Far UV and air filtration system

Abstract

A system for inactivating a pathogen in air, the system including a far-UV radiation source and an air filtration system. The far-UV radiation source and the air filtration system are operationally linked. The air filtration system can be configured for removing PM2.5 particles from air. The disclosure also provides a far-UV apparatus and a method for inactivation of a pathogen in air.

Description

FAR UV AND AIR FILTRATION SYSTEMTECHNICAL FIELD

[0001] This document pertains generally, but not by way of limitation, to far- UV systems for inactivating pathogens. More specifically, but not by way of limitation, the present application relates to a system useful providing 222 nm light.BACKGROUND

[0002] Research and development in the field of far-UV light has shown promise in its potential to provide effective germicidal properties while ensuring the safety of human occupants. With a wavelength of 222 nm, far-UV light has the ability to inactivate pathogens without deeply penetrating eye or skin tissue. Due to this unique characteristic, far-UV light has attracted considerable interest as it presents a valuable solution for disinfection in various settings, such as schools, hospitals, offices, and public spaces. Further exploration and refinement of far-UV light technology holds the potential to revolutionize disinfection methods and enhance public health and safety.

[0003] There is a need for improved systems for use with far-UV light.SUMMARY

[0004] The disclosure provides a method, system, and apparatus for inactivating pathogens in air of a treatment space. The method, system, and apparatus involve use of a far-UV radiation source that is operationally linked with an air purification unit. In various aspects, method, system, and apparatus can be configured so that the far-UV radiation source and the air purification unit operate in concert, for example, simultaneously, concomitantly, sequentially, one in response to the other, one in anticipation of the other, or by way of an interlock mechanism.

[0005] The disclosure further provides a system for inactivating a pathogen in air of a treatment space, comprising: a far-UV radiation source that emits radiation comprising one or more wavelengths of about 210 nm to about 230 nm and an air purification unit configured for removing airborne particulate matter,wherein the far-UV radiation source and the air purification unit are operationally linked.

[0006] The disclosure also provides a method for inactivating a pathogen in air in a treatment space, comprising: receiving an instruction to irradiate a treatment space; verifying an operational state of an air purification unit configured for removing airborne particulate matter in the treatment space; irradiating air in the treatment space with radiation from a far-UV radiation source based on the operational state of the air purification unit.

[0007] The disclosure further provides a method for inactivating a pathogen in air in a treatment space, comprising: receiving an instruction to irradiate a treatment space; activating an air purification unit configured for removing airborne particulate matter in the treatment space; and irradiating air in the treatment space with radiation from a far-UV radiation source that emits radiation comprising one or more wavelengths of about 210 nm to about 230 nm.

[0008] The disclosure also provides a method for inactivating a pathogen in air in a treatment space, comprising: receiving an instruction to irradiate a treatment space; evaluating the operational state of an air purification unit against one or more interlock conditions to determine an interlock state, wherein the one or more interlock conditions are determined based an operational state of an air purification unit; irradiating air in the treatment space with radiation from a far-UV radiation source based on the interlock state.

[0009] The disclosure yet further provides an apparatus for inactivating a pathogen in air of a treatment space, comprising a UV radiation source that emits radiation comprising one or more wavelengths of about 210 nm to about 230 nm, and a control module that that operationally links the far-UV radiation source with operation of an air purification unit.

[0010] Various aspects of the presently described system and method can have one or more of the advantages of (i) improved energy efficiency, (ii) improved safety, (iii) improved effective transmittance of UV light and reduced non-germicidal consumption of far-UV radiation, (iv) preventing PM2.5 from forming in the treatment space rather than simply removing it after it has formed.BRIEF DESCRIPTION OF THE FIGURES

[0011] FIG. 1 illustrates an example of a system including a far-UV radiation source, an air purifier, and a control module.

[0012] FIG. 2A and FIG. 2B illustrate examples of an apparatus including a UV radiation source and an air purification unit.

[0013] FIG. 3 provides a flow diagram of an example use of a far-UV irradiation source operationally linked with an air purification unit in a process for irradiating a treatment space.

[0014] FIG. 4A and FIG. 4B provide flow diagrams of further examples of using a far-UV irradiation source operationally linked with an air purification unit in a process for irradiating a treatment space.

[0015] FIG. 5 provides a flow diagram of yet another example use of a far- UV irradiation source operationally linked with an air purification unit in a process for irradiating a treatment space.

[0016] FIG. 6 illustrates a block diagram of an example comprising a machine upon which any one or more of the methods discussed herein may be performed.DETAILED DESCRIPTION OF THE INVENTION

[0017] The present disclosure provides, among other things, apparatus, systems, and methods for inactivating pathogens in air. The apparatus, system, and method involve use of a far-UV radiation source that is operationally linked to an air filtration system. When operationally linked, the apparatus, system, or methods are configured so that the far-UV radiation source and the air purification unit operate in concert, for example, simultaneously, concomitantly, one in response to the other, one in anticipation of the other, or by way of an interlock mechanism. The air purification unit is device or component configured to remove various components from air, such as by utilizing one or more mechanical filters, scrubbers, and fresh air exchange (ventilation). The air purification unit can be a portable air purifier or a non-portable air purifier, such as those included in a central air handling system, HVAC system, or in ducts. The air purification unit can be configured to remove airborne particles, undesirable contaminants, various non-pathogenic contaminants, volatile organic compounds, ultrafines, or any combination thereof, from air of the treatment space. The far-UV radiation sourcecan be configured to provide germicidal UV radiation, such as far-UV radiation comprising one or more wavelengths between 210 nm and 230 nm. The air filtration system can be configured for removing airborne particulate matter, such as PM2.5 particles, from the air. Interdependence between the far-UV radiation source and the air filtration system provides various advantages with respect to safety (for example, reduced generation of harmful airborne contaminants), improved delivery of germicidal UV (for example, reduced loss of UV light to pathogenic components of air), efficiency (for example, reduced energy consumption for the same germicidal effect), and air quality (for example, reduced large aggregated oxygenated particles). In various aspects, safer irradiation with far-UV is achieved by controlling far-UV radiation emission based on certain components of air, particularly ultrafines, airborne particulate matter (e.g., PMO.1, PM1.0, PM2.5, PM5, or PM10), ozone, and volatile organic compounds (VOCs), rather than based merely on exposure limits (e.g., threshold limit values or TLV). Various aspects of the present disclosure thus permit access to safer far-UV exposure, including at levels below or above far-UV threshold limit values.Definitions

[0018] Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

[0019] In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “atleast one of A and B” or “at least one of A or B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[0020] In the methods described herein, the acts can be carried out in any order without departing from the principles of the invention, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doingY can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0021] The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.

[0022] The term “substantially” as used herein, depending on context, can refer to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%.

[0023] In the methods described herein, the acts can be carried out in any order without departing from the principles of the invention, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doingY can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0024] As used herein, the term “pathogen” includes viruses, bacteria, infectious microbes, fungi, protozoa, parasites, and other agents, or components thereof, that are capable of causing disease or infection in humans or animals. Pathogens includes pathogens in droplets, pathogens in aerosols, pathogens on surfaces, and free pathogens in air.

[0025] As used herein, the term “inactivation” refers to a partial or complete reduction in a pathogen’s ability to cause disease or infection. Without intending to limit to any particular theory of mechanism, inactivation may be achieved by damaging or destroying the pathogen’s genetic material, membrane, or other structures through exposure to UV radiation (e.g., far-UV radiation). In some contexts, inactivation can refer to inactivating a pathogen’s ability to reproduce, replicate, enter a cell, or evade the immune system. Inactivation of pathogens can be useful for disinfection or decontamination purposes.

[0026] As used herein, the term “treatment space” refers to the space being irradiated to inactivate pathogens in air of said treatment space. Typically, the air of the treatment space includes the entire volume of the space, e.g., a room, as such air readily mixes and treatment of a given space is typically configured to provide a germicidal effect to the entire space not simply a subsection thereof. The terms “human-use space” or “occupiable space” refer to an area that is designed or intended for use by humans. Examples include, but are not limited to, rooms, restaurants, schools, workplaces, offices, hospitals, cafeterias, event space, bars, theaters, gyms, retail space, public transportation vehicles, public transportation stations, airports, and airplanes. Human-use space or occupiable space can include indoor space and outdoor space. Human-use space or occupiable space can be empty, or it can be occupied space, for example by one or more occupants. Indoor space can include indoor space that is open, ventilated, or non-ventilated. In various examples, indoor space can have windows, or mechanical ventilation such as a HVAC system including air supplies and air returns. An occupiable space or occupied space can also refer to an animal-use space or plant-use space. Occupiable space can have certain areas expected to be occupied. In various aspects, areas of an occupiable space that may be expected to be occupied can include seats, desks, tables, bar tops, waiting areas, patient beds, reception space, checkout areas, cubicles, stairways, walkways, and elevators. Typically, areas of expected human occupancy are less than 7 feet from a floor. In various aspects, a far-UV system can be configured for inactivating a pathogen on a surface. In various aspects of the systems, methods, and apparatus described herein, it may be useful to understand how a far-UV radiation source or an air purifier acts upon a treatment space. Generally, the far-UV radiation source is located or otherwiseconfigured to act upon a particular target treatment space, and thus relevant monitored, measured, and assessed parameters refer to those of that treatment space. On the other hand, in the case of the air purifier, various aspects can involve use of air purifier that can be configured or located for treatment of a particular target, or of multiple spaces. In various aspects, the air purifier is located outside of the treatment space, but acts upon the treatment space. Thus, in various cases, relevant parameters can involve parameters of the treatment space, parameters that control how an air parameter acts upon the treatment space in particular, or general parameters that apply to the treatment space as well as other spaces. For example, when monitoring the activity of an air purifier on the treatment space, it may be useful to monitor activity of an HVAC system containing the air purifier and located outside of the treatment space, yet which nonetheless serves to purifier air in the treatment space. As such, parameters relevant to the air purification unit and to purification of air in the treatment space can sometimes suitably include general parameters of plenum, shared ducts, central, zone, building-wide, and multi-room units and systems, as well as parameters that specifically concern the treatment space, such as room specific controls, vents and ducts specific to the treatment space, air flow measurements to and from the treatment space, and ventilation of the treatment space. For example, an operational parameter of an air purification unit in an HVAC system may involve status of the HVAC system is on, status of the air purification unit within the HVAC system, status of one or more blower in the HVAC system, status of air flow within the HVAC system, status of airflow to or from the treatment space, and parameters related to how the HVAC system is specifically managing or acting upon the treatment space.

[0027] Various components described herein may be combined to carry out a machine process. Various components described herein can refer to a physical entity or a software entity having boundaries defined by function or subroutine calls, branch points, APIs, or other technologies that provide for the partitioning or modularization of particular processing or control functions. A component may be a packaged functional hardware unit designed for use with other components and a part of a program that usually performs a particular function of related functions. Components may constitute either software components (e.g., code embodied on a machine-readable medium) or hardware components.A "hardware component" is a tangible unit capable of performing certain operations, and may be configured or arranged in a certain physical manner. In examples, one or more computer systems (e.g., a standalone computer system, a client computer system, or a server computer system) or one or more hardware components of a computer system (e.g., a processor or a group of processors) may be configured by software (e.g., an application or application portion) as a hardware component that operates to perform certain operations as described herein. A hardware component may also be implemented mechanically, electronically, or any suitable combination thereof. For example, a hardware component may include dedicated circuitry or logic that is permanently configured to perform certain operations. A hardware component may be a special-purpose processor, such as a field-programmable gate array or an application specific integrated circuit. A hardware component may also include programmable logic or circuitry that is temporarily configured by software to perform certain operations. For example, a hardware component may include software executed by a general-purpose processor or other programmable processor. Once configured by such software, hardware components become specific machines (or specific components of a machine) uniquely tailored to perform the configured functions and are no longer general-purpose processors. A decision to implement a hardware component mechanically, in dedicated and permanently configured circuitry, or in temporarily configured circuitry (e.g., configured by software), may be driven by cost and time considerations. Accordingly, the phrase "hardware component" (or "hardware-implemented component") should be understood to encompass a tangible entity that is physically constructed, permanently configured (e.g., hardwired), or temporarily configured (e.g., programmed) to operate in a certain manner or to perform certain operations described herein. Considering examples in which hardware components are temporarily configured (e.g., programmed), each of the hardware components need not be configured or instantiated at any one instance in time. For example, where a hardware component comprises a general-purpose processor configured by software to become a special-purpose processor, the general-purpose processor may be configured as different special-purpose processors (e.g., comprising different hardware components) at different times.Software accordingly configures a particular processor or processors, for example, to constitute a particular hardware component at one instance of time and to constitute a different hardware component at a different instance of time. Hardware components can provide information to, and receive information from, other hardware components. Accordingly, the described hardware components may be regarded as being communicatively coupled. Where multiple hardware components exist contemporaneously, communications may be achieved through signal transmission (e.g., over appropriate circuits and buses) between or among two or more of the hardware components. In examples in which multiple hardware components are configured or instantiated at different times, communications between such hardware components may be achieved, for example, through the storage and retrieval of information in memory structures to which the multiple hardware components have access. For example, one hardware component may perform an operation and store the output of that operation in a memory device to which it is communicatively coupled. A further hardware component may then, at a later time, access the memory device to retrieve and process the stored output. Hardware components may also initiate communications with input or output devices, and can operate on a resource (e.g., a collection of information). The various operations of example methods described herein may be performed, at least partially, by one or more processors that are temporarily configured (e.g., by software) or permanently configured to perform the relevant operations. Whether temporarily or permanently configured, such processors may constitute processor-implemented components that operate to perform one or more operations or functions described herein. As used herein, "processor-implemented component" refers to a hardware component implemented using one or more processors. Similarly, the methods described herein may be at least partially processor-implemented, with a particular processor or processors being an example of hardware. For example, at least some of the operations of methods described herein may be performed by one or more processors or processor-implemented components. Moreover, the one or more processors may also operate to support performance of the relevant operations in a "cloud computing" environment or as a "software as a service" (SaaS). For example, at least some of the operations may be performedby a group of computers (as examples of machines including processors), with these operations being accessible via a network (e.g., the Internet) and via one or more appropriate interfaces (e.g., an API). The performance of certain of the operations may be distributed among the processors, not only residing within a single machine, but deployed across a number of machines. In some examples, the processors or processor-implemented components may be located in a single geographic location (e.g., within a home environment, an office environment, or a server farm). In some examples, the processors or processor-implemented components may be distributed across a number of geographic locations. A "computer-readable medium" or “machine-readable medium” refers, for example, to one or more tangible storage devices and media (e.g., a centralized or distributed database, and associated caches and servers) that store executable instructions, routines and data. The term specifically excludes intangible carrier waves, modulated data signals, and other such media, at least some of which are covered under the term "signal medium." The term shall accordingly be taken to include, but not be limited to, solid-state memories, and optical and magnetic media, including memory internal or external to processors. Additionally, one or more device or component described herein may include, or may operate by, logic or a number of components, or mechanisms. Such device or component may have circuitry specifically adapted for providing an interlock as described herein. “Circuitry” refers generally a collection of circuits implemented in tangible entities that include hardware (e.g., simple circuits, gates, logic elements, etc.). Circuitry membership may be flexible over time and underlying hardware variability. Circuitries include members that may, alone or in combination, perform specified operations when operating. In an example, hardware of the circuitry may be immutably designed to carry out a specific operation (e.g., hardwired). In various examples, the hardware comprising the circuitry may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) including a computer readable medium physically modified (e.g., magnetically, electrically, such as via a change in physical state or transformation of another physical characteristic, etc.) to encode instructions of the specific operation.

[0028] As used herein, the term “ultraviolet radiation” or “UV radiation” refers to electromagnetic radiation having one or more wavelength of about 100 nm to about 400 nm. UV radiation can further be subdivided into several categories based on wavelength: UVA (about 315 nm to about 400 nm), UVB (about 280 nm to about 315 nm), UVC (about 200 nm to about 280 nm), far-UV (about 200 nm to about 230 nm), vacuum UV (about 100 nm to about 200 nm), extreme UV (about 10 nm to about 100 nm). “Germicidal UV” can refer to about 200 nm to about 400 nm. In various aspects and contexts, UV radiation can refer to various sub-ranges of UV radiation, for example, 180 nm to 400 nm, 200 nm to 400 nm, 210 nm to 400 nm, 200 nm to 370 nm, 200 nm to 300 nm, 200 nm to 230 nm, 200 nm to 240 nm, 210 nm to 230 nm, or 210 nm to 280 nm. Radiation sources suitable for the presently described apparatus, system and method would not typically emit vacuum UV or extreme UV. Indeed, in various aspects, the radiation sources are configured so as to not emit certain wavelengths, such as one or more of UVA, UVB, UVC, far-UV, vacuum UV, extreme UV, visible light, or wavelengths longer than 400 nm, or wavelengths shorter than 100 nm. For example, the UV radiation source can emit radiation comprising or substantially consisting of one or more wavelengths between 200 nm and 400 nm. A given radiation source can emit a spectrum having wavelengths according to multiple categories of light. For example, a far-UV radiation source may emit radiation having wavelengths corresponding to UVA, UVB, or UVC. The far- UV radiation sources described in the present disclosure can provide a range of wavelengths of UV radiation. In some aspects, the UV radiation sources, including far-UV radiation sources, can emit visible light or be coupled together with a secondary light source that emits visible light. In various aspects, the UV radiation sources can emit radiation having at least one wavelength from 210 nm to 230 nm. In various aspects, the UV radiation sources can emit radiation having at least one wavelength from 240 nm to 280 nm and at least one wavelength from 210 nm to 230 nm. In various aspects, the far-UV radiation sources can emit radiation having at least one wavelength from 210 nm to 230 nm. In further aspects, far-UV radiation sources can emit radiation having at least one wavelength outside of 200 nm to 230 nm. In yet further aspects, thefar-UV radiation sources can emit radiation having at least one wavelength from230 nm to 280 nm.

[0029] As used herein, the term “visible light” is defined as light having a wavelength of from 380 nm to 750 nm. In some alternative examples, visible light can have a wavelength greater than 380 nm and up to 700 nm, or greater than 400 nm and up to 700 nm. In various examples, the far-UV radiation source, apparatus, and the like, relate to electromagnetic radiation that is outside of the visible light range. In various examples, the far-UV radiation source produces far-UV radiation but not visible light, and the filter can be configured to pass or stop various wavelengths of far-UV radiation, but need not necessarily pass or stop visible light. Yet, in various other aspects, the far-UV radiation source, apparatus, and the like, can further involve a visible light source and visible light emission.

[0030] As used herein, “UV irradiation” refers to UV radiation delivered to a treatment space from one or more UV radiation source. “Far-UV irradiation” refers to far-UV radiation delivered to air in a treatment space from one or more far-UV radiation source. For comparison, “UV output” and “radiation output” may refer to radiation emitted from one or more UV source, but may differ from the amount of UV effectively acting upon the air in the treatment space. UV irradiation, including far-UV irradiation, can be difficult to accurately calculate based only on the specifications or configuration of a given radiation source. UV irradiation, including far-UV irradiation, can also be difficult to accurately measure if relying merely on the result of a photometer, spectrometer, or dosimeter. For example, a UV radiation source emission can result in inhomogeneous light spatial distributions, different treatment spaces can have different reflectivity of materials at the various UV wavelengths, and there can be variation with respect to obstructions and air motion. Different spaces and environments are affected by UV irradiation, including far-UV irradiation, in different ways and an amount of UV radiation that is effective in one space may not be an effective amount of UV radiation in another space. There are various ways to quantify and qualify UV irradiation, including: irradiance, radiant flux (total optical power), effective air changes per hour, and germicidal efficacy with respect to a particular pathogen. As used herein, “effective UV irradiation” refers to the useful amount of irradiation acting on the treatment space from one or moreUV radiation source. As used herein, “effective far-UV irradiation” refers to the useful amount of irradiation acting on the treatment space from one or more far- UV radiation source. As such, the “effective” irradiation can differ from an amount of radiation that is emitted from one or more UV radiation source. UV irradiation and far-UV irradiation can also be used in a non-measurement context, such as to refer to the application or the rate of application of radiation to a treatment space.

[0031] As used herein, “irradiance” is a measurement of power delivered to a certain surface area in units of ‘W / m2’ (watts per square meter), mW / m2or pW / cm2. As a certain surface area moves away from a light source the power delivered to it decreases as the square of the distance. This can be arrived at from a radiance value by specifying a distance for the irradiance value. This can be arrived at from total optical power with knowledge of the distance from the source and the relative position of the surface in the radiation pattern of the source. Under a fixed spectra this can be equated with a certain photon arrival rate for a certain surface area in photons / (second»cm2). Irradiance as used herein is used in a ‘radiant’ context integrated over a relevant germicidally effective UV spectral range, e.g., often conveniently integrated across 180 nm to 400 nm. In various aspects, total irradiance is useful for determining an instantaneous amount of radiation provided to a treatment space or for determining an average amount of radiation provided to a treatment space over a given period of time

[0032] As used herein, “radiant exposure” is a measurement of energy delivered to a certain surface area in units of ‘ J / m2’ or joules per square meter. This expresses the amount of energy delivered to a surface. This can be arrived at from an irradiance by specifying an amount of time to integrate over. Under a fixed spectra this can be equated with a certain arrived photon count for a certain area in photons / cm2. Exposure can be useful for correlating to threshold limit values (TLV). Exposure can be determined based on assuming a 222 nm narrowband light source or based on a weighted integration of a multispectral source. Spectral weighting factors can be selected as suitable for a given use case: for example contribution to exposure limits, germicidal efficacy, or ozone generation. For example, when determining exposure in the context of a TLV value, a narrow-band 222 nm source may be approximated as 222 nm lightcompared against a TLV for 222 nm light. A broader band spectrum of a UV light source may be integrated across the broad band spectrum and weighted at each wavelength according to how each wavelength contributes to exposure relative to 222 nm light.

[0033] As used herein, “radiant flux”, “total optical power”, or “total optical power” is a measurement of the total power output of a lamp or other radiating device. This measures the total power output of the lamp in units of ‘W’ or watts. This is distinct from the ‘wall power’ consumption of the lamp which is not related to this term in any meaningful way besides bounding it above. Under a fixed spectra this can be equated with a certain photon generation rate in photons / second. “Radiant flux”, “total optical power”, or “total optical power” used herein is used in a ‘radiant’ context integrated over a relevant germicidally effective UV spectral range, e.g., often conveniently integrated across 180 nm to 400 nm.

[0034] As used herein, “ppb” refers to parts per billion, which refers to a volumetric mixing ratio. For example, a 1 Liter volume of air with a 1 ppb ozone concentration would contain 1 nanoLiter of ozone. Ozone concentration can also be measured in units of mass per volume, such as ‘ug / m3’ or micrograms per meter. Assuming standard temperature and pressure, 1 ppb is approximately 2 ug / m3. See, e.g., Poppendieck et al., Environ. Sci. Technol. Lett. 2023, 10, 8, 675-679. UL2998 sets a 5-ppb ozone threshold for validating a device as low / no ozone emission. Various national agencies have set an exposure limit for ozone of 50-70 ppb. Ozone production rate can be measured in ‘ug / h’ or micrograms per hour. This is an absolute production rate. It can also be measured in ‘ppb / hr’ or parts per billion (volumetrically) per hour under a fixed volume. Various other units of concentration can also be suitably used to describe the concentration of ozone or other components in the air of a treatment space. In various aspects, equivalents and near equivalents of concentration can be useful for the carrying out aspects of the present disclosure. For example, in some aspects, it can be equally useful to measure concentration of VOCs as it is to measure VOC number, mass, or volume. In various aspects, it can be useful to utilize rates, such as generation or consumption rates, rather than concentration.

[0035] As used herein, “ACH” is a measure of the rate at which the air volume of a space is mechanically exchanged with ‘outside’ air. It is measured in units of inverse hours (h ') which is commonly expressed as the unit ‘ACH’. A value of 1 ACH means that over an hour an amount of gas is exchanged without outside equal to the volume of the space, so for a 3000-cu. ft. office 3000 cu. ft. would be exchanged. Note that - since this is a continuous process - the air will mix as it is exchanged diluting but not eliminating pollutant and pathogenic content. This means that 1 ACH does not result in complete removal of pollutant and pathogenic content after 1 hour, but an attenuation by 1 - exp(-l) = 63%. Additionally, when pollutant content is present in the outside air (for example trace atmospheric ozone) this also contributes to the attenuation rate. ACH can be determined from cubic feet of ventilation per minute (CFM) x 60 / volume of the space. In various contexts, ACH can be better understood by referring to ASHRAE Standard 62 and ANSI Standard 136, each of which are incorporated by reference herewith.

[0036] As used herein, “eACH” is a measure of the rate at which pollutants or pathogens are removed from a space. It describes the mechanical ventilation rate that would achieve an equivalent reduction in pollutants or pathogens. It has the same units as ACH. eACH is relevant when pathogens and pollutants are removed by non-ventilation means such as filters or inactivation by UV lights. For example in a sealed space (i.e., 0 ACH) the value 1 eACH would report that the rate at which pollutants or pathogens are removed by a certain air-cleaning intervention could also have been achieved (absent that intervention) by mechanical ventilation at the rate of 1 ACH. In various contexts, eACH may report the removal rate only for a certain class of pathogen or pollutant. For example, 60 eACH achieved with UV irradiation only reports the rate at which pathogenic viral particles of a certain type are removed (by inactivation) but does not indicate a similar removal rate for airborne particulate or ozone. Similarly, an ozone scrubber may remove ozone at a rate of 20 eACH while not removing pathogenic particles at all.

[0037] In the context of infectious disease, eACH can serve to equate the effect of inactivating pathogens and removing pathogens. The resulting value is an ACH equivalent determined by combining the ACH of the given space together with an irradiation-derived ACH equivalent value. In context of inactivatingpathogens, the eACH refers to an ACH equivalent number of times the entire volume of air within a given space, e.g., a room, would need to be replaced with filtered air in one hour to obtain an equivalent result with respect to eliminating active pathogens.

[0038] As used herein, “germicidal efficacy” is a measurement of the fraction of a pathogen inactivated (rendered non-pathogenic) by a certain procedure. This is a unitless ratio where the value of 0 represents no inactivation and the value of 1 represents complete inactivation. It can be expressed as a percentage where 0=0% and 1=100%. This can also be expressed as a survival fraction, which is the fraction of a pathogen not inactivated (i.e., remaining pathogenic.) These can be interconverted by subtracting the value from 1 : i.e., survival fraction = 1 - germicidal efficacy, and germicidal efficacy = 1 - survival fraction. This can also be expressed as a certain ‘n-log’ inactivation, which expresses the base- 10 log of the survival fraction. For example, a 99.9% inactivation yields a survival fraction of 0.1% = 0.001 = le-3 = ‘3-log disinfection’. Various methods, systems, and apparatus of the present disclosure can achieve a germicidal efficacy of 99.9% or 3-log disinfection.

[0039] As used herein, “PM2.5” refers to airborne particulate matter with an aerodynamic diameter of up to 2.5 micron, sometimes referred to as the fine particle fraction. In various contexts, PM2.5 can encompass smaller particulate matter. However, in other contexts, for example where distinguishing between a device specifically configured removing PM2.5 vs a device specifically configured for removing ultrafines, then for example when a device is calibrated for removing PM2.5 vs removing ultrafines, then PM2.5 may refer more specifically to particles around 2.5 pm. As used herein, “ultrafines,” “ultrafine particles” or “UFPs” refers to airborne particulate matter with an aerodynamic diameter of less than 0.1 micron. In various contexts, it can also be useful to refer to E2 filtration per the ASHRAE 52.2 test, which refers to particles 1.0 microns to 3.0 microns, but can approximate penetration at 2.5 microns. In some contexts it can be useful to refer to El filtration per the ASHRAE 52.2 test, which refers to particles 0.3 microns to 1.0 microns, but can approximate penetration at 0.3 microns. As such, in various contexts described herein, it is fully envisaged that one can utilize an ASHRAE standard value (e.g., El, E2, or E3) or other referencevalue to distinguish between various ultrafine and fine components. For example, an air purification unit can be configured for removing particles smaller than El based on the ASHRAE 52.2 test.Operationally Linked UV Radiation Source and Air purification unit

[0040] Reference will now be made in detail to certain embodiments of the disclosed subject matter, examples of which are illustrated in part in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter. Aspects of the present disclosure can be realized by various examples, some of which are provided in the drawings, but a person skilled in the art would readily appreciate that the specific examples provided herein are neither limiting nor exhaustive, and that any number of additional variations can be immediately envisaged as falling within the spirit of the invention. The various examples and drawings illustrated herein can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using combinations of those elements shown or described, either with respect to a given example, or with respect to other examples shown or described herein. Use of headers in this document is not intended to limit the subject matter in any way, and it is further contemplated that the various aspects discussed with respect to one particular illustrated example can be envisaged with respect to each other.

[0041] FIG. 1 illustrates an example of a system useful for irradiating a human-occupied space to safely inactivate pathogens in air. A far-UV apparatus 100 provides a far-UV radiation source 101, which is configured to irradiate a treatment space 110. Far-UV radiation can interact with certain volatile or ultrafine components in air, even components that are typically desired by occupants, components that are safe, or common components at non-hazardous levels that would not warrant removal. However, without intending to limit to any particular theory, over time those components can react with far-UV radiation viaozonolysis or other mechanisms to generate undesirable levels of particulate matter and hazardous components. Removing the precursor components, even if they may be safe or desirable components like fragrances, advantageously can prevent formation of hazardous particulate matter, such as PM2.5. An air purification unit 140 is configured to remove one or more of volatile organic compounds, ultrafines, or other particulate matter. The air purification unit 140 is in communication with a control module 130. The control module 130 assures concerted operation of the air purification unit 140 and the far-UV radiation source 101. For example, the control module 130 can be configured to activate the air purification unit 140 whenever the far-UV radiation source 101 is operating, or it can be configured to activate the far-UV radiation source 101 following activation of the air purification unit 140. The control module 130 is also configured to receive data from air purification unit 140 to determine its operational state, and optionally, to determine content about air quality in the treatment space. Based on the operational state of the air purification unit 140, the control module 130 controls activation and / or operation of the far-UV apparatus 100. For example, the control module 130 can restrict operation of the far-UV radiation source 101 except when the air purification unit 140 is operating or has been operating for a predetermined period of time. In various aspects, the far-UV radiation source 101 receives power from a power supply 120 and, optionally, a driver 125, any of which may be configured to receive instructions from the control module 130 to control the power supplied to the far-UV radiation source 101 and thus regulate operation of the far-UV radiation source 101. In various aspects, the far-UV radiation apparatus 100 comprises a power supply 120, a driver 125, or both, regulated by the control module 130 in response to a signal based on the operational state of the air purification unit 140. The system can optionally include additional far-UV radiation sources, ozone detectors, VOC detectors, particulate matter detectors, and other sensors.

[0042] The far-UV apparatus 100 and the air purification unit 140 are operationally linked. That is, operation of the far-UV apparatus 100 modulates operation of the air purification unit 140, operation of the air purification unit 140 modulates operation of the far-UV apparatus 100, or both. In various examples, including the example illustrated in FIG. 1, the far-UV apparatus 100 isoperationally linked with the air purification unit 140 via a control module that directs operation of the far-UV apparatus 100 and / or the air purification unit 140. In various examples, operation of the far-UV apparatus 100 is controlled in various manners based on the operational status of the air purification unit 140, operation of the air purification unit 140 can be controlled in various manners based on the operational status of the far-UV apparatus 100, or both. Operational status of the air purification unit 140 can refer to the on-off status of the air purification unit 140, one or more operational parameters of the air purification unit 140, or a combination thereof. Operational status of the air purification unit 140 can refer to whether the air purification unit 140 is fully functioning or achieving its normal target performance. Examples of operational parameters include low-, medium-, or high-settings, which represent relative settings of fan speeds, air flow speeds, power delivery, clean air delivery rate (CADR), or eACH. Controlling the operation of the far-UV apparatus 100 can be managed by a control module 130. In various aspects, irradiation with the far-UV apparatus 100 is configured to initiate operation at the approximately the same time or after operation of the air purification unit is initiated. Yet, in various further aspects, it can be suitable for the far-UV apparatus 100 to initiate operation before operation of the air purification unit is initiated. For example, there may be acceptable delay periods during which operation of the far-UV radiation source can proceed before significant or steady state levels of ozone are realized, during such period it may be within the scope of the various operationally linked safety mechanisms for the far-UV radiation source to provide irradiation for a time before operation of the air purification unit. The period of acceptable delay can vary based on the treatment space, ozone generation rate of the far-UV radiation source, and clearance rate of VOCs, particles, or other contaminants from the air purification unit. As a further example, the systems, apparatus, or methods described herein may utilize a grace period during which operational linkage, or any interlock or status criteria, is checked; that is, the far-UV radiation source may operate and activate, while status of the air purification unit or other parameters are checked, and a subsequent failure to confirm a satisfactory state will stop operation of the far-UV radiation source. Thus, in various aspects, the far-UV radiation source and the air purification can be operationally linked yet can employ one or more delaybased on time or other criteria before operation of the far-UV radiation source, employ one or more delay based on time or other criteria before operation of the air purification unit, or both.

[0043] If certain conditions are met, the control module 130 can trigger a safety mechanism, which can include electronic, mechanical, and software implementations. For example, the safety mechanism can take the form of a mechanical, electronic, or software logic or gate. The safety mechanism can be implemented via circuitry by configuring the far-UV apparatus 100 and the air purification unit 140 to operate in parallel. The safety mechanism can be a fuse, breaker, or trip. The safety mechanism can be software control that evaluates the system state based on any number of parameters that relate to operation of the far- UV apparatus 100, air purification unit 140, or both. In various aspects, a safety mechanism is an interlock. The interlock can have an open state and a closed state, which can be based on one or more interlock conditions. A closed interlock state indicates that all interlock conditions have been met and the process, system, or apparatus is permitted to proceed to irradiation. An open interlock indicates that one or more interlock conditions are not satisfied and the process, system, or apparatus is not permitted to proceed to irradiation. The interlock can be a permissive interlock. The interlock can be self-resetting or manually reset by a user. In some, but not all aspects, the interlock can be a hard interlock configured to impose a set of strict requirements that must always be satisfied in order for the far-UV radiation source to irradiate the treatment space. In other aspects, the interlock need not be so strict. The interlock can be various types of soft interlock. In various aspects, the interlock can serve a purpose of providing advantages including one or more of (i) improved energy efficiency, (ii) improved safety, (iii) improved effective transmittance of UV light and reduced non-germicidal consumption of far-UV radiation, (iv) preventing PM2.5 from forming in the treatment space rather than simply removing it after it has formed.Far-UV Radiation Source

[0044] The far-UV apparatus 100 comprises a far-UV radiation source 101 that is configured to act upon air in a treatment space where a pathogen may pose an infection risk to occupants or users of the space. Generally, the treatment spaceis a occupiable space, such as a human-use space. The far-UV apparatus 100 is generally located within the treated space itself (e.g., within the room), although some configurations exist where the far-UV radiation source is located in the plenum, walls, or adjacent to the treatment space, wherein the far-UV radiation source 101 is directed to irradiate air in the treatment space. In various aspects, the far-UV radiation source 101 is configured and positioned to irradiate a occupiable space or human-use space, and thus does not irradiate the inside of ducts or the inside of air treatment modules. As further examples, the far-UV radiation apparatus 100 can be a moveable unit, an installed unit placed on a desktop, ceiling, wall, or floor, or an installed unit placed adjacent to a vent or duct while directing irradiation from the far-UV radiation source 101 inwards to the room. The far-UV radiation source 101 generates radiation which is emitted from the far-UV apparatus 100 to irradiate air in the treatment space. The far-UV radiation source 101 can utilize various technologies, including one or more bulbs, light-emitting diodes (LEDs), or other sources configured to emit UV radiation in an amount effective to inactivate pathogens in air. The radiation is typically transmitted through a transparent substrate optionally comprising an optical filter.

[0045] The optical filter can be configured to reduce emission of certain wavelengths, such as harmful wavelengths or wavelengths that generate harmful contaminants. In various aspects, the optical filter can be configured to transmit wavelengths around 222 nm and reduce wavelengths below 210 nm or above 230 nm, 235 nm, 240 nm, or 245 nm. In various example, the apparatus provides an emission at one or more wavelengths between 237 nm and 245 nm having an intensity of about 1%, 2%, 3%, 4%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%, or more of the peak emission, or any range of values therein, as measured at an incident angle of zero degrees. In another example, the apparatus provides an emission at one or more wavelengths between 241 nm and 260 nm having an intensity of about 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5%, 10%, 15%, 20%, or 25% of the peak emission, or any range of values therein, as measured at an incident angle of zero degrees. In another example, the apparatus provides an emission at one or more wavelengths between 250 nm and 265 nm having an intensity of about 0.1%, 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5%, 10%, 15%, 20%, or 25% of the peak emission, or any range of values therein, as measured at anincident angle of zero degrees. The optical filter can be disposed directly onto a far-UV generating bulb, or disposed upon a window or lens through which the apparatus emits far-UV radiation.

[0046] The far-UV radiation source 101 can include one or more excimer bulb. Excimer bulbs can include a combination of a rare gas and halogen which emits one or more wavelength of far-UV light when excited by an electrical stimulus. Excimer bulbs excitation can be triggered in various ways including, for example, glow discharge, pulsed discharge, dielectric barrier discharge, short arc, or combinations thereof. In various examples, the far-UV radiation source comprises a KrCl excimer bulb or a KrBr excimer bulb.

[0047] The far-UV radiation generated and emitted by the far-UV radiation source 101 (and thus far-UV apparatus 100) includes one or more wavelengths between about 210 nm to about 230 nm. Other wavelengths may be emitted as well. In various aspects, the radiation can also comprise one or more wavelengths below about 210 nm and / or above 230 nm. In various aspects, the radiation includes one or more wavelength of visible light. In various aspects, the radiation consists of UV light. In various aspects, the radiation consists of UVC light. In various aspects, the radiation consists of far-UV light. For example, the far-UV radiation source 101 generates and emits radiation comprising, or substantially consisting of, one or more wavelengths of about 200 nm to about 280, about 210 nm to about 230 nm, and / or about 222 nm. In some examples, the far-UV radiation source 101 can be a source that provides a peak unfiltered emission between 200 nm to 280 nm, such as 222 nm. In some examples, the far-UV radiation source 101 is configured to emit some amount of 254 nm light. In various further examples, the far-UV radiation source 101 can emit UV wavelengths other than far-UV. In some examples, it can emit visible light. In further examples, the excimer bulb generates and emits 222 nm light.

[0048] Various shapes and types of bulbs can be used in the far-UV radiation source 101. Bulbs are typically substantially tube-like, and can be rod-shaped, oblong, toroidal, or flattened versions of the same. The far-UV radiation source 101 can include a bulb having an annular body having an outer surface and defining an internal discharge cavity, wherein the annular body has a major axial dimension and a minor radial dimension, and comprises an electrode in theinternal discharge cavity that traverses along the major axial dimension of the annular body. Krypton chloride excimer lamps typically emit a peak emission at 221.8 nm, but convention in the art is to refer to such emission as 222 nm. The far-UV radiation source 101 can include a housing, which may also be the housing of the far-UV apparatus 100 or a subcomponent thereof. The housing can take many suitable forms. Typically, the far-UV radiation source 101 includes a housing containing one or more bulb. In various aspects, the housing partially encloses the one or more bulb and provides at least one opening through which radiation can be emitted. For example, the housing can be a box where one face has an opening that is covered by a UV-transparent material serving as a protective window. The window can be substantially planar, or it can be curved. The window can be a crystal such as quartz, or a glass such as fused silica. In some aspects, the window can be CORNING® 7980 or HERAUS SUPRASIL®. The window can be coated with an optical filter. The far-UV radiation source 101 can further include any number of optical components, such as optical filters, reflectors, diffusers, and lenses. For example, the inside of the housing can be furnished with reflectors to direct light out the housing and maximize emitted radiation. As another example, the far-UV radiation source 101 can include one or more component for adjusting the direction, intensity, or focus of the emitted light. The far-UV radiation source 101 can include a diffuser or lens.

[0049] The far-UV radiation source 101 can be configured such that germicidal wavelengths are transmitted while harmful wavelengths are controlled. For example, the apparatus can be configured such that when used in an apparatus that generates UV light providing radiation upon human eyes or skin of less than or about 1 mJ / cm2, 10 mJ / cm2, 20 mJ / cm2, 30 mJ / cm2, 40 mJ / cm2, 50 mJ / cm2, 60 mJ / cm2, 70 mJ / cm2, 80 mJ / cm2, 90 mJ / cm2, 1000 mJ / cm2, 110 mJ / cm2, 120 mJ / cm2, 130 mJ / cm2, 140 mJ / cm2, 150 mJ / cm2, or 160 mJ / cm2at a wavelength of 200 nm to 400 nm, or a wavelength of 210 nm to 230 nm, when measured at its intended distance from a person over an anticipated maximum exposure period, such as an 8 hour period, with such exposure values based on assuming a 222 nm narrow-band light source or based on a weighted integration of a multispectral source. Spectral weighting factors can be selected as suitable for a given use case: for example contribution to exposure limits, germicidal efficacy, or ozonegeneration. The apparatus can be configured such that when used in an apparatus that generates UV light providing radiation upon human eyes or skin of less than or about 1 mJ / cm2, 2 mJ / cm2, 3 mJ / cm2, 4 mJ / cm2, 5 mJ / cm2, 6 mJ / cm2, 7 mJ / cm2, 8 mJ / cm2, 9 mJ / cm2, or 10 mJ / cm2between a wavelength of 240 and 280 nm. As a further example, the apparatus can be configured such that the emitted radiation is about 0.5 pW / cm2to about 60 pW / cm2at one or more occupant or area of expected occupancy, for example, about, at least, or less than 0.5 pW / cm2, 0.6 pW / cm2, 0.7 pW / cm2, 0.8 pW / cm2, 0.9 pW / cm2, 1.0 pW / cm2, 1.5 pW / cm2, 2.0 pW / cm2, 2.5 pW / cm2, 3.0 pW / cm2, 3.5 pW / cm2, 4.0 pW / cm2, 4.5 pW / cm2, 5, pW / cm2, 6 pW / cm2, 7 pW / cm2, 8 pW / cm2, 9 pW / cm2, 10 pW / cm2, 11 pW / cm2, 12 pW / cm2, 13 pW / cm2, 14 pW / cm2, 15 pW / cm2, 16 pW / cm2, 17 pW / cm2, 18 pW / cm2, 19 pW / cm2, 20 pW / cm2, 21 pW / cm2, 22 pW / cm2, 23 pW / cm2, 24 pW / cm2, 25 pW / cm2, 26 pW / cm2, 27 pW / cm2, 28 pW / cm2, 29 pW / cm2, 30 pW / cm2, 35 pW / cm2, 40 pW / cm2, 45 pW / cm2, 50 pW / cm2, 55 pW / cm2, or 60 pW / cm2based on assuming 222 nm narrow-band light source or based on a weighted integration of a multispectral source. Spectral weighting factors can be selected as suitable for a given use case: for example contribution to exposure limits, germicidal efficacy, or ozone generation. The far-UV apparatus 100 can be configured such that when deployed in an occupied space, the emitted radiation provides the intensity, power, effective irradiance, total irradiance, or total optical power flux sufficient to inactivating pathogens in air. The far-UV apparatus 100 can be configured such that when deployed in an occupied space, the emitted radiation lacks an intensity, power, effective irradiance, total irradiance, or total optical power flux beyond the ACGIH threshold limits for far-UV radiation or other radiation. The far-UV apparatus 100 can be configured such that when deployed in an occupied space, the emitted radiation lacks the intensity, power, effective irradiance, total irradiance, or total optical power flux necessary for inactivating pathogens on the skin or other surface of an occupant. The far-UV apparatus 100 can be configured such that when deployed in an occupied space, the emitted radiation lacks the intensity, power, effective irradiance, total irradiance, or total optical power flux necessary for inactivating pathogens on objects or surfaces in the treatment space. The UV radiation source can beconfigured to duty cycle between active periods and inactive periods to control exposure.

[0050] The far-UV radiation source can be configured to irradiate the treatment space with a total optical power flux of about or less than 4 mW, 5 mW, 6 mW, 7 mW, 8 mW, 9 mW, 10 mW, 15 mW, 20 mW, 25 mW, 30 mW, 35 mW, 40 mW, 45 mW, 50 mW, 55 mW, 60 mW, 65 mW, 70 mW, 75 mW, 80 mW, 85 mW, 90 mW, 95 mW, 100 mW, 105 mW, 110 mW, 115 mW, 120 mW, 125 mW, 130 mW, 135 mW, 140 mW, 145 mW, 150 mW, 155 mW, 160 mW, 165 mW,170 mW, 175 mW, 180 mW, 185 mW, 190 mW, 195 mW, 200 mW, 205 mW,210 mW, 215 mW, 220 mW, 225 mW, 230 mW, 235 mW, 240 mW, 245 mW,250 mW, 255 mW, 260 mW, 265 mW, 270 mW, 275 mW, 280 mW, 285 mW,290 mW, 295 mW, 300 mW, 305 mW, 310 mW, 315 mW, 320 mW, 325 mW,330 mW, 335 mW, 340 mW, 345 mW, 350 mW, 355 mW, or 360 mW, or any range of values therein.Air Purification Unit

[0051] The air purification unit 140 is a device or component configured for removing airborne particles, undesirable contaminants, volatile organic compounds, or any combination thereof, from air of the treatment space 110. In various aspects, undesirable contaminants can include substances harmful to human health, such as ozone and other toxic substances. In various aspects, undesirable contaminants can include non-pathogenic contaminants. The air purification unit 140 can be configured for removing ultrafines or other airborne particulate matter. The air purification unit can be a portable air purifier or a non-portable air purifier. Examples of portable air purifiers include desktop, hand-held, wearable, and floor units. Examples of a non-portable air purifiers include units that are installed into the structure of the room, zone, plenum, basement, utility closet, ductwork, or building in which they are deployed. Further examples of a non-portable air purifiers include units that are installed on a permanent or semi-permanent basis, as well as units that are configured specifically for the spaces or buildings in which they are deployed. For example, non-portable air purification units can include units incorporated into an air handling system, ventilation system, air-conditioning system, heating system,HVAC system, whole-building air purification system, air exchange system, fresh air supply, air exhaust, air intake, air recirculator, fan system, ventilation points (e.g., windows, doors, retractable roofs), central air system, clean room air system, medical space air system, or any combination thereof. As yet another example, the air purification unit can be installed in or adjacent to one or more duct that provides air flow to or from the space to be treated. The air purification unit 140 can employ various techniques to remove airborne particles, undesirable contaminants, and / or volatile organic compounds from air, including use of a filter system, fresh air exchange (e.g., ventilation), or reactive materials.

[0052] The air purification unit 140 can include a filter system. As used herein, a “filter system” or “purification system” refers to the one or more mechanical filters and one or more scrubbers, whichever components are present. A filter system can comprise a plurality of mechanical filters, a plurality of scrubbers, one filter and one scrubber, a plurality of mechanical filters and one scrubber, or one scrubber and a plurality of mechanical filters. For example, the air purification unit 140 can comprise a plurality of mechanical filters, a plurality of scrubbers, one filter and one scrubber, a plurality of mechanical filters and one scrubber, or one scrubber and a plurality of mechanical filters. In some aspects, the air filtration system does not include a scrubber. In some aspects, the air filtration system does not include a mechanical filter and utilizes a scrubber to remove small particles, volatile organics, or other contaminants from air.

[0053] The air purification unit 140 can include one or more mechanical filter. A mechanical filter is designed to physically capture and remove particles from the air. The mechanical filter can be made of any variety of materials, such as fiberglass, natural fibers such as cotton, synthetic fibers such as polyester, borosilicate glass microfibers, electrostatically charged polypropylene fibers, spun polymer nanofibers, or metal mesh. In some examples, the mechanical filter is other than borosilicate microfibers. The mechanical filter can be an electrostatic filter.

[0054] The mechanical filter can have a particular particle size rating, such as a MERV rating or HEPA rating. MERV and HEPA ratings indicate the size of particles that can be captured with a certain efficiency. MERV refers tominimum efficiency reporting value, which is typically based on a filter’s ability to capture particles between 0.3 microns and 10 microns. Unless otherwise specified, MERV values correspond to ANSI / ASHRAE Standard 52.2-2017. In some contexts, the MERV value can be described with respect to 0.3 -micron particles, specifically. In various examples, the filter can be a MERV 6, MERV 7, MERV 8, MERV 9, MERV 10, MERV 11, MERV 12, MERV 13, MERV 14, MERV 15, MERV 16, MERV 17, MERV 18, MERV 19, or MERV 20 filter. In further examples, the filter can have a MERV rating of about or at least 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. HEP A filter refers to high efficiency particulate air filter, and include H10, Hl 1, H12, H13, and H14 grades. The filter can have a HEPA rating of about or at least H10, Hl 1, H12, H13, H14, U15, U16, or U17. Unless otherwise specified, HEPA designation and values corresponds to ISO 294363-1 2017. In some context, the HEPA designation or values can be described with respect to 0.3-micron particles, specifically. In some aspects, the filter can be a HEPA filter. In other aspects, the filter is other than a HEPA. In various examples, the apparatus does not include any HEPA filter.

[0055] In various aspects, the one or more mechanical filter can be rated as having a maximum flow rate of about or at least 100 ft3 / min, 200 ft3 / min, 300 ft3 / min, 400 ft3 / min, 500 ft3 / min, 600 ft3 / min, 700 ft3 / min, 800 ft3 / min, 900 ft3 / min, 1000 ft3 / min, 2000 ft3 / min, 3000 ft3 / min, 4000 ft3 / min, or 5000 ft3 / min. The one or more mechanical filter can be rated as having a pressure drop of 0.25 mm H2O to 25 mm H2O. For example, the pressure drop can be 0.25 mm H2O, 0.30 mm H2O, 0.35 mm H2O, 0.40 mm H2O, 0.45 mm H2O, 0.50 mm H2O, 0.55 mm H2O, 0.60 mm H2O, 0.65 mm H2O, 0.70 mm H2O, 0.75 mm H2O, 0.80 mm H2O, 0.85 mm H2O, 0.90 mm H2O, 0.95 mm H2O, 1 mm H2O, 2 mm H2O, 2 mm H2O, 4 mm H2O, 5 mm H2O, 6 mm H2O, 7 mm H2O, 8 mm H2O, 9 mm H2O, 10 mm H2O, 11 mm H2O, 12 mm H2O, 13 mm H2O, 14 mm H2O, 15 mm H2O, 16 mm H2O, 17 mm H2O, 18 mm H2O, 19 mm H2O, 20 mm H2O, 21 mm H2O, 22 mm H2O, 23 mm H2O, 24 mm H2O, or 25 mm H2O, or a range of values therein.

[0056] The present filter system can be configured particularly for removing non-pathogenic contaminants in air, including ozone, oxygenated particles, oxygenated organic small molecules, oxygenated organic macromolecules andmaterials, oxygenated dust particles, non-pathogenic degradants of pathogens, and aggregated particles containing the same.

[0057] The present filter system can be configured particularly for removing contaminants other than ozone, oxygenated particles, oxygenated organic small molecules, oxygenated organic macromolecules and materials, oxygenated dust particles, non-pathogenic degradants of pathogens, and aggregated particles containing the same.

[0058] The present filter system can be configured particularly for removing ultrafines.

[0059] The present filter system can be configured particularly for removing particles having an aerodynamic diameter of 0.01 pm or less, an aerodynamic diameter of 0.1 pm or less, an aerodynamic diameter of 1 pm or less, an aerodynamic diameter of 2.5 pm or less, an aerodynamic diameter of 5 pm or less, or an aerodynamic diameter of 10 pm or less.

[0060] The present filter system can be configured particularly for airborne volatile organic compounds.

[0061] In various aspects, the presently described systems and methods have the advantage of permitting use of powerful, stringent filtration systems at reduced cost of energy or filter media. Use of the filter system prior to generation of larger aggregated molecules and complexed oxygenated species permits more efficient filtering using a filter system particularly for removing ultrafines and VOCs.

[0062] The present filter system can be configured for single passes, for example for achieving an ISO 20E or better using ISO 29463-1 2017 in a single pass. In some examples, the one or more mechanical filter, or filter system as a whole, is configured for multiple passes.

[0063] The apparatus, method, system, air purification unit, air filtration system, or far-UV radiation source can include a scrubber. A scrubber is designed to remove contaminants from air using a chemical process or physicochemical processes, such as adsorption. The scrubber can be made of a variety of materials including, but not limited to, activated carbon, graphene, carbon nanoparticles, homogenous metal doped catalyst, heterogenous doped metal, or zeolite or other absorbent microporous materials. Catalytic metals caninclude platinum, palladium, rhodium, and manganese. The catalyst can be granular activated carbon & impregnated alumina, granular activated carbon, granular impregnated alumina, or granular impregnated activated carbon. In some aspects, the scrubber is configured for operating at a speed of 50 CFM, 60 CFM, 70 CFM, 80 CFM, 90 CFM, 100 CFM, 110 CFM, 120 CFM, 130 CFM, 140 CFM, 150 CFM, 160 CFM, 170 CFM, 180 CFM, 190 CFM, 200 CFM, 210CFM, 220 CFM, 230 CFM, 240 CFM, 250 CFM, 260 CFM, 270 CFM, 280CFM, 290 CFM, 300 CFM, 310 CFM, 320 CFM, 330 CFM, 340 CFM, 350CFM, 360 CFM, 370 CFM, 380 CFM, 390 CFM, 400 CFM, 450 CFM, 600CFM, 650 CFM, 700 CFM, 750 CFM, 800 CFM, 850 CFM, 900 CFM, 950CFM, or 1000 CFM. The scrubber can be a passive scrubber or an active scrubber. The scrubber can be configured to remove ozone from air. The scrubber can be configured to remove ozone derivatives or products arising from reaction with ozone. The scrubber can be configured to remove highly oxygenated organic molecules (HOMs) from air. The scrubber can be configured to remove particles resulting from clustered highly oxygenated organics. In various aspects, the apparatus, method, system, air purification unit, far-UV radiation source, any combination, or all, do not include a scrubber. The scrubber can be located within or coupled with the air purification unit, air filtration system, or far-UV radiation apparatus. The scrubber can be particularly configured to remove non-ozone molecules from air. The scrubber can be particularly configured to remove organic compounds. The scrubber can be particularly configured to remove volatile organic compounds.

[0064] As an example, a suitable air purifier can have a filtration system having multiple components including one or more of an activated carbon & impregnated alumina (for example, for removing gaseous compounds), granular activated carbon (for example, for removing VOCs), granular impregnated alumina (for example, for chemisorption), granular impregnated activated carbon (for example, for removing ammonia-related compounds), a pre-filter, a HEPA filter, a non-HEPA, and / or a post-filter, and be configured with a number of air delivery speeds (for a six speed fan system configured for 40-60 CFM, 75-110 CFMR, 130-180 CFM, 170-230 CFM, 200-300 CFM, and 300-500CFM). Examples of suitable components can be obtained from IQ Air (Goldach,Germany), for example, a GC or GCX series air purifier utilizing one or more of a GC / GCX VOC (volatile organic compound filter), GC / GCX MultiGas (gaseous compound filter), GC / GCX ChemiSorber (small compound absorber), and GC / GCX Post-Filter Sleeve Set.Control Module

[0065] The control module 130 can be configured to serve as a safety mechanism, such as an interlock that mediates operation of the far-UV radiation source relative to the air purification unit 140, or vice versa. The control module 130 can activate, shut off, adjust the intensity, adjust the duration, or other parameters of the far-UV radiation source 101 and the air purification unit 140 based on configuration of the safety mechanism.

[0066] The control module 130 can also be configured to process data to determine one or more interlock conditions, such as by utilizing one or more of arithmetic, algorithms, machine learning models, statistical analysis, trend analysis, or other forms of data processing to identify said interlock conditions. The processed data can include the operational status of the air purification unit 140, duration of operation of air purification unit 140, measurements related to the treatment space, measurements related to the air in the treatment space, environmental information (such as PM2.5 content in outside air), or other measured or reference data. In various aspects, the processed data can include a measurement, estimate, or reference value of PM0.01 concentration, PM0.1 concentration, PM0.5 concentration, PM1 concentration, PM2.5 concentration, PM5 concentration, orPMIO concentration. Amounts other that concentration can be useful as well, including particular matter number, mass, or volume, or particulate matter generation rate, or consumption rate. Other types of parameters that can be utilized by the control module 130 include parameters selected from the group consisting of temperature, humidity, time of day, date, season, location, elevation, ambient pressure, volatile organic compound (VOC) concentration, VOC molecular profile, CO2 concentration, air quality index (AQI), amount of windows in the treatment space, amount of ventilation in the treatment space, amount of air purification in the treatment space, amount of air exchanges or effective air exchanges provided to the treatment space, volume of treatmentspace, surface area of treatment space, type of materials in treatment space, weather, UV index, number of actual or intended occupants of the treatment space, type of actual or intended use of the treatment space, current use status of treatment space, power provided to far-UV radiation source, on-off status of far- UV radiation source, emission spectra of far-UV radiation source, model information and specifications of far-UV radiation source, details of ozone sources, details of sources of airborne particulate, and details of any additional far- UV radiation sources in treatment space. Parameters related to other amounts of VOC, ultrafines, particulate matter, and CO2, can be useful as well, such as number, mass, or volume, generation rate, consumption rate, or stead state values. In various aspects, the control module can communicate with, or monitor, multiple far-UV apparatus as presently described herein. In various aspects, the control module can communicate with, or monitor, a far-UV apparatus as presently described herein, and further can communicate with, or monitor, one or more far- UV radiation source lacking one or more features of the presently described far- UV apparatus, including a far-UV light other than the inventive far-UV lights described herein. Configurations where the control module is communication with, or monitoring, multiple far-UV radiation sources can be useful in order to account for effects of other sources, including those that may lack the presently described safety features, adaptive features, or communication features. In some aspects, the presently described method, system, or apparatus, can extend some advantages such as improved safety and efficacy to far-UV apparatus that lack safety features. For example, a far-UV source other than the inventive far-UV sources described herein may be utilized to provide a limited base-line level of far-UV, but the presently described method, system, or apparatus can be utilized to supplement the baseline far-UV while accounting for the effect of the source other than the inventive far-UV lights described herein, thus providing safe and effective germicidal action.

[0067] In various aspects, the control module can utilize the emission spectra of one or more far-UV radiation source. This parameter can be useful because some far-UV radiation sources may provide radiation having wavelengths with different relative effects on the generation of aggregated airborne particulate matter, for example, due to differing effects on ozone generation or consumption.Indeed, different far-UV radiation sources can have different ozone generation characteristics, which can be related to emission spectra of the source, amount of radiation provided, size and scope of emission pattern, electronic and power supply configurations, and type of technology or process used to generate the radiation. In various aspects, it can be useful to determine or refer to a measured, calculated, or estimated ozone generation characteristic of a given far-UV radiation source, apparatus, or system containing the same. The amount (e.g., rate or concentration) of ozone generated by a far-UV radiation source can be useful for determining how strict to configure one or more interlock criteria or operational linkage parameter. For example, acceptable delay periods between activation of the far-UV radiation source or air purification unit can be determined based on ozone generation characteristics of the far-UV radiation source. In yet further aspects, certain treatment spaces have greater or less ozone consumption characteristics, and such qualities can be useful parameters to ascertain or employ for determining one or more interlock criteria or operational linkage parameter.

[0068] Parameters related to ventilation and windows can be useful because outdoor air can be a significant source of airborne contaminants. Ventilation can be quantified by monitoring the decay of CO2 after an injection from a compressed gas cylinder, for example with an Aranet4 sensor (SAFTehnika, Latvia). Parameters such as volume and air exchange can be useful as they can impact the generation of aggregated airborne particulate matter. Parameters such as materials and surface area of the treatment space can be useful because they represent a potential ozone sink, and ozone can be involved in forming reactive oxygenated species that lead to aggregated airborne particulate matter. VOC related parameters can be useful because different volatile compounds have differing interactions with ozone. Some VOC compounds represent a substantial consumption term for ozone and different VOC compounds can have different consumption coefficients, and differing VOC compounds can result in oxygenated compounds having differing tendencies to aggregate into harmful particles or not; as such it can be useful to separate out terms for certain VOC compounds from other consumption terms. Examples of different VOC compounds include monoterpenes, diterpenes, alkanes, (e.g., cycloalkanes), alkenes (e.g., alkene monoterpenes or cyclic alkenes), aldehydes, and othercompounds. VOC molecule profile refers to the chemical constituents of VOC content. Ultrafine content can also be useful. Ultrafines subjected to far-UV radiation can aggregate to form harmful aggregated particles.

[0069] In various aspects, the control module can utilize parameters related to an air handling system, ventilation system, air-conditioning system, heating system, HVAC system, whole-building air purification system, air exchange system, fresh air supply, air exhaust, air intake, air recirculator, fan system, ventilation points (e.g., windows, doors, retractable roofs), central air system, clean room air system, medical space air system, or any combination thereof. As yet another example, the control module can utilize parameters related to movement of air through one or more duct that provides air flow to or from the space to be treated. In various examples, the control module 130 is configured to communicate, control, or monitor an air handling system, ventilation system, air- conditioning system, heating system, HVAC system, whole-building air purification system, air exchange system, fresh air supply, air exhaust, air intake, air recirculator, fan system, ventilation points (e.g., windows, doors, retractable roofs), central air system, clean room air system, medical space air system, or any combination thereof. For example, in various aspects, the control module 130 is in wired or wireless communication with an air handling system, ventilation system, air-conditioning system, heating system, cooling system, humidity control system, HVAC system, whole-building air purification system, air exchange system, fresh air supply, air exhaust, air intake, air recirculator, fan system, ventilation points (e.g., windows, doors, retractable roofs), central air system, clean room air system, medical space air system, or any combination thereof. In various yet further aspects, the control module 130 can communicate, control, or monitor one or more such system via one or more of a low voltage wiring, a thermostat, a mol ex connector, a wiring at approximately 12 volts or less, a wiring at approximately 24 volts or less, an HVAC relay, a blower relay, a motor relay, and the like. As further examples, in some embodiments, the methods, systems, and apparatus described herein involve an interlock that has an interlock condition requiring one or more signal from a an air handling system, ventilation system, air-conditioning system, heating system, cooling system, humidity control system, HVAC system, whole-building air purificationsystem, air exchange system, fresh air supply, air exhaust, air intake, air recirculator, fan system, ventilation points (e.g., windows, doors, retractable roofs), central air system, clean room air system, medical space air system, which may be provided wirelessly or via a low voltage wiring, a thermostat, a mol ex connector, a wiring at approximately 12 volts or less, a wiring at approximately 24 volts or less, an HVAC relay, a blower relay, a motor relay, and the like. As a yet further example, the interlock can require a low-voltage signal indicating that a blower in an HVAC system is on. As another further example, the interlock can require a low-voltage signal indicating that an air handler is operational, active, or on duty. In some various aspects, activation of an HVAC system or a blower in an HVAC system also activates, in parallel or in series, simultaneously or subsequently, a far-UV radiation source treating the room. In various aspects, the activation of the far-UV radiation source can be optionally delayed to provide time for air purification prior to irradiation.

[0070] The thermostat can be a non-programmable thermostat, a programmable thermostat, or a smart thermostat. In various yet further aspects, the control module 130 can be configured to communicate with a thermostat via a wired connection or wireless. In various further aspects, the control module 130 is configured to interface with a room management system, including building management systems, site management system, industrial management systems, air management system of a transport vehicle or airplane, classroom management systems, hospital management system, operating room management system, security systems, janitorial system, grounds management system, and the like. Such management systems may monitor, manage, or control treatment of air of a managed space. In various aspects, management system can coordinate or inform operation of the air purification unit and / or operation of the far-UV radiation source, based on how the space is managed by the management system, based on janitorial activities or schedules, based on power management, based on use of the space, based on occupancy or occupant activities, based on open or closed status, based on accessible or inaccessible status, based on cleaning or janitorial status, and the like. In various aspects, the building management system informs or controls when air of the treatment space is being ventilated, conditioned, heated, cooled, humidity controlled, cleaned,filtered, scrubbed, purified, disinfected, and the like. In can be useful to integrate the presently described systems, methods, and apparatus with a building management system, air handling system, ventilation system, air-conditioning system, heating system, cooling system, humidity control system, HVAC system, whole-building air purification system, air exchange system, central air system, clean room air system, medical space air system, building management systems, site management system, industrial management systems, air management system of a transport vehicle or airplane, classroom management systems, hospital management system, operating room management system, security systems, janitorial system, grounds management system, and the like.

[0071] Parameters related to generation of aggregated airborne particulate matter can be employed to provide stricter or more permissive interlock conditions depending on the air quality and conditions of the treatment space. Treatment spaces that are low in VOCs, ultrafines, and has favorable conditions for ozone decay (e.g., air having low ozone, rooms with high passive ozone consumption) can advantageously benefit from a more permissive interlock involving less use of the air purification unit 140. On the other hand, air that is high in VOCs, ultrafines, and has conditions that lead to increased ozone generation will advantageously benefit from a strict interlock involving greater use of the air purification unit 140.

[0072] The control module 130 can be any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. In various aspects, the control module 130 can be an electrical logic, for example a electrical switch or wiring configuration that simultaneously activates and powers both the air purification device 130 and the far-UV radiation source 101. In various aspects, the control module 130 can comprise a processor and a memory. The memory can store instructions or data structures (e.g., software) embodying any one or more of the methodologies or functions described herein. The processor can execute the instructions. The control module can be a hardware component, a software component, computer, a tablet device, a smart phone, a web appliance, or a network appliance, each of which may be a dedicated or multipurpose device specifically configured for providing a safety mechanism, or interlock, between a far-UV radiation source 101 and an air purification unit 140.The control module 130 can be communicatively coupled with the far-UV apparatus 100 and the air purification unit 140 by a wired connection, a wireless connection, or both. The control module 130 can also be communicatively coupled with one or more additional components, such as a remote processor, a remote memory, an I / O component, additional control modules, additional far-UV radiation sources, or additional air purification units. I / O components can include user interface components, communication components, and sensor components, among others. User interface components can include visual components (e.g., a light-emitting diode (LED) display), acoustic components (e.g., speakers), haptic components (e.g., a vibratory motor, resistance mechanisms), or other signal generators. The user interface components can also include alphanumeric input components (e.g., a keyboard), point-based input components (e.g., a mouse), tactile input components (e.g., a physical button, a touch screen that provides location and / or force of touches or touch gestures, or other tactile input components), audio input components (e.g., a microphone), and the like.

[0073] Sensor components can include, for example, one or cameras, illumination sensor components (e.g., photometer), temperature sensor components (e.g., one or more thermometers that detect ambient temperature), humidity sensor components, pressure sensor components (e.g., barometer), acoustic sensor components (e.g., one or more microphones that detect background noise), proximity sensor components (e.g., millimeter wave radar sensor, lidar sensor, infrared sensors that detect nearby objects), other proximity sensors (e.g., techniques utilizing carbon dioxide concentration, techniques utilizing millimeter wave radar or lidar), airborne particulate matter sensors, condensation particle counters (CPCs), non-CPC sensors for detecting particles or pollutants in air, or other components that may provide indications, measurements, or signals corresponding to a surrounding physical environment. The position components include location sensor components (e.g., a Global Positioning System (GPS) receiver component), altitude sensor components (e.g., altimeters or barometers that detect air pressure from which altitude may be derived), orientation sensor components (e.g., magnetometers), and the like.

[0074] Instructions transmitted between the control module 130 and the far-UV apparatus 100, far-UV radiation source 101, power supply 120, and / or driver125 can be transmitted or received across wired or wireless connections. For example, the instructions can be transmitted or received over a network, using a transmission medium, via a network interface device (e.g., a network interface component) and using any one of several well-known transfer protocols (e.g., hypertext transfer protocol (HTTP)). Similarly, the instructions may be transmitted or received using a transmission medium via a coupling (e.g., a peer- to-peer coupling) to the devices. For example, the control module 130 can be in communication with the far-UV apparatus 100 and / or air purification unit 140 via a wireless connection. A wireless connection may be established according to a wireless communication standard such as Bluetooth® (e.g. , Bluetooth® Low Energy) (BLE), Wi-Fi® (e.g., according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards), mobile communications standards such as relating to 4G / Long Term Evolution (LTE), or the IEEE 802.15.4 family of standards, as illustrative examples. The far-UV apparatus 100, control module 130, and air purification unit 140, can each include a communication component. The communication components can include a network interface component to interface with a network. Communication components include wired communication components, wireless communication components, cellular communication components, Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), WiFi® components, and other communication components to provide communication via other modalities. In addition, a variety of information may be derived via the communication components, such as location via Internet Protocol (IP) geolocation, location via Wi-Fi® signal triangulation, or location via detecting an NFC beacon signal that may indicate a particular location. Examples of a network include an ad hoc network, an intranet, an extranet, a virtual private network (VPN), a local area network (LAN), a wireless LAN (WLAN), a wide area network (WAN), a wireless WAN (WWAN), a metropolitan area network (MAN), the Internet, a portion of the Internet, a portion of the Public Switched Telephone Network (PSTN), a plain old telephone service (POTS) network, a cellular telephone network, a wireless network, a Wi-Fi® network, another type of network, or a combination of two or more such networks.

[0075] FIG. 2 illustrates an example far-UV apparatus 100 having a far-UV radiation source 101 and a control module 130 in communication with an air purification unit 140 (not shown) configured to serve as a safety mechanism, or interlock, that operationally links the far-UV radiation source 101 with the air purification unit 140. The far-UV radiation source 101 can include a bulb 102, a reflector 103, and lens 104, which are contained within a lamp housing 105. The lamp housing 105 provides a cavity where the bulb 102 is secured and protected. The reflector 103 serves to reflect light away from the inside of the lamp housing out through the lens 104. In various aspects, the lens 104 can include an optical filter. The lens 104 can, but need not necessarily, magnify, focus, or disperse light. The far-UV radiation source 101 emits radiation that is useful for germicidal treatment of air in a space. In yet further aspects, the far-UV apparatus 100 illustrated in FIG. 2 can be configured to implement the system of FIG. 1 into an apparatus. In some aspects, the far-UV apparatus 100 contains a far-UV radiation source 101 and a control module 130 that interacts with a remote air purification unit. In other aspects, the far-UV apparatus 100 contains a far-UV radiation source 101, a control module 130, and an air purification unit 140 (not shown) located together. The far-UV radiation source 101 and air purification unit 140 can be physically coupled together to provide a single physical apparatus or they can be separately located. Various approaches can be taken to physically couple the far- UV radiation source 101, the control module 130, and / or the air purification unit 140. For example, in various aspects, the air purification unit 140 can share a housing with the far-UV radiation source 101, or the air purification unit 140 can be mounted on a stand shared with the far-UV radiation source 101, the air purification unit 140 can serve as a base or counterweight for the far-UV radiation source 101.

[0076] The control module 130 can be located within the housing of the far UV radiation apparatus or it may be remotely located. The control module 130 is configured to process data using one or more of arithmetic, algorithms, machine learning models, statistical analysis, trend analysis, and other forms of data processing to compare the operational status of the air purification unit 140 and other parameters to one or more interlock conditions. The control module 130 may access a local or remote database or memory unit containing such reference valuesor models. The control module 130 includes a processor, a memory, and can be any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. The control module 130 can regulate the on-off operational status, intensity, duration, frequency, or other parameters of the far-UV radiation source 101. In various aspects, the control module 130 receives a signal from an air purification unit to indicate its operational status (e.g., on or off), and the control module 130 subsequently signals the far-UV radiation source 101 according to the logic of the safety mechanism or interlock. In some aspects, the control module 130 sends a signal to a power management module 118 to adjust performance of a driver 125. Additionally, the control module 130 can regulate the on-off status, intensity, or other operational parameter of the air purification unit 140. The control module may regulate the air purification unit 140 in response to, or based on, operation of the control module 130, or based on receiving instructions to irradiate a treatment space. For example, the air purification unit 140 can be activated when a user turns on a far-UV radiation source 101 or system containing the same. The driver 125 delivers power from the power supply 120 and modulates it to manage output from the far-UV radiation source 101. The far-UV apparatus 100 can be mounted on a stand 129 to provide convenient set up and for orienting and elevating the lamp to position to either maximize or minimize areas of direct irradiation, depending on use case. A stand can facilitate portability and placement of the device so that it does not disrupt the intended use of the space being treated. Optionally, the far-UV apparatus can include an air purification unit 140, which can include one or more mechanical filter and / or one or more scrubber. The scrubber can be an ozone scrubber, a scrubber configured for removing VOCs, or both. The scrubber may be integrated together with one or more of the air purification unit 140, control module 130, or far-UV apparatus 100. As also illustrated in FIG. 2, the system can be configured as multiple separate components into a system 200A or the system can integrate multiple components together into a single apparatus 200B. A separate air purification unit 140 can communication with the control module 130 or the far- UV radiation apparatus 100 via wireless communication, such as by way of an antennae 149. A separate air purification unit 140 can also be mounted on a stand 148. Various further configurations are possible. In some aspects, such as theaspect illustrated by apparatus 200B, the air purification unit 140 can be located below the far-UV radiation source 101 such that the far-UV radiation source 101 is coupled with the stand 129 and the air purification unit 140 serves to stabilize the stand or serves as its base. In various aspects, integration of the far-UV radiation source 101, a control module 130, and an air purification unit 140 into a single apparatus can have advantages related to assuring or configuring how that the far-UV radiation source 101 and the far-UV radiation source 101 are operationally linked; for example they can be configured on a shared power supply 120, control module 130, or other components.

[0077] FIG. 3 provides a flow diagram of an example use of a far-UV irradiation source operationally linked with an air purification unit. In a first step 310, instructions are provided to a far-UV irradiation system to irradiate a treatment space to inactivate pathogens in air. In step 320, the system or user checks an interlock state that can be based on an operational status of an air purification unit and optionally other parameters such as ultrafine, PM0.1, PM2.5, PM10, ozone, or volatile organic compound (VOC) content in the air. In some aspects, checking the interlock state is to verify the operational status of an air purification unit (e.g., check to see if it is on or off, or verify that it is fully functioning). In step 330, the system or user triggers a safeguard mechanism 340 if the interlock is open. The safeguard mechanism 340 can initiate a process to satisfy the interlock condition and close the interlock lock, or it can return a warning or fault, or it can shut down the process of irradiating the treatment space. In some aspects, the safeguard mechanism is to turn on the air purification unit. Typically, step 340 involves a process that serves to satisfy the interlock condition and thus after step 340, the process returns to step 320 and satisfaction of the interlock condition is verified. In step 350, a signal is delivered to activate the far- UV radiation source and irradiate air in the treatment space. In alternative aspects, after step 340, the process can involve identifying an open interlock, then addressing the interlock condition, and then immediately proceeding to step 350 activation of the far-UV radiation source and irradiation of the treatment space assuming that the interlock condition has been satisfied without explicitly verifying. In yet further alternative aspects, step 330 triggers a safeguard 340 that does not necessarily address the interlock condition but safeguard 340 may delivera warning or fault, or it may terminate the process without performing step 350. In various aspects, during step 350 the operational status of the far-UV radiation source 101 can be used to modulate the air purification unit 140, for example to turn off the air purification unit if operation of the far-UV radiation source terminates. In various aspects, the apparatus or system described herein can be configured such that operation of the air purification unit (for example which can involve a visual or audible aspect) can inform a user that the far-UV radiation source is active or that the space is being sufficiently treated. The system can audibly or visually alert a user or occupant if the space is not being sufficiently treated. This configuration can be useful given that far-UV irradiation may not be visible to an occupants or user.

[0078] FIG. 4 provides a flow diagram of another example use of a far-UV irradiation source operationally linked with an air purification unit. Process 400A illustrates an example process that simultaneously or concomitantly activates an air purification unit and a far-UV radiation source. In a first step 410 of process 400A, instructions are provided to a far-UV irradiation system to irradiate a treatment space to inactivate pathogens in air. In step 420 of process 400A, the system or user activates an air purification unit and activates a far-UV radiation source. The air purification unit and the far-UV radiation source can be activated at the same time, or there can be a delay 435 so that the far-UV radiation source activates after the air purification unit activates. The delay 435 can correspond to a predetermined period of time, such as the amount of time needed for the air purification unit to achieve a steady state with respect to air quality, PM2.5, PM0.1, PM10, ultrafines, ozone, or other air quality parameter. The delay can be determined by monitoring air quality indicators. The delay can be a predetermined delay together with a further delay based on monitoring air quality indicators. Process 400B illustrates an example process that activates an air purification unit and subsequently activates a far-UV irradiation system. In a first step 410 of process 400B, instructions are provided to a far-UV irradiation system to irradiate a treatment space to inactivate pathogens in air. In step 420 of process 400B, the system or user activates an air purification unit. Activation of the air purification unit thus occurs prior to activation of the far-UV radiation source. In various aspects, activation of the air purification unit can serve as a gate for activating thefar-UV radiation source. In some aspects, the air purification unit directly or indirectly signals the far-UV radiation source to activate. In various aspects, there can be a delay 435b so that the far-UV radiation source activates after the air purification unit has operated for a period of time. The delay 435b can correspond to a predetermined period of time, such as the amount of time needed for the air purification unit to achieve a steady state with respect to air quality, PM2.5, PM0.1, PM10, ultrafines, ozone, or other air quality parameter.

[0079] FIG. 5 provides a flow diagram of yet another example use of a far- UV irradiation source operationally linked with an air purification unit. In a first step 510, instructions are provided to a far-UV irradiation system to irradiate a treatment space to inactivate pathogens in air. In step 515, the process optionally involves activating an air purification unit. In various aspects, the air purification unit may already be running or managed by a separate system. In step 520, the system checks an interlock state which can be based on an operational status of an air purification unit and / or other parameters that can indicate operation of an air purification unit such as ultrafine, PM0.1, PM2.5, PM10, ozone, or volatile organic compound (VOC) content in the air. In various aspects, the interlock state is based on at least one parameter that indicates the state of air purification mechanisms in the air of the treatment space, particularly with respect to removal of small airborne particles and VOCs. In various aspects, checking the interlock state is to verify the operational status of an air purification unit (e.g., checking to see if it is on or off, or verify that it is fully functioning). In yet further aspects, step 520 checks an operational status of an air purification unit and / or other parameters against a determined interlock condition 550. The interlock condition 550 can be determined by using sensor data 551 (e.g., PM0.1 concentration, PM2.5 concentration, VOC content, temperature, occupancy), external parameters552 (e.g., geolocated environmental particulate matter, such as provided by the Environmental Protection Agency (EP A) AirNow database), system configuration553 (e.g., target air disinfection or risk level, or fan speeds, air flow, power settings of the air purification unit), or air purification unit status 554 (e.g., relative high, medium, or low settings, on or off status). Data such as sensor data can be used to determine an interlock condition related to the status of the air purification unit (e.g., target ACH provided by air purification unit), or it can be used to provide aseparate or additional interlock condition related to the treatment space (e.g., target ultrafine concentration). In step 530, the system or user triggers a safeguard mechanism 540 if the interlock is open. The safeguard mechanism 540 can initiate processes to satisfy the interlock condition and close the interlock lock, or it can return a warning or fault, or it can shut down the process of irradiating the treatment space. In some aspects, the safeguard mechanism is to check if the air purification unit is on as per step 541, turn on the air purification unit as per step 542, or adjust air purification settings or configuration 543. Typically, step 540 involves initiating a process that aims to satisfy the interlock condition and thus after step 540, the process returns to step 520 to verify satisfaction of the interlock condition. In step 560, a signal is delivered to activate the far-UV radiation source and irradiate air in the treatment space. In alternative aspects, after step 540, the process can involve addressing the interlock condition and then proceeding to step 560 activation of the far-UV radiation source and irradiation of the treatment space assuming that the interlock condition has been satisfied without explicitly verifying. In yet further alternative aspects, step 530 triggers a safeguard 540 that does not necessarily address the interlock condition but safeguard 540 may deliver a warning or fault, or it may terminate the process without performing step 550. In yet further alternative aspects, the process involves a ventilation source, such as windows or a pre-existing HVAC system, instead of an air purification unit, instead, and the interlock is based on the presence of adequate ventilation.

[0080] FIG. 6 illustrates a block diagram of an example comprising a machine 600 through which one or more of the presently described methods can be performed. The disclosure provides a machine 600 specifically adapted for providing a safety mechanism, or interlock, that operationally links a UV radiation source with an air purification unit. The machine 600 may be included as a portion of elements shown in the system of FIG. 1, such as the far-UV apparatus 100, the control module 130, or the air purification unit 140. In various examples, the machine 600 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 600 may operate in the capacity of a server machine, a client machine, or both in serverclient network environments. In an example, the machine 600 may act as a peer machine in peer-to-peer (P2P) (or other distributed) network environment. Themachine 600 may be a personal computer (PC), a tablet device, a personal digital assistant (PDA), a mobile telephone, a web appliance, a network router, switch or bridge, a portable (e.g., hand-held) spectrometer such as including a microprocessor or microcontroller, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

[0081] Machine (e.g., computer system) 600 may include a hardware processor 602 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 604 and a static memory 606, some or all of which may communicate with each other via an interlink (e.g., bus) 630. The machine 600 may further include a display device 610, an alphanumeric input device 612 (e.g., a keyboard), and a user interface (UI) navigation device 614 (e.g., a mouse). In an example, the display unit 610, input device 612 and UI navigation device 614 may be a touch screen display. The machine 600 may additionally include a storage device (e.g., drive unit) 614, a signal generation device 618 (e.g., a speaker), a network interface device 620, and one or more sensors 616, such as a global positioning system (GPS) sensor, a thermometer, or humidity sensor. The machine 600 may include an output controller 628, such as a serial (e.g., universal serial bus (USB)), parallel, or other wired or wireless (e.g., infrared (IR)) connection to communicate or control one or more peripheral devices. Memory and mass storage device(s) 622 may include a machine-readable medium on which is stored one or more sets of data structures or instructions 624 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 624 may also reside, completely or at least partially, within the main memory 604, within static memory 606, or within the hardware processor 602 during execution thereof by the machine 600. In an example, one or any combination of the hardware processor 602, the main memory 604, the static memory 606, or the storage device 608 may constitute machine readable media. Machine readablemedium can be a single medium, the term "machine readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) configured to store the one or more instructions 624. The term “machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine 600 and that cause the machine 600 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine-readable medium examples may include solid-state memories, and optical and magnetic media. Accordingly, machine-readable media are not transitory propagating signals. Specific examples of massed machine-readable media may include: non-volatile memory, such as semiconductor memory devices and flash memory devices; magnetic or other phase-change or state-change memory circuits; and magnetic disks.

[0082] The instructions 624 may further be transmitted or received over a communications network 626 using a transmission medium via the network interface device 620 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks such as conforming to one or more standards such as a 4G standard or Long Term Evolution (LTE)), Plain Old Telephone (POTS) networks, and wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi®, IEEE 802.15.4 family of standards, peer-to-peer (P2P) networks, among others. In an example, the network interface device 620 may include one or more physical jacks (e.g., Ethernet, coaxial, or phonejacks) or one or more antennas to connect to the communications network 626. In an example, the network interface device 620 may include a plurality of antennas to wirelessly communicate using at least one of single input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. The term “transmission medium” shall be taken to include any intangible medium that is capable ofstoring, encoding or carrying instructions for execution by the machine 600, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

[0083] The various aspects described herein are not intended to be construed as exclusive or specific. Rather, a person of ordinary skill would appreciate that combinations and permutations of the aforementioned aspects are within the scope of invention. The present invention can be further understood by reference to the following Examples which are offered by way of illustration. The present invention is not limited to the Examples given herein.Exemplified Aspects

[0084] The following aspects are provided as example aspects of the various disclosed subject matter:

[0085] Aspect 1 provides a system for inactivating a pathogen in air of a treatment space, comprising: a far-UV radiation source that emits radiation comprising one or more wavelengths of about 210 nm to about 230 nm and an air purification unit configured for removing airborne particulate matter, wherein the far-UV radiation source and the air purification unit are operationally linked.

[0086] Aspect 2 provides a system of Aspect 1, wherein the far-UV radiation source and the air purification unit are operationally linked to trigger activation of the air purification unit prior to activation of the far-UV radiation source, or simultaneously with activation of the far-UV radiation source.

[0087] Aspect 3 provides a system of any one of Aspects 1 to 2, wherein the far-UV radiation source and the air purification unit are operationally linked to impose operation of the air purification unit when the far-UV radiation source operates, or impose operation of the air purification unit prior to operation of the far-UV radiation source, optionally for a predetermined period of time.

[0088] Aspect 4 provides a system of any one of Aspects 1 to 3, comprising a control module configured to control operation of the far-UV radiation source based on the operational status of the air purification unit, an amount, such as a concentration or rate, of an airborne contaminant in the air of the treatment space, or any combination thereof.

[0089] Aspect 5 provides a system of any one of Aspects 1 to 4, wherein the operational status of the air purification unit is whether it is on or off.

[0090] Aspect 6 provides a system of any one of Aspects 1 to 5, wherein the operational status of the air purification unit is whether it is nominally functioning.

[0091] Aspect 7 provides a system of any one of Aspects 1 to 6, wherein the operational status of the air purification unit is whether it is achieving nominal target performance.

[0092] Aspect 8 provides a system of any one of Aspects 1 to 7, wherein the control module is configured to trigger a safeguard mechanism when the system has an instruction to irradiate the treatment space and the air purification unit is not active.

[0093] Aspect 9 provides a system of any one of Aspects 1 to 8, wherein the control module is configured to trigger a safeguard mechanism when the system has an instruction to irradiate the treatment space and one or more of the following: the air purification unit is not active, the air purification unit is not operating at a target filtration activity level, the air of the treatment space is above a predetermined amount (e.g., concentration, generation rate, consumption rate, mass, volume, or number) of an airborne contaminant, the air of the treatment space has a amount of ultrafines above a predetermined amount of the air of the treatment space has a amount of volatile organic compounds (VOCs) above a predetermined amount of VOCs, the air of the treatment space has a amount of PM0.1 above a predetermined amount of PM0.1, the air of the treatment space has a amount of PM2.5 above a predetermined amount of PM2.5, the air of the treatment space has a amount of ozone above a predetermined amount or any combination thereof.

[0094] Aspect 10 provides a system of any one of Aspects 1 to 9, wherein the far-UV radiation source will not operate, or will provide a reduced amount of radiation, when: the air purification unit is not operating, the air purification unit is not operating at a target filtration activity level, the air of the treatment space is above a predetermined amount of an airborne contaminant.

[0095] Aspect 11 provides a system of any one of Aspects 1 to 10, wherein the control module is configured to trigger a safeguard mechanism when thesystem has an instruction to irradiate the treatment space and the air of the treatment space is above a predetermined concentration of an airborne contaminant.

[0096] Aspect 12 provides a system of any one of Aspects 1 to 11, wherein the control module is configured to trigger a safeguard mechanism when the system has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of volatile organic compounds (VOCs) above a predetermined concentration.

[0097] Aspect 13 provides a system of any one of Aspects 1 to 12, wherein the control module is configured to trigger a safeguard mechanism when the system has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of ultrafines above a predetermined concentration.

[0098] Aspect 14 provides a system of any one of Aspects 1 to 13, wherein the control module is configured to trigger a safeguard mechanism when the system has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of PM0.1 above a predetermined concentration.

[0099] Aspect 15 provides a system of any one of Aspects 1 to 14, wherein the control module is configured to trigger a safeguard mechanism when the system has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of PM2.5 above a predetermined concentration.

[0100] Aspect 16 provides a system of any one of Aspects 1 to 15, wherein the control module is configured to trigger a safeguard mechanism when the system has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of ozone above a predetermined concentration.

[0101] Aspect 17 provides a system of any one of Aspects 1 to 16, wherein the control module is configured to trigger a safeguard mechanism when the system has an instruction to irradiate the treatment space and, the air of the treatment space has a amount (e.g., concentration, generation rate, consumption rate, mass, volume, or number) of ultrafines above a predetermined amount (e.g.,concentration, generation rate, consumption rate, mass, volume, or number) of the air of the treatment space has a amount of volatile organic compounds (VOCs) above a predetermined amount of VOCs, the air of the treatment space has a amount of PMO.1 above a predetermined amount of PMO.1, the air of the treatment space has a amount of PM2.5 above a predetermined amount of PM2.5, the air of the treatment space has a amount of ozone above a predetermined amount, or any combination thereof, wherein the predetermined amount is based on an ozone generation characteristic of the far-UV radiation source.

[0102] Aspect 18 provides a system of any one of Aspects 1 to 17, wherein the safeguard mechanism shuts down the far-UV radiation source, or blocks an activation signal to the far-UV radiation source.

[0103] Aspect 19 provides a system of any one of Aspects 1 to 18, wherein the safeguard mechanism activates the air purification unit.

[0104] Aspect 20 provides a system of any one of Aspects 1 to 19, wherein the safeguard mechanism adjusts one or more operational parameter of the air purification unit.

[0105] Aspect 21 provides a system of any one of Aspects 1 to 20, wherein the safeguard mechanism shuts down the far-UV radiation source, blocks an activation signal to the far-UV radiation source, reduces radiation output of the far-UV radiation source, reduces power supplied to the far-UV radiation source, activates the air purification unit, adjusts one or more operational parameter of the air purification unit, provides an alert to a user, or provides an alert to an occupant of the treatment space.

[0106] Aspect 22 provides a system of any one of Aspects 1 to 21, wherein the control module is configured as an interlock that prevents operation of the far-UV radiation source unless one or more interlock conditions are satisfied.

[0107] Aspect 23 provides a system of any one of Aspects 1 to 22, wherein one or more interlock conditions are based on amount (e.g., concentration, generation rate, consumption rate, mass, volume, or number) of an airborne contaminant in the air of the treatment space.

[0108] Aspect 24 provides a system of any one of Aspects 1 to 23, comprising an ozone detection unit that mediates operation of the far-UV radiation source, air purification unit, or both.

[0109] Aspect 25 provides a system of any one of Aspects 1 to 24, comprising a condensation particle counter (CPC) that mediates operation of the far-UV radiation source, air purification unit, or both.

[0110] Aspect 26 provides a system of any one of Aspects 1 to 25, comprising a condensation particle counter (CPC) configured for measuring airborne particulate matter.

[0111] Aspect 27 provides a system of any one of Aspects 1 to 26, comprising a condensation particle counter (CPC) capable of measuring ultrafines.

[0112] Aspect 28 provides a system of any one of Aspects 1 to 27, wherein operation of the far-UV radiation source, the air purification unit, or both, is modulated based on a measurement from a condensation particle counter or an ozone detection unit.

[0113] Aspect 29 provides a system of any one of Aspects 1 to 28, wherein one or more interlock conditions are a target filtration activity level determined from a measurement of airborne particulate matter, ozone, or volatile organic compounds (VOCs).

[0114] Aspect 30 provides a system of any one of Aspects 1 to 29, wherein a measurement of airborne particulate matter, ozone, or volatile organic compounds (VOCs), is used to determine whether the air purification unit has achieved a target filtration activity level.

[0115] Aspect 31 provides a system of any one of Aspects 1 to 30, wherein the control module is configured to prevent operation of the far-UV radiation source when air quality of the treatment space is below a predetermined threshold.

[0116] Aspect 32 provides a system of any one of Aspects 1 to 31, wherein the control module is configured to operate the far-UV radiation source without operation of air purification unit when air quality of the treatment space is above a predetermined threshold.

[0117] Aspect 33 provides a system of any one of Aspects 1 to 32, wherein a measurement of airborne particulate matter, ozone, or volatile organic compounds (VOCs), is used to determine air quality of the treatment space.

[0118] Aspect 34 provides a system of any one of Aspects 1 to 33, wherein the control module is configured to operate the far-UV radiation source without operation of the air purification unit when the air purification unit has operated for a predetermined period of time.

[0119] Aspect 35 provides a system of any one of Aspects 1 to 34, wherein one or more interlock conditions are based on a measured, estimated, or calculated amount (e.g., concentration, generation rate, consumption rate, mass, volume, or number) of volatile organic compounds (VOCs), ultrafines, ozone, or any combination thereof, in the air of the treatment space or generated by operation of the far-UV radiation source.

[0120] Aspect 36 provides a system of any one of Aspects 1 to 35, wherein one or more interlock conditions are based on: a measured, calculated, or estimated amount of ozone generated from operation of the far-UV radiation source, or a measured, calculated, or estimated amount of UV radiation provided to the treatment space; and a measured, calculated, or estimated amount of volatile organic compounds (VOCs), ultrafines, or both, in air of the treatment space.

[0121] Aspect 37 provides a system of any one of Aspects 1 to 36, wherein one or more interlock conditions are based on an assessment of: the combination of a measured, calculated, or estimated amounts of ozone and amounts of volatile organic compounds (VOCs) contemporaneously in the treatment space; the combination of a measured, calculated, or estimated amounts of ozone and amounts of amounts of ultrafines contemporaneously in the treatment space; the combination of a measured, calculated, or estimated amounts of ozone-generating UV radiation and amounts of volatile organic compounds (VOCs) contemporaneously in the treatment space; or the combination of a measured, calculated, or estimated amounts of ozone-generating UV radiation and amounts of ultrafines in the treatment space;not based solely on assessing amounts of volatile organic compounds (VOCs), ultrafines, or both, in the absence of considering ozone amount or ozone-generating UV radiation; and not based solely on assessing amounts of ozone amount or ozonegenerating UV radiation in the absence of considering volatile organic compounds (VOCs), ultrafines, or both.

[0122] Aspect 38 provides a system of any one of Aspects 1 to 37, comprising an ozone detection unit, a photometer, camera, a volatile organic compound (VOC) detector, a particulate matter detector, or any combination thereof.

[0123] Aspect 39 provides a system of any one of Aspects 1 to 38, which comprises a volatile organic compound (VOC) detector, a particulate matter detector, or both, configured to collect measurements of one or more airborne contaminant in the treatment space based on time series or based on one or more operational parameter of the air purification unit or far-UV radiation source, and the control module is configured to infer or determine from the collected data one or more of: volume of the treatment space, dimensions of the treatment space, air quality of the treatment space, volatile organic compound (VOC) consumption rates, volatile organic compound (VOC) generation rates, an ultrafine consumption rate, ultrafine generation rate, air purification unit efficacy, filtration efficacy, scrubber efficacy, performance of the far-UV radiation source, total room air purification efficacy, germicidal efficacy, or other information about air in the treatment space.

[0124] Aspect 40 provides a system of any one of Aspects 1 to 39, wherein the control module is configured to operate the far-UV radiation source via duty cycling during operation of the air purification unit.

[0125] Aspect 41 provides a system of any one of Aspects 1 to 40, wherein the control module is configured to operate the air purification unit via duty cycling, or scheduled or periodic operation, during operation of the far-UV radiation source.

[0126] Aspect 42 provides a system of any one of Aspects 1 to 41, wherein the air purification unit operates via duty cycling, and the control module isconfigured to operate the far-UV radiation source during, or in anticipation of, cycles of the duty cycling air purification unit.

[0127] Aspect 43 provides a system of any one of Aspects 1 to 42, wherein the far-UV radiation source operates via duty cycling, and the control module is configured to operate the air purification unit during, or in anticipation of, cycles of the duty cycling far-UV radiation source.

[0128] Aspect 44 provides a system of any one of Aspects 1 to 43, wherein the air purification unit is coupled with the far-UV radiation source to provide a single device.

[0129] Aspect 45 provides a system of any one of Aspects 1 to 44, wherein the control module is configured to operate the far-UV radiation source via duty cycling during operation of the air purification unit, the control module is configured to operate the air purification unit via duty cycling during operation of the far-UV radiation source, or both.

[0130] Aspect 46 provides a system of any one of Aspects 1 to 45, wherein the air purification unit is separately located from the far-UV radiation source.

[0131] Aspect 47 provides a system of any one of Aspects 1 to 46, wherein the air purification unit is a portable unit.

[0132] Aspect 48 provides a system of any one of Aspects 1 to 47, wherein the air purification unit is part of an HVAC system, a ventilation system, or an air exchange system, or physically or operationally integrated with an air handling system, ventilation system, air-conditioning system, heating system, HVAC system, whole-building air purification system, air exchange system, fresh air supply, air exhaust, air intake, air recirculator, fan system, ventilation points (e.g., windows, doors, retractable roofs), central air system, clean room air system, medical space air system, building management systems, site management system, industrial management systems, air management system of a transport vehicle or airplane, classroom management systems, hospital management system, operating room management system, security systems, janitorial system, grounds management system, or any combination thereof.

[0133] Aspect 49 provides a system of any one of Aspects 1 to 48, wherein the air purification unit is configured for removing airborne particulate matter.

[0134] Aspect 50 provides a system of any one of Aspects 1 to 49, wherein the air purification unit is configured for removing ultrafines from air in the treatment space.

[0135] Aspect 51 provides a system of any one of Aspects 1 to 50, wherein the air purification unit is configured for removing PM2.5 from air in the treatment space.

[0136] Aspect 52 provides a system of any one of Aspects 1 to 51, wherein the air purification unit is configured for removing volatile organic compounds (VOCs) from air in the treatment space.

[0137] Aspect 53 provides a system of any one of Aspects 1 to 52, wherein the air purification unit comprises a mechanical filter.

[0138] Aspect 54 provides a system of any one of Aspects 1 to 53, wherein the mechanical filter is an electrostatic filter.

[0139] Aspect 55 provides a system of any one of Aspects 1 to 54, wherein the air purification unit comprises a HEPA filter.

[0140] Aspect 56 provides a system of any one of Aspects 1 to 55, wherein the air purification unit comprises a scrubber.

[0141] Aspect 57 provides a system of any one of Aspects 1 to 56, wherein the air purification unit comprises a fan system or power supply that is modulated by a control module.

[0142] Aspect 58 provides a system of any one of Aspects 1 to 57, wherein the operational status of the far-UV radiation source controls operation of the air purification unit such that operation of the air purification unit indicates that the far-UV radiation source is operating in a fully functional operational state, or that the treatment space is being treated.

[0143] Aspect 59 provides a system of any one of Aspects 1 to 58, wherein the operational status of the far-UV radiation source controls operation of the air purification unit such that operation of the air purification unit indicates that the far-UV radiation source is operating in a fully functional operational state, or that the treatment space is being treated.

[0144] Aspect 60 provides a system of any one of Aspects 1 to 59, wherein the air purification unit is configured for removing airborne particulate matter, volatile organic compounds, or ozone, in the treatment space.

[0145] Aspect 61 provides a system of any one of Aspects 1 to 60, wherein the air purification unit comprises a mechanical filter, an electrostatic filter, a scrubber, or any combination thereof.

[0146] Aspect 62 provides a system of any one of Aspects 1 to 61, wherein the air purification unit comprises a scrubber containing a catalytic scrubber, activated carbon, potassium permanganate, or any combination thereof.

[0147] Aspect 63 provides a system of any one of Aspects 1 to 62, wherein the air purification unit is configured for removing airborne particulate matter from air in the treatment space and comprises a mechanical filter.

[0148] Aspect 64 provides a system of any one of Aspects 1 to 63, wherein the air purification unit is configured for removing volatile organic compounds (VOCs) from air in the treatment space and comprises a scrubber.

[0149] Aspect 65 provides a system of any one of Aspects 1 to 64, wherein the far-UV radiation source will not operate when the air purification unit is not operating.

[0150] Aspect 66 provides a system of any one of Aspects 1 to 65, wherein the system or a component thereof is configured to perform one or more of the presently described methods.

[0151] Aspect 67 provides a method for inactivating a pathogen in air in a treatment space, comprising: receiving an instruction to irradiate a treatment space; verifying an operational status of an air purification unit configured for removing airborne particulate matter, volatile organic compounds, or ozone, in the treatment space; irradiating air in the treatment space with radiation from a far-UV radiation source based on the operational status of the air purification unit.

[0152] Aspect 68 provides a method for inactivating a pathogen in air in a treatment space, comprising: receiving an instruction to irradiate a treatment space; activating an air purification unit configured for removing airborne particulate matter, volatile organic compounds, or ozone, in the treatment space; and irradiating air in the treatment space with radiation from a far-UVradiation source that emits radiation comprising one or more wavelengths of about 210 nm to about 230 nm.

[0153] Aspect 69 provides a method for inactivating a pathogen in air in a treatment space, comprising: receiving an instruction to irradiate a treatment space; evaluating the operational status of an air purification unit against one or more interlock conditions to determine an interlock state, wherein the one or more interlock conditions are determined based an operational status of an air purification unit; irradiating air in the treatment space with radiation from a far-UV radiation source based on the interlock state.

[0154] Aspect 70 provides the method of any one of Aspects 67-69, wherein the irradiating step is performed simultaneously, concomitantly, or following, the air purification unit removing airborne particulate matter, volatile organic compounds, or ozone, from air in the treatment space.

[0155] Aspect 71 provides the method of any one of Aspects 67-70, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source so that it will not operate when the air purification unit is not operating.

[0156] Aspect 72 provides the method of any one of Aspects 67-71, preventing activation, deactivating, or imposing an interlock on action of the far- UV radiation prior to activation of the far-UV radiation source, or preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation unless simultaneously activating the far-UV radiation source.

[0157] Aspect 73 provides the method of any one of Aspects 67-72, comprising imposing operation of the air purification unit when the far-UV radiation source operates, or imposing operation of the air purification unit prior to operation of the far-UV radiation source, optionally for a predetermined period of time.

[0158] Aspect 74 provides the method of any one of Aspects 67-73, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source based on the operational status of the airpurification unit, an amount, such as a concentration, of an airborne contaminant in the air of the treatment space, or any combination thereof.

[0159] Aspect 75 provides the method of any one of Aspects 67-74, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source based on whether it is on or off.

[0160] Aspect 76 provides the method of any one of Aspects 67-75, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source based on whether the air purification unit is nominally functioning.

[0161] Aspect 77 provides the method of any one of Aspects 67-76, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source based on whether the air purification unit is achieving nominal target performance.

[0162] Aspect 78 provides the method of any one of Aspects 67-77, comprising triggering a safeguard mechanism when an instruction is received to irradiate the treatment space and the air purification unit is not active, operating, or nominally functioning.

[0163] Aspect 79 provides the method of any one of Aspects 67-78, comprising triggering a safeguard mechanism when an instruction is received to irradiate the treatment space and one or more of the following: the air purification unit is not active, the air purification unit is not operating at a target filtration activity level, the air of the treatment space is above a predetermined amount of an airborne contaminant, the air of the treatment space has a amount of ultrafines above a predetermined amount of the air of the treatment space has a amount of volatile organic compounds (VOCs) above a predetermined amount of VOCs, the air of the treatment space has a amount of PM0.1 above a predetermined amount of PM0.1, the air of the treatment space has a amount of PM2.5 above a predetermined amount of PM2.5, the air of the treatment space has a amount of ozone above a predetermined amount or any combination thereof.

[0164] Aspect 80 provides the method of any one of Aspects 67-79, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source when the air purification unit is notoperating, the air purification unit is not operating at a target filtration activity level, the air of the treatment space is above a predetermined amount of an airborne contaminant, or any combination thereof.

[0165] Aspect 81 provides the method of any one of Aspects 67-80, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source when an instruction is received to irradiate the treatment space and the air of the treatment space is above a predetermined concentration of an airborne contaminant.

[0166] Aspect 82 provides the method of any one of Aspects 67-81, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source when an instruction is received to irradiate the treatment space and the air of the treatment space has a concentration of volatile organic compounds (VOCs) above a predetermined concentration.

[0167] Aspect 83 provides the method of any one of Aspects 67-82, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source when an instruction is received to irradiate the treatment space and the air of the treatment space has a concentration of ultrafines above a predetermined concentration.

[0168] Aspect 84 provides the method of any one of Aspects 67-83, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source when an instruction is received to irradiate the treatment space and the air of the treatment space has a concentration of PM0.1 above a predetermined concentration.

[0169] Aspect 85 provides the method of any one of Aspects 67-84, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source when an instruction is received to irradiate the treatment space and the air of the treatment space has a concentration of PM2.5 above a predetermined concentration.

[0170] Aspect 86 provides the method of any one of Aspects 67-85, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source when an instruction is received to irradiate the treatment space and the air of the treatment space has a concentration of ozone above a predetermined concentration.

[0171] Aspect 87 provides the method of any one of Aspects 67-86, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source when an instruction is received to irradiate the treatment space and, the air of the treatment space has a amount of ultrafines above a predetermined amount of the air of the treatment space has a amount of volatile organic compounds (VOCs) above a predetermined amount of VOCs, the air of the treatment space has a amount of PMO.1 above a predetermined amount of PMO.1, the air of the treatment space has a amount of PM2.5 above a predetermined amount of PM2.5, the air of the treatment space has a amount of ozone above a predetermined amount, or any combination thereof, wherein the predetermined amount is based on an ozone generation characteristic of the far- UV radiation source.

[0172] Aspect 88 provides the method of any one of Aspects 67-87, wherein the safeguard mechanism shuts down the far-UV radiation source, or blocks an activation signal to the far-UV radiation source.

[0173] Aspect 89 provides the method of any one of Aspects 67-88, wherein the safeguard mechanism activates the air purification unit.

[0174] Aspect 90 provides the method of any one of Aspects 67-89, wherein the safeguard mechanism adjusts one or more operational parameter of the air purification unit.

[0175] Aspect 91 provides the method of any one of Aspects 67-90, wherein the safeguard mechanism shuts down the far-UV radiation source, blocks an activation signal to the far-UV radiation source, reduces radiation output of the far-UV radiation source, reduces power supplied to the far-UV radiation source, activates the air purification unit, adjusts one or more operational parameter of the air purification unit, provides an alert to a user, or provides an alert to an occupant of the treatment space.

[0176] Aspect 92 provides the method of any one of Aspects 67-91, comprising detecting ozone and managing operation of the far-UV radiation source, air purification unit, or both, based on the detected ozone.

[0177] Aspect 93 provides the method of any one of Aspects 67-92, comprising detecting airborne particulate matter and managing operation of thefar-UV radiation source, air purification unit, or both, based on the detected airborne particulate matter.

[0178] Aspect 94 provides the method of any one of Aspects 67-93, comprising detecting ultrafines and managing operation of the far-UV radiation source, air purification unit, or both, based on the detected ultrafines.

[0179] Aspect 95 provides the method of any one of Aspects 67-94, comprising measuring airborne particulate matter, ozone, or volatile organic compounds (VOCs), to determine whether the air purification unit has achieved a target filtration activity level.

[0180] Aspect 96 provides the method of any one of Aspects 67-95, wherein air quality of the treatment space is defined based on a measurement of airborne particulate matter, ozone, or volatile organic compounds (VOCs) in the air the treatment space.

[0181] Aspect 97 provides the method of any one of Aspects 67-96, wherein the predetermined threshold is based on a measured, calculated, or estimated ozone generation amount of the far-UV radiation source, or based on a measured, calculated, or estimated amount of ozone-generating irradiation provided by the far-UV radiation source.

[0182] Aspect 98 provides the method of any one of Aspects 67-97, comprising operating the far-UV radiation source without operation of the air purification unit when the air purification unit has operated for a predetermined sufficient period of time.

[0183] Aspect 99 provides the method of any one of Aspects 67-98, comprising preventing activation, deactivating, or imposing an interlock on action of the far-UV radiation source when air quality of the treatment space is below a predetermined threshold.

[0184] Aspect 100 provides the method of any one of Aspects 67-99, comprising imposing an interlock on action of the far-UV radiation source, wherein one or more interlock conditions are based on a measured, estimated, or calculated amount of volatile organic compounds (VOCs), ultrafines, ozone, or any combination thereof, in the air of the treatment space or generated by operation of the far-UV radiation source.

[0185] Aspect 101 provides the method of any one of Aspects 67-100, comprising imposing an interlock on action of the far-UV radiation source, wherein one or more interlock conditions are based on: a measured, calculated, or estimated amount of ozone generated from operation of the far-UV radiation source, or a measured, calculated, or estimated amount of UV radiation provided to the treatment space; and a measured, calculated, or estimated amount of volatile organic compounds (VOCs), ultrafines, or both, in air of the treatment space.

[0186] Aspect 102 provides the method of any one of Aspects 67-101, comprising imposing an interlock on action of the far-UV radiation source, wherein one or more interlock conditions are based on an assessment of: the combination of a measured, calculated, or estimated amounts of ozone and amounts of volatile organic compounds (VOCs) contemporaneously in the treatment space; the combination of a measured, calculated, or estimated amounts of ozone and amounts of amounts of ultrafines contemporaneously in the treatment space; the combination of a measured, calculated, or estimated amounts of ozone-generating UV radiation and amounts of volatile organic compounds (VOCs) contemporaneously in the treatment space; or the combination of a measured, calculated, or estimated amounts of ozone-generating UV radiation and amounts of ultrafines in the treatment space; not based solely on assessing amounts of volatile organic compounds (VOCs), ultrafines, or both, in the absence of considering ozone amount or ozone-generating UV radiation.

[0187] Aspect 103 provides the method of any one of Aspects 67-102, comprising imposing an interlock on action of the far-UV radiation source and comprising use of a photometer, a camera, an ozone detector, a volatile organic compound (VOC) detector, a particulate matter detector, or any combination thereof, to determine whether one or more interlock conditions are satisfied.

[0188] Aspect 104 provides the method of any one of Aspects 67-103, comprising using a volatile organic compound (VOC) detector, a particulate matter detector, or both, to collect measurements of one or more airbornecontaminant in the treatment space based on time series or based on one or more operational parameter of the air purification unit or far-UV radiation source, and determine from the collected data one or more of: volume of the treatment space, dimensions of the treatment space, air quality of the treatment space, volatile organic compound (VOC) consumption rates, volatile organic compound (VOC) generation rates, an ultrafine consumption rate, ultrafine generation rate, air purification unit efficacy, filtration efficacy, scrubber efficacy, performance of the far-UV radiation source, total room air purification efficacy, germicidal efficacy, or other information about air in the treatment space.

[0189] Aspect 105 provides the method of any one of Aspects 67-104, comprising operating the far-UV radiation source via duty cycling during operation of the air purification unit.

[0190] Aspect 106 provides the method of any one of Aspects 67-105, comprising operating the air purification unit via duty cycling during operation of the far-UV radiation source.

[0191] Aspect 107 provides the method of any one of Aspects 67-106, comprising operating the air purification unit via duty cycling, and the operating the far-UV radiation source during, or in anticipation of, cycles of the duty cycling air purification unit.

[0192] Aspect 108 provides the method of any one of Aspects 67-107, comprising operating the far-UV radiation source via duty cycling, and operating the air purification unit during, or in anticipation of, cycles of the duty cycling far-UV radiation source.

[0193] Aspect 109 provides the method of any one of Aspects 67-108, comprising operating the far-UV radiation source via duty cycling, during operation of the air purification unit, operating the air purification unit via duty cycling during operation of the far-UV radiation source, or both.

[0194] Aspect 110 provides the method of any one of Aspects 67-109, wherein the air purification unit is coupled with the far-UV radiation source to provide a single device.

[0195] Aspect 111 provides the method of any one of Aspects 67-110, wherein the air purification unit is separately located from the far-UV radiation source.

[0196] Aspect 112 provides the method of any one of Aspects 67-111, wherein the air purification unit is a portable unit.

[0197] Aspect 113 provides the method of any one of Aspects 67-112, wherein the air purification unit is part of an HVAC system, a ventilation system, or an air exchange system, or physically or operationally integrated with an air handling system, ventilation system, air-conditioning system, heating system, HVAC system, whole-building air purification system, air exchange system, fresh air supply, air exhaust, air intake, air recirculator, fan system, ventilation points (e.g., windows, doors, retractable roofs), central air system, clean room air system, medical space air system, building management systems, site management system, industrial management systems, air management system of a transport vehicle or airplane, classroom management systems, hospital management system, operating room management system, security systems, janitorial system, grounds management system, or any combination thereof.

[0198] Aspect 114 provides the method of any one of Aspects 67-113, wherein the air purification unit is configured for removing airborne particulate matter.

[0199] Aspect 115 provides the method of any one of Aspects 67-114, wherein the air purification unit is configured for removing ultrafines from air in the treatment space.

[0200] Aspect 116 provides the method of any one of Aspects 67-115, wherein the air purification unit is configured for removing PM2.5 from air in the treatment space.

[0201] Aspect 117 provides the method of any one of Aspects 67-116, wherein the air purification unit is configured for removing volatile organic compounds (VOCs) from air in the treatment space.

[0202] Aspect 118 provides the method of any one of Aspects 67-117, wherein the air purification unit is configured for removing airborne particulate matter, volatile organic compounds (VOCs), or ozone, in the treatment space.

[0203] Aspect 119 provides the method of any one of Aspects 67-118, wherein the air purification unit comprises a mechanical filter.

[0204] Aspect 120 provides the method of any one of Aspects 67-119, wherein the mechanical filter is an electrostatic filter.

[0205] Aspect 121 provides the method of any one of Aspects 67-120, wherein the air purification unit comprises a HEPA filter.

[0206] Aspect 122 provides the method of any one of Aspects 67-121, wherein the air purification unit comprises a scrubber.

[0207] Aspect 123 provides the method of any one of Aspects 67-122, wherein the air purification unit comprises a mechanical filter, an electrostatic filter, a scrubber, or any combination thereof.

[0208] Aspect 124 provides the method of any one of Aspects 67-123, wherein the air purification unit comprises a scrubber containing a catalytic scrubber, activated carbon, potassium permanganate, or any combination thereof.

[0209] Aspect 125 provides the method of any one of Aspects 67-124, wherein the air purification unit is configured for removing airborne particulate matter from air in the treatment space and comprises a mechanical filter.

[0210] Aspect 126 provides the method of any one of Aspects 67-125, wherein the air purification unit is configured for removing volatile organic compounds (VOCs) from air in the treatment space and comprises a scrubber.

[0211] Aspect 127 provides the method of any one of Aspects 67-126, wherein the air purification unit is configured for removing ozone from air in the treatment space and comprises a scrubber.

[0212] Aspect 128 provides the method of any one of Aspects 67-127, wherein the air purification unit comprises a fan system or power supply and the method comprises modulating performance of the fan system or power supply during operation of the air purification unit.

[0213] Aspect 129 provides the method of any one of Aspects 67-128, comprising controlling operation of the air purification unit based on operational status of the far-UV radiation source such that operation of the air purification unit indicates that the far-UV radiation source is operating in a fully functional operational state, or that the treatment space is being treated.

[0214] Aspect 130 provides an apparatus for inactivating a pathogen in air of a treatment space, comprising a UV radiation source that emits radiationcomprising one or more wavelengths of about 210 nm to about 230 nm, and a control module that that operationally links the far-UV radiation source with operation of an air purification unit.

[0215] Aspect 131 provides the apparatus of Aspect 130, wherein the air purification unit is separate from the apparatus.

[0216] Aspect 132 provides the apparatus of any one of Aspects 130-131, wherein the air purification unit is coupled with the apparatus.

[0217] Aspect 133 provides the apparatus of any one of Aspects 130-132, wherein the far-UV radiation source is mounted on a stand secured to the air purification unit, which serves as base or counterweight.

[0218] Aspect 134 provides the apparatus of any one of Aspects 130-133, wherein the air purification unit is located within a housing shared with the far- UV radiation source, the air purification unit is mounted on a stand shared with the far-UV radiation source, the air purification unit serves as a base or counterweight for the far-UV radiation source.

[0219] Aspect 135 provides the apparatus of any one of Aspects 130-134, wherein the far-UV radiation source will not operate when the air purification unit is not operating.

[0220] Aspect 136 provides the apparatus of any one of Aspects 130-135, wherein the far-UV radiation source and the air purification unit are operationally linked to trigger activation of the air purification unit prior to activation of the far-UV radiation source, or simultaneously with activation of the far-UV radiation source.

[0221] Aspect 137 provides the apparatus of any one of Aspects 130-136, wherein the far-UV radiation source and the air purification unit are operationally linked to impose operation of the air purification unit when the far- UV radiation source operates, or impose operation of the air purification unit prior to operation of the far-UV radiation source, optionally for a predetermined period of time.

[0222] Aspect 138 provides the apparatus of any one of Aspects 130-137, wherein the control module is configured to control operation of the far-UV radiation source based on the operational status of the air purification unit, anamount, such as a concentration, of an airborne contaminant in the air of the treatment space, or any combination thereof.

[0223] Aspect 139 provides the apparatus of any one of Aspects 130-138, wherein the operational status of the air purification unit is whether it is on or off

[0224] Aspect 140 provides the apparatus of any one of Aspects 130-139, wherein the operational status of the air purification unit is whether it is nominally functioning.

[0225] Aspect 141 provides the apparatus of any one of Aspects 130-140, wherein the operational status of the air purification unit is whether it is achieving nominal target performance.

[0226] Aspect 142 provides the apparatus of any one of Aspects 130-141, wherein the control module is configured to trigger a safeguard mechanism when the apparatus has an instruction to irradiate the treatment space and the air purification unit is not active.

[0227] Aspect 143 provides the apparatus of any one of Aspects 130-142, wherein the control module is configured to trigger a safeguard mechanism when the apparatus has an instruction to irradiate the treatment space and one or more of the following: the air purification unit is not active, the air purification unit is not operating at a target filtration activity level, the air of the treatment space is above a predetermined amount of an airborne contaminant, the air of the treatment space has a amount of ultrafines above a predetermined amount of the air of the treatment space has a amount of volatile organic compounds (VOCs) above a predetermined amount of VOCs, the air of the treatment space has a amount of PM0.1 above a predetermined amount of PM0.1, the air of the treatment space has a amount of PM2.5 above a predetermined amount of PM2.5, the air of the treatment space has a amount of ozone above a predetermined amount or any combination thereof.

[0228] Aspect 144 provides the apparatus of any one of Aspects 130-143, wherein the far-UV radiation source will not operate, or will provide a reduced amount of radiation, when: the air purification unit is not operating, the air purification unit is not operating at a target filtration activity level, the air of the treatment space is above a predetermined amount of an airborne contaminant.

[0229] Aspect 145 provides the apparatus of any one of Aspects 130-144, wherein the control module is configured to trigger a safeguard mechanism when the apparatus has an instruction to irradiate the treatment space and the air of the treatment space is above a predetermined concentration of an airborne contaminant.

[0230] Aspect 146 provides the apparatus of any one of Aspects 130-145, wherein the control module is configured to trigger a safeguard mechanism when the apparatus has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of volatile organic compounds (VOCs) above a predetermined concentration.

[0231] Aspect 147 provides the apparatus of any one of Aspects 130-146, wherein the control module is configured to trigger a safeguard mechanism when the apparatus has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of ultrafines above a predetermined concentration.

[0232] Aspect 148 provides the apparatus of any one of Aspects 130-147, wherein the control module is configured to trigger a safeguard mechanism when the apparatus has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of PM0.1 above a predetermined concentration.

[0233] Aspect 149 provides the apparatus of any one of Aspects 130-148, wherein the control module is configured to trigger a safeguard mechanism when the apparatus has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of PM2.5 above a predetermined concentration.

[0234] Aspect 150 provides the apparatus of any one of Aspects 130-149, wherein the control module is configured to trigger a safeguard mechanism when the apparatus has an instruction to irradiate the treatment space and the air of the treatment space has a concentration of ozone above a predetermined concentration.

[0235] Aspect 151 provides the apparatus of any one of Aspects 130-150, wherein the control module is configured to trigger a safeguard mechanism when the apparatus has an instruction to irradiate the treatment space and, the airof the treatment space has a amount of ultrafines above a predetermined amount of the air of the treatment space has a amount of volatile organic compounds (VOCs) above a predetermined amount of VOCs, the air of the treatment space has a amount of PMO.1 above a predetermined amount of PMO.1, the air of the treatment space has a amount of PM2.5 above a predetermined amount of PM2.5, the air of the treatment space has a amount of ozone above a predetermined amount, or any combination thereof, wherein the predetermined amount is based on an ozone generation characteristic of the far-UV radiation source.

[0236] Aspect 152 provides the apparatus of any one of Aspects 130-151, wherein the safeguard mechanism shuts down the far-UV radiation source, or blocks an activation signal to the far-UV radiation source.

[0237] Aspect 153 provides the apparatus of any one of Aspects 130-152, wherein the safeguard mechanism activates the air purification unit.

[0238] Aspect 154 provides the apparatus of any one of Aspects 130-153, wherein the safeguard mechanism adjusts one or more operational parameter of the air purification unit.

[0239] Aspect 155 provides the apparatus of any one of Aspects 130-154, wherein the safeguard mechanism shuts down the far-UV radiation source, blocks an activation signal to the far-UV radiation source, reduces radiation output of the far-UV radiation source, reduces power supplied to the far-UV radiation source, activates the air purification unit, adjusts one or more operational parameter of the air purification unit, provides an alert to a user, or provides an alert to an occupant of the treatment space.

[0240] Aspect 156 provides the apparatus of any one of Aspects 130-155, wherein the control module is configured as an interlock that prevents operation of the far-UV radiation source unless one or more interlock conditions are satisfied.

[0241] Aspect 157 provides the apparatus of any one of Aspects 130-156, wherein one or more interlock conditions are based on amount of an airborne contaminant in the air of the treatment space.

[0242] Aspect 158 provides the apparatus of any one of Aspects 130-157, comprising an ozone detection unit that mediates operation of the far-UV radiation source, air purification unit, or both.

[0243] Aspect 159 provides the apparatus of any one of Aspects 130-158, comprising a condensation particle counter (CPC) that mediates operation of the far-UV radiation source, air purification unit, or both.

[0244] Aspect 160 provides the apparatus of any one of Aspects 130-159, comprising a condensation particle counter (CPC) configured for measuring airborne particulate matter.

[0245] Aspect 161 provides the apparatus of any one of Aspects 130-160, comprising a condensation particle counter (CPC) capable of measuring ultrafines.

[0246] Aspect 162 provides the apparatus of any one of Aspects 130-161, wherein operation of the far-UV radiation source, the air purification unit, or both, is modulated based on a measurement from a condensation particle counter or an ozone detection unit.

[0247] Aspect 163 provides the apparatus of any one of Aspects 130-162, wherein one or more interlock conditions are a target filtration activity level determined from a measurement of airborne particulate matter, ozone, or volatile organic compounds (VOCs).

[0248] Aspect 164 provides the apparatus of any one of Aspects 130-163, wherein a measurement of airborne particulate matter, ozone, or volatile organic compounds (VOCs), is used to determine whether the air purification unit has achieved a target filtration activity level.

[0249] Aspect 165 provides the apparatus of any one of Aspects 130-164, wherein the control module is configured to prevent operation of the far-UV radiation source when air quality of the treatment space is below a predetermined threshold.

[0250] Aspect 166 provides the apparatus of any one of Aspects 130-165, wherein the control module is configured to operate the far-UV radiation source without operation of air purification unit when air quality of the treatment space is above a predetermined threshold.

[0251] Aspect 167 provides the apparatus of any one of Aspects 130-166, wherein a measurement of airborne particulate matter, ozone, or volatile organic compounds (VOCs), is used to determine air quality of the treatment space.

[0252] Aspect 168 provides the apparatus of any one of Aspects 130-167, wherein the control module is configured to operate the far-UV radiation source without operation of the air purification unit when the air purification unit has operated for a predetermined period of time.

[0253] Aspect 169 provides the apparatus of any one of Aspects 130-168, wherein one or more interlock conditions are based on a measured, estimated, or calculated amount of volatile organic compounds (VOCs), ultrafines, ozone, or any combination thereof, in the air of the treatment space or generated by operation of the far-UV radiation source.

[0254] Aspect 170 provides the apparatus of any one of Aspects 130-169, wherein one or more interlock conditions are based on: a measured, calculated, or estimated amount of ozone generated from operation of the far-UV radiation source, or a measured, calculated, or estimated amount of UV radiation provided to the treatment space; and a measured, calculated, or estimated amount of volatile organic compounds (VOCs), ultrafines, or both, in air of the treatment space.

[0255] Aspect 171 provides the apparatus of any one of Aspects 130-170, wherein one or more interlock conditions are based on an assessment of: the combination of a measured, calculated, or estimated amounts of ozone and amounts of volatile organic compounds (VOCs) contemporaneously in the treatment space; the combination of a measured, calculated, or estimated amounts of ozone and amounts of amounts of ultrafines contemporaneously in the treatment space; the combination of a measured, calculated, or estimated amounts of ozone-generating UV radiation and amounts of volatile organic compounds (VOCs) contemporaneously in the treatment space; or the combination of a measured, calculated, or estimated amounts of ozone-generating UV radiation and amounts of ultrafines in the treatment space; not based solely on assessing amounts of volatile organic compounds(VOCs), ultrafines, or both, in the absence of considering ozone amount or ozone-generating UV radiation.

[0256] Aspect 172 provides the apparatus of any one of Aspects 130-171, comprising an ozone detection unit, a photometer, camera, a volatile organic compound (VOC) detector, a particulate matter detector, or any combination thereof.

[0257] Aspect 173 provides the apparatus of any one of Aspects 130-172, which comprises a volatile organic compound (VOC) detector, a particulate matter detector, or both, configured to collect measurements of one or more airborne contaminant in the treatment space based on time series or based on one or more operational parameter of the air purification unit or far-UV radiation source, and the control module is configured to infer or determine from the collected data one or more of volume of the treatment space, dimensions of the treatment space, air quality of the treatment space, volatile organic compound (VOC) consumption rates, volatile organic compound (VOC) generation rates, an ultrafine consumption rate, ultrafine generation rate, air purification unit efficacy, filtration efficacy, scrubber efficacy, performance of the far-UV radiation source, total room air purification efficacy, germicidal efficacy, or other information about air in the treatment space.

[0258] Aspect 174 provides the apparatus of any one of Aspects 130-173, wherein the control module is configured to operate the far-UV radiation source via duty cycling during operation of the air purification unit.

[0259] Aspect 175 provides the apparatus of any one of Aspects 130-174, wherein the control module is configured to operate the air purification unit via duty cycling during operation of the far-UV radiation source.

[0260] Aspect 176 provides the apparatus of any one of Aspects 130-175, wherein the air purification unit operates via duty cycling, and the control module is configured to operate the far-UV radiation source during, or in anticipation of, cycles of the duty cycling air purification unit.

[0261] Aspect 177 provides the apparatus of any one of Aspects 130-176, wherein the far-UV radiation source operates via duty cycling, and the control module is configured to operate the air purification unit during, or in anticipation of, cycles of the duty cycling far-UV radiation source.

[0262] Aspect 178 provides the apparatus of any one of Aspects 130-177, wherein the air purification unit is coupled with the far-UV radiation source to provide a single device.

[0263] Aspect 179 provides the apparatus of any one of Aspects 130-178, wherein the control module is configured to operate the far-UV radiation source via duty cycling during operation of the air purification unit, the control module is configured to operate the air purification unit via duty cycling during operation of the far-UV radiation source, or both.

[0264] Aspect 180 provides the apparatus of any one of Aspects 130-179, wherein the air purification unit is separately located from the far-UV radiation source.

[0265] Aspect 181 provides the apparatus of any one of Aspects 130-180, wherein the air purification unit is a portable unit.

[0266] Aspect 182 provides the apparatus of any one of Aspects 130-181, wherein the air purification unit is part of an HVAC system, a ventilation system, or an air exchange system, or physically or operationally integrated with an air handling system, ventilation system, air-conditioning system, heating system, HVAC system, whole-building air purification system, air exchange system, fresh air supply, air exhaust, air intake, air recirculator, fan system, ventilation points (e.g., windows, doors, retractable roofs), central air system, clean room air system, medical space air system, building management systems, site management system, industrial management systems, air management system of a transport vehicle or airplane, classroom management systems, hospital management system, operating room management system, security systems, janitorial system, grounds management system, or any combination thereof.

[0267] Aspect 183 provides the apparatus of any one of Aspects 130-182, wherein the air purification unit is configured for removing airborne particulate matter.

[0268] Aspect 184 provides the apparatus of any one of Aspects 130-183, wherein the air purification unit is configured for removing ultrafines from air in the treatment space.

[0269] Aspect 185 provides the apparatus of any one of Aspects 130-184, wherein the air purification unit is configured for removing PM2.5 from air in the treatment space.

[0270] Aspect 186 provides the apparatus of any one of Aspects 130-185, wherein the air purification unit is configured for removing volatile organic compounds (VOCs) from air in the treatment space.

[0271] Aspect 187 provides the apparatus of any one of Aspects 130-186, wherein the air purification unit comprises a mechanical filter.

[0272] Aspect 188 provides the apparatus of any one of Aspects 130-187, wherein the mechanical filter is an electrostatic filter.

[0273] Aspect 189 provides the apparatus of any one of Aspects 130-188, wherein the air purification unit comprises a HEPA filter.

[0274] Aspect 190 provides the apparatus of any one of Aspects 130-189, wherein the air purification unit comprises a scrubber.

[0275] Aspect 191 provides the apparatus of any one of Aspects 130-190, wherein the air purification unit comprises a fan apparatus or power supply that is modulated by a control module.

[0276] Aspect 192 provides the apparatus of any one of Aspects 130-191, wherein the operational status of the far-UV radiation source controls operation of the air purification unit such that operation of the air purification unit indicates that the far-UV radiation source is operating in a fully functional operational state, or that the treatment space is being treated.

[0277] Aspect 193 provides the apparatus of any one of Aspects 130-192, wherein the operational status of the far-UV radiation source controls operation of the air purification unit such that operation of the air purification unit indicates that the far-UV radiation source is operating in a fully functional operational state, or that the treatment space is being treated.

[0278] Aspect 194 provides the apparatus of any one of Aspects 130-193, wherein the air purification unit is configured for removing airborne particulate matter, volatile organic compounds, or ozone, in the treatment space.

[0279] Aspect 195 provides the apparatus of any one of Aspects 130-194, wherein the air purification unit comprises a mechanical filter, an electrostatic filter, a scrubber, or any combination thereof.

[0280] Aspect 196 provides the apparatus of any one of Aspects 130-195, wherein the air purification unit comprises a scrubber containing a catalytic scrubber, activated carbon, potassium permanganate, or any combination thereof.

[0281] Aspect 197 provides the apparatus of any one of Aspects 130-196, wherein the air purification unit is configured for removing airborne particulate matter from air in the treatment space and comprises a mechanical filter.

[0282] Aspect 198 provides the apparatus of any one of Aspects 130-197, wherein the air purification unit is configured for removing volatile organic compounds (VOCs) from air in the treatment space and comprises a scrubber.

[0283] Aspect 199 provides the apparatus of any one of Aspects 130-198, wherein the apparatus or a component thereof is configured to perform one or more of the presently described methods.

[0284] Aspect 200 provides the system, method, or apparatus of any one of Aspects 1-199, wherein operation of the UV radiation source requires operation of the air purification unit.

[0285] Aspect 201 provides the system, method, or apparatus of any one of Aspects 1-200, wherein operation of the UV radiation source requires that air quality of the treatment space is above a predetermined level.

[0286] Aspect 202 provides the system, method, or apparatus of any one of Aspects 1-201, wherein operation of the UV radiation source requires that air in the treatment space has below a predetermined level of ultrafines.

[0287] Aspect 203 provides the system, method, or apparatus of any one of Aspects 1-202, wherein operation of the UV radiation source requires that air in the treatment space has below a predetermined level of PM0.1.

[0288] Aspect 204 provides the system, method, or apparatus of any one of Aspects 1-203, wherein operation of the UV radiation source requires that air in the treatment space has below a predetermined level of PM2.5.

[0289] Aspect 205 provides the system, method, or apparatus of any one of Aspects 1-204, wherein operation of the UV radiation source requires that air in the treatment space has below a predetermined concentration of volatile organic compounds (VOCs).

[0290] Aspect 206 provides the system, method, or apparatus of any one of Aspects 1-205, wherein operation of the UV radiation source requires that air in the treatment space has below a predetermined level of ozone.

[0291] Aspect 207 provides the system, method, or apparatus of any one of Aspects 1-206, wherein operation of the UV radiation source requires that air in the treatment space has below a predetermined amount of volatile organic compounds (VOCs), ultrafines, PM0.1, PM2.5, or any combination thereof.

[0292] Aspect 208 provides the system, method, or apparatus of any one of Aspects 1-207, wherein the predetermined amount of volatile organic compounds (VOCs), ultrafines, PM0.1, PM2.5, or any combination thereof, is based on a measured, calculated, or estimated ozone generation amount of the far-UV radiation source, or based on a measured, calculated, or estimated amount of ozone-generating irradiation provided by the far-UV radiation source.

[0293] Aspect 209 provides the system, method, or apparatus of any one of Aspects 1-208, wherein operation of the UV radiation source requires that the air treatment space has been treated for reducing, or reduced of, volatile organic compounds (VOCs), ultrafines, PM0.1, PM2.5, or any combination thereof.

[0294] Aspect 210 provides the system, method, or apparatus of any one of Aspects 1-209, wherein operation of the UV radiation source requires operation of the air purification unit.

[0295] Aspect 211 provides the system, method, or apparatus of any one of Aspects 1-210, wherein operation of the UV radiation source requires prior operation of the air purification unit.

[0296] Aspect 212 provides the system, method, or apparatus of any one of Aspects 1-211, wherein operation of the UV radiation source requires simultaneous or concomitant operation of the air purification unit.

[0297] Aspect 213 provides the system, method, or apparatus of any one of Aspects 1-212, wherein the UV radiation source will not operate unless one or more interlock conditions based on sufficient operation of the air purification unit, or based on sufficiently low volatile organic compounds (VOCs), ultrafines, PM0.1, or PM2.5, amount in the treatment space.

[0298] Aspect 214 provides a system, method, or apparatus having any combination or permutation of features recited in one or more of Aspects 213.

Claims

CLAIMSWhat is claimed:

1. A system for inactivating a pathogen in air of a treatment space, comprising: a far-UV radiation source that emits radiation comprising one or more wavelengths of about 210 nm to about 230 nm and an air purification unit configured for removing airborne particulate matter, wherein the far-UV radiation source and the air purification unit are operationally linked.

2. The system of claim 1, wherein the far-UV radiation source will not operate when the air purification unit is not operating.

3. The system of claim 1, wherein the far-UV radiation source and the air purification unit are operationally linked to trigger activation of the air purification unit prior to activation of the far-UV radiation source, or simultaneously with activation of the far-UV radiation source.

4. The system of claim 1, wherein the far-UV radiation source and the air purification unit are operationally linked to impose operation of the air purification unit when the far-UV radiation source operates, or impose operation of the air purification unit prior to operation of the far-UV radiation source, optionally for a predetermined period of time.

5. The system of claim 1, comprising a control module configured to control operation of the far-UV radiation source based on the operational status of the air purification unit, an amount of an airborne contaminant in the air of the treatment space, or any combination thereof.

6. The system of claim 5, wherein the control module is configured to trigger a safeguard mechanism when the system has an instruction to irradiate the treatment space and one or more of the following: the air purification unit is not active, the air purification unit is not operating at a target filtration activity level, the air of the treatment space is above a predetermined amount of an airborne contaminant, the air of the treatment space has a amount of ultrafines above a predetermined amount of the air of the treatment space has a amount ofvolatile organic compounds (VOCs) above a predetermined amount of VOCs, the air of the treatment space has a amount of PMO.1 above a predetermined amount of PMO.1, the air of the treatment space has a amount of PM2.5 above a predetermined amount of PM2.5, the air of the treatment space has a amount of ozone above a predetermined amount or any combination thereof.

7. The system of claim 1, wherein the far-UV radiation source will not operate, or will provide a reduced amount of radiation, when: the air purification unit is not operating, the air purification unit is not operating at a target filtration activity level, the air of the treatment space is above a predetermined amount of an airborne contaminant, the air of the treatment space has a amount of ultrafines above a predetermined amount of the air of the treatment space has a amount of volatile organic compounds (VOCs) above a predetermined amount of VOCs, the air of the treatment space has a amount of PMO.1 above a predetermined amount of PMO.1, the air of the treatment space has a amount of PM2.5 above a predetermined amount of PM2.5, the air of the treatment space has a amount of ozone above a predetermined amount, or any combination thereof, wherein the predetermined amount is based on an ozone generation characteristic of the far- UV radiation source.

8. The system of claim 7, wherein the safeguard mechanism shuts down the far-UV radiation source, blocks an activation signal to the far-UV radiation source, reduces radiation output of the far-UV radiation source, reduces power supplied to the far-UV radiation source, activates the air purification unit, adjusts one or more operational parameter of the air purification unit, provides an alert to a user, or provides an alert to an occupant of the treatment space.

9. The system of claim 5, wherein the control module is configured as an interlock that prevents operation of the far-UV radiation source unless one or more interlock conditions are satisfied.

10. The system of claim 9, wherein one or more interlock conditions are based on amount of an airborne contaminant in the air of the treatment space.

11. The system of claim 9, wherein one or more interlock conditions are based on a measured, estimated, or calculated amount of volatile organiccompounds (VOCs), ultrafines, ozone, or any combination thereof, in the air of the treatment space or generated by operation of the far-UV radiation source.

12. The system of claim 9, wherein one or more interlock conditions are based on: a measured, calculated, or estimated amount of ozone generated from operation of the far-UV radiation source, or a measured, calculated, or estimated amount of UV radiation provided to the treatment space; and a measured, calculated, or estimated amount of volatile organic compounds (VOCs), ultrafines, or both, in air of the treatment space.

13. The system of claim 9, wherein at least one interlock condition is based on an assessment of the combination of a measured, calculated, or estimated amounts of ozone and amounts of volatile organic compounds (VOCs) contemporaneously in the treatment space; the combination of a measured, calculated, or estimated amounts of ozone and amounts of amounts of ultrafines contemporaneously in the treatment space; the combination of a measured, calculated, or estimated amounts of ozone-generating UV radiation and amounts of volatile organic compounds (VOCs) contemporaneously in the treatment space; or the combination of a measured, calculated, or estimated amounts of ozone-generating UV radiation and amounts of ultrafines in the treatment space; not based solely on assessing amounts of volatile organic compounds (VOCs), ultrafines, or both, in the absence of considering ozone amount or ozone-generating UV radiation; and not based solely on assessing ozone amount or ozone-generating UV radiation, in the absence of considering amounts of volatile organic compounds (VOCs), ultrafines, or both.

14. The system of claim 1, comprising an ozone detection unit, a photometer, camera, a volatile organic compound (VOC) detector, a particulate matter detector, or any combination thereof.

15. The system of claim 5, which comprises a volatile organic compound (VOC) detector, a particulate matter detector, or both, configured to collect measurements of one or more airborne contaminant in the treatment space based on time series or based on one or more operational parameter of the air purification unit or far-UV radiation source, and the control module is configured to infer or determine from the collected data one or more of: volume of the treatment space, dimensions of the treatment space, air quality of the treatment space, volatile organic compound (VOC) consumption rates, volatile organic compound (VOC) generation rates, an ultrafine consumption rate, ultrafine generation rate, air purification unit efficacy, filtration efficacy, scrubber efficacy, performance of the far-UV radiation source, total room air purification efficacy, germicidal efficacy, or other information about air in the treatment space.

16. The system of claim 5, wherein the control module is configured to operate the far-UV radiation source via duty cycling during operation of the air purification unit, the control module is configured to operate the air purification unit via duty cycling during operation of the far-UV radiation source, or both.

17. The system of claim 1, wherein the air purification unit is physically coupled together with the far-UV radiation source to provide a single device.

18. The system of claim 1, wherein the air purification unit is separately located from the far-UV radiation source.

19. The system of claim 1, wherein the air purification unit is a portable unit.

20. The system of claim 1, wherein the air purification unit is part of an HVAC system, a ventilation system, or an air exchange system.

21. The system of claim 1, wherein the air purification unit is configured for removing one or more of airborne particulate matter, volatile organic compounds, or ozone, in the treatment space;22. The system of claim 1, wherein the air purification unit comprises a mechanical filter, an electrostatic filter, a scrubber, or any combination thereof.

23. The system of claim 1, wherein the air purification unit comprises a scrubber containing a catalytic scrubber, activated carbon, potassium permanganate, manganese dioxide, or any combination thereof.

24. The system of claim 1, wherein the air purification unit is configured for removing airborne particulate matter from air in the treatment space and comprises a mechanical filter.

25. The system of claim 1, wherein the air purification unit is configured for removing volatile organic compounds (VOCs) from air in the treatment space and comprises a scrubber.

26. An apparatus for inactivating a pathogen in air of a treatment space, comprising a UV radiation source that emits radiation comprising one or more wavelengths of about 210 nm to about 230 nm, and a control module that that operationally links the far-UV radiation source with operation of an air purification unit.

27. The apparatus of claim 27, wherein the air purification unit is located within a housing shared with the far-UV radiation source, the air purification unit is mounted on a stand shared with the far-UV radiation source, the air purification unit serves as a base or counterweight for the far-UV radiation source.

28. The apparatus of claim 27, wherein operation of the UV radiation source requires operation of the air purification unit.

29. The apparatus of claim 27, wherein operation of the UV radiation source requires that air in the treatment space has below a predetermined amount of volatile organic compounds (VOCs), ultrafines, PM0.1, PM2.5, or any combination thereof.

30. The apparatus of claim 29, wherein the predetermined amount of volatile organic compounds (VOCs), ultrafines, PM0.1, PM2.5, or any combination thereof, is based on a measured, calculated, or estimated ozone generation amount of the far-UV radiation source, or based on a measured, calculated, orestimated amount of ozone-generating irradiation provided by the far-UV radiation source.

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