpose of replacing the filter cassettes (the filter opening). The filter opening is covered by a rigid, rectangular shaped door (the filter door). The filter door is secured to the casing along one of its edges using a hinge mechanism that allows the door to swing open and provide access to the filter cassettes. The door is secured in the closed position between filter cassette changes using a spring retention clip. The filter door is further secured in place with a foam rubber seal applied along its edges to prevent leakage of air through the filter opening.
The flow of air through the device is thus unidirectional, such that room air is pulled upward into the device through its inlet opening, is constrained to pass through all filter cassettes, then through the cavity containing the motor and fan, and finally propelled out through the outlet opening which returns the air to the room below. The direction of airflow is generally parallel with the long-axis of the external casing. Figure 4 shows a schematic representation of a desirable airflow pattern in a room having two fan-filter units according to an embodiment of the present invention.
Operation of the device is controlled via the circuit board, which provides electrical power to the motor and to a panel of status light indicators, which include Power Standby, Power On, Motor Rotational Speed Setting, and a Filter Change Indicator, as well as a mechanical on-off switch.
The circuit board can be remotely linked to a hand-held or wall-mounted remote operation unit,

- 12 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 that can include On-Off function, Pre-Set Timer operation, and Motor Speed Setting for remote operation of the device.
While most other air-purification/disinfecting products found on the market are floor-based or wall-mounted, this device is set apart by having been designed to be installed from the ceiling of an enclosed space. In a preferred embodiment, the rigid casing of the device is fitted with multiple mounting points to which removable angled mounting brackets can be securely affixed with metal screws. The mounting brackets can be used to directly mount the device to a solid ceiling surface, or to suspend the device at a variable offset distance from the ceiling using either multiple rigid metal rods fixed to the solid ceiling above the device, or using high-strength cables fixed to the ceiling above the device. The offset distance from the ceiling surface can be varied by the length of suspension rods or cables used. The offset distance can thus be used as a parameter to optimize airflow. Another feature is the ability to further customize the deployment of this device by installing it in either a vertical or horizontal orientation, with respect to the longitudinal axis of the casing and the principal direction of airflow within the device. To achieve this, the rigid casing of the device employs several sets of pre-made mounting points along orthogonal sides and edges of the casing. Using one set of mounting points, the mounting brackets can be attached so the device can be mounted vertically, and using the orthogonal set of mounting points, the mounting brackets can be attached so the device can be mounted horizontally, depending on the specific usage requirements of the enclosed space.
The device further comprises an optional, removable extension air duct, that can be securely affixed to either the inlet opening or the outlet opening in the casing, using multiple screws and a rubber or foam gasket interposed between the casing and the base of the extension air duct. The duct has a quarter-circle profile designed to redirect either the inlet or outlet airflow at 90 to the principal direction of airflow through the device, for the purpose of further optimizing the airflow pattern generated by the device, and can be used with the device installed in a vertical or horizontal orientation.
The purpose of the device described above, known as a Fan-Filter Unit (FFU), in this application, is to minimize the exposure of occupants of the space to airborne infectious agents carried and expelled by other occupants who share the same space. This is achieved by (1) using

- 13 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 the FFU to maximize the total volume of air that is circulated through the filters in a unit of time, measured in equivalent Air Changes per Hour (ACH), and (2) by using the FFU to create an optimal airflow pattern that draws expelled air and airborne infectious agents as rapidly as possible up toward the ceiling mounted FFU, before they have sufficient time to mix into and become disseminated in room air and be transmitted to other occupants. The device is, therefore, designed to be deployed either as a single unit in a small enclosed space where it can generate a sufficiently high ACH rate and optimal airflow pattern on its own, or can be deployed as an array of multiple, identical such devices (an FFU Array) in large or complex-shaped enclosed spaces.
As an array, the number of FFUs and the height, position and orientation of each FFU can be independently determined, using Computational Fluid Dynamics (CFD) modelling based on room dimensions, shape, configuration and expected use, to achieve the desired optimal airflow pattern for that room. The individual FFUs in the FFU Array are further designed to link together, either via wired relay or wireless connection, to allow operation of all FFUs from a single control point.
Such a method of deployment is innovative in that it provides flexibility to cover any size, shape and configuration of space, something that is not possible with existing products.
The device can be deployed as a single unit in an enclosed space, or as a plurality of such units, arranged in 3 dimensional space as an array with predetermined individual orientation, height, and location, for the purpose of generating a desired total airflow in the space, measured by the Air Changes per Hour rate, and for achieving an optimal airflow pattern which is customized for the particular space through the use of Computational Fluid Dynamics simulations. When deployed as an array of devices, the plurality of devices can be controlled via a single control point or remote operation device.
Multi-Directional UV Fixture In one embodiment, the fixture comprises a metal casing that internally houses one or more electronic drivers (ballasts/circuit boards/other controllers) that can power one or more UV light sources (bulbs). External to the metal casing are mounting points for either screw-in or pressure-inserted connectors for UV bulbs that are connected by wires to the drivers, arrayed on both the upper and lower surfaces of the metal casing. The current fixture can accommodate up to 2

- 14 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 bulbs on the lower surface, and up to 2 bulbs on the upper surface (i.e., the current fixture can be populated with 1, 2, 3 or 4 UV-generating bulbs). As would be clear to the person skilled in the art, the fixture may be adapted for any desired number of bulbs or other suitable UV sources.
Figure 5 shows a fixture according to an embodiment of the invention.
The metal casing is surrounded by shaped metal panels that function to: (1) reflect or absorb UV
light, in order to restrict and/or direct the irradiation pattern and distribution of the UV light to desired angles, and (2) to enhance the aesthetic appearance of the fixture.
The lighting fixture is configured to be suspended from, mounted on, and/or adjacent to the ceiling of the space.
In some embodiments, the metal panels can be customized for each space to align with the space's decor and/or a user's taste. As non-limiting examples, panels may feature different shape profiles or radii, different paint colours, different textures and finishes, as well as different materials, as desired to match the needs and preferences of each application and location/space.
In some embodiments, the fixture incorporates a Radio-Frequency receiver for remote operation of the unit with a hand-held or wall-fixed remote control. As would be clear, any suitable remote .. control method can be used. Additionally, of course, the fixture may not be configured for remote control. For instance, in some embodiments, the fixture may emit UV
light at predefined times (e.g., a shift change or a time when the space is usually unoccupied, such as 2 AM).
However, it is preferable that the fixture have at least a remote-control and/or motion sensing safety feature, particularly when the fixture is configured for regular Lower Room UVGI, in order to protect potential occupants of the room. Figure 6A shows a schematic representation of fixtures according to an embodiment of the present invention, with Lower Room UVGI in progress. Figure 6B shows a schematic representation of fixtures according to an embodiment of the present invention, with Upper Room UVGI in progress.
Use Data, Airflow Data, and Customization Use data of the space is data related to any use(s) of the space by its occupants. As non-limiting examples, use data may include the number of people who regularly use the space, the average length of time a user spends inside the space, and/or the purposes to which the space is put. As should be clear, these data may vary widely between different spaces: for instance, the use data related to a private office will be different from the use data for a heavily trafficked ground floor

- 15 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 restroom, and both will be different from the use data for a lecture hall.
Airflow data is data related to airflow patterns and air movement within the space. As would be clear to the person skilled in the art, these data may take many forms, including for instance the number and type of vents (e.g., diffusers and returns connected to a central air system, windows, etc.) and fluid mechanics data related to the configuration of the space and furniture/fixtures within it. Further, in some cases use data and airflow data may overlap: as non-limiting examples, users may use personal fans within the space, or frequent entries and exits from the space may shape airflow patterns across doorways.
The data is then analyzed using mathematical, statistical, computational, and/or simulation techniques, including techniques drawn from Computational Fluid Dynamics and UVGI
Irradiation modeling.
Additionally, as should be clear, the embodiments of the present invention may be used for air quality control and/or as components of a comprehensive HVAC system. That is, the systems, methods, and devices disclosed herein may be used specifically to address a risk of transmission of airborne infectious disease, but also may be used when such risk is less of a concern. For instance, as would be clear to the person skilled in the art, FFUs as described herein may be useful to deal with a variety of airborne contaminants in a space. Similarly, the UV light fixtures as described herein may be useful for inactivating a variety of airborne contaminants as well as contaminants on surface(s).
In an eighth aspect, this document discloses a lighting fixture, comprising:
at least one electronic ballast or at least one circuit board; a longitudinal casing that contains said at least one electronic ballast or said at least one circuit board; a plurality of electrical connectors attached at opposing ends of said longitudinal casing for the purpose of attaching Ultraviolet Germicidal light emitting sources; one or more removable or not-removable Ultraviolet light emitting sources attached to said longitudinal casing via said plurality of electrical connectors, and electrically connected to said at least one electronic ballast or said at least one circuit board.
In a ninth aspect, this document discloses a lighting fixture as in the eighth aspect, wherein: each of said removable or not-removable Ultraviolet light emitting sources comprises an LED or fluorescent bulb.

- 16 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 In a tenth aspect, this document discloses a lighting fixture as in the ninth aspect, further comprising: said one or more Ultraviolet light emitting sources that can be attached to said electrical connectors on one or more surfaces of said longitudinal casing, such that said Ultraviolet light emitting sources, when attached to said surfaces of said longitudinal casing, can emit Ultraviolet light simultaneously or independently in a plurality of cardinal directions (up, down, left or right) away from said casing.
In an eleventh aspect, this document discloses a lighting fixture as in the tenth aspect, wherein:
the said casing may be attached to or suspended from the ceiling via a plurality of mounting points incorporated into said casing, or said casing may be optionally mounted to a vertical wall via one or more mounting brackets attached to the said casing.
In a twelfth aspect, this document discloses a lighting fixture as in the eleventh aspect, wherein:
Ultraviolet Germicidal light may be directed in one or more independent cardinal directions (up, down, left, or right) to the longitudinal axis of the casing.
In a thirteenth aspect, this document discloses a lighting fixture as in the twelfth aspect, wherein:
the said lighting fixture can be operated via a hand-held or wall-mounted remote operating device, the said remote operating device may include pre-set timer operating function, the said lighting fixture can be turned off with a motion-sensing apparatus.
In a fourteenth aspect, this document discloses a lighting fixture array comprising lighting fixtures as in the thirteenth aspect, wherein: a plurality of said lighting fixtures can be deployed in a given enclosed space, each in a predetermined position and orientation, in order to achieve an optimal Ultraviolet radiation pattern for maximum germicidal effect, based on the dimensions and three-dimensional configuration of said enclosed space.
In a fifteenth aspect, this document discloses a lighting fixture array as in the fourteenth aspect, wherein: each of the lighting fixtures in said lighting fixture array can be operated by a single control point, such as a hand-held or wall-mounted remote operation unit, each of the lighting fixtures in said lighting fixture array can be shut off by a one or more motion-sensing apparatus.
In a sixteenth aspect, this document discloses a lighting fixture as in the eighth aspect, further comprising: a plurality of mounting points in one or more sides of said casing, a plurality of

- 17 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 fixed or removable, rigid panels that can be attached to said plurality of mounting points, for the purpose of controlling or restricting the direction and amount of Ultraviolet Germicidal light radiation in order to produce a desired Ultraviolet radiation pattern, a coating applied to one or more surfaces of said rigid panels, for the purpose of reflecting or absorbing UV radiation, in order to produce a desired Ultraviolet radiation pattern.
In a seventeenth aspect, this document discloses a lighting fixture as in the sixteenth aspect, wherein: the exterior surface of each of said rigid panels can be provided in a variety of paint colors, coatings, materials or textures for the purpose of customizing the aesthetic appearance of the lighting fixture.
.. In an eighteenth aspect, this document discloses a Fan-Filter unit (FFU) comprising: an electric motor and fan; at least one circuit board; a plurality of removable air filter cassettes; a casing that contains said electric motor and fan, said at least one circuit board, and said plurality of removable air filter cassettes; said casing that encompasses an opening for the intake of air (the inlet), an opening for the outflow of air (the return), and an opening for the replacement of said removable air filter cassettes.
In a nineteenth aspect, this document discloses a FFU as in the eighteenth aspect, wherein at least one of said removable air filter cassettes is capable of removing airborne infectious biological agents.
In a twentieth aspect, this document discloses a FFU Fan-Filter unit as the nineteenth aspect, .. wherein: said FFU is designed to be deployed in an enclosed space either rigidly mounted to or suspended from the ceiling of said enclosed space.
In a twenty-first aspect, this document discloses a Fan-Filter unit as in the twentieth aspect, further comprising: a removable extension air duct that can be optionally affixed to either the said inlet opening of said casing, or said return opening of said casing, for the purpose of changing the direction of airflow to be different from the principal direction of airflow within the said FFU; said removable extension air duct that can be affixed to either the said inlet opening of said casing, or said return opening of said casing, in a plurality of angular orientations about the long-axis of said FFU.

- 18 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 In a twenty-second aspect, this document discloses a Fan-Filter unit as in the twenty-first aspect, further comprising: a plurality of removable metal brackets for mounting or suspending said Fan-Filter Unit to or from the ceiling; a plurality of mounting points in the said casing for affixing said plurality of removable mounting brackets to said casing in a plurality of positions.
In a twenty-third aspect, this document discloses a Fan-Filter unit as in the twenty-second aspect, wherein: said FFU can be optionally mounted to or suspended from the ceiling in either a vertical or horizontal orientation to the long-axis of said casing or to the principal direction of airflow within the said FFU.
In a twenty-fourth aspect, this document discloses a Fan-Filter unit as in the twenty-third aspect, wherein: said FFU can be operated via a hand-held or wall-mounted remote operating device; the said remote operating device may optionally control the rotational speed of the motor; the said remote operating device may optionally allow pre-set timer operation of the motor; said FFU can be optionally operated via a manual controls located on the said casing that override said remote operating device.
In a twenty-fifth aspect, this document discloses a Fan-Filter unit as in the eighteenth aspect, comprising: a plurality of fixation points on the sides of the said casing; a plurality of rigid panels that can be optionally affixed to said plurality of fixation points;
the exterior surface of said plurality of rigid panels can be finished in a variety of paint colors, coatings, materials or textures for the purpose of customizing the aesthetic appearance of the said FFU.
In a twenty-sixth aspect, this document discloses a Fan-Filter unit as in the eighteenth aspect, wherein: a plurality of said FFUs are deployed in a given enclosed space, each in a specified position and orientation (an FFU Array), so that said plurality of FFUs, when operated in unison, generate an optimal pattern of airflow in said enclosed space for the purpose of extracting airborne contaminants as rapidly as possible and minimizing occupant exposure to said airborne contaminants.
In a twenty-seventh aspect, this document discloses a Fan-Filter unit array as in the twenty-sixth aspect, wherein: said specified position and orientation of said FFU's within said FFU Array are

- 19 -Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 determined by a Computational Fluid Dynamics (CFD) analysis based on the unique dimensions, shape and configuration of each enclosed space to generate said optimal pattern of airflow.
In a twenty-eighth aspect, this document discloses a Fan-Filter Unit Array, as in the twenty-seventh aspect, wherein: said FFU within said FFU Array can all be operated by a single control point, such as a hand-held or wall-mounted remote operation unit; said remote operation unit may optionally control the rotational speed of all motors in said FFU Array and may optionally offer pre-set timer operation for all motors in said FFU Array.
In a twenty-ninth aspect, this document discloses a method for deploying a combination of a lighting fixture array as in the fourteenth aspect and a FFU array as in the twenty-sixth aspect, wherein: the position, orientation and distribution of each component of said lighting fixture array and said FFU array can be determined by computational analysis based on Computational Fluid Dynamics and UVGI Irradiation modelling, in order to determine a desirable airflow pattern within said enclosed space and a desirable distribution of UVGI in the enclosed space, as well as desirable delivery by said FFU array of air volume and velocity to said UVGI array components to obtain a maximum clearing of airborne infectious agents from said enclosed space.
The skilled person may also refer to the attached Appendix for greater clarity.
For clarity, the phrase "at least one of [x] and [y]", as used herein, means and should be construed as meaning "[x], [y], or both [x] and [y]".
A person understanding this invention may now conceive of alternative structures and embodiments or variations of the above all of which are intended to fall within the scope of the invention as defined in the claims that follow.

- 20 -Date Recue/Date Received 2020-09-04 APPENDIX
Date Recue/Date Received 2020-09-04 Minimizing Exposure to Covid-19 & Other Airborne Diseases In Commercial, retail, & Public Spaces A Science-Based Solution m g o'-'0 rip 1 e% = , ' i, 1 ' ' ' Pt Il .eipõõ, oil , 1,A # ,e ? cif -11 "2 P = i ,i . i / A.
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The covid_19 pandemic The Covid-19 pandemic has had a profound impact on businesses that depend on consumer traffic and will have significant long-term implications for the safety concerns of staff, customers and patrons.
Much of the concern is based on the risk of virus transmission when people gather in enclosed spaces.
What is Known About SARS-Cov-2 Transmission?
Covid-19 is the infectious disease that is caused when the Novel Corona Virus (named SARS-Cov-2) enters the respiratory tract of a healthy person , and spreads, resulting in infection.
The SARS-Cov-2 virus is present in nasal & respiratory secretions of carriers f;
even if they have no symptoms. When a carrier of the virus sneezes, coughs, sings or even speaks in a normal voice they generate streams of nasal and respiratory fluid droplets that contain live virus particles.
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(3 - 6 ft) and then settle on the ground or other surfaces.
Very small droplets form invisible clouds known as aerosols. They can remain suspended in air for hours and travel distances of 6 -8 m (20 -26 ft) or more - About 1 meter from individual in an enclosed room.
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It was initially believed that Covid-19 was spread only by inhalation of large respiratory droplets, or by direct ji. ==
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touch and contact transmission from hand to face, so that rus-containing I , ovuulo transmission mainly happened at close proximity (under ' 111 id droplets are the 2 m) to an infected person. 0 oo am n mechanism of oo The WHO and CDC now accept that the virus is airborne, 1 = ease . d.
1 Hõ:";õ 1 - silo l000 so mogiol000 and that it can be carried in aerosols over large distances of 6 - 8 m or more and remain viable in air for 3 hours or more.
Date Recue/Date Received 2020-09-04 Clearing the Air If droplets and aerosols are not quickly cleared from In poorly ventilated spaces the air they can be breathed in by other people in the room, -he virus can be transmitted or by people who enter the room at a later time - this is called r 1111 in aerosols over large airborne transmission. distances, and the risk of transmission increases as If droplets and aerosols are not quickly cleared, they can the number of people in the also settle on exposed surfaces, depositing live viral particles room and the time spent in called "fomites," that can transmit infection by touch the room increase.
and contact - this is called contact transmission.
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What Protection is Offered by Screening and Testing for the Virus?
V Administration of a symptom & exposure questionnaire, temperature checks and viral PCR
testing via throat swab are currently the universally recommended screening protocols.
.7 However, 30 - 40% of people who carry the virus and can transmit the infection have no symptoms, no fever and have a negative screening questionnaire.
The widely-used SARS-Cov-2 virus swab test has a false negative rate of 67% in the first 5 days after infection, and 21% even at the peak of infection symptoms. [Ann Intern Med, May13, 20203 , = -= = =
= = =
= = = A significant number of people who test negative still have &
transmit the virus. This means that current screening protocols cannot be relied upon for protection.
Physical interventions are still needed to safeguard people in public gatherings.
Date Recue/Date Received 2020-09-04 Current GuicLaiines & Recommendations Public Health Ontario and the CDC have established minimum guidelines &
recommendations to reduce the risk of virus transmission in enclosed, public spaces.
=
¨ METRES
h r (6 FEET) Wear a mask or face Maintain social Frequently clean covering distancing surfaces I Di t n in Ent = Wearing gloves and avoiding touching the face reduce the risk of contact transmission.
= Social distancing can reduce the risk of inhalation of large droplets but not the risk of inhalation of aerosols in a poorly ventilated room or contact transmission from contaminated surfaces.
= Wearing a mask can reduce, but not eliminate, the risk of inhalation of droplets and aerosols, and a face shield offers little protection from aerosols.
Much better aerosol protection can be achieved 1. Airflow Optimization and Air Filtering 2. Ultraviolet Light Germicidal Irradiation Date Recue/Date Received 2020-09-04 Airflow Optimization Airborne infectious agents are cleared when contaminated air is removed by the building's HVAC system and replaced with fresh air. Air circulation and air exchange, therefore, are of critical importance in indoor gatherings.
= When replacement with fresh air is not possible, the air can be recirculated through a HEPA
filter. A HEPA filter can remove 99.97% of droplets & aerosols suspended in air.
= The Air Changes per Hour (ACH) rate determines how long a room takes to clear of contaminants:
At 6 ACH it takes 46 min to clear a room of 99% of airborne contaminants. At 20 ACH (used in operating rooms) it takes only 14 min to clear a room of 99% of airborne contaminants.
/ Most public buildings typically provide only 6 ACH, and many older buildings as little as 1-2 ACH.
= Recognizing that most built-in HVAC systems were not designed to protect occupants from airborne disease transmission, adding a stand-alone HEPA Fan-Filter Unit (FFU) may seem like a good solution to the problem.
' = Most commercial Fan-Filter Units (FFUs) are floor-standing, portable units that have v two major shortcomings: 1. They fail to create a proper airflow pattern to protect ,ccupants. 2. They do not have sufficient true airflow capacity for the size of the roo Airflow Pattern A floor-standing FFU draws air & aerosols = ' ¨
horizontally, across the room's occupants and across fr."
exposed surfaces & equipment. Aerosols disseminate =
across the room before they are cleared by the HEPA filter.
ig171 AIL 1111 r via wr A Ceiling Mounted FFU draws contaminated air directly up and away from room , occupants & surfaces. Aerosols are removed as soon as they are generated without dissemination.
r =
47 le `11 I 4.1 f 1,7 ;

Airflow Capacity & Advertised Flow Rate Depending on price, most commercial FFU's advertise flow rates of 100 - 300 cfm (cubic feet per minute) - adequate for residential use but not enough for public & commercial spaces.

= ..
Some products advertise an airflow rate based only on their motor specifications (sometimes =400 GM tan speed (400 series) labelled "fan speed" or "no load" capacity).
This is misleading.
impeller - 115 V (part 300 cfm (no load) True, measured airflow with filters in place is typically 40% lower than advertised, significantly increasing time to process & clear the air in the room.
Date Recue/Date Received 2020-09-04 Ultraviolet G ==di Irradiation (UVGI) UV-C light has been in widespread use for decades to disinfect our drinking water supply, disinfect food, and clean food-processing plants.
UV-C light is a tested and proven strategy to inactivate & disinfect surface and airborne pathogens in healthcare facilities.
UV-C light (254 nm) irreversibly damages microbial DNA & RNA and, at the correct dose, is a universal germicidal agent effective against not only viruses, but also bacteria, molds, and fungus.
There are two types of UVGI used in healthcare applications:
Upper Room UVGI is used in rooms with high -ceilings to inactivate airborne pathogen.
Lower Room UVGI is used when the space is unoccupied to disinfect exposed surfaces and equipment, including high-touch, difficult-to-clean surfaces such as computer keyboards, cables, door handles, switches, I hi: I I I , registers, railings, fabrics, furniture, and is especially effective when used t I
in public washrooms.
Date Recue/Date Received 2020-09-04 A Comprehensive, Customizable Solution / A high-performance, cost-effective solution for air & surface disinfection outperforming existing products costing 3x - 4x the price = Custom-engineered based on scientific evidence, Computational Fluid Dynamics & physics modelling = Combines optimized airflow, HEPA filtration and Ultraviolet Germicidal Irradiation / Can be custom-tailored for each facility for coverage &
performance, and is suitable for both large and small spaces / Professionally installed without permanent structural modifications / Exceeds Public Health Ontario and the CDC recommendations for aerosol mitigation A high-performance Fan-Filter Unit (FFU) = Ceiling-mounted & positioned to carry aerosols & droplets away from room occupants & surfaces =
104144, = Multilayer NEPA & Charcoal filters = True 485 CFM true airflow = 65 dB at full power (equivalent to normal conversation) = Filter change sensor & RF remote control õ Ultraviolet Germicidal IrradEtion (UVGI) = The only system that can deliver Total Room (Upper & Lower) UVGI
= Over 100W of true UV-C power inactivates surface pathogens, including ..õ most viruses & bacteria, in under 10 minutes = 55W of Upper Room UVC power to inactivate airborne pathogens = 9,000 hour bulb life (18 years at 2 hours usage per workday) = Motion-sensing safety auto-shutoff & RF remote control Date Recue/Date Received 2020-09-04 Customized Solutions for = 11 Iiidustris / Surgical Specialist Offices V Dental Clinics / Community Healthcare Providers V Hospital Clinics / Surgical Clinics V
Restaurants & Cafes / Board Rooms &
Conference Spaces V Family Practice Clinics Date Recue/Date Received 2020-09-04 Herein Incorporated by Reference 1. Illuminating Engineering Society. IES CR-2-20-V1, IES Committee Report:
Germicidal Ultraviolet (GUV) - Frequently Asked Questions. New York: IES, 2020.https://media.ies.org/docs/standards/IES-CR-2-20-V1-6d.pdf 2. Malayeri AH et al. Illuminating Engineering Society: Fluence (UV Dose) Required to Achieve Incremental Log Inactivation of Bacteria, Protozoa, Viruses and Algae. www.iuva.org [https://iuva.org/resources/Resource%20Documents/Malayeri-Fluence%20Required%20to%20Achieve%20Incremental%20Log%201nactivation%20of%20Bac teria,%20Protozoa,%20 Viruses%20and%20Algae.pdf]
3. International Commission on Illumination. May 2020. CIE Position Statement on Ultraviolet (UV) Radiation to Manage the Risk of COVID-19 Transmission. http://cie.co.at/publications/cie-position-statement-use-ultraviolet-uv-radiation-manage-risk-covid-19-transmission 4. U.S. Food & Drug Administration. March 2020. Enforcement Policy for Sterilizers, Disinfectant Devices, and Air Purifiers During the Coronavirus Disease 2019 (Covid-19) Public Health Emergency.
Guidance for Industry and Food and Drug Administration Staff. https://www.fda.gov/media/136533/download 5. Darnell MER, et al. Aug 2004. Inactivation of the coronavirus that induces severe acute respiratory syndrome, SARS-CoV.
J of Virological Methods 6(6), 2004 6. Ansaldi F, et al. 2004. SARS-CoV, influenza A and syncytial respiratory virus resistance against common disinfectants and ultraviolet irradiation. J of Preventative Medicine & Hygiene. v45. March 2004 7. Tseng CC, et al. 2007. Inactivation of Viruses on Surfaces by Ultraviolet Germicidal Irradiation. J of Occupational & Envir Hygiene, v4(6), p 400-405.
8. Bedell K, et al. 2016. Efficacy of an Automated Multiple Emitter Whole-Room Ultraviolet-C Disinfection System Against Coronavirus MHV and MERS-CoV. Infect Control Hosp Epidemiol, 2016, v37. pp 598-9. Welch D, et.al. 2018. Far-UVC light: A new tool to control the spread of airborne-medicated microbial diseases. Nature.
Feb 2018, 8:2752 10. Lindblad L, et al. 2019. Ultraviolet-C decontamination of a hospital room:
Amount of UV light needed. Burns (2019) - in press - https://doi.org/10.1016/j.burns.2019.10.004 11. Song K, et al. 2019. Microorganism inactivation by wavelength combinations of ultraviolet light-emitting diodes (UV-LEDs). Science of the Tot Environ. V665, 2019. pp 1103-1110.
12. Garcia de Abajo F, et al. 2020. Back to Normal: An Old Physics Route to Reduce SARS-CoV-2 Transmission in Indoor Spaces. ACSNano - in press - https://dx.doi.org/10.1021/acsnano.0c04596 13. Hollaender, A., du Buy, H. G., Ingraham, H. S. & Wheeler, S. M. Control of air-borne microorganisms by ultraviolet floor irradiation. Science 99, 130-131 (1944).
14. Conner-Kerr, T. A., Sullivan, P. K., Gaillard, J., Franklin, M. E. &
Jones, R. M. The effects of ultraviolet radiation on antibiotic resistant bacteria in vitro. Ostomy Wound Manage 44, 50-56 (1998) 15. Chao, C. Y. H. et al. Characterization of expiration air jets and droplet size distributions immediately at the mouth opening.
J. Aerosol Sci 40, 122-133 (2009).
16. Morawska, L. et al. Size distribution and sites of origin of droplets expelled from the human respiratory tract during expiratory activities. J. Aerosol Sci 40, 256-269 (2009).
17. World Health Organization. Scientific Brief. July 9, 2020. Transmission of SARS-Cov-2: Implications for infection prevention precautions. https://www.whoint/news-room/commentaries/detail/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions 18. Mittal R. et al. 2020. The flow physics of Covid-19. J Fluid Mech. 2020;
v894 19. Stadnytskyi V, et. Al. 2020. The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission. Proc Ntl Acad Sci. 2020;117:11875-7 20. Somsen GA, et. Al. 2020. Small droplet aerosols in poorly ventilated spaces and SARS-CoV-2 transmission. Lancet Respir Med. 2020:S2213260020302459.

21. Van Doremalen N, et al. 2020. Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. N Engl J Med.
2020;382:1564-7 Date Recue/Date Received 2020-09-04

Claims (17)

Attorney Docket No. 1512P001CA01 We claim:

1. A system for reducing a risk of transmission of airborne infectious disease within a space, the system comprising:
- at least one aerosolized particle neutralization device; and - at least one controller for controlling said at least one aerosolized particle neutralization device, wherein said at least one aerosolized particle neutralization device is selected from a group comprising ceiling-mounted fan-filter units and multi-directional ultraviolet (UV) light sources, and wherein a number of said at least one aerosolized particle neutralization device and a configuration of said system are based on airflow data related to said space and on use data related to said space, said use data relating to how said space is used and said airflow data relating to an airflow in said space.

2. The system according to claim 1, wherein said airborne infectious disease is SARS-Cov-2.

3. A fan-filter unit for reducing a concentration of airborne infectious disease in a space, said fan-filter unit comprising:
- a housing having an intake vent and an exhaust vent, said housing containing:
- an intake fan;
- a motor for powering said intake fan; and - at least one filter, wherein, when said intake fan is in operation, air surrounding said fan-filter unit is drawn in through said intake vent and filtered through said at least one filter before being directed back into the space by way of said exhaust vent, and wherein said fan-filter unit is located adjacent a ceiling of said space.

Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01

4. The fan-filter unit according to claim 3, wherein said housing comprises at least one removable panel and wherein said at least one removable panel is customizable.

5. The fan-filter unit according to claim 3, wherein said airborne infectious disease is SARS-Cov-2.

6. A multi-directional ultraviolet (UV) light fixture for inactivating airborne infectious disease particles in a space, the fixture comprising:
- at least one UV light source;
- at least one electronic controller for controlling said at least one UV
light source; and - a casing for containing said at least one controller and said at least one UV light source, wherein said fixture is located adjacent a ceiling of said space, and wherein said UV light source is positioned in said fixture to emit UV light into an area external to said fixture in a first direction orthogonal to a longitudinal axis of said fixture and in at least one second direction, said at least one second direction being selected from a group comprising: directly opposite to said first direction and orthogonal to said first direction, and wherein said at least one second direction is also orthogonal to said longitudinal axis.

7. The multi-directional UV light fixture according to claim 6, wherein said fixture is spaced apart from said ceiling such that said longitudinal axis of said fixture is parallel to a plane of said ceiling, and wherein said at least one first direction is upwards from said fixture and said at least one second direction is downwards from said fixture, such that said fixture is configured to irradiate an irradiation area about said fixture.

8. The multi-directional UV light fixture according to claim 7, wherein said irradiation area is at least one of an upper volume of the space and a lower volume of the space, said upper volume being above the fixture and said lower volume being below the fixture.

9. The multi-directional UV light fixture according to claim 6, wherein at least some of said airborne infectious disease particles are SARS-Cov-2 particles.

Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01

10. A method for reducing a risk of transmission of airborne infectious disease within a space, said method comprising the steps of:
- obtaining use data related to said space, said use data relating to how said space is used;
- obtaining airflow data related to said space, said airflow data relating to an airflow in said space;
- determining a configuration for a system for reducing said risk, wherein said system comprises at least one aerosolized particle neutralization device and wherein said configuration is based on said use data and said airflow data, such that said system is customized for said space; and - installing said system in said space, wherein said at least one aerosolized particle neutralization device is selected from a group comprising ceiling-mounted fan-filter units and multi-directional ultraviolet (UV) light sources.

11. The method according to claim 10, further comprising the steps of:
- monitoring a post-installation concentration of said aerosolized particles in said space after said system has been installed; and - obtaining later use data and later airflow data, said later use data related to a use of said space after said system has been installed and later airflow data being related to a later airflow in said space after said system has been installed.

12. The method according to claim 11, further comprising the step of altering said system based on at least one of said post-installation concentration, said later use data, and said later airflow data.

13. The method according to claim 10, wherein said airborne infectious disease is SARS-Cov-2.

14. A multi-directional ultraviolet (UV) light fixture for inactivating airborne infectious disease particles in a space, said UV light fixture comprising:

Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 - at least one UV light source;
- at least one controller for controlling said at least one UV light source; and - a casing for containing said at least one controller and said at least one UV light source, wherein said casing comprises at least one removable panel and wherein said at least one removable panel is used to direct an irradiation pattern from said UV light fixture.

15. A multi-directional ultraviolet (UV) light fixture for inactivating airborne infectious disease particles in a space, said UV light fixture comprising:
- at least one UV light source;
- at least one controller for controlling said at least one UV light source; and - a casing for containing said at least one controller and said at least one UV light source, wherein said casing comprises at least one removable panel and wherein said at least one removable panel is customizable.

16. A fan-filter unit for reducing a concentration of airborne infectious disease in a space, said fan-filter unit comprising:
- a housing having an intake vent and an exhaust vent, said housing containing:
- an intake fan;
- a motor for powering said intake fan; and - at least one filter, wherein, when said intake fan is in operation, air surrounding said fan-filter unit is drawn in through said intake vent and filtered through said at least one filter before being directed back into the space by way of said exhaust vent, wherein said fan-filter unit is adjacent a ceiling of said space, Date Recue/Date Received 2020-09-04 Attorney Docket No. 1512P001CA01 wherein said housing comprises at least one removable panel, and wherein said at least one removable panel is customizable.

17. An invention according to the attached figures and text.

Date Recue/Date Received 2020-09-04