GB2600136A

GB2600136A - Air treatment assembly, ambulatory article, air treatment unit and air treatment method

Info

Publication number: GB2600136A
Application number: GB2016783.9A
Authority: GB
Inventors: Bruce Logan-Sinclair Ronald
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-10-22
Filing date: 2020-10-22
Publication date: 2022-04-27
Anticipated expiration: 2040-10-22
Also published as: GB2600136B; GB202016783D0

Abstract

Provided is an air treatment assembly 1 comprising a filter arrangement. The filter arrangement includes a filtration layer 12 configured to filter pathogens in air passing therethrough, a pathogen inactivation layer 14 which comprises copper and/or silver species for contacting the pathogens and a temperature control arrangement 16 coupled to the pathogen inactivation layer and configured to control the temperature of the pathogen inactivation layer. The temperature control element may cool the pathogen inactivation assembly, preferably to 0-10 °C, or it may heat it, preferably to 50-90 °C. The filter arrangement may further comprise an activated carbon layer. The air treatment assembly may comprise an optical sanitizing arrangement. A wearable article comprising the air treatment assembly and at least one attachment element for attaching the air treatment assembly to a wearer. An air treatment unit for providing treated air to the interior of a building or vehicle comprising the air treatment assembly and an outlet assembly.

Description

Intellectual Property Office Application No G1320167839 RTM Date:23 March 2021 The following terms are registered trade marks and should be read as such wherever they occur in this document: Spiroguard p8 Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo AIR TREATMENT ASSEMBLY, AMBULATORY ARTICLE, AIR TREATMENT UNIT AND AIR TREATMENT METHOD

FIELD OF THE INVENTION

This invention relates to an air treatment assembly, in particular an air treatment assembly for filtering and inactivating pathogens passing therethrough. The invention also provides a wearable article comprising the air treatment assembly, an air treatment unit comprising the air treatment assembly, and an air treatment method.

BACKGROUND OF THE INVENTION

Efforts have been made to stem the spread of infectious diseases, and in particular viral respiratory diseases such as COVID-19/SARS-CoV-2, by guidance and regulations intended to cause individuals to maintain distance from others. Various minimum distances have been proposed, such as two meters.

Stipulating such distancing is not, however, without problem. Distancing requirements may be detrimental to the viability of businesses and industries where space is at a premium, such as cinemas, theatres, and the aviation industry. It is accordingly desirable to find ways of enabling individuals to approach each other more closely whilst minimizing the risk of transmission of infectious diseases.

Air filters are known which are capable of filtering pathogens, such as viruses and bacteria, from air. However, the pathogen abatement performance via the filtering provided by conventional air filters may not itself be sufficient to relax distancing requirements.

Accordingly, such air filters, e.g. incorporated in facial coverings, are currently not recommended as an alternative to maintaining the stipulated minimum distance.

SUMMARY OF THE INVENTION

The invention is defined by the claims.

According to an aspect there is provided an air treatment assembly comprising: a filter arrangement including: a filtration layer configured to filter pathogens in air passing therethrough; and a pathogen inactivation layer adjacent the filtration layer, the pathogen inactivation layer comprising copper and/or silver species for contacting the pathogens; and a temperature control arrangement coupled to the pathogen inactivation layer and configured to control the temperature of the pathogen inactivation layer.

Conventional filtration layers for filtering pathogens suffer from certain disadvantages. Such filtration layers may permit a certain quantity of pathogenic material to pass therethrough, and may be prone to sporadic pathogenic material breakthroughs. Inclusion of a pathogen inactivation layer comprising copper and/or silver species may assist to mitigate such disadvantages. This is because copper and silver may inactivate, e.g. destroy, pathogens on contact. This may be via disassembly of the pathogens on contact with the copper and/or silver species. However, ensuring that the pathogen inactivation layer is appropriately configured for effective inactivation of pathogens remains a challenge.

The present invention is based on the realization that the pathogen inactivation properties of the copper and/or silver species can be tuned by controlling the temperature of the pathogen inactivation layer in which they are included. To this end, the temperature control arrangement included in the air treatment assembly enables the temperature of the pathogen inactivation layer to be controlled. Thus, the efficiency of the air treatment assembly for inactivating pathogens may be improved, with concomitant improvement in the effectiveness of the air treatment assembly in diminishing the concentration of pathogens in the treated air.

In an embodiment, the temperature control arrangement is configured to provide cooling to the pathogen inactivation layer.

Such cooling may assist to condense water vapor in the air passing through the filter arrangement on the surface of the pathogen inactivation layer. This, in turn, may assist to promote oxidation and/or maintain an oxidized state of the silver and/or copper species. This may enhance the pathogen inactivation properties of the silver and/or copper species. Cu(I), for instance, is more effective for contact inactivation of pathogens than metallic copper, in other words Cu(0).

The temperature control arrangement may, for example, be configured to cool the pathogen inactivation layer to a temperature in the range of 0°C to 10°C, preferably 1°C to 5°C, e.g. about 2°C.

The temperature control arrangement may alternatively or additionally be configured to operate in a heating mode to heat the pathogen inactivation layer. Heating the pathogen inactivation layer during the heating mode may assist to promote pathogenic inactivation processes.

The temperature of the pathogen inactivation layer may, for instance, be controlled by the temperature control arrangement to be in the range of 50°C to 90°C, such as 70°C, during the heating mode.

In other examples, the temperature of the pathogen inactivation layer may be controlled to reach higher temperatures, depending on factors such as the duration of the heating mode and the intended application of the air treatment assembly. For example, the temperature of the pathogen inactivation layer may be controlled by the temperature control arrangement to be in the range of 180°C to 220°C, such as 200°C, during the heating mode.

In an embodiment, the temperature control arrangement comprises a Peltier element. Such a Peltier element may benefit from providing the temperature control without moving parts or circulating liquid. The relatively small size of the Peltier element may also mean that the air treatment assembly can, for instance, be straightforwardly incorporated into a wearable article.

The filtration layer may, for example, comprise a nonwoven filter material. In a particular non-limiting example, the filtration layer comprises or consists of a so-called high efficiency particulate air (HEPA) filter. Such a HEPA filter may trap pathogenic particles having, for instance, a diameter in the range of 0.5 to 10 pm.

In an embodiment, the filter arrangement comprises a further filtration layer for filtering the pathogens. In this case, the pathogen inactivation layer may be interposed between the filtration layer and the further filtration layer. The further filtration layer may, for example, comprise a nonwoven filter material.

The pathogen inactivation layer may comprise apertures for permitting air to pass therethrough. In such cases, any pathogens in the air may contact the pathogen inactivation layer as the air is passing through the apertures.

The apertures may be dimensioned so as to be large enough to avoid undue flow restriction, whilst small enough to increase the likelihood of pathogens contacting the copper and/or silver species. In this respect, the aperture diameter may, for instance, be in the range of 0.05 mm to 2 mm, preferably 0.1 mm to 1 mm.

The pathogen inactivation layer may comprise a metallic mesh or perforate metallic sheet, and the copper and/or silver species are provided at least on a surface of the metallic mesh or perforate metallic sheet for contacting the pathogens. The metallic mesh may, for example, be a woven metallic mesh, e.g. a woven metallic gauze. The apertures of the perforate sheet may, for example, be formed via a laser drilling process.

In a non-limiting example, the metallic mesh may be a copper gauze, e.g. a woven copper gauze.

In a non-limiting example, the perforate sheet may be a perforate copper sheet. The filter arrangement may further comprise an activated carbon layer. The activated carbon layer may assist to remove certain pollutants, such as volatile organic compounds, from air passing through the filter arrangement. Such an activated carbon layer may assist to remove combustion gases, for example included in roadside pollution or derived from jet fuel combustion when the air treatment assembly is employed for aviation purposes.

In an embodiment, the air treatment assembly further comprises a humidification layer for humidifying the air treated by the filter arrangement.

The filtration layer(s) may tend to absorb moisture from the air, and the resulting dryer air may be less desirable for breathing. Accordingly, the humidification layer may assist to replenish the humidity of the treated air which has passed through the filter arrangement.

The filter arrangement may be included in a filter cartridge which is detachable from the temperature control arrangement.

The powered components of the air treatment assembly, and in particular the temperature control arrangement, may be reused with a fresh filter cartridge following detachment of a spent filter cartridge.

The air treatment assembly may comprise: an optical sanitizing arrangement comprising at least one ultraviolet light source; and an optically transmissive region located between a surface of the filtration layer and an opposing surface of the pathogen inactivation layer. In this embodiment, the at least one ultraviolet light source is directed towards the optically transmissive region, and arranged to irradiate at least one of the surface and the opposing surface.

The optical sanitizing arrangement may assist to enhance the pathogenic inactivation performance of the air treatment assembly. The ultraviolet light emitted by the at least one ultraviolet light source may assist to inactivate any pathogens residing at or close to the surface of the filtration layer and/or the opposing surface of the pathogen inactivation layer.

When the air treatment assembly comprises the above-described further filtration layer, a further optically transmissive region may be provided between a further surface of the further filtration layer and an opposing further surface of the pathogen inactivation layer. In this case, the at least one ultraviolet light source may be directed towards the further optically transmissive region, and arranged to irradiate at least one of the further surface and the opposing further surface.

The air treatment assembly may further comprise a fan arrangement for passing air through the filter arrangement.

According to another aspect there is provided a wearable article comprising: the air treatment assembly defined above, and at least one attachment element for attaching the air treatment assembly to a wearer of the article.

The enhanced pathogen inactivation provided by the air treatment assembly included in the wearable article may enable the safe distance between the wearer and others, and in particular others also wearing the wearable article, to be reduced.

When the air treatment assembly includes the fan arrangement, the fan arrangement may be arranged to direct air from the air treatment assembly towards and/or adjacent to the wearer's nose and/or mouth. Thus, the wearer may be supplied with air cleaned by the air treatment assembly.

In an embodiment, the air treatment assembly is included in a facial covering configured to cover at least the wearer's mouth and/or nose.

When the air treatment assembly includes the fan arrangement, the fan arrangement may be further configured to pressurize the air downstream of the air treatment assembly and arranged to direct the air in the form of an air curtain in front of and extending at least partially around the wearer's face.

Such an air curtain may assist to block lateral or horizontal flow of exhaled breath from the wearer, and may also assist to minimize ingress of external, e.g. contaminated, air into the vicinity of the treated air being inhaled by the wearer.

According to yet another aspect there is provided an air treatment unit for providing treated air to the interior of a building or vehicle, the unit comprising: the air treatment assembly defined above, and an outlet assembly for directing the air treated by the air treatment assembly towards the interior.

The air treatment unit may, for example, comprise an air conditioning unit.

The air treatment assembly may, for instance, be provided in the air conditioning unit which supplies conditioned air to an aircraft cabin.

According to a further aspect there is provided an air treatment method comprising: passing air into a filter arrangement, the filter arrangement comprising a filtration layer configured to filter pathogens in air passing therethrough; and a pathogen inactivation layer adjacent the filtration layer, wherein the pathogen inactivation layer comprises copper and/or silver species for contacting the pathogens; and controlling the temperature of the pathogen inactivation layer.

Embodiments described herein in relation to the air treatment assembly, and in particular the filter arrangement, are applicable to the method, and embodiments described herein in relation to the method are applicable to the air treatment assembly. Similarly, embodiments described herein in relation to the wearable article and the air treatment unit are applicable to the method, and embodiments described herein in relation to the method are applicable to the wearable article and the air treatment unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described in more detail and by way of non-limiting examples with reference to the accompanying drawings, wherein: FIG. 1 provides a cross-sectional schematic depiction of an air treatment assembly according to a first example; FIG. 2 provides a cross-sectional schematic depiction of an air treatment assembly according to a second example; FIG. 3 provides a cross-sectional schematic depiction of an air treatment assembly according to a third example; FIG. 4 provides a cross-sectional schematic depiction of an air treatment assembly according to a fourth example; FIG. 5 provides a cross-sectional schematic depiction of an air treatment assembly according to a fifth example; FIG. 6 provides a cross-sectional schematic depiction of an air treatment assembly according to a sixth example; FIG. 7 provides a cross-sectional schematic depiction of an air treatment assembly according to a seventh example; FIG. 8 provides a cross-sectional schematic depiction of an air treatment assembly according to an eighth example; FIG. 9 provides a cross-sectional schematic depiction of an air treatment assembly according to a ninth example; FIG. 10 provides a cross-sectional schematic depiction of an air treatment assembly according to a tenth example; FIG. 11 provides a cross-sectional schematic depiction of an air treatment assembly according to an eleventh example; FIG. 12 provides a cross-sectional schematic depiction of a first example of a wearable article comprising an air treatment assembly; FIG. 13 provides a cross-sectional schematic depiction of a second example of a wearable article comprising an air treatment assembly; FIG. 14 provides a cross-sectional schematic depiction of application of the wearable article in an aircraft cabin; FIG. 15 schematically depicts wearers wearing the wearable article according to a

third example; and

FIG. 16 provides a flowchart of an air treatment method according to an example.

DETAILED DESCRIPTION OF THE EMBODIMENTS

It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

Provided is an air treatment assembly comprising a filter arrangement. The filter arrangement includes a filtration layer configured to filter pathogens in air passing therethrough, and a pathogen inactivation layer adjacent the filtration layer. The pathogen inactivation layer comprises copper and/or silver species for contacting the pathogens. The air treatment assembly further comprises a temperature control arrangement coupled to the pathogen inactivation layer and configured to control the temperature of the pathogen inactivation layer. The filter arrangement may, for example, be regarded as a pathogen attenuation stack. Further provided is wearable article comprising the air treatment assembly, an air treatment unit comprising the air treatment assembly, and an air treatment method.

Conventional filtration layers for filtering pathogens suffer from certain disadvantages. Such filtration layers may permit a certain quantity of pathogenic material to pass therethrough, and may be prone to sporadic pathogenic material breakthroughs. Inclusion of a pathogen inactivation layer comprising copper and/or silver species upstream and/or downstream of such a filtration layer may assist to mitigate such disadvantages. This is because copper and silver may inactivate, in other words destroy, pathogens on contact.

This may be via disassembly of the pathogens on contact with the copper and/or silver species. However, ensuring that the pathogen inactivation layer is appropriately primed for inactivating pathogens remains a challenge.

The air treatment assembly may, in at least some embodiments, be regarded as attenuating, e.g. progressively attenuating, pathogens as air passes therethrough.

FIG. 1 provides a cross-sectional schematic depiction of an exemplary air treatment assembly 10. The air treatment assembly 10 comprises a filter arrangement, which filter arrangement comprises a filtration layer 12 and a pathogen inactivation layer 14.

The filtration layer 12 is configured to filter pathogens, in particular viruses and/or bacteria, in air passing through the filtration layer 12. Any suitable type of filtration layer 12 may be employed for this purpose.

In an embodiment, the filtration layer 12 comprises, or is defined by, a nonwoven filter material. In such a material, the pathogenic particles, e.g. virus and/or bacteria particles, may become trapped between the fibers of the nonwoven material.

The filtration layer 12 may, for example, comprise or consist of a so-called high efficiency particulate air (NEPA) filter. Such a filter may trap pathogenic particles having, for instance, a diameter in the range of 0.5 to 10 pm. Particular mention is made of Spiroguard 2800/22 from Air Safety Limited, having a specified pore diameter of 0.27 pm, as a suitable HEPA filter for use as or in the filtration layer 12 of the filter arrangement. Alternative suitable materials for the filtration layer 12 are well-known to the skilled person, and these will not be further described herein for the sake of brevity only.

The pathogen inactivation layer 14 comprises copper and/or silver species arranged to contact pathogens. At least some of the copper and/or silver species may be arranged on a surface of the pathogen inactivation layer 14 in order to contact any pathogens in the air.

Copper and/or silver species may inactivate pathogens, such as viruses and/or bacteria. Depending on whether the pathogen inactivation layer 14 is disposed downstream or upstream of the filtration layer 12, the pathogen inactivation layer 14 may inactivate pathogens which have been able to pass through the filtration layer 12 or which are directed towards the filtration layer 12 respectively.

The term "species" refers to the metallic element, in other words copper metal in the case of copper species, and silver metal in the case of silver species, and/or compounds of the metallic element, such as copper oxide, copper sulfate, etc. in the case of copper species, and silver oxide, etc. in the case of silver species.

The pathogen inactivation layer 14 may, for example, comprise at least one selected from copper metal, silver metal, copper-silver alloy, and copper-zinc alloy, in other words brass.

The filtration layer 12 may filter, and the pathogen inactivation layer 14 may inactivate, pathogens, such as coronaviruses, human rhinoviruses, influenza viruses, staphylococcus, mycobacterium tuberculosis, and the like.

In some embodiments, the pathogen inactivation layer 14 may delimit apertures for permitting the air to pass therethrough. In such cases, any pathogens in the air may contact the pathogen inactivation layer 14 as the air is passing through the apertures. The apertures may be dimensioned so as to be large enough to avoid undue flow restriction, whilst small enough to increase the likelihood of pathogens contacting the copper and/or silver species. In this respect, the aperture diameter may, for instance, be in the range of 0.05 mm to 2 mm, preferably 0.1 mm to 1 mm.

In an embodiment, the pathogen inactivation layer 14 comprises or consists of a metallic mesh, and the copper and/or silver species are provided at least on a surface of the mesh for contacting the pathogens. The aperture diameter of the metallic mesh may, for instance, be in the range of 0.05 mm to 2 mm, preferably 0.1 mm to 1 mm.

In a non-limiting example, the metallic mesh comprises or is defined by a copper mesh, e.g. a woven copper gauze.

Alternatively or additionally, the pathogen inactivation layer 14 comprises or consists of a perforate metallic sheet, such as a perforate copper sheet.

The apertures of the perforate sheet may, for example, be formed via a laser drilling process.

In a non-limiting example, the perforate metallic sheet may comprise a perforate metallic matrix, e.g. a perforate copper matrix.

In the case of a perforate metallic matrix, the apertures may define a tortuous path for the air to pass through. This may increase the likelihood of pathogens contacting the copper and/or silver species, and thereby inactivated.

In other examples, the pathogen inactivation layer 14 may be formed by depositing the copper and/or silver species onto a suitable substrate.

The substrate may, for example, be in the form of a woven textile or nonwoven material. In such an example, the copper and/or silver species may, for instance, be sputtered onto the surface of the substrate. The resulting metallic layer of the copper and/or silver species may be coupled to the temperature control arrangement 16.

The copper and/or silver species may be applied to the surface of the substrate in other suitable ways. For example, copper may applied in liquid form to the surface of the substrate to form an effective surface layer for contacting the pathogens. Plating, e.g. electroplating, of the copper and/or silver may also be contemplated.

In other examples, the pathogen inactivation layer 14 may be formed from a synthetic, e.g. polymeric, substrate in which the copper and/or silver is or are embedded in order to define an embedded metallic region to which the temperature control arrangement 16 may be coupled.

More generally, the air treatment assembly 10 comprises the temperature control arrangement 16 which is coupled, e.g. thermally conductively coupled, to the pathogen inactivation layer 14. The temperature control arrangement 16 is configured to control the temperature of the pathogen inactivation layer 14.

By controlling the temperature of the pathogen inactivation layer 14 using the temperature control arrangement 16 coupled thereto, the pathogen inactivation properties of the copper and/or silver species can be tuned, with concomitant improvement in the effectiveness of the air treatment assembly 10 in diminishing the concentration of pathogens downstream thereof.

In an embodiment, the temperature control arrangement 16 is configured to provide cooling to the pathogen inactivation layer 14. Such cooling may assist to condense water vapor in the air passing through the filter arrangement on the surface of the pathogen inactivation layer 14. This, in turn, may assist to promote oxidation and/or maintain an oxidized state of the silver and/or copper species. This may enhance the pathogen inactivation properties of the silver and/or copper species. Cu(I), for instance, is more effective for contact inactivation of pathogens than metallic copper.

The temperature control arrangement 16 may, for example, be configured to cool the pathogen inactivation layer 14 to a temperature in the range of 0°C to 10°C, preferably 1°C to 5°C, e.g. about 2°C.

The temperature control arrangement 16 may, for instance, be configured to provide intermittent cooling to the pathogen inactivation layer 14. The cooling may assist to promote reoxidation of the copper and/or silver species, and the intervening periods may assist to promote pathogenic inactivation. Such cycling of the cooling may also assist to minimize the energy consumption of the temperature control arrangement 16, and thus that of the air treatment assembly 10 as a whole. Such improvements in energy efficiency may be particularly beneficial when the air treatment assembly is included in a wearable article, as will be described in more detail herein below.

The temperature control arrangement 16 may comprise any suitable component for controlling the temperature of, e.g. cooling, the pathogen inactivation layer 14. The temperature control arrangement 16 may, for example, comprise a Peltier element.

Such a Peltier element may benefit from providing the temperature control without moving parts or circulating liquid. The relatively small size of the Peltier element may also mean that the air treatment assembly 10 can be straightforwardly incorporated into the abovementioned wearable article.

As an alternative or in addition to the above-described cooling of the pathogen inactivation layer 14, the temperature control arrangement 16 may be configured to operate in a heating mode to heat the pathogen inactivation layer 14. Heating the pathogen inactivation layer 14 during the heating mode may assist to promote the pathogenic inactivation processes.

The temperature of the pathogen inactivation layer 14 may, for instance, be controlled by the temperature control arrangement 16 to be in the range of 50°C to 90°C, such as 70°C, during the heating mode.

In other examples, the temperature of the pathogen inactivation layer 14 may be controlled to reach higher temperatures, depending on factors such as the heating duration and the intended application of the air treatment assembly 10. For example, the temperature of the pathogen inactivation layer 14 may be controlled by the temperature control arrangement 16 to be in the range of 180°C to 220°C, such as 200°C, during the heating mode.

The temperature control arrangement 16 may comprise any suitable heating element, such as a resistive heating element, for heating the pathogen inactivation layer 14 in the heating mode. A Peltier element, e.g. which is the same as or different from the above-described Peltier element arranged to cool the pathogen inactivation layer 14, may be employed as an alternative or in addition to the resistive heating element. In this case, the Peltier element may be configurable to transfer heat to the pathogen inactivation layer 14 when the heating mode is to be implemented.

More generally, the heating element of the temperature control arrangement 16 may be conductively coupled to the pathogen inactivation layer 14 in order to transfer heat thereto during the heating mode.

In an embodiment, the temperature control arrangement 16 is configured to provide cooling to the pathogen inactivation layer 14, e.g. to 0°C to 10°C, followed by heating the pathogen inactivation layer 14, e.g. to 50°C to 90°C or 180°C to 220°C. The cooling may assist to activate the copper and/or silver species for pathogen inactivation, as previously described, and the subsequent heating mode may promote pathogen inactivation via the thus activated copper and/or silver species.

The temperature control arrangement 16 may, for example, be configured to implement a plurality of cycles, each cycle comprising the cooling and the heating mode. Cycling the temperature of the pathogen inactivation layer 14, for example in the form of the above-described copper gauze, in this manner may assist to enhance the pathogen inactivation performance of the air treatment assembly 10.

In a non-limiting example, the temperature control arrangement 16 is configured to operate in a standby mode in which the temperature of the pathogen inactivation layer 14 is maintained for a predetermined time interval, e.g. 30 minutes to 8 hours, at a temperature in the range of 30°C to 50°C, such as about 40°C. Such gentle heating of the filter arrangement may assist to reduce excess humidity therein. This may also assist to extend the life of the filtration layer 12.

More generally, the temperature control implemented by the temperature control arrangement 16 may be implemented in any suitable manner, for example via a processor, e.g. microcontroller, configured to implement the cooling and/or heating modes by sending control signals to one or more suitable components, such as the above-described Peltier element and/or resistive heating element.

In some embodiments, predetermined time duration(s) and/or temperature(s) of the cooling and/or heating mode may be selected according to the application, for example to target inactivation of a certain pathogen or a certain class of pathogens.

Whilst not visible in the schematic depiction provided in FIG. 1, the filter arrangement may comprise a support scaffold for supporting the filtration layer 12 and the pathogen inactivation layer 14, and any further layers which may be included in the filter arrangement.

A thermal isolator (not visible) may, for example, be provided between the filtration layer 12 and the pathogen inactivation layer 14. The thermal isolator may assist to protect the filtration layer 12, e.g. HEPA filter, from damage due to the temperature changes of the pathogen inactivation layer 14, e.g. copper gauze. Any suitable thermally insulating material may be used to form the thermal isolator, such as a polymer and/or ceramic. A plurality of thermal isolators may, in certain examples, be included in the filtration arrangement/air treatment assembly 10 in order to isolate respective layers from each other.

The manner of supplying power to the temperature control arrangement may be determined according to, for instance, the intended application of the air treatment assembly 10. In a non-limiting example, the temperature control arrangement, e.g. including one or more Peltier elements for implementing the above-described cooling and/or heating mode, may be powered via one or more supercapacitors.

Alternatively or additionally, the cooling and/or heating mode may be implemented intermittently by the temperature control arrangement 16, e.g. with a low power sleep mode between each cooling or heating stage. By ensuring that the high current draw associated with the cooling or heating mode is intermittent, energy may be advantageously conserved.

The power conversion efficiency of the air treatment assembly 10 may, for example, be at least 92%. This may assist to prolong operation of the air treatment assembly 10, particularly in the case that the air treatment assembly 10 is employed in a wearable article. FIG. 2 schematically depicts an exemplary air treatment assembly 10 comprising an optical sanitizing arrangement 18 comprising at least one ultraviolet light source 20. An optically transmissive region is located between a surface of the filtration layer 12 and an opposing surface of the pathogen inactivation layer 14, and the at least one ultraviolet light source 20 is directed towards the optically transmissive region, as shown in FIG. 2. This arrangement of the ultraviolet light source 20 means that at least one of the surface of the filtration layer 12, and the opposing surface of the pathogen inactivation layer 14 is irradiated with ultraviolet light.

The optical sanitizing arrangement 18 may assist to enhance the pathogenic inactivation performance of the air treatment assembly 10. The ultraviolet light emitted by the at least one ultraviolet light source 20 may assist to inactivate any pathogens residing at or close to the surface of the filtration layer 12 and/or the opposing surface of the pathogen inactivation layer 14.

Any suitable ultraviolet light may be emitted for this purpose. Particular mention is made of UVC light, e.g. having a wavelength in range of 200 nm to 300 nm, such as 205 nm to 270 nm, due to its efficacy in inactivating pathogens. The at least one ultraviolet light source may, for example, be configured to emit light having a wavelength of 253.7 nm, since this wavelength may be preferred for germicidal activity. The ultraviolet light source 20 may comprise, for example, one or more ultraviolet light emitting elements, e.g. gas filled UV lamps or UV light emitting diodes.

Whilst FIG. 2 depicts a single ultraviolet light source 20 directed towards the optically transmissive region between the filtration layer 12 and the pathogen inactivation layer 14, this is not intended to be limiting. The optical sanitizing arrangement 18 may, for example, comprise a plurality of ultraviolet light sources 20. A pair of ultraviolet light sources 20 may, for instance, oppose each other from opposite sides of the air treatment assembly 10. This may assist to provide more uniform optical sanitizing of the filter arrangement than the scenario in which the ultraviolet light is emitted from a single side of the air treatment assembly 10.

Relatively prolonged periods, e.g. 5 to 30 minutes, of ultraviolet light exposure may be required in order to inactivate pathogens on the surface of the filtration layer 12 and/or the opposing surface of the pathogen inactivation layer 14. Accordingly, the optical sanitizing arrangement 18 may be configured to control the ultraviolet light source(s) 20 to emit ultraviolet light during a low power sleep or standby mode of the air treatment assembly 10, e.g. during above described low power sleep mode provided between the (intermittent) cooling and/or heating mode implemented by the temperature control arrangement 16.

At this point it is noted that the pathogen inactivation layer 14, e.g. in the form of a copper gauze, may further serve to provide a degree of protection for the filtration layer 12, and in particular the fibers which may constitute the filtration layer 12. The thermal conduction properties of the pathogen inactivation layer 14, particularly when copper metal is included in the pathogen inactivation layer 14, may assist to protect the filtration layer 12 from exposure to relatively high temperatures. Moreover, when the optical sanitizing arrangement 18 is included in the air treatment assembly 10, the pathogen inactivation layer, e.g. copper gauze, may further assist to protect the filtration layer 12, and in particular the fibers thereof, from damage by excessive ultraviolet light exposure.

FIG. 3 schematically depicts an exemplary air treatment assembly 10 in which the filter arrangement comprises the filtration layer 12, and a further filtration layer 22. In this example, the pathogen inactivation layer 14 is interposed between the filtration layer 12 and the further filtration layer 22.

The further filtration layer 22 may be configured to filter pathogens in air passing therethrough. The description of suitable filter materials, e.g. nonwoven filter materials, provided above in respect of the filtration layer 12 is also applicable to the further filtration layer 22.

In a non-limiting example, the further filtration layer 22 may be provided downstream of the filtration layer 12, and the further filtration layer 22 may have a pore size which is smaller than that of the filtration layer. Thus, the pathogen filtration becomes finer in the downstream direction. In other examples, the pore size/filter material of the further filtration layer 22 and the filtration layer 12 may be the same as each other.

As well as enhancing the pathogen filtering performance of the filter arrangement, sandwiching the pathogen inactivation layer 14 between the filtration layer 12 and the further filtration layer 22 may assist to enhance the degree of thermal insulation provided for the pathogen inactivation layer 14. This, in turn, may assist the temperature control arrangement 16 to control the temperature of the pathogen inactivation layer 14, and thus tuning of the temperature of the pathogen inactivation layer 14 for pathogen inactivation.

Alternatively or additionally, the filter arrangement may comprise a further pathogen inactivation layer 24. In the non-limiting example schematically depicted in FIG. 4, the filtration layer 12 is interposed between the pathogen inactivation layer 14 and the further pathogen inactivation layer 24. The further pathogen inactivation layer 24 comprises copper and/or silver species for contacting the pathogens. The description of suitable species/materials for the pathogen inactivation layer 14, such as metallic, e.g. copper, mesh, provided above is also applicable to the further pathogen inactivation layer 24.

In an embodiment, the temperature control arrangement 16 is coupled to and further configured to control the temperature of the further pathogen inactivation layer 24.

In a non-limiting example, the temperature control arrangement 16 is configured to control the temperature of the pathogen inactivation layer 14 independently of the control over the temperature of the further pathogen inactivation layer 24.

This may enable, for instance, the temperature control arrangement 16 to implement a temperature gradient in the filter arrangement. Inclusion of the above-described thermal isolator(s) may also assist in terms of providing the temperature gradient. Such a temperature gradient may assist to tune the pathogenic inactivation performance/reactivity of the copper and/or silver species in the downstream direction through the filter arrangement.

In a non-limiting example, the pathogen inactivation layer 14 and the further pathogen inactivation layer 24 each delimit apertures for permitting the air to pass therethrough. For example, the pathogen inactivation layer 14 and the further pathogen inactivation layer 24 may each comprise, or be formed from, a metallic mesh, such as a copper gauze.

The aperture diameter for each of the pathogen inactivation layer 14 and the further pathogen inactivation layer 24 may be the same as or different from each other, and may be, for example, in the range of 0.05 mm to 2 mm, preferably 0.1 mm to 1 mm.

In a non-limiting example, the aperture diameters of the pathogen inactivation layer 14, e.g. in the form of a copper gauze, and the further pathogen inactivation layer 24, e.g. in the form of a copper gauze, are different from each other. Alternation of the aperture dimensions of the pathogen inactivation layer 14 and the further pathogen inactivation layer 24 respectively may assist to improve the pathogenic inactivation performance of the filter arrangement.

The exemplary air treatment assembly 10 depicted in FIG. 5 comprises the filtration layer 12, the pathogen inactivation layer 14, the further filtration layer 22, and the further pathogen inactivation layer 24. In this non-limiting example, the temperature control arrangement 16 is coupled to the pathogen inactivation layer 14 and the further pathogen inactivation layer 24, and is configured to control the temperature of each of these pathogen inactivation layers 14, 24. The temperature of each of the pathogen inactivation layers 14, 24 may, for instance, be independently controlled by the temperature control arrangement 16, as previously described.

In an embodiment, and as schematically depicted in FIG. 6, the filter arrangement comprises an activated carbon layer 26. The activated carbon layer 26 may assist to remove certain pollutants, such as volatile organic compounds, from air passing through the filter arrangement. Such an activated carbon layer 26 may assist to remove combustion gases, for example included in roadside pollution or derived from jet fuel combustion when the air treatment assembly 10 is employed for aviation purposes. The latter will be described in more detail herein below with reference to FIG. 14.

In some non-limiting examples, the activated carbon layer 26 may also include copper and/or silver species loaded or impregnated onto/into the activated carbon. This may assist the filter arrangement to inactivate pathogens in air passing therethrough.

In the example depicted in FIG. 6, the activated carbon layer 26 is interposed between the pathogen inactivation layer 14 and the further filtration layer 22. In this manner, volatile organic compounds may be removed following inactivation of pathogens by the pathogen inactivation layer 14, but prior to additional filtration of any residual active pathogens by the further filtration layer 22. However, any suitable ordering of the respective layers of the filtration arrangement may be contemplated. For example, the activated carbon layer 26 may be interposed between the filtration layer 12 and the pathogen inactivation layer 14.

In some non-limiting examples, the filter arrangement may comprise a plurality, e.g. two, three, four, or more, activated carbon layers 26.

In an embodiment, and as schematically depicted in FIG. 7, the air treatment assembly 10 comprises a humidification layer 28 for humidifying the air treated by the filter arrangement. The humidification layer 28 may thus be provided downstream of the filter arrangement, and in particular downstream of the further filtration layer 22 in the non-limiting example shown in FIG. 7.

The filtration layer(s) 12, 22 may tend to absorb moisture from the air, and the resulting dryer air may be less desirable for breathing. Accordingly, the humidification layer 28 may assist to replenish the humidity of the treated air which has passed through the filter arrangement.

The humidifcation layer 28 may, for instance, comprise a suitable reservoir, e.g. sponge, in which water is retained and contacts the airflow downstream of the filter arrangement. A suitable polymeric membrane, such as ionomer membrane, e.g. the ionomer sold under the name NafionTM by the Chemours company, may be alternatively or additionally employed as the humidification layer 28.

The reservoir may be configured to be refillable/rewettable so that water in the humidification layer 28 may be replenished for continued use.

FIG. 8 shows another non-limiting example in which the air treatment assembly 10 comprises the activated carbon layer 26 and the humidification layer 28. In this sense, FIG. 8 may be considered a combination of the examples shown in FIGs. 6 and 7.

In an embodiment, the air treatment assembly 10 further comprises a fan arrangement 30 for passing air through the filter arrangement. In the non-limiting example shown in FIG. 9, the fan 30 is positioned downstream of the filter arrangement and draws air therethrough in the direction represented by the arrows 31.

The fan arrangement 30 may be implemented in any suitable manner. In certain examples, a centrifugal fan may be used to draw air through the filter arrangement, as will be explained in more detail herein below with reference to FIGs. 12 and 13.

The fan arrangement 30 may comprise a suitable motor for rotating a fan, e.g. the abovementioned centrifugal fan. The motor is preferably a brushless motor, e.g. a brushless D.C. electric motor, in order to improve safety of operation. Brushless motors may alleviate risks associated with commutator sparks of motors comprising brushes. It may thus be particularly desirable to employ brushless motors in scenarios where the air treatment assembly 10 is employed for filtering relatively oxygen-rich air/gas.

Brushless motors may also assist in terms of reducing the noise of operating the air treatment assembly 10. More generally, the fan arrangement 30 may have limited noise output, e.g. <30dB during operation.

FIG. 10 shows another example in which the air treatment assembly 10 comprises the fan arrangement 30 described above in relation to FIG. 9. In this non-limiting example, a combination of the features described above in relations to FIGs. 1 to 8 is also included in the air treatment assembly 10.

In particular, the filter arrangement comprises four air filtration layers 12, 22, 32, 42, and six pathogen inactivation layers 14, 24, 34, 44, 54, 64. A first air filtration layer 12 is interposed between first and second pathogen inactivation layers 14, 24. A second air filtration layer 22 is interposed between the second pathogen inactivation layer 24 and a third pathogen inactivation layer 34.

In the non-limiting example shown in FIG. 10, the activated carbon layer 26 is interposed between the third pathogen inactivation layer 34 and a fourth pathogen inactivation layer 44. However, the activated carbon layer 26 may be positioned elsewhere in the filter arrangement. In a preferred embodiment, the activated carbon layer 26 is interposed between the first pathogen inactivation layer 14 and the first air filtration layer 12.

A third air filtration layer 32 is interposed between the fourth pathogen inactivation layer 44 and a fifth pathogen inactivation layer 54. A fourth air filtration layer 42 is interposed between the fifth pathogen inactivation layer 54 and a sixth pathogen inactivation layer 64.

The humidification layer 28 is interposed between the sixth pathogen inactivation layer 64 and the fan arrangement 30; the latter in this particular example being downstream of the filter arrangement and the humidification layer 28.

In the non-limiting example shown in FIG. 10, the temperature of one or more, e.g. each, of the pathogen inactivation layers 14, 24, 34, 44, 54, 64 is controlled by the temperature control arrangement 16.

For example, independent temperature control over each of the pathogen inactivation layers 14, 24, 34, 44, 54, 64 may be implemented via the temperature control arrangement 16, e.g. to provide temperature gradient(s) in the filter arrangement, as previously described.

As schematically depicted in FIG. 10, ultraviolet light sources 20 are provided in the air treatment assembly 10 for optically sanitizing the filter arrangement, as previously described in relation to the optical sanitizing arrangement 18 shown in FIG. 2.

As shown in FIG. 10, a first pair of opposing ultraviolet light sources 20 emit light into the optically transmissive region between the first filtration layer 12 and the second pathogen inactivation layer 24. A second pair of opposing ultraviolet light sources 20 emit light into the optically transmissive region between the second filtration layer 22 and the third pathogen inactivation layer 34. A third pair of opposing ultraviolet light sources emit light into the optically transmissive region between the activated carbon layer 26 and the fourth pathogen inactivation layer 44. A fourth pair of opposing ultraviolet light sources emit light into the region between the third filtration layer 34 and the fifth pathogen inactivation layer 54.

The ultraviolet light sources, e.g. UVC light emitting diodes, may thus be regarded as interleaving the layers of the filter arrangement, in other words filter stack.

More generally, the successive one or more air filtration layer(s) 12, 22, 32, 42 and one or more pathogen inactivation layer(s) 14, 24, 34, 44, 54, 64 of the filter arrangement, e.g. filter stack, may be regarded as attenuating, e.g. progressively attenuating, pathogens as air passes through the filter arrangement/stack.

In an embodiment, the filter arrangement is included in a filter cartridge 70 which is detachable from the remainder of the air treatment assembly 10.

FIG. 11 shows the air treatment assembly 10 shown in FIG. 10 but with the dotted line 70 denoting the detachable filter cartridge.

The powered components of the air treatment assembly 10, and in particular the temperature control arrangement 16 and/or the optical sanitizing arrangement 18, are preferably reused with a fresh filter cartridge 70.

The filter cartridge 70 may be attachable/detachable to the remainder of the air treatment assembly 10 in any suitable manner, e.g. using a snap-fit connection. Such a snap-fit connection may facilitate removal of the filter cartridge 70.

Upon attachment of a fresh filter cartridge 70, the pathogen inactivation layer(s) 14, 24, 34, 44, 54, 64 may become coupled to the temperature control arrangement 16, e.g. via thermal contact point(s) which align with and contact each pathogen inactivation layer(s) 14, 24, 34, 44, 54, 64 when the filter cartridge 70 is attached.

Similarly, in examples in which the optical sanitizing arrangement 18 is included in the air treatment assembly 10, attachment of the fresh filter cartridge 70 may involve alignment of the ultraviolet light sources 20 with the above-described optically transmissive region(s). More generally, the filter cartridge 70 may be replaced once the maximum operating lifetime of, in particular, the filtration layer(s) 12, 22, 32, 42 has been reached. This may, for example, depend on how the air treatment assembly 10 has been used. The maximum operating lifetime of the filter cartridge 70 may be, for example, 1 week to 1 month.

The materials for the filter cartridge 70, and in particular the housing of the filter cartridge 70 (not visible in FIG. 11), may be selected to be relatively low cost and/or recyclable. For example, the housing of the filter cartridge 70 may be fabricated from an engineering thermoplastic, e.g. by an injection molding process.

In the non-limiting example shown in FIG. 11, the humidification layer 28 is not included in the filter cartridge 70, and in this case detachment of the filter cartridge may permit the user to access the humidification layer 28 thereunder in order to replenish the water in the humidification layer 28. In alternative examples, the humidification layer 28 may be included in the filter cartridge 70 or the humidification layer 28 may be removable independently of the filter arrangement/filter cartridge 70.

In some non-limiting examples, the air treatment assembly 10 comprises a cleaning module (not visible) for implementing cleaning within the filter arrangement. This may assist to prolong the operating lifetime of the filter arrangement. The cleaning module may, for instance, be configured to vibrate the filter arrangement to liberate trapped contaminants, e.g. using ultrasonic vibration within the filter stack. Such ultrasonic vibration may, for instance, be modulated.

In an embodiment, the air treatment assembly 10 according to any of the above-described examples is included in a wearable article 100. The wearable article 100 may further comprise at least one attachment element 102 for attaching the air treatment assembly 10 to a wearer of the article 100.

The wearable article 100 may be, for instance, a facial covering, e.g. a face mask.

In such an example, the air treatment assembly 10 may be arranged to cover at least the wearer's mouth and/or nose, and the at least one attachment element 102 may comprise one or more straps for securing the air treatment assembly 10 over at least the wearer's mouth and/or nose. For example, such a strap or straps may be secured over the wearer's ears or around the back of the wearer's head.

In the non-limiting example shown in FIG. 12, the wearable article 100 is in the form of headgear, and the at least one attachment element 102 attaches the air treatment assembly 10 to the head of the wearer 103.

The headgear 100 may take any suitable form. For example, the headgear 100 may be a head-mounted visor, a hat or cap, a laboratory shield, a helmet, e.g. a builder's hardhat or a motorcyclist's crash helmet, and so on.

In another non-limiting example, the headgear 100 may take the form of a hood for wearing by an aircraft passenger when sitting in their cabin seat, as will be described in more detail herein below with reference to FIG. 14.

More generally, the headgear 100 may be fabricated using relatively lightweight but relatively robust materials, such as engineering polymers so that the headgear 100 can be comfortably worn for relatively prolonged periods during which air treatment is required. Moreover, the external profile of the headgear 100 may be designed to encourage the wearing of the headgear 100, particularly by the general public.

The headgear 100 may, for example, be equipped with vibration damping elements 30 to enhance wearer comfort.

In a non-limiting example, the attachment element 102 is resiliently mounted, e.g. via one or more spring elements, to a part of the headgear 100 which comprises the fan arrangement 30. In this manner, the head of the wearer 103 may be substantially isolated from vibrations of the fan arrangement 30 and/or other components of the air treatment assembly 10.

In some examples, the headgear 100 may have an enclosure which houses components of the air treatment assembly 10. The enclosure may, for instance, be waterproof, e.g. to a specified standard, such as IP65. Such waterproofing may be achieved in any suitable manner, e.g. using hydrophobic materials to construct the enclosure and/or hydrophobic surface coatings.

Returning to FIG. 12, the attachment element 102 may, for example, comprise an adjustment mechanism 104 for adjusting the attachment element 102 to fit the head of the wearer 103.

In alternative examples, an auto size adjust head band, adjustable straps, etc. may be included in the attachment element 102 in order to assist fitting to the head of the wearer 103.

As schematically depicted in FIG. 12, an inlet 106 may be provided in the headgear through which air may enter the headgear 100, and the air treatment assembly 10 provided in the headgear 100. The inlet 106 may, for example, be in the form of an opening or grille defined in the top of the headgear 100.

Alternatively or additionally, a further inlet (not visible in FIG. 12) may be provided in the side of the headgear 100 and/or in a different portion of the top of the headgear 100 from the portion of the top of the headgear 100 in which the inlet 106 is provided.

The air treatment assembly 10 may be assembled into a cavity 108 provided in the headgear 100, as shown in FIG. 12. The filter arrangement may, for instance, be in the form of the above-described detachable filter cartridge 70, and may be detached from the remainder of the air treatment assembly 10 and removed from the cavity 108 in order to be exchanged for a fresh filter cartridge 70.

In the non-limiting example depicted in FIG. 12, the air treatment assembly 10 comprises three pathogen inactivation layers 14, 24, 34, and two filtration layers 12, 22. The first filtration layer 12 is interposed between the first and second pathogen inactivation layers 14, 24, and the second filtration layer 22 is interposed between the second and third pathogen inactivation layers 24, 34. In this particular example, each of the three pathogen inactivation layers 14, 24, 34 are coupled to the temperature control arrangement 16. The temperature control arrangement 16 is accordingly configured to control the temperature of the pathogen inactivation layers 14, 24, 34, e.g. independently of each other, as previously described.

It is noted that the temperature control arrangement 16 may, in the case of the headgear 100, also assist to control the temperature of the treated air approaching the head and/or face of the wearer 103. Gentle heating and cooling of treated air approaching the head of the wearer 103 may, in some circumstances, provide a form of thermal follicle therapy.

Air is drawn through the filter arrangement by the fan arrangement 30 which is, in the example shown in FIG. 12, a centrifugal fan arrangement 30.

The outlet of the fan arrangement 30 may be provided with a suitable blocking member (not visible) for preventing the wearer's hair from becoming entangled in the fan arrangement 30. The blocking member may, for instance, comprise a grille or mesh. A blocking member in the form, for example, of a copper mesh, e.g. a copper gauze, may have the additional purpose of contributing to the pathogen inactivation performance of the wearable article 100.

The wearable article 100, and in this case the headgear 100, may comprise a funnel element 110 which guides the treated air towards the fan arrangement 30.

In a non-limiting example, the funnel element 110 comprises copper and/or silver species at least on a surface thereof which contacts the treated air. The funnel element 110 may, for instance, be formed from copper metal. In this manner, the funnel element 110 may assist to inactivate any pathogens in the treated air emerging from the filter arrangement upstream of the fan arrangement 30.

In an embodiment, the optical sanitizing arrangement 18 may comprise, as an alternative or in addition to the at least one ultraviolet light source, a further at least one ultraviolet light source (not visible in FIG. 12) for irradiating the funnel element 110 and/or the fan outlet downstream of the fan arrangement 30. The further at least one ultraviolet light source may assist to inactivate pathogens downstream of the filter arrangement. The latter may be as an alternative or in addition to providing copper and/or silver species at least on the surface of the funnel element 110 which contacts the treated air.

More generally, the fan arrangement 30 may be, for example, configured to cause air to flow in both forwards and reverse directions, e.g. in an oscillating or cyclic manner.

Returning to FIG. 12, the wearable article 100, and in this case the headgear 100, comprises a flow channel 112 which guides air emerging from the fan arrangement 30 towards a space provided between a transparent visor 113 included in the headgear 100, and the face of the wearer 103. This movement of the treated air is represented in FIG. 12 by the arrows 25 114.

The wearer 103 may inhale the treated air, and exhale. Exhalation is represented in FIG. 12 by the arrow 116. The exhaled air may be carried by the flow of treated air in the direction represented by the arrow 120 towards a pathogen inactivation member 118 extending from the transparent visor 113 towards the wearer 103, e.g. towards the neck of the wearer 103, as shown. The flow of treated air may assist to reduce carbon dioxide build-up in the space between the wearer 103 and the transparent visor 113. This, in turn, may assist to alleviate the risk of carbon dioxide-induced hyperventilation.

The pathogen inactivation member 118 may comprise copper and/or silver species at least on a surface thereof for contacting the air flowing thereto and/or therethrough. For example, the pathogen inactivation member 118 may comprise, or be in the form of, a copper mesh, e.g. gauze.

More generally, the fan arrangement 30 may be arranged to direct air treated by the air treatment assembly 10 towards or adjacent to the wearer's nose and/or mouth.

In an embodiment, the fan arrangement 30 is further configured to pressurize the treated air downstream of the air treatment assembly 10, and arranged to direct the pressurized treated air in the form of a focused air curtain in front of the wearer's 103 face.

Such an air curtain may assist to block lateral or horizontal flow of exhaled breath from the wearer 103, and may also assist to minimize ingress of external, e.g. contaminated, air into the vicinity of the treated air being inhaled by the wearer 103.

In this respect, FIG. 13 depicts a wearable article 100 in the form of headgear 100 which is similar to that shown in FIG. 12, but has a dual centrifugal fan arrangement 30A, 30B in which a first centrifugal fan 30A directs a pressurized flow of treated air along a first flow channel 112A. A flow directing member 122 diverts the treated airflow in front of the wearer's 103 face in order to form the air curtain. This air curtain is for screening off the wearer 103 from the ambient environment, and is represented in FIG. 13 by the arrows 114A.

In a non-limiting example, the air curtain 114A may replace the transparent visor As shown in FIG. 13, a second centrifugal fan 30B generates a lower pressure flow of treated air which is guided along a second flow channel 112B, and is deflected by an air deflection member 124 towards the wearer's 103 nose and/or mouth. Thus, a lower flow 114B of treated air is provided adjacent the wearer's 103 face/head which can be comfortably inhaled by the wearer 103. This lower flow may also assist to purge carbon dioxide from the space between the wearer 103 and the transparent visor 113, as previously described. The humidification layer 28 is provided beneath the second centrifugal fan 30B in the example depicted in FIG. 13. Thus, the lower flow 114B provided for the wearer 103 to breathe is of humidified and treated air.

More generally, the fan arrangement 30 may enable the treated air to be provided to the wearer 103 at a higher pressure than atmospheric pressure. In other words, the wearer 103 may be exposed to a positive pressure of the treated air. This positive pressure may assist to lower the risk of ingress of untreated air towards the wearer 103, and thus lower the risk of exposure to pathogens.

Whilst the filter arrangement is head-mounted in the headgear 100 shown in FIGs. 12 and 13, this should not be regarded as being limiting. In other examples, the filter arrangement may be worn on/attached to a different part of the body of the wearer 103, in other words a body part other than the head. In further examples, the filter arrangement may not be part of the wearable article 100, e.g. headgear 100. The fan arrangement 30 may nonetheless be configured to draw treated air from the filter arrangement towards the face, and particularly the nose and/or mouth, of the wearer 103, as previously described.

FIG. 14 provides a cross-sectional schematic depiction of application of the wearable article 100 in an aircraft cabin 300. It is noted that the seats in the aircraft cabin 300 may be movable.

In this example, conditioned air is supplied to the passengers from an overhead duct 302 via air outlets 304. The conditioned air is directed towards vents 306 in the floor of the cabin, as represented by arrows 308. Some of the air received from the cabin 300 is purged to the atmosphere, as represented by arrow 309. The remaining air received from the cabin 300 is mixed in a mixing chamber 310 with air from an air conditioning unit 312. The air conditioning unit 312 receives outside air via the aircraft's engines, as represented in FIG. 14 by the arrow 314. The mixed air is then directed by fans 316 back towards the overhead duct 302 and the air outlets 304 in the direction represented by the arrows 318.

The inlet 106 may be located on the top of the headgear 100, as previously described. This positioning may assist in terms of filtering the air from the outlets 304 prior to this air reaching the wearer 103. Thus, the wearer 103 may be afforded greater protection from any pathogens circulating in the aircraft cabin 300.

It is noted that combustion gases may be drawn into the cabin 300, since outside air is received via the aircraft's engines (see arrow 314). The air treatment assembly 10 may accordingly include the activated carbon layer 26 in order to assist removal of such contaminants.

In a non-limiting example, the headgear 100 may be integrated with the aircraft cabin 300. For instance, the headgear 100 may mounted to the cabin interior and lowered onto the seated passengers' heads. The transparent visors 113, in cases where such a visor 113 is included in the headgear 100, may then be moved, e.g. pivoted via a hinge, in order to cover each of the passengers' faces.

Whilst the treated airflow is depicted in FIGs. 12 to 14 at the front of the wearer's 103 face, this is not intended to be limiting. Alternatively or additionally, the treated airflow may be provided at the sides of the wearer's 103 head.

FIG. 15 schematically depicts wearers wearing the wearable articles 100A, 100B. FIG. 15 depicts a first wearer wearing a first wearable article 100A, and a second wearer wearing a second wearable article 100B. In this particular example, the first wearable article 100A has the same design as the second wearable article 100B.

The enhanced pathogen inactivation provided by the air treatment assemblies 10 included in the wearable articles 100A, 100B may enable the safe distance 400 between the wearers to be reduced, e.g. to a 200 mm minimum.

In the non-limiting example depicted in FIG. 15, each of the wearable articles 100A, 100B comprises radio communication equipment comprising antennae 402A, 402B, microphones 404A, 404B, and loudspeakers 406A, 406B, e.g. ear pods. The wearers may communicate with each other using the radio communication equipment.

Any suitable radio communication equipment may be employed for providing wireless communication and/or wireless connectivity. The wearable articles 100A, 100B may, for instance, be WiFi enabled, e.g. with 4+ 128 bit encryption for secure communications.

Alternatively or additionally, the communications may employ an open radio channel for the wearers to communicate with each other.

Microphone(s) 404A, 404B may be placed at the front and/or towards the side of the respective transparent visor 113.

A noise cancellation system may, for instance, be provided such that the loudspeakers 406A, 406B, e.g. ear pods, abate and/or cancel background noise, e.g. the noise generated by the motor of the fan arrangement 30 and/or the airflow within the wearable articles 100A, 100B.

Alternatively or additionally, noise attenuation may be effected via swept spectrum/Helmholtz resonation within the layers of the filter arrangement.

In addition to assisting communication with others, the loudspeakers 406A, 406B may provide alerts, music and/or film audio, etc. As shown in FIG. 15, the wearable article 100A, 100B may also include a headup display 408A, 408B provided on the transparent visor 113. The headup display 408A, 408B may, for example, provide satellite navigation guidance, a user interface to view/control mobile phone applications, a screen to view films, television, and/or a computer monitor, etc. When, for instance, the wearable article 100A, 100B is for aircraft cabin 300 use, it may be particularly advantageous to include such headup display capability.

At least some of the functions of the wearable article 100A, 100B may be controlled via software, such as via a mobile phone application. In a non-limiting example, the wearable article 100A, 100B may be configured to operate only when being worn by a single individual, at least partly to avoid contamination. For example, the wearable article 100A, 100B may only be operable by the user being authorized via their mobile phone. A OR code on the wearable article 100A, 100B may enable the wearable article 100A, 100B to be synced to the wearer's mobile phone, e.g. making use of a suitable wireless protocol, such as Bluetooth®.

In some non-limiting examples, the wearable article 100A, 100B may include a diagnostics and/or monitoring system.

The diagnostics and/or monitoring system may, for instance, comprise a forehead temperature and/or sweat monitor for determining whether the wearer is feverish. The forehead sweat monitor may, for instance, detect sweat via impedance monitoring.

In some examples, the diagnostics and/or monitoring system comprises an oximeter for attachment to, for instance, the ear or finger, and/or a heart rate monitor.

In further examples, the diagnostics and/or monitoring system comprises a carbon dioxide detector and/or a breathing rate monitor.

Alternatively or additionally, the diagnostics and/or monitoring system may be configured for airflow monitoring, such as monitoring the outflow air and exhaled gases, monitoring the quality/composition of untreated air entering the air treatment assembly 10, and/or monitoring air leakage around the edges or peripheries of the wearable article 100A, 100B.

The diagnostics and/or monitoring system may, in examples in which the air filter arrangement is detachable from the remainder of the air treatment assembly 10, comprise a change filter alert monitor configured to alert the wearer when the filter arrangement/filter cartridge 70 should be replaced. This alert may, for instance, be based on operating lifetime and/or sensory information, e.g. a differential pressure change across the filter arrangement. Particulates in the untreated and/or treated air may, for example, be monitored via a suitable detector, e.g. a light scattering detector, included in the diagnostics and/or monitoring system. The level of particulates in the treated air may, for example, be used as an input in the above-described change filter alert monitor.

Outflow monitoring may, for instance, be implemented via a thermal dissipation flowmeter/thermistor, although more elaborate sensing techniques will be also be apparent to the skilled person.

The air leakage detection may, for example, employ capacitive sensing between the wearer's face and the edge of the wearable article 100A, 100B.

In another non-limiting example, the diagnostics and/or monitoring system is configured to sense a condition of the fan bearing included in the fan arrangement 30. The diagnostics and/or monitoring system may, for example, comprise a dedicated sensor, e.g. microphone, for this purpose, or the microphone 404A, 404B may be adapted for this purpose.

In still another non-limiting example, the diagnostics and/or monitoring system is configured to detect the proximity 400 between wearers of the wearable articles 100A, 100B. On the basis of the detected proximity, the wearers may be issued with a warning to increase their distance 400, and/or the proximity and duration at that proximity, may be recorded. Such data may, for instance, be transmitted to a test and trace system via the abovemenfioned wireless communication/connectivity equipment.

In a related example, the diagnostics and/or monitoring system may be configured for GPS/SWARM monitoring, such that the wearable article 100A, 100B may assist to stem the spread of infections, in particular respiratory infections.

More generally, data from the diagnostics and/or monitoring system may be displayed to the wearer via the above-described headup display 408A, 408B. In this way, the wearer may be informed of the status of the wearable article 100A, 100B and/or provided with health and wellbeing feedback.

The wearable article 100A, 100B may be powered in any suitable manner, e.g. using non-combustible and fire-proof batteries, solar panels, a bodily heat power converter and/or a bodily movement power converter.

Power to the wearable article 100A, 100B may, for instance, be automatically switched on and off, e.g. in response to the wearer putting on and taking off the wearable article 100A, 100B respectively. The above-described sleep/standby modes may also assist to conserve power, and thereby prolong battery life.

Whilst FIGs. 12 to 15 depict application of the air treatment assembly 10 in a wearable article 100, this is not intended to be limiting. In an embodiment, the air treatment assembly 10 is included in an air treatment unit for providing treated air to the interior of a building or vehicle. In such an embodiment, the air treatment unit may further comprise an outlet assembly for directing the air treated by the air treatment assembly towards the interior.

In a non-limiting example, the air treatment unit comprises an air conditioning unit.

Such an air conditioning unit may be domestic or industrial. Referring again to Fig. 14, the air treatment assembly 10 may, for example, be provided in the air conditioning unit 312 which supplies conditioned air to the aircraft cabin 300.

In further examples, the air treatment assembly 10 may be included in Medical Class I or Class I IA devices.

It is noted that a plurality of air treatment assemblies 10, e.g. two, three, four, five, six, seven, eight, or more, may, in certain examples, be included in the air treatment unit. In such examples, supply of air to the air treatment assemblies 10 may be sequenced, e.g. under the control of a processor, in order to optimize the operating lifetime of the air treatment assemblies 10, and permit air treatment assembly replacement while other air treatment assemblies 10 are operational or operating.

FIG. 16 provides a flowchart of an air treatment method 500 according to an example. The method 500 comprises passing 502 air into a filter arrangement. The filter arrangement comprises a filtration layer configured to filter pathogens in air passing therethrough; and a pathogen inactivation layer adjacent the filtration layer. The pathogen inactivation layer comprises copper and/or silver species for contacting the pathogens. The filter arrangement may, for instance, be any of the exemplary filter arrangements described above.

The method 500 further comprises controlling 504 the temperature, e.g. cooling or heating, the pathogen inactivation layer. The controlling 504 may, for instance, be implemented via the above-described temperature control arrangement 16.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS: An air treatment assembly comprising: a filter arrangement including: a filtration layer configured to filter pathogens in air passing therethrough, and a pathogen inactivation layer adjacent the filtration layer, the pathogen inactivation layer comprising copper and/or silver species for contacting said pathogens; and a temperature control arrangement coupled to the pathogen inactivation layer and configured to control the temperature of the pathogen inactivation layer.
2. The air treatment assembly according to claim 1, wherein the temperature control arrangement is configured to provide cooling to the pathogen inactivation layer.
3. The air treatment assembly according to claim 2, wherein the temperature control arrangement is configured to cool the pathogen inactivation layer to a temperature in the range of 0°C to 10°C during said cooling.
4. The air treatment assembly according to any of claims 1 to 3, wherein the temperature control arrangement is configured to operate in a heating mode to heat the pathogen inactivation layer.
5. The air treatment assembly according to claim 4, wherein the temperature control arrangement is configured to heat the pathogen inactivation layer to a temperature in the range of 50°C to 90°C during said heating mode.
6. The air treatment assembly according to any of claims 1 to 5, wherein the temperature control arrangement comprises a Peltier element.
7. The air treatment assembly according to any of claims 1 to 6, wherein the filtration layer comprises a nonwoven filter material.
8. The air treatment assembly according to any of claims 1 to 7, wherein the filter arrangement comprises a further filtration layer for filtering said pathogens, the pathogen inactivation layer being interposed between the filtration layer and the further filtration layer.
9. The air treatment assembly according to claim 8, wherein the further filtration layer comprises a nonwoven filter material.
10. The air treatment assembly according to any of claims 1 to 9, wherein the pathogen inactivation layer comprises apertures for permitting air to pass therethrough.
11. The air treatment assembly according to claim 10, wherein said apertures have a diameter in the range 0.05 mm to 2 mm.
12. The air treatment assembly according to any of claims 1 to 11, wherein the pathogen inactivation layer comprises a metallic mesh or perforate metallic sheet, said copper and/or silver species being provided at least on a surface of the mesh or sheet for contacting said pathogens.
13. The air treatment assembly according to claim 12, wherein the metallic mesh is a copper mesh, or wherein the perforate metallic sheet is a perforate copper sheet.
14. The air treatment assembly according to any of claims 1 to 13, wherein the filter arrangement further comprises an activated carbon layer.
15. The air treatment assembly according to any of claims 1 to 14, further comprising a humidification layer for humidifying the air treated by the filter arrangement.
16. The air treatment assembly according to any of claims 1 to 15, wherein the filter arrangement is included in a filter cartridge which is detachable from the temperature control 30 arrangement.
17. The air treatment assembly according to any of claims 1 to 16, comprising: an optical sanitizing arrangement comprising at least one ultraviolet light source; and an optically transmissive region located between a surface of the filtration layer and an opposing surface of the pathogen inactivation layer, wherein the at least one ultraviolet light source is directed towards the optically transmissive region, and arranged to irradiate at least one of said surface and said opposing surface.
18. The air treatment assembly according to claim 17 as according to claim 8 or claim 9, comprising a further optically transmissive region between a further surface of the further filtration layer and an opposing further surface of the pathogen inactivation layer, wherein the at least one ultraviolet light source is directed towards said further optically transmissive region, and arranged to irradiate at least one of said further surface and said opposing further surface.
19. The air treatment assembly according to any of claims 1 to 18, further comprising a fan arrangement for passing air through the filter arrangement.
20. A wearable article comprising: the air treatment assembly according to any of claims 1 to 19; and at least one attachment element for attaching the air treatment assembly to a wearer of the article.
21. The wearable article according to claim 20, wherein the wearable article comprises the air treatment assembly according to claim 19, and wherein the fan arrangement is arranged to direct air treated by the air treatment assembly towards and/or adjacent to the wearer's nose and/or mouth.
22. The wearable article according to claim 20 or claim 21, wherein said air treatment assembly is included in a facial covering configured to cover at least the wearer's mouth and/or nose.
23. The wearable article according to claim 21, wherein the fan arrangement is further configured to pressurize the air downstream of the air treatment assembly and arranged to direct the air in the form of an air curtain in front of and extending at least partially around the wearer's face.
24. An air treatment unit for providing treated air to the interior of a building or vehicle, the air treatment unit comprising: the air treatment assembly according to any of claims 1 to 19; and an outlet assembly for directing the air treated by the air treatment assembly towards said interior; optionally wherein the air treatment unit comprises an air conditioning unit.
25. An air treatment method comprising: passing air into a filter arrangement, the filter arrangement comprising a filtration layer configured to filter pathogens in air passing therethrough; and a pathogen inactivation layer adjacent the filtration layer, wherein the pathogen inactivation layer comprises copper and/or silver species for contacting the pathogens; and controlling the temperature of the pathogen inactivation layer.