This application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/134,344, filed January 6, 2021, and is related to the disclosures of U.S. Patent Application Ser. Nos. 63/054,871, 63/040,274, 63/039,788, 63/060,826, 63/045,882, 63/038,446, 63/029,105, 63/062,666, and 16/405,482. All of the foregoing applications are fully incorporated herein by reference.

Technical Field

[0001 ] This application relates to the air circulation arts and, more particularly, to a fan system adapted for improving indoor air quality, such as by reducing the presence of selected airborne pathogens, and also for determining the efficacy of the reduction efforts against selected airborne pathogens.

Background

[0002] A variety of fan systems have been made and used over the years in a variety of contexts. For instance, various ceiling fans are disclosed in U.S. Pat. No. 7,284,960, entitled “Fan Blades,” issued October 23, 2007; U.S. Pat. No. 6,244,821, entitled “Low Speed Cooling Fan,” issued June 12, 2001; U.S. Pat. No. 6,939,108, entitled "Cooling Fan with Reinforced Blade," issued September 6, 2005; and U.S. Pat. No. D607,988, entitled "Ceiling Fan," issued January 12, 2010. The disclosures of each of those U.S. patents are incorporated by reference herein. Additional exemplary fans are disclosed in U.S. Pat. Pub. No. 2008/0008596, entitled "Fan Blades," published January 10, 2008; U.S. Pat. Pub. No. 2009/0208333, entitled "Ceiling Fan System with Brushless Motor," published August 20, 2009; and U.S. Pat. Pub. No. 2010/0278637, entitled "Ceiling Fan with Variable Blade Pitch and Variable Speed Control," published November 4, 2010, the disclosures of which are also incorporated by reference herein. It should be understood that teachings herein may be incorporated into any of the fans described in any of the above- referenced patents, publications, or patent applications. It should also be understood that a fan may include sensors or other features that are used to control, at least in part, operation of a fan system. For instance, such fan systems are disclosed in U.S. Pat. Pub. No. 2009/0097975, entitled "Ceiling Fan with Concentric Stationary Tube and Power-Down Features," published April 16, 2009, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2009/0162197, entitled "Automatic Control System and Method to Minimize Oscillation in Ceiling Fans," published June 25, 2009, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2010/0291858, entitled "Automatic Control System for Ceiling Fan Based on Temperature Differentials," published November 18, 2010, the disclosure of which is incorporated by reference herein; and U.S. Provisional Patent App. No. 61/1165582, entitled "Fan with Impact Avoidance System Using Infrared," filed April 1, 2009, the disclosure of which is incorporated by reference herein. Alternatively, any other suitable control systems/features may be used in conjunction with embodiments described herein.

[0003] In some environments, it is desirable to sterilize the air and/or remove airborne diseases and disease vectors from the air. Existing methods for reducing airborne disease transmission between room occupants include fresh air ventilation, filtration, and direct deactivation/destruction methods such as irradiation or oxidation of the pathogens themselves. For instance, this can be achieved through the use of one or more dynamic germicidal generators, such as an air ionizer or ion generator, which is a device that uses high voltage energy to ionize (electrically charge) air molecules. Airborne particles become charged as they attract charged ions from the ionizer by electrostatic attraction. The particles in turn are then attracted to any nearby earthed (grounded) conductors, such as plates within an air cleaner, or simply the nearest walls and ceilings, and disabled as a result.

[0004] In addition, reducing airborne disease transmission between room occupants can be achieved through the use of ultraviolet radiation (in the form of light having a particular range of short wavelengths, such as between about 200 nm and 300 nm, and is often referred to as ultraviolet germicidal irradiation (UVGI)). UVGI is a disinfection method that uses ultraviolet (UV) light at sufficiently short wavelength to kill pathogens. It is used in a variety of applications, such as food, air, and water purification. UVGI utilizes short- wavelength ultraviolet radiation (UV- C) that is harmful to microorganisms. It is effective in destroying the nucleic acids in these organisms so that their DNA is disrupted by the UV radiation, leaving them unable to perform vital cellular functions (see, e.g., U.S. Patent No. 8,481,985, the disclosure of which is incorporated herein by reference).

[0005] Known past systems for achieving a reduction in germs and improving air quality using a fan for circulating air are not adapted for determining whether the arrangement is effective for its intended purpose, either proactively or retroactively. Thus, time, expense, and energy may be wasted in an effort to provide air treatment capabilities that are either ineffective or marginally effective because they are not predictive or reactive in nature.

[0006] Accordingly, a need is identified for an improved manner of providing a fan system that avoids the problems associated with the above-mentioned approaches and determines the efficacy of the efforts to improve air quality, such as by achieving a reduction in airborne pathogens.

Summary

[0007] According to a first aspect of the disclosure, a system for minimizing exposure of at least one occupant to a pathogen and for circulating air within a space is disclosed. The system comprises a fan for circulating air within the space, a germicidal generator for applying germicidal energy to the air circulated by the fan, and a controller configured for determining an infection risk reduction based upon the operation of the fan and the germicidal generator.

[0008] In one embodiment, the germicidal generator is mounted to the fan. The fan may include a motor, a rotatable hub coupled to the motor, at least one fan blade comprising a first end coupled to the rotatable hub and a second end radially distant from the rotatable hub, and a winglet is attached to the second end of the at least one fan blade. The germicidal generator may be mounted to the fan, such as on the winglet. Specifically, the germicidal generator may be mounted to the winglet along an inner face thereof, below a bottom plane of the at least one fan blade. [0009] In one example, the germicidal generator comprises an ion generator. A rotary coupling may be connected to the fan for transmitting power to the germicidal generator.

[0010] A user input may also be provided for inputting one or more parameters to the controller for determining the infection risk reduction. The one or more parameters may include, for example the dimensions of the space, operating parameters of the fan and/or activity level of the at least one occupant. [001 1] In one particular version, the germicidal generator is configured to deliver a first concentration of germicidal energy. Based upon the determined infection risk reduction rate, the controller is further configured to adjust the first concentration of germicidal energy to a second concentration of germicidal energy.

[0 12] The system may further include a graphical user interface for displaying the infection risk reduction. The graphical user interface may display the infection risk reduction at a plurality of different levels of germicidal energy.

[0013] According to a further aspect of the disclosure, a system for determining an infection risk reduction for at least one pathogen within a space is provided. The system comprises a fan, one or more generators for providing germicidal energy, and a controller configured to control a first amount of germicidal energy provided by the one or more generators within the space. The controller may be further configured for determining the infection risk reduction for the at least one pathogen based on the first amount of germicidal energy provided by the one or more generators.

[0014] In one example, the controller determines a first infection risk for the at least one pathogen within the space based upon no germicidal energy being provided by the one or more generators. The controller may also determine a second infection risk for the at least one pathogen within the space based on the first amount of germicidal energy provided by the one or more generators. The controller may compare the first infection risk with the second infection risk to calculate the infection risk reduction. The controller may also be configured to change the first amount of germicidal energy provided by the one or more generators within the space to a second amount of germicidal energy provided by the one or more generators within the space based on the infection risk reduction.

[0015] In one embodiment, the one or more generators of germicidal energy are mounted to the fan. A graphical user interface may also be provided for displaying the infection risk reduction, including at a plurality of different levels of germicidal energy.

[0016] According to a further aspect of the disclosure, a method of reducing exposure of at least one occupant to a coronavirus within a space is provided. The method comprises determining a risk of exposure of the at least one occupant to the coronavirus, and controlling a fan for circulating air within the space based on the determined risk of exposure. In one embodiment, the method further includes the step of delivering germicidal energy to the space based on the risk of exposure.

[0017] Still a further aspect of the disclosure pertains to a method of measuring an effectiveness of reducing exposure of at least one occupant to at least one pathogen within a space. The method includes determining an effectiveness of a generator of germicidal energy in reducing a risk of exposure of the at least one occupant to the at least one pathogen, and operating a fan for circulating air based on the determined effectiveness. In one embodiment, the method comprises the step of applying germicidal energy to the circulating air based on the determined effectiveness.

Brief Description of the Drawings

[0018] The accompanying drawing figures incorporated herein and forming a part of the specification, illustrate several aspects of the disclosure and, together with the description, serve to explain certain principles thereof. In the drawing figures:

[0019] FIG. 1 is a partially schematic perspective view illustrating a system for minimizing the risk of an occupant of being exposed to airborne pathogens;

[0020] FIG. 2 depicts a top perspective view of an exemplary fan;

[0021 ] FIG. 3 depicts a side view of the exemplary fan in FIG. 2;

[0022] FIG. 4 is a top view of the exemplary fan in FIG. 2;

[0023] FIG. 5 is a top perspective view of a support for the exemplary fan in FIG. 2;

[0024] FIG. 6 is a perspective view of a circuit board for use with the exemplary fan in FIG.

2;

[0025] FIG. 7 depicts a perspective view of another exemplary fan;

[0026] FIG. 8 is a partially cutaway view of a germicidal generator mounted to the winglet of the exemplary fan in FIG. 7;

[0027] FIG. 9 is a partially cutaway view of an outer face of the winglet of the exemplary fan in FIG. 8;

[0028] FIG. 10 is a partially cutaway, partially cross-sectional view of the exemplary fan in FIG. 8 including a rotary coupling for transmitting power to the fan blades;

[0029] FIGS. 11, 12, 13, 14, 15, and 16 are graphical indications of the reduction of risk infection based on the additive effective air change for various pathogens using the disclosed techniques based on inputter information. [0030] The following description of certain examples of the invention should not be used to limit the scope of the disclosed invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the art from the following description, which includes by way of illustration, one or more of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.

Detailed Description

[0031 ] With reference to Figure 1 , an exemplary fan system 10 according to one embodiment includes a fan 11. The fan 11 may comprise a rotatable hub 12, which may include a motor (which may be partially enclosed or contained within or adjacent to hub 12). The fan 11 may be connected to a support 14, a light 16 for producing light L (which could be germicidal in nature) and may also include a plurality of fan blades 18. In the present example, fan 11 has a diameter of approximately 2-8 feet. In other variations, fan 11 has a diameter of up to 24 feet. Alternatively, fan 11 may have any other suitable dimensions depending on a particular application.

[0032] Support 14 is configured to be coupled to a surface (such as a ceiling) or other stable support structure (such as a joist, beam, or the like) at a first end such that fan 11 is substantially attached to the surface or other structure. Support 14 of the present example comprises an elongate metal tube-like structure that couples fan 11 to a ceiling, though support 14 may be constructed and/or configured in a variety of other suitable ways as will be apparent to one of ordinary skill in the art in view of the teachings herein. By way of example only, support 14 need not be coupled to a ceiling or other overhead structure, and instead may be coupled to a wall or to the ground. For instance, support 14 may be positioned on the top of a post that extends upwardly from the ground. Alternatively, support 14 may be mounted in any other suitable fashion at any other suitable location. By way of example only, support 14 may be configured in accordance with the teachings of U.S. Pat. Pub. No. 2009/0072108, entitled "Ceiling Fan with Angled Mounting," published March 19, 2009, the disclosure of which is incorporated by reference herein. As yet another alternative, support 14 may have any other suitable configuration. Furthermore, support 14 may be supplemented in numerous ways. [0033] The motor may comprise an AC induction motor having a drive shaft, though it should be understood that motor may alternatively comprise any other suitable type of motor (e.g., a permanent magnet brushless DC motor, a brushed motor, an inside-out motor, etc.). In the present example, motor is fixedly coupled to support 14 and rotatably coupled to hub 12. Furthermore, motor is operable to rotate hub 12 and the plurality of fan blades 18. By way of example only, motor may be constructed in accordance with at least some of the teachings of U.S. Pat. Pub. No. 2009/0208333, entitled "Ceiling Fan System with Brushless Motor," published August 20, 2009, the disclosure of which is incorporated by reference herein. Furthermore, fan 10 may include control electronics that are configured in accordance with at least some of the teachings of U.S. Pat. Pub. No. 2010/0278637, entitled “Ceiling Fan with Variable Blade Pitch and Variable Speed Control,” published November 4, 2010, the disclosure of which is incorporated by reference herein. Alternatively, motor may have any other suitable components, configurations, functionalities, and operability, as will be apparent to those of ordinary skill in the art in view of the teachings herein.

[0034] Hub 12 may be constructed in accordance with at least some of the teachings of U.S. Pat. Pub. No. 2010/0278637, entitled “Ceiling Fan with Variable Blade Pitch and Variable Speed Control,” published November 4, 2010, the disclosure of which is incorporated by reference herein. Alternatively, hub 12 may be constructed in accordance with any of the teachings or other patent references cited herein. Still other suitable ways in which hub 12 may be constructed will be apparent to those of ordinary skill in the art in view of the teachings herein. It should also be understood that an interface component (not shown) may be provided at the interface of each fan blade 18 and hub 12. By way of example only, such an interface component may be configured in accordance with the teachings of U.S. Pat. Pub. No. 2009/0081045, entitled “Aerodynamic Interface Component for Fan Blade,” published March 26, 2009, the disclosure of which is incorporated by reference herein.

[0035] Fan blades 18 may further be constructed in accordance with some or all of the teachings of any of the patents, patent publications, or patent applications cited herein. For example, fan blades 18 may be configured in accordance with the teachings of U.S. Pat. No. 7,284,960, entitled “Fan Blades,” issued October 23, 2007; U.S. Pat. No. 6,244,821, entitled “Low Speed Cooling Fan,” issued June 12, 2001; and/or U.S. Pat. No. 6,939,108, entitled “Cooling Fan with Reinforced Blade,” issued September 6, 2005. The disclosures of each of those U.S. patents are incorporated by reference herein. As another merely illustrative example, fan blades 18 may be configured in accordance with the teachings of U.S. Pat. Pub. No. 2008/0008596, entitled “Fan Blades,” published January 10, 2008, the disclosure of which is also incorporated by reference herein. As yet another merely illustrative example, fan blades 18 may be configured in accordance with the teachings of U.S. Pat. Pub. No. 2010/0104461, entitled “Multi-Part Modular Airfoil Section and Method of Attachment Between Parts,” published April 29, 2010, the disclosure of which is incorporated by reference herein. Alternatively, any other suitable configurations for fan blades 18 may be used in conjunction with the examples described herein. For example, fan blades 18 may be formed of aluminum through an extrusion process such that each fan blade has a substantially uniform cross section along its length. It should be understood that fan blades 18 may alternatively be formed using any suitable material, or combination of materials, by using any suitable technique, or combination of techniques, and may have any suitable cross-sectional properties or other properties as will be apparent to one of ordinary skill in the art in view of the teachings herein.

[0036] Turning to Figures 2-6, another representative fan 11 having a plurality of fan blades 40 is illustrated. The fan 11 in this example may be provided with a lighting module 60 configured 10 providing light, such as in the form of uplight (and light in the UV-C range, in particular). This module 60 may be annular in nature, and adapted to overlie the motor housing 20. Specifically, the module 60 may surround the support 14, and be located between an optional decorative covering 62 and the motor housing 20.

[0037] With reference to Figure 5, an upwardly projecting portion of the module 60 may comprise a stanchion 64 having an annular opening 64a for receiving the support 14, and depending supports 64b for underlying the covering 62. The stanchion 64 may be connected to an annular base 66 forming a recess in the nature of an annular tray 68 for receiving one or more lights, such as LED(s) for emitting light of a selected wavelength, either for providing general lighting, providing germicidal capability, or both depending on a selected mode of operation. The stanchion 64 may also be provided with a fastener for connecting it with the support 14.

[0038] As shown in Figure 6, the LED(s) for providing uplight are arranged on a circuit board (which is an insulated board on which conductive pathways are constructed and components are mounted), such as a printed circuit board assembly (PCBA) 70. The PCBA 70 may be annular in nature, but not necessarily circular. The PCBA 70 may be adapted to connect to a power supply, such as that associated with the fan 10. The connection may be by way of a releasable plug or connector to promote interchangeability.

[0039] Overlying the tray 68 is an optional lens 72. The lens 72 may comprise an annular transparent or translucent material that overlies the PCBA 70 when present and allows light to pass therefrom in a direction opposite the base 66, which may be opaque. The lens 72 may include one or more releasable connectors 74 for connecting with the base 66, such as along a radially inward portion for engaging corresponding portions of the stanchion 64. These connectors 74 allow for the lens 72 to be disconnected and then raised or lowered relative to the base 66, such as long the support 14 with which it is generally concentric.

[0040] The module 60 maybe positioned over the support 14 of the fan 10 prior to installation, or even in a retrofit situation by removing the fan 10 from the ceiling temporarily and positioning the module thereupon. When connected to the power supply, the lighting provided by LEDs 70a associated with the PCBA 70 thus provides the fan 10 with uplighting capability (that is, light directed upwardly toward the ceiling to which the fan is mounted), which may be turned on or off as the user desires (such as by way of a remote control). In the case where the LEDs 70a provide UVGI, the uplighting provided thus gives the fan 10 germicidal capabilities (which may be indicated by providing the LEDs with a particular color of light, such as for example blue, to indicate to the remote user that the germicidal capabilities are enabled).

[0041] Figures 7-10 show a fan system 10 using yet another exemplary fan 100. Fan 100 comprises fan blades 120 and a rotating hub 130. Winglets 140 are secured to the outer end 122 of each fan blade 120. In this example, fan 100 also includes a motor 150 and a gearbox 160 that rotationally drive hub 130, a mounting member 170 by which fan 100 may be mounted to a ceiling or other structure and a control box 180.

[0042] With reference to Figures 8 and 9, the fan 100 may be provided with one or more dynamic germicidal generators, such as ion generators 200 mounted to a movable portion of the fan 100, such as one or more of the blades 120. The dynamic mounting of the ion generator(s) 200 is advantageous in that such increases the number of ions generated (such as by the associated brushes 200a depending therefrom) and hence the efficacy of germicidal action. Indeed, the generator(s) 200 may be located adjacent to or at the radially outward end of the associated blade 120, where the airspeed is at a maximum. An exemplary ion generator 200 suitable for use is manufactured by Plasma Air International (Model: PA601, 12V DC) of Stamford, Connecticut, which device generates both positive and negative ions. This particular generator consumes little power, is lightweight and presents a low-profile so as to create a negligible impact on the operation of fan 100 in terms of generating air movement in an efficient manner.

[0043] In one exemplary embodiment, the winglet 140 associated with the outer end 122 of each fan blade 120 carries the generator 200. The generator 200 may be connected anywhere along the winglet 140, such as for example on a depending portion and underneath the plane of the blade 120. The connection of the generator 200 to the individual winglet 140 may be achieved using fasteners F, which may pass through the body of the winglet 140.

[0044] Power for the generator 200 may be supplied via a conduit including a dynamic rotary connector for transmitting power through a rotary coupling, such as a slip ring 300. Turning to Figure 10, the slip ring 300 may be mounted within a housing 302 supported by the stationary tube 110, such as by a depending support 304. The conduit further comprises wires 306 for supplying power extend from a power source associated with the fan 10 to connectors 308 on the upper portion 300a of the slip ring 300, which is held stationary by a mount 312. A torque arm 314 may be provided for engaging a stop 315 mounted to the tube 110.

[0045] The lower portion 300b of the slip ring 300 includes connectors 316, which connect with individual pairs of wires (not shown) arranged in parallel for conveying power along the fan blade(s) 20 to the associated ion generator 200. Specifically, the wire pairs may extend through a channel in the hollow interior of the fan blade 20 to connect to the generator 200. In the case where the generator 200 is mounted to the winglet 140 as shown, the wires may pass through an opening in the winglet 40. Thus, when the fan 100 is actuated to cause hub 130 to rotate, the lower portion 300b of the slip ring 300 may also rotate while the upper portion 300a remains stationary. Nevertheless, the power connection and transmission remain continuous and hence dynamic ion generation occurs in a most efficient and effective manner as compared to a stationary source. [0046] The above arrangements illustrate a fan 11, 100 with an integrated generator of germicidal energy, such as a UV-C light or an ion generator. However, the fan 11, 100 and a generator of germicidal energy may be two separate and independent structures. For example, the generator may be mounted on a wall, ceiling, or other location within the space in which fan 11, 100 is located, and could even be associated with a conduit or duct for delivering air to the space. [0047] According to one aspect, this disclosure relates to a fan system 10 that calculates a risk of transmission of one or more pathogens, diseases, or disease vectors (collectively referred to as “pathogens”) at any given time and implements changes to address the presence of these pathogens. These pathogens may be bacteria, fungi, or viruses, including but not limited to Coronavirus (e.g., SARS-COV-1 or SARS-COV-2), Influenza A virus and Mycobacterium tuberculosis. For instance, the fan 11, 100 may include integral germ-killing technologies, such as ionization or UV-C/UVGI, but as noted above, such may simply be located in an associated space including the fan or the circulating air (e.g., a duct).

[0048] In assessing risk associated with various pathogens and determining the effectiveness of the reduction efforts, the system may cause the fan 11, 100 to adjust speed and/or direction, may turn germicidal generators (UV lights or ion generators, for example) on/off and/or alter their intensity or concentration, may turn ventilation fans on/off, may adjust ventilation fan(s) airflow rate(s). The fan may provide operators with maintenance notifications and efficacy data based on real-time performance feedback as to the effectiveness of risk reduction achieved for a given measure implemented. Wireless controls, strategies, and user interfaces may be employed, which may drastically reduce installation costs.

[0049] Referring back to Figure 1, one or more sensors S may be used for detecting environmental parameters within a given space that are indicative of indoor air quality. For instance, the sensors S may include, be associated with, and/or be in communication with sensors for sensing temperature, humidity, occupancy, sound, light, and/or carbon dioxide level. The sensors S may be connected directly to the fan 11, or may form part of a separate structure within the room (e.g., wall controller) that may communicate with and provide signals for controlling the fan (such as by wireless communication).

[0050] Various manners exist for determining a risk of an airborne disease being transmitted to another based on measured environmental parameters, such as, for example, risk of airborne disease transmission as a function of “rebreathed” air in a space, which correlates to the carbon dioxide level. According to one manner of determining a risk of airborne disease transmission, the probability P of exposure may be evaluated as follows:

[0051 ] Another measure involves determining a ventilation rate based on a function of indoor CO2 concentration, which may be expressed by: G

Q = r '-i.n C. out

[0052] The critical rebreathed fraction ( f _c ) represents the fraction of ambient CO2 under which a reduction in transmission would be expected to occur. Substituting ( f _c ) for the indoor CO2 concentration yields:

G

Q f _c - C _t out

[0053] The indoor CO2 generation rate may be expressed by:

G = V C _ex

[0054] These equations take one or more of the following parameters into consideration: [0055] Environmental factors that may affect the risk of pathogens and/or pathogen transmission within a space include occupancy, duration of occupancy, ventilation flow rate, CO2 concentration and generation rate. In addition, factors such as air temperature and relative humidity may be important in addressing pathogens in the space, since these factors may impact UV effectiveness. Ventilating a room prior to a space being occupied, rather than waiting for risk to build, may be accomplished based on a time of day and a known time of occupancy of the space. Assessments of these factors can be used to preempt risk by making changes when known occupancies will occur. For instance, the following represents actions that may be taken based upon an assessed probability:

As can be appreciated, the above presents an example only, and the probability values may vary depending on a particular situation or application.

[0056] According to one aspect of the disclosure, the fan 11 (or 100) may form part of a system 10 and thereby utilize output from the one or more sensors S associated therewith in order to operate based on a potential risk of exposure to air pathogens. A corresponding controller C may implement the output into one or more of the equation(s) above for enacting real time responses based on the conditions in a given space. For instance, the controller C may use combined output from the occupancy and carbon dioxide sensors together to understand the duration or time and number of people in a given space, or if a room is occupied and how long it has been occupied, and CO2 concentrations.

[0057] Based on an analysis of the above equation(s) as a function of real-time data in a space, the controller C may determine a risk level within that space. Using this calculated risk level, the controller C may cause the fan to activate, deactivate, increase speed, decrease speed, and/or in some way adjust one or more of the germicidal functions (increasing the level, or concentration, of germicidal energy) in order to help deal with the presence of pathogens within the space, and thereby reduce the risk of disease transmission as a result.

[0058] In addition or as an alternative to actively reducing the number of active airborne pathogens in a space, the system 10 including the fan 11 and controller C may use inputted information to determine an overall effectiveness of the reduction efforts achieved via germicidal energy, such as ionization or light (e.g., UV-C). The high-level input information may be inputted via a user input I to the controller C. The inputted information may relates to the area of concern, i.e., where the fan(s) is/are located, the details about the particular fan(s) installed, and occupant characteristics in the space where the fan(s) is/are located to show system effectiveness against selected pathogens and a corresponding Wells-Riley infection risk reduction via effective pathogen dilution in the indoor air. Based upon the results of the overall effectiveness at a particular rate of the application of germicidal energy (ionization or UV-C, for example), automatic adjustments may be made in real-time to the operation of the fan 11 to regulate airflow in real time. The use of the overall effectiveness of the minimization efforts may also be performed pre-emptively. For example, prior to an event or gathering, if the expected parameters are known, i.e., space geometry, number of occupants, type of event (low, medium, or high activity level), then the estimated effectiveness of an application of germicidal energy may be determined and then pre-selected such that the space is prepared for a particular level of occupancy.

[0059] In order to calculate the overall effectiveness of the system 10 against a particular pathogen, one or more of the following parameters or calculation inputs may be used:

• Unit system o English (IP) or Metric (SI)

• Geometry of the space where the fan(s) is/are located o Space length (L) o Space width (W) o Space ceiling height (H)

• Fan Details o Fan Mounting Height o Fan Model o Quantity of Fans o Fan Size o Fan Extension Tube Length o Fan Speed o Path Length Through Disinfection Zone

• Occupant Characteristics o Exposure Time o Number of Infectious Sources o Occupant Activity Level

^■ Low = rested/seated

^■ Moderate = standing/walking

^■ High = running

• Mechanical System o Baseline outdoor air ventilation rate in air changes per hour

• Pathogen Selection o Coronavirus (SARS-CoV-2) o Influenza A o Mycobacterium Tuberculosis o Other

[0060] Once the information is provided, such as via input I, the controller C initiates the calculation steps as follows:

1. Convert all inputs to English (IP) units if entered as metric values

2. Calculate Space Area: A = L*W 3. Calculate Space Volume: V = A*H

4. Calculate disinfection zone height: Z = H-d, where d = drop length as defined in the Table 1 below depending on the fan model, size, and length of a support, such as a drop tube:

5. Calculate disinfection zone air volume: Vd = A*(H-Z)

6. Calculate required displacement (D) to achieve 25 zonal air turnovers (ZATH) per hour (air volume in the disinfection zone displaced outside of the disinfection zone and replaced with air from outside the disinfection zone) in the disinfection zone with an applied safety factor of 2.0, wherein D = 2.0 * 25 ZATH * Vd

7. Calculate the total delivered air displacement from specified fans using information from the Table 2 below: D Fan = Fan Qty * Fan Operating CFM

8. Check that the total fan displacement (D Fan) is greater than or equal to the required displacement (D):

If (D_Fan>=D, TRUE, FALSE);

FALSE stops calculation.

9. Determine an average UVC fluence in the disinfection zone (i) in pW/cm2 using the simulation results matrix (below) that indexes results based on the quantity of UVC fans specified and the floor area of the targeted space.

Note: the result is scaled linearly for results that fall outside of the matrix inputs (absolute inputs of more than 9 fans or more than 2500 square feet and inputs where more fans are placed in areas than the upper bound of standard designs - example: more than 2 fans in a 300 square foot space).

10. Define airspeed through disinfection zone (v_air) based on fan selection and operating speed based on Table 3 below:

11. Define path length through the disinfection zone of a representative air element (p) in feet. Typically, this is half the distance between adjacent fans or from the singular fan to the nearest wall/space boundary.

12. Calculate average residence of a representative air element in the disinfection zone per pass (t_res), wherein t res = p / v air * 60

13. Calculate average non-residence of a representative air element (time spent outside of disinfection zone per pass), t non, wherein t non = 60 / ( D Fan * 60 / V ) * 60

14. Calculate the total pass time (t tot), wherein t tot = t res + t non 15. Define occupant exposure time (t), i.e., the length of time that representative occupants will be in the space

16. Define effectiveness correction (x) for UVC wavelengths relative to 254nm; e.g., 265nm = 1.25

17. Calculate average germicidal dose per pass (d), where d = i * x * t res

18. Calculate number of passes for representative air element in exposure time N = t / t tot

19. Calculate total cumulative dose (d tot) over the course of exposure time d tot = d * N

20. Define dose effectiveness with/without ceiling fans:

With ceiling fans, d eff = 0.87

Without ceiling fans, d eff = 0.12

21. Calculate system effectiveness of total dose, d tot, versus a pathogen with a known UVC susceptibility constant, k.

E = 1 - exp( -k * d eff * d tot)

22. Correlate system effectiveness to an estimate for additive effective air changes (eACH) for each pathogen studied using the results of Ko, 2002. Line of best fit below: eACH = 0.393 * exp( 5.37 * E)

23. Define inputs for Wells-Riley infection risk calculations Number of infectious sources (n_i)

Baseline OA ventilation rate in OACH (outdoor air changes per hour) and convert to m3/s using space volume, report as (v base)

Activity level to drive occupant breathing rates (a occ) in m3/s based on Table 4 below:

Quanta by pathogen (q) see table:

24. Calculate baseline risk from Wells-Riley:

R base = 1 - exp(( -q * n_i * a occ * t * 60) / (v base))

25. Calculate after UVC intervention risk, R uvc, from Wells-Riley with new ventration rates considering eACH’s role in increasing effective OA rate in the new term, v_eq, wherein: v_eq = (OACH / v_base) * (OACH + eACH) and R uvc = 1 - exp(( -q * n_i * a occ * t * 60) / (v_eq))

26. Calculate risk reduction, R red, wherein:

R red = (R base - R uvc) / R base

For at least items 10-14, these metrics (in particular, airspeed through the disinfection zone and the residence time in the disinfection zone) may be obtained using computational fluid dynamics software, such as for example using the SPECLAB software of the present applicant, as disclosed in U.S. Patent Application Ser. Nos. 63/062,666, and 16/405,482 and also in U.S. Copyright Reg. No. TX0008782511, the disclosure of which is incorporated herein by reference.

Example 1

[0061] To test the efficacy of fan system utilizing ionization as the germicidal energy, the following parameters relating to a space where the fan is installed/positioned are inputted into the controller and determined by the controller: space length, space width and space height (in feet). Furthermore, the occupant parameters are also inputted and determined for the space. In this example, these parameters include occupant exposure time, which may be inputted based on exposure time in minutes of a representative occupant (e.g., greater or equal to 10 minutes). The baseline outdoor air ventilation rate is inputted based on outdoor air exchange rate of base mechanical system (default = 0.5-1.0 ACH). The number of infectious sources, which is based on number of assumed occupants who are contagious (default = 1). Finally, the occupant activity level in terms of breathing rate is inputted (low = 6L/min; medium 15L/min; and high 30L/min). [0062] The system effectiveness may be measured at different bi-polar ionization concentrations. In this example, the system effectiveness for ionization (E, which is the difference between pathogen decay at X concentration of air ions compared to baseline concentration of ions (<1000/cc)) is measured at an ionization rate, such as 40k ions/cc. The system effectiveness is then translated to an additive effective air change (eACH) per the experimental results of Ko, 2002, “The Characterization of Upper-Room Ultraviolet Germicidal Irradiation in Inactivating Airborne Microorganisms,” incorporated herein by reference, and the line of best fit using system effectiveness (E) is outlined above at item 20. The additive effective air change (eACH) is derived at 40k ions/cc and compared to a baseline ACH of 0.0 with no ionization. However, it should be appreciated that the additive effect air change (eACH) may be estimated at a plurality of different ion concentrations, i.e., baseline (corresponding to no ionization), 6k ions/cc, 10k ions/cc, 40k ions/cc and 150k ions/cc. Figure 11 represents a graphical representations based on inputs provided (e.g., via input I such as a graphical user interface for receiving various information) to make the risk calculation, as shown in Figure 12, such as by using a controller C.

[0063] The Infection Risk Reduction is calculated via the Wells-Riley equation, wherein the baseline risk (R base represents the probability of infection) is the Wells-Riley infection risk equation based on the inputs above and no ionization:

R base = 1 - exp(( -q * n_i * a occ * t * 60) / (v base))

[0064] Once the baseline risk is calculated, the infection risk at one or more ionization rates (in this example, 40k ions/cc) is calculated as follows:

R uvc = 1 - exp(( -q * n_i * a occ * t * 60) / (v_eq))

The infection risk at one or more ionization rates takes into consideration the additive effective air change (eACH) as a result of the minimization efforts of the airborne pathogen within the space. [0065] The baseline risk (R base) and infection risk at the ionization rate (R uvc) is then used to calculate the overall risk reduction based on the change in the baseline risk and the infection risk at the ionization rate to determine the efficacy of the ionization reduction measures in the space as shown below:

R red = (R base - R uvc) / R base

The effectiveness of these efforts are plotted as shown in Figures 11 and 13, as a function of ion concentration, as well as in terms of particular pathogens, to demonstrate efficacy. These values are representative of a fitness environment typical for ion tech use (larger area, higher deck, higher baseline ventilation, higher occupant activity rates), based on inputted information via a graphical user interface, per Figures 12 and 14.

[0066] Example 2

[0067] To test the efficacy of a fan system utilizing UVC as the germicidal energy, the same parameters as Example 1 related to the fan space are entered: space length, space width and space height. In addition to the space parameters, various fan parameters are also inputted, such as fan mounting height (height of fan mount point above finished floor), number of fans in space, fan size (diameter of fan used - if more than 1 fan is used, all fans must be same size for calculation), extension tube length (ET lengths on universal mounts - if different sizes used, the maximum should be entered), fan design speed, and path length through disinfection zone (typically minimum value from fan center to wall as a conservative measure). The length of time for the testing (default is sixty minutes to align with chamber testing) is inputted. The baseline outdoor air ventilation rate is inputted based on outdoor air exchange rate of base mechanical system (most < 1.0; default = 0.75 ACH). The occupant activity level in terms of breathing rate is inputted (low = 6L/min; medium 15L/min; and high 30L/min). Finally, the different pathogens being measured may be displayed, i.e., Coronavirus (SARS-COV-2), Influenza A virus, and Mycobacterium tuberculosis.

[0068] The following system checks may be performed based upon the following inputs: (1) space area; (2) space volume; (3) fan airfoil height (which is height of the airfoils AFF and the start of the disinfection zone); (4) required number of fans for mixing (e.g., checking to confirm that the total fan CFM is greater than the required displacement for effective mixing (minimum 25 zATH)); and (5) cumulative dose (total dose over study time).

[0069] The additive effect air change (eACH) is derived for each of the following pathogens Coronavirus (SARS-COV-2), Influenza A virus, and Mycobacterium tuberculosis. Again, the Infection Risk Reduction is calculated via the Wells-Riley equation, wherein the baseline risk is the Wells-Riley infection risk equation based on the inputs above and quanta gen for first pathogen with no UV-C. Once the baseline risk is calculated, the infection risk with UV-C is calculated based on the inputs above and quanta gen for first pathogen with a particular level of UV-C. The baseline risk and infection risk with UV-C is then used to calculate an overall risk reduction based on the percent change in risk in the baseline risk and the infection risk utilizing UV-C at the particular level for the first pathogen. These steps are repeated for the other two pathogens, such that the efficacy of the UV-C reduction measures in the space may be determined to demonstrate efficacy. The effectiveness of the UV-C reduction measures appear graphically and in table form in Figures 15-16 based on inputs provided, such as via a graphical user interface. These values are representative of a classroom/office environment typical for UV-C use (smaller area, lower deck, lower baseline ventilation, lower occupant activity rates).

[0070] The system 10 including the fan 11 (or 100) and controller C (which may be local or remote) may include software that utilizes the above equation(s) in a closed loop feedback system. As measured environmental parameters change, the system including the fan 11 may adjust the various elements of the system accordingly, including for example fan speed or the amount of germicidal energy provided (intensity/concentration level), in order to achieve a desired risk reduction. As noted above, a graphical user interface and associated display may be provided for interaction with and/or control of the fan 11, 100 and/or other elements of the system 10. The graphical user interface may be provided via a mobile application operating on a mobile device (e.g., a smart phone or a tablet), may be provided in association with a stationary control (e.g., a wall controller) or mobile remote control, and/or may be provided on the fan itself. In the case of a wall controller, it may be bactericidal in nature.

[0071 ] In connection with the associated controller C, the fan 11 can be used to actively reduce the number of active airborne pathogens in a space or can trigger ventilation (such as from an external source (e.g., using a blower for causing an air exchange with the space) when more fresh air is needed). This can be implemented into ceiling fans or other electric fans of all sizes, from high-volume-low-speed fans a large as 24 feet in diameter to smaller residential fans that are four feet in diameter. Applicable space types include schools, offices, hospitals, fitness centers, public spaces/shopping malls, and homes.

[0072] Furthermore, automating the controls and having access to real-time and trended data may be used to implement risk management strategies and can save energy. For example, real time data can be collected and transmitted via local connections through technologies such as WiFi, Bluetooth, etc., including without internet connectivity. General data storage and analytics such as risk level trends, risk level alerts, equipment usage rates, as well as remote monitoring of real time data can occur via cloud connections locally or remotely from the fan. [0073] Having shown and described various embodiments, further adaptations of the apparatuses, methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the disclosure. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometries, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Furthermore, while a ceiling fan 11 or 100 is shown, it should be appreciated that the disclosed concepts may be applied to other fans, such as directional fans, blowers, ventilators, HVAC units, exhaust fans, or the like, separately or in addition to a ceiling fan. Furthermore, while the germicidal energy generators are shown integral with the fans, it should be appreciated that they may be provided separate therefrom, as noted. Accordingly, the scope of the disclosure should be considered in terms of claims that may be presented, and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.

[0074] As used herein, the following terms have the following meanings:

[0075] “A”, “an”, and “the” as used herein refers to both singular and plural referents unless the context clearly dictates otherwise. By way of example, “a compartment” refers to one or more than one compartment.

[0076] “About,” “substantially,” “generally” or “approximately,” as used herein referring to a measurable value, such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/- 20% or less, preferably +/- 10% or less, more preferably +/-5% or less, even more preferably +/-1% or less, and still more preferably +/-0.1% or less of and from the specified value, in so far such variations are appropriate to perform in the disclosed invention. However, it is to be understood that the value to which the modifier “about” refers is itself also specifically disclosed.

[0077] “Comprise”, “comprising”, and “comprises” and “comprised of’ as used herein are synonymous with “include”, “including”, “includes” or “contain”, “containing”, “contains” and are inclusive or open-ended terms that specifies the presence of what follows, e.g., “component includes” does not exclude or preclude the presence of additional, non-recited components, features, element, members, steps, known in the art or disclosed therein.

[0078] While certain embodiments have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the protection under the applicable law and that methods and structures within the scope of these claims and their equivalents be covered thereby.