FIELD

The present teachings relate to an air sterilisation device, a ceiling assembly, and a method of installing an air sterilisation device.

BACKGROUND

Air filtration and sterilisation devices or systems are known for their use in removing harmful contaminants and particulates, for example bacteria, viruses, mould etc., from air within an enclosed space, such as within a room of a building. People are exposed to a growing number of health-threatening contaminants, and so the use of these systems is becoming increasingly important. Ultraviolet (UV) light has been long used for disinfection and sterilisation of air, and known sterilisation devices use such UV light to remove contaminants from air within an enclosed space.

In order to increase the volume of the air within an enclosed space that is sterilised, known sterilisation devices are provided with a fan to draw air into the device. These known sterilisation devices generate an increased airflow over the room, which can disperse the contaminants in the air over an increased area, thus exposing an increased number of people to the contaminants in the air.

The present teachings seek to overcome or at least mitigate one or more problems associated with the prior art.

SUMMARY

A first aspect of the teachings provides an air sterilisation device for sterilising contaminants in air within an enclosed space, the air sterilisation device comprising: a housing defining an inlet intended to be lowermost in use, an outlet intended to be uppermost in use so as to define an air flow path therethrough from the inlet to the outlet; first and second radiation shields spaced apart so as to define a chamber therebetween within the housing, wherein the first and second radiation shields are configured to enable air to flow therethrough; an ultraviolet (UV) radiation source within the chamber, the UV radiation source configured and arranged to irradiate air flowing through the chamber, in use; and a fan assembly configured to generate a region of negative pressure below the air sterilisation device, in use, so as to only draw air from within the region of negative pressure into the housing via the inlet, wherein the region of negative pressure defines a cross-sectional area of negative pressure at a pre-determined distance from the inlet of the air sterilisation device; and wherein the air sterilisation device comprises a control system configured to adjust the cross-sectional area of negative pressure at a pre-determined distance from the inlet of the air sterilisation device.

This arrangement advantageously enables the size/area/region of negative pressure below an air sterilisation device to be adjusted to the size required for the specific application. This, in turn, helps to ensure that air that is drawn into the air sterilisation device is only taken from a pre-determined area, which helps to reduce/prevent potentially contaminated air from flowing across large areas of an enclosed space. The pre-determined area creates a localised space associated with each air sterilisation device from which air is drawn. Should the air contain contaminants, this helps to minimise the number of people exposed to said contaminant. Moreover, this arrangement helps to shield people within the region of negative pressure from contaminants outside of the region of negative pressure, and to shield people outside of the region of negative pressure from contaminants within the region of negative pressure.

The fan assembly may comprise an impeller and a motor configured to drive the impeller, and wherein the control system is configured to adjust the speed of the impeller.

Adjusting the speed of the impellor works to change the speed at which the air is drawn into the inlet, which advantageously adjusts the cross-sectional area of negative pressure at a predetermined distance away from the air sterilisation device.

The fan assembly may be configured such that air flow through the chamber is in the range 15m3/h to 60m3/h.

Air flow through the chamber at this rate has been found to produce an optimum sized region of negative pressure for sterilising air.

The UV radiation source may be configured to emit UV-C radiation

The UV radiation source may comprise one or more UV bulbs, e.g. one or more mercury bulbs and/or one or more UV emitting LEDs. The UV radiation source may be located within a receptacle defining an air flow path therethrough.

The receptacle is a simple way to store the UV radiation source whilst creating a volume in which the air can be sterilised.

The receptacle may comprise at least one interior surface comprising a reflective material configured to reflect UV radiation emitted by the UV radiation source.

The reflective surface of the receptacle advantageously prevents dangerous UV rays from being emitted into the enclosed space, which could be potentially harmful to people within the enclosed space.

An entirety of the interior surface of the receptacle may comprise the reflective material.

This arrangement prevents dangerous UV rays from being emitted from all sides of the receptacle.

The reflective material may comprise a plastics material, such as polytetrafluoroethylene (PTFE) or polyvinyl chloride (PVC), or a metallic material, such as stainless steel or aluminium.

PTFE, PVC, stainless steel and aluminium have all been found to be successful at reflecting UV rays, whilst being relatively low cost and readily available.

The reflective material may comprise polytetrafluoroethylene (PTFE).

PTFE has been found to be a particularly good reflector the UV rays.

The air sterilisation device may comprise a sensor configured to detect the UV radiation emitted by the UV radiation source.

The control system may be configured to activate an indicator to indicate whether the UV radiation source is active or inactive.

This arrangement enables a user to determine how the UV emitter is functioning within the enclosed chamber, which is not safe to determine visually. Thus, an operator is able to visually determine whether or not the UV radiation source is functioning within pre-determined parameters. The control system may be configured to calculate the UV dosage given to the air in the chamber based on a speed of air flow through the housing, and the control system may be configured to adjust the speed of the impeller to adjust the speed of air flow through the chamber such that the UV radiation dosage given to the air in the enclose chamber is equal to or greater than the required UV radiation dosage.

The air sterilisation device may comprise an air flow meter configured to determine the speed of air flow through the housing.

This arrangement is to help to ensure that the air flowing through air sterilisation device is sterilised prior to exiting the system.

The control system may be configured to calculate the UV radiation dosage required to sterilise air within the chamber, and to compare this with the UV radiation dosage received by air in the chamber based on the detected UV radiation emitted by the UV radiation source, and to provide an output based on the comparison.

This enables an operator to be altered if an insufficient UV dosage is being applied to the air flowing through the air sterilisation device.

The cross-sectional area of negative pressure may have a diameter is in the range 0.5m to 10m, for example in the range 2m to 5m.

This range of diameters has been found optimal to sterilise the majority of the air in the room, whilst minimising the number of air sterilisation units required.

The air sterilisation device may comprise a reservoir for receiving a cleaning agent and a nozzle connected to the reservoir, wherein the nozzle is configured to dispense the cleaning agent over the cross-sectional area of negative pressure.

The air sterilisation device may comprise a control system, wherein the control system is configured to control the nozzle to dispense cleaning agent periodically, and/or wherein the nozzle dispenses the cleaning agent upon receiving an input from a user.

This arrangement advantageously enables objects within the cross-sectional area of negative pressure to be sterilised, for example a surface of a desk in a room or a steering wheel of a car.

The cleaning agent may be hypochlorous acid or an anti-microbial fluid. Hypochlorous acid is strong enough to kill microbes, whilst being gentle on human skin. This means it a suitable cleaning agent for dispensing in enclosed spaces occupied by humans.

The air sterilisation device may comprise a light assembly comprising an antimicrobial light source.

The anti-microbial light source may be a violet-blue LED light.

The light assembly provides an additional sterilisation step, and is successful at killing microbes found in the air.

The anti-microbial light source may be configured to emit light with a wavelength in the range 380nm to 450nm, for example approximately 405nm.

This wavelength range has been found to kill microbes found in the air, whilst being safe for humans. This means the light assembly is suitable for mounting to the air sterilisation device without additional safety components such as radiation shields.

The light assembly may comprise a white light source, for example an LED, arranged proximate or adjacent to the anti-microbial light source.

The white light source absorbs the wavelengths of the violet-blue LED light. This means the air is still sterilised, without the violet-blue colour being visible to the human eye.

The light emitting assembly may be provided on a shade mounted to the air sterilisation device, or the light emitting assembly may be directly mounted to the air sterilisation device.

A shade may be used to disperse the light so as to maximise the area of air sterilised. Directly mounting the light emitting assembly to the air sterilisation device is a simple and space efficient arrangement, without requiring a complex mounting arrangement.

The air sterilisation device may comprise at least one sensor configured to detect the positions of the first and second radiation shields.

The control system may be configured to cut power to the UV radiation source in response to a signal being received from the at least one sensor that at least one of the radiation shields is in an incorrect position, The at least one sensor may comprise a proximity sensor.

This arrangement advantageously ensures that dangerous UV rays are not emitted into the enclosed space, which could be potentially harmful to people within the enclosed space.

The air sterilisation device may comprise a filter assembly comprising at least one filter element configured to filter air flowing through the housing for removing contaminants and particulates therefrom.

The at least one filter element may comprise a high efficiency particulate filter.

The at least one filter element may comprise a fibrous material, for example cotton material.

The filter assembly may comprise an ozone filter configured to filter ozone generated by the UV radiation source.

The at least one filter element may comprise an activated carbon cotton material configured to filter contaminants and particulates from the air and to filter ozone generated by the UV radiation source.

The air sterilisation device may comprise a sensor for monitoring the at least one filter element and to provide an output when the at least one filter elements needs replacing.

The air sterilisation device may comprise a transmitter configured to transmit a signal indicative of whether or not the at least one filter element needs replacing to a processor at a remote location.

This arrangement advantageously allows for the state of the filter elements to be monitored without visual inspection, e.g. it enables the filter elements to be monitored remotely.

The air sterilisation device may comprise an inlet duct connected to the housing and positioned at or near an upstream inlet of the housing, wherein the inlet duct tapers in a direction towards the inlet.

The inlet duct directs air into the inlet, therefore increasing the amount of air that can be sterilised by the air sterilisation device. The air sterilisation device comprises a suspension arrangement for suspending the device from above.

The suspension arrangement may comprise a mounting arrangement for connecting the air sterilisation device to a support structure of a ceiling assembly.

The fan assembly maybe configured to draw air into the housing via the inlet, through the enclosed chamber and out of the outlet.

The housing may be substantially tubular, e.g. substantially cylindrical.

The tubular housing may have a diameter in the range 80-120mm, in the range 90-110mm, e.g. approximately 100mm.

The housing may define an inlet opening configured and arranged to draw air into the housing at a pre-determined angle. The control system may be configured to adjust the inlet opening to adjust angle at which the air is drawn into the housing.

Adjusting the angle at which the air enters the inlet advantageously enables the cross-sectional area of negative pressure at a predetermined distance away from the air sterilisation device to be adjusted as required for the specific application.

The air sterilisation device may comprise an end cover partially covering the housing inlet and spaced apart therefrom so as to define an inlet opening therebetween, said inlet opening configured to draw air into the housing at a predetermined angle.

Advantageously, this arrangement enables a different inlet opening to be provided on different air sterilisation assemblies by providing a differently configured cowl.

The end cover may be moveable relative to the housing so as to adjust the angle at which the air is drawn into the housing.

Adjusting the angle at which the air enters the inlet advantageously enables the cross-sectional area of negative pressure at a predetermined distance away from the air sterilisation device to be adjusted as required for the specific application.

The inlet opening may be substantially annular.

The annular inlet opening may define an annular opening in the range 5-15mm, for example approximately 10mm. The housing may define an inlet opening configured to draw air into the housing at a pre-determined angle, and wherein the inlet opening defines a substantially curved inlet duct.

The inlet opening duct may be arranged to be curved in a direction towards the floor of an enclosed space, e.g. curved downwards, in use.

This arrangement has been found to increase the effectiveness of the air sterilisation device to generate a region of negative pressure below the air sterilisation device over a pre-determined area at a distance below the system.

The chamber may define an air flow path therethrough, and wherein one or more interior surfaces of the chamber air flow path is configured to reflect UV radiation emitted by the UV radiation source.

This arrangement helps to further increase the UV dosage received by air flowing through the chamber, without having to increase the output of the UV radiation source.

The chamber may define one or more air flow paths or ducts therethrough having a length greater than the spacing between the first and second radiation shields, and wherein the UV radiation source is configured and arranged irradiate the air as it flows through the one or more air flow paths or ducts.

An interior surface of each of the one or more air flow paths or ducts may be configured to reflect UV radiation emitted by the UV radiation source.

The air sterilisation device may comprise an indicator configured to indicate whether or not the air sterilisation device is functioning within pre-determined parameters.

The indicator may be an audio and/or visual indicator, for example a visual indicator ring.

This arrangement effectively alerts an operator to the occupancy state of the containers.

The air sterilisation device may comprise temperature and/or humidity sensors for monitoring the quality of air flowing through the housing.

The air sterilisation device may comprise a display for displaying the quality of air drawn into the inlet and driven out of the outlet. The air sterilisation device may comprise a transmitter configured to transmit a signal indicative of air quality into and out of the air sterilisation device to a processor at a remote location and/or to transmit a signal indicative of whether or not the air sterilisation device has sterilised air flowing therethrough to a processor at a remote location.

This arrangement advantageously allows for the air sterilisation device, or a series/array of air sterilisation devices, to be monitored remotely.

The air sterilisation device may comprise a receiver, wherein the control system is configured to adjust the size of the area of negative pressure at a pre-determined distance below the air sterilisation device upon receipt of a signal received by the receiver.

A further aspect of the teachings provides a ceiling assembly comprising : a support structure; and a sterilisation device according to the first aspect suspended from the support structure, wherein the support structure is a ceiling or a support frame of a suspended ceiling.

A further aspect of the teachings provides a method of installing at least one air sterilisation device according to the first aspect in an enclosed space, the method comprising the steps of: identifying one or more areas within the enclosed space to be sterilised; positioning an air sterilisation device a pre-determined distance above each of the one or more identified areas within the enclosed space; configuring each air sterilisation device such that the cross-sectional area of negative pressure generated by the air sterilisation device at the pre-determined distance corresponds to the cross-sectional area of the identified area within the enclosed space; and mounting the or each air sterilisation device to a support structure within the enclosed space.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described with reference to the accompanying drawings, in which:

Figure 1 is an isometric view of an air sterilisation device according to an embodiment;

Figure 2 is a cross-sectional side view of the air sterilisation device of Figure 1; Figure 3 is a bottom view of the air sterilisation device of Figure 1;

Figure 4 is an isometric view of an air sterilisation device according to an alternative embodiment;

Figure 5 is an isometric view of an air inlet of the air sterilisation device of Figure 4;

Figure 6 is an isometric view of a receptacle of the air sterilisation device of Figure 4;

Figure 7 is a cross-sectional side view of the air sterilisation device of Figure 4; and

Figure 8 is a top view of an enclosure split into discrete positions.

DETAILED DESCRIPTION OF EMBODIMENT(S)

Referring to Figure 1, an air sterilisation system or device configured to sterilise contaminants in air within an enclosed space such as a room of a building, a vehicle, or any other enclosed space is illustrated and indicated generally at 10.

The air sterilisation device 10 includes a housing 12. The housing 12 defines an inlet 14 intended to be lowermost in use. The housing 12 includes an outlet 16 intended to be uppermost in use. The housing 12 is substantially tubular, e.g. substantially cylindrical, in the illustrated arrangement. The tubular housing 12 may have a diameter in the range 80-120mm, in the range 90-110mm, e.g. approximately 100mm. It will be appreciated that in alternative arrangements, the housing 12 may be any suitable shape, configuration or size to suit the needs to the application.

The air sterilisation device 10 includes a cowl 18. The cowl 18 is positioned around the housing 12, e.g. substantially around the inlet 14 of the housing 12. The cowl 18 is configured to conform to the shape of the inlet 14 of the housing 12. In the illustrated arrangement, the cowl is substantially circular.

The cowl 18 is provided with a cowl plate 20 extending therearound. The cowl plate 20 is provided in the form of a substantially square or rectangular plate 20, but any suitable shaped cowl plate 20 may be provided. The cowl plate 20 includes one or more, four in the present embodiment, cowl mounts 22. The cowl mounts 22 are provided for mounting ancillary components, such as lights (not shown) to the air sterilisation device 10. In alternative arrangements, it will be appreciated that the cowl plate 20, and so the cowl mounts 22, may be omitted.

The air sterilisation device 10 includes a suspension arrangement for suspending the device 10 from above. The suspension arrangement includes a mounting arrangement 24 for connecting the air sterilisation device 10 to a support structure of a ceiling assembly (not shown) above the air sterilisation device 10. In this way, the air sterilisation device 10 is configured to be suspended from a structure, such as a ceiling, thereabove. The air sterilisation device 10 may be mounted vertically, horizontally or integrated into a void in a ceiling.

The suspension arrangement includes a suspension member 26, e.g. such as a wire, a cable or any other suitable means for suspending the air sterilisation device 10. A first end 28 of the suspension member 26 is connected to the housing 12 via the mounting arrangement 24. A second end 30 of the suspension member 26 is configured to be attached to a support structure of a ceiling assembly (not shown). It will be appreciated that any suitable number of suspension members 26 may be provided.

Referring now to Figures 2 and 3, the air sterilisation device 10 includes a UV radiation source 32. The UV radiation source 32 is mounted within the housing 12 via a UV source mount 34. In the illustrated arrangement, the UV radiation source 32 is provided in the form of a UV bulb, e.g. a mercury bulb. In alternative arrangements, the UV radiation source may be provided in the form of one or more UV emitting light emitting diodes (LEDs), or a combination of UV emitting LEDs and UV bulbs, or via any other suitable UV generating means.

The UV radiation source 32 is configured to emit UV-C radiation. UV-C is a high frequency wavelength of light within the ultraviolet band and has been shown to be particularly effective at sterilising contaminants (e.g. viruses and/or bacteria). UV- C radiation may have wavelengths below 280nm, for example in the range lOOnm to 280 nm or 200nm to 280 nm.

The air sterilisation device 10 includes first and second radiation shields spaced apart so as to define a chamber 36 therebetween. The radiation shields are configured to conform to the internal shape of the housing 12 such that there is substantially no space therebetween. The radiation shields are configured to prevent UV radiation from passing therethrough and to enable air to flow therethrough. The UV radiation source 32 is positioned within the chamber 36 and is configured and arranged to irradiate air flowing through the housing 12. The radiation shields are configured such that the UV radiation emitted by the UV radiation source is unable to penetrate the shield such that the radiation emitted by the UV radiation source 32 is contained within the chamber 36. This helps to prevent dangerous UV radiation from being emitted out of the housing 12 and into a surrounding room. The interior walls of the chamber 36, in the illustrated embodiment defined by the interior surface of the housing 12, are coated with a reflective material. The reflective material is selected so as to be particularly reflective to UV-C light, such as a metallic material.

In the illustrated arrangement, the chamber 36 defines a direct flow path from the first to the second radiation shield, i.e. from the inlet of the chamber 36 to the outlet of the chamber 36. In alternative arrangements, however, the air flow path through the chamber 36 may be greater than the distance between the first and second radiation shields. The chamber 36 may define one or more convoluted air flow paths or ducts extending between the inlet and outlet of the chamber 36 so as to increase the length of the flow path along which air has to travel. Put another way, in some alternative arrangements the chamber 36 is configured and arranged to define a tortuous air flow path therethrough. In such arrangements, the UV radiation source is configured and arranged to irradiate the air as it flows through the convoluted air flow path or duct. Thus, this increased air flow path through the chamber 36 works to increase the UV radiation dosage applied to the air flowing through the housing 12 without requiring the length of the housing 12 to be increased. Moreover, in arrangements including the one or more convoluted air flow paths or ducts, it will be appreciated that the interior surfaces of these paths or ducts may be coated with a reflective material. The reflective material is selected so as to be particularly reflective to UV-C light, such as a metallic material.

Although not illustrated, the air sterilisation device 10 may include a sensor configured to detect the positions of the first and second radiation shields. A control system 42 may be configured to cut power to the UV radiation source 32 in response to a signal being received from the sensor that one or both of the radiation shields are incorrectly positioned/fitted within the housing. In such arrangements, the sensor may be a proximity sensor, a compression sensor, a camera or any other suitable sensing arrangement. The air sterilisation device 10 includes a filter assembly configured and arranged to filter air flowing through the housing 12 for removing contaminants and particulates therefrom. The size of the area of negative pressure at a pre-determined distance below the air sterilisation device 10 may be adjusted by adjusting the flow rate of air through the filters. For example, if an area of the apertures in the filter assembly is increased, this would increase the flow rate of air through the filter assembly. It shall be appreciated that the control system 42 may use any suitable method of adjusting the flow rate of air through the filters. For example, the control system 42 may control at least one shutter to adjust the flow rate of air through the filters.

The filter assembly includes a first filter element 38. The first filter element 38 is positioned at or near the outlet 16 of the housing 12. The filter assembly includes a second filter element 40. The second filter element 40 is positioned at or near the inlet 14 of the housing 12. In the present arrangement, the first and second filter elements 38, 40 form the first and second radiation shields. In alternative arrangements, it will be appreciated that the first and second radiation shields may be provided separately from the first and second filter elements 38, 40.

The first and/or second filter elements 38, 40 may be provided in the form of a high efficiency particulate filter. The filter elements 38, 40 may include a fibrous material, for example a fibrous cotton material. The first and/or second filter elements 38, 40 may be configured to act as an ozone filter configured to filter ozone generated by the UV radiation source 32. In such arrangements, the first and/or second filter elements 38, 40 may include an activated carbon cotton material. In alternative arrangements, the air sterilisation device 10 may include one or more ozone filters that are separate from the first and/or second filter elements 38, 40.

Although not illustrated, the air sterilisation device 10 may include one or more sensors configured to monitor the state of the filter elements 38, 40. The control system 42 may be configured to generate a signal when one or more filter elements 38, 40 needs to be replaced.

In some arrangements, the control system 42 may activate an indicator (not shown) on the air sterilisation device 10 to indicate when a filter element 38, 40 needs to be replaced, and/or the control system 42 may transmit a signal to a remote location via a transmitter (not shown) when a filter element 38, 40 needs to be replaced. The air sterilisation device 10 includes an end cover 44 partially covering the inlet 14 of the housing 12. The end cover 44 is spaced apart from the housing 12 so as to define an inlet opening 46 therebetween. Put another way, the end cover 44 is radially spaced apart from a radially inner surface of the housing 12 so as to define an inlet opening 46 therebetween. The end cover 44 and the second filter element 40 form the second radiation shield.

In the illustrated arrangement, the inlet opening 46 is substantially annular, but the shape of the inlet opening 46 may be changed to suit the application or to correspond to the shape of the housing 12 the inlet opening may define an opening, e.g. an annular opening, in the range 5 to 15mm, for example the inlet opening 46 may be approximately 10mm. Put another way, the end cover 44 may be spaced apart from the housing by a distance in the range 5 to 15mm, e.g. approximately 10mm, so as to define the inlet opening 46.

The inlet opening 46 is configured to draw air into the housing 12 at a predetermined angle. This configuration (e.g. liner, curved, angled), defines the predetermined angle at which air is drawn into the housing 12. Thus, by the fitting of a differently configured end cover 44 to the housing 12, the pre-determined angle may be able to be changed.

The air sterilisation device 10 includes a fan assembly. The fan assembly is configured to draw air into the housing 12 via the inlet 14, through the chamber 36 and out of the housing via the outlet 16. The fan assembly includes an impeller 48 and a motor 50 configured to drive the impeller 48.

The fan assembly is configured to generate a region of negative pressure below the air sterilisation device 10 so as to draw air into the housing 12. The region of negative pressure defines an area of negative pressure at a pre-determined distance below the air sterilisation device 10. Only air from within the cross- sectional area of negative pressure is drawn into the housing, thus creating a localised area to be sterilised. This prevents air from being pulled into the device 10 over large areas, potentially cross-contaminating the enclosed space. The control system 42 is configured to adjust the size of this area of negative pressure at a pre-determined distance below the air sterilisation device 10. Thus, the size/area/region of negative pressure below the air sterilisation assembly 10 can be adjusted to the size required for a particular application. This, in turn, helps to reduce/prevent potentially contaminated air from flowing across large areas of a room. In some arrangements, the control system 42 may be configured to adjust the fan assembly to adjust the size of the area of negative pressure below the air sterilisation device 10. Put another way, the control system 42 may adjust the speed of the impeller 48 via the motor 50 to adjust the size of the area of negative pressure at a pre-determined distance below the air sterilisation device 10. The adjustment of the fan assembly adjusts the flow rate of air through the housing 12, and the size of the cross-sectional area of negative pressure below the air sterilisation device 10. It is the flow rate of the air through the housing 12 which inhibits air from outside the cross-sectional area of negative pressure from being drawn into the housing 12.

In some arrangements, the control system 42 may be configured to adjust the angle at which the air is drawn into the housing 12 to adjust the size of the area of negative pressure below the air sterilisation device 10. The control system 42 may be configured to adjust the inlet opening 46 to adjust the angle at which the air is drawn into the housing 12.

The end cover 44 is moveable relative to the housing 12. Adjustment of the inlet opening 46 may be carried out by adjusting the position of the end cover 44 relative to the housing 12. This adjustment may be carried out by the control system 42. In some arrangements, the adjustment of the end cover 44 may be able to be carried out manually.

As discussed above, the opposing surfaces of the end cover 44 and housing 12 define the inlet opening 46. Put another way, the end cover 44 and housing 12 define an inlet duct therebetween. The control system 42 is configured to adjust the angle of this inlet duct so as to adjust the angle at which air enter the housing 12.

The inlet duct may be substantially curved, e.g. the inlet duct may be curved downwardly (i.e. towards the floor of an enclosed space in use). In alternative arrangements, the inlet duct may be substantially linear and may be angled relative to an elongate axis of the housing 12.

The air sterilisation device 10 includes a sensor (not shown) configured to detect the UV radiation emitted (i.e. wavelength and intensity) by the UV radiation source 22. In order to detect the UV radiation emitted, the sensor monitors the electrical resistance of the UV radiation source 32. The control system 42 is configured to generate a signal indicative of whether the UV radiation source 32 is active or inactive. In some arrangements, the control system 42 may activate an indicator (not shown) on the air sterilisation device 10 to indicate whether or not the UV radiation source is active or inactive, and/or the control system may transmit a signal to a remote location via a transmitter (not shown) relating to the state of the UV radiation source 32.

The control system 42 is configured to calculate the UV radiation dosage required to sterilise air within the chamber 36. This required UV radiation dosage is then compared with the UV radiation dosage given to air in the chamber 36. The determination of the UV radiation dosage given to air in the chamber 36 is based on the detected UV radiation emitted by the UV radiation source 32. The control system 42 calculates the UV dosage given to the air in the chamber 36 based on the expected speed of the air flow through the housing 12 due to the impeller 48. The control system 42 may also calculate the UV dosage given to the air in the chamber 36 based on the monitored electrical resistance of the UV radiation source 32. In some arrangements, the air sterilisation device 10 may be provided with an air flow meter (not shown) to determine the rate or speed of the air flow through the housing 12. The air flow meter helps to improve the accuracy of the control system 42 calculation of the UV dosage given to the air in the chamber 36.

The control system 42 is configured to provide an output based on the comparison. The control system 42 is configured to generate a signal based on the comparison. In some arrangements, the control system 42 may activate an indicator (not shown) on the air sterilisation device 10 to indicate whether or not a sufficient UV radiation dosage is being applied to air within the chamber 36, and/or the control system 42 may transmit a signal to a remote location via a transmitter (not shown) relating to whether or not a sufficient UV radiation dosage is being applied to air within the chamber 36.

The control system 42 may be configured to adjust the speed of the impeller 48 to adjust the speed of air flow through the chamber 36 such that the UV radiation dosage given to the air in the enclose chamber 36 is equal to or greater than the required UV radiation dosage.

Although not illustrated, the air sterilisation device 10 may include an indicator (not shown) configured to indicate whether or not the air sterilisation device 10 is functioning correctly. Put another way, the air sterilisation device 10 may include an indicator (not shown) configured to indicate whether or not the air flow through the device 10 has been sterilised sufficiently. The indicator may be provided in the form of an audio or visual indicator. The visual indicator may take the form of an indicator ring, e.g. having different colours to indicate the operational state of the airt sterilisation device 10. The indicator ring may be provided on the end cover 44, on the cowl 18, or on the housing 12.

Although not illustrated, the air sterilisation device 10 may include a display for displaying the quality of air drawn into the inlet and driven out of the outlet.

The information regarding the state of the filters, the dosage applied to the air flowing through the chamber 36, the air quality in and out of the device 10, and all of the other information processed by the control system 42 may be stored on memory (not shown) for later use or record keeping. The information may be transmitted via a transmitter (not shown) to another device, such as a computer or mobile telephone, at a remote location. This arrangement advantageously allows for the air sterilisation device 10, or a series of air sterilisation devices 10, to be monitored remotely.

Although not illustrated, the air sterilisation device 10 may also include a heat exchanger, e.g. contained within the housing 12. In such arrangements, the heat exchanger is provided to heat or cool air flowing through the air sterilisation device 10 to a pre-determined temperature. The control system 42 may be configured to control operation of the heat exchanger based on an air temperature sensed within the housing and a pre-determined target temperature.

Referring now to Figure 4, an air sterilisation system or device is illustrated and indicated generally at 110. Like parts to the embodiment of Figures 1 to 3 are labelled by like reference numerals with prefix "1". Only differences with the embodiment of Figures 1 to 3 are discussed below.

The air sterilisation device 110 includes a housing 112, as illustrated in Figure 4. The housing 112 defines an inlet 114 intended to be lowermost in use. The housing 112 includes an outlet 116 intended to be uppermost in use. The housing 112 defines a substantially rectangular based prism. It shall be appreciated that in alternative arrangements, the housing 112 may be any suitable shape, configuration or size to suit the needs of the application.

Referring now to Figure 5, the inlet 114 includes an inlet plate 144 located at a first end of the housing 112, and an inlet opening (not shown). The inlet plate 144 forms a cover over the inlet opening. The inlet plate 144 includes a plurality of apertures 147, which are approximately aligned in an axial direction with the inlet opening. In this embodiment, the apertures are substantially arcuate, having a range of arc diameters. Each of the arcuate apertures has a common centre with each other and with the inlet opening. The arcuate apertures 147 are arranged in segments. A circular aperture is located at the centre point of the arcuate apertures 147. This arrangement has been found to encourage air flow through into the inlet 114. In alternative embodiments any suitable arrangement of apertures, or a single opening, for example a circular opening, may be used.

Although not illustrated, the inlet 114 may also include an inlet duct or cowl for directing air through the inlet plate 144 and into the inlet opening. The inlet duct is connected to the housing 112 and positioned near an upstream inlet of the housing. The inlet duct tapers in a direction towards the inlet. The taper may be angled or curved. In alternative embodiments, any suitable shape of inlet may be used, or a hood or cone may be used.

The outlet 116 includes an outlet plate 145 located at a second end of the housing 112 opposite the first end. The outlet plate 145 includes apertures 149 of substantially the same configuration to the inlet apertures 147. The outlet plate 145 also includes an electromagnetic compatibility (EMC) port 152 and a suspension arrangement mounted thereto.

In this embodiment, the suspension arrangement for suspending the air sterilisation device 110 includes mounting arrangement 124a-d. The air sterilisation device 110 may be suspended vertically, horizontally or integrated with the void in the ceiling. The mounting arrangement 124a-d includes a plurality of attachment devices 124a- d in the form of loops. In this embodiment, the mounting arrangement 124a-d includes four loops 124a-d, however in alternative embodiments any number of suitable attachment devices may be used, for example hooks.

The suspension arrangement includes at least one suspension member 126a-d of substantially the same configuration to the embodiment of Figures 1 to 3. The number of suspension members may correspond to the number of attachment devices 124a-d, or alternatively a continuous suspension member may be used. In this embodiment, there are four suspension members 126a-d attached to each of the four attachment devices 124a-d

Referring now to Figures 6 and 7, a UV radiation source 132 and a receptacle 156 of the air sterilisation device 110 are illustrated. In this embodiment, the UV radiation source is mounted within the receptacle 156. The receptacle 156 is located within the housing 112. The UV radiation source 132 is located substantially in a centre of the receptacle 156. This helps improve the uniformity of the sterilisation of the air. However, in alternative embodiments, the UV radiation source 132 may be located anywhere within the receptacle 156, or the receptacle 156 may be omitted and the UV radiation source 132 may be located within the housing 112.

In the illustrated arrangement, the UV radiation source 132 is provided in the form of two elongate UV bulbs, e.g mercury bulbs, as illustrated in Figure 7. In alternative embodiments, any number of UV bulbs may be used. The elongate UV bulbs 132 extend along a majority of a length of the receptacle 156. In alternative arrangements, the UV radiation source 132 may be provided in the form of one or more UV emitting light emitting diodes (LEDs), or a combination of UV emitting LEDs and UV bulbs, or via any other suitable UV generating means.

A UVC ballast 154a, 154b is mounted to the housing 112. The UV radiation source 132 may be mounted directly to the UVC ballast, or alternatively the UVC ballast may be connected to the UV radiation source 132 by a wire. Alternatively, the UVC ballast may be substantially cylindrical and located within the receptacle 156.

The UV radiation source 132 performs substantially the same function as the UV radiation source 32, of emitting UV-C radiation in order to sterilise the air drawn into the receptacle 156.

The receptacle 156 defines the inlet opening at a first end. The receptacle 156 defines the outlet opening at a second end opposite the first end. The receptacle defines an air flow path therethrough from the inlet opening to the outlet opening. The receptacle 156 is substantially tubular, e.g. substantially cylindrical, in the illustrated arrangement. It will be appreciated that in alternative arrangements, the receptacle 156 may be any suitable shape, configuration or size to suit the needs to the application.

The receptacle 156 includes at least one interior surface having a reflective material configured to reflect UV radiation emitted by the UV radiation source 132. Put another way, one or more of the interior surfaces, or the entirety of the interior surface of the receptacle 156 is formed from or coated with a reflective material. The reflective material may be a polymer or a metallic material. The entirety of the receptacle 156 may be manufactured from the polymer or metallic material, or alternatively the interior surface may be coated with the polymer or metallic material. In this embodiment, the entirety of the interior surface of the receptacle 156 is manufactured from polytetrafluoroethylene (PTFE). In alternative embodiments, the receptacle 156 may be manufactured from or coated with any suitable material for reflecting UV radiation, such as stainless steel, polyvinyl chloride or aluminium.

Although not illustrated in Figures 4 to 7, the air sterilisation device 110 may include any of the first and second radiation shields, the filter assemblies, and sensors for detecting the positions of the first and second radiation shields and the state of the filters, of substantially the same configuration to those of Figures 1 to 3. The first and second radiation shield and/or the filter assemblies may be located in the inlet and outlet openings of the receptacle 156. This prevents harmful UVC radiation from escaping the air sterilisation device 110.

The air sterilisation device 110 includes a fan assembly of substantially the same configuration as the air sterilisation device 10, having an impeller and a motor (not shown).

The air sterilisation device 110 also includes a control system 142 for adjusting the speed of the impeller. The control system 142 of this embodiment is mounted to the housing 112. The control system 142 is located within a recessed section of the housing 112. The control system 142 sits on an internal surface of the inlet plate 144. In alternative embodiments, the control system 142 may be located at any suitable location on the air sterilisation device 110.

The control system 142 adjusts the flow rate of air through the receptacle 156 by adjusting the speed of the fan assembly, and therefore the size of the cross- sectional area of negative pressure. This creates localised area from which the area is drawn by each of the air sterilisation devices 110. For example, the control system 142 may adjust the speed of the fan assembly such that flow rate of air through the receptacle 156 is in the range 15m ³ /h to 60m ³ /h. This range of flow rates has been found to optimise the size of the cross-sectional area of negative pressure for sterilising localised area of air in the enclosed space. An optimum diameter of the cross-sectional area of negative pressure has been found to be in the range 0.5m to 10m, for example 2m to 5m.

Although not illustrated, the air sterilisation device 110 may include a reservoir (not shown) for storing a cleaning agent, and a nozzle (not shown) connected to the reservoir for dispensing the cleaning agent over the cross-sectional area of negative pressure. Instead of each sterilisation device 110 including a reservoir, the cleaning agent may be stored in a central reservoir or feed system, and the nozzles may be supplied with cleaning agent by a pipework.

The nozzle dispenses the cleaning agent as a mist, a fog or a spray over the area. There may also be a plurality of nozzles located at different locations on the air sterilisation device for dispensing the cleaning agent. Advantageously, the cleaning agent can be used to sterilise one of the localised areas, for example surfaces onto which the cleaning agent is dispensed, for example a table or desk in a room of a building, or a steering wheel of a vehicle. In this embodiment, the cleaning agent is hypochlorous acid, however in alternative embodiments any suitable cleaning agent may be used, such as alternative antimicrobial fluids, for example bleach.

Additionally or alternatively, the air sterilisation device 110 may include a reservoir (not shown) for storing an air freshener, and at least one nozzle (not shown) connected the reservoir for dispensing the air freshener as a mist or spray over the localised area. The same nozzle or plurality of nozzles may be used to dispense the air freshener and the cleaning agent, or different nozzles may be used.

The control system 142 may control the nozzle to dispense cleaning agent periodically. For example, the control system 142 may control the nozzle to dispense cleaning agent once every four hours. Alternatively, the control system 142 may control the nozzle to dispense cleaning agent once in the morning and once in the evening. Additionally or alternatively, the control system 142 may control the nozzle to dispense cleaning agent upon receiving an input from a user. For example, the air sterilisation device may include a button for the user to press, or the dispensing may be actuated remotely.

Although not illustrated, the air sterilisation device 110 may include a light emitting assembly having an anti-microbial light source and/or a white light source. The anti-microbial light source may be a violet-blue LED light. The wavelength of the light may be in the range 380nm to 450nm, for example 405nm. This range of wavelengths has been found to be suitable for killing microbes found in the air and surrounding surfaces. The white light source may be a light emitting diode (LED) or any suitable white light source, for example a fluorescent light bulb. The white light source has the advantage of absorbing the wavelength of the violet-blue light produced from the anti-microbial light source such that the surrounding area is not seen as violet/blue to the human eye. The white light source is arranged proximate or adjacent to the anti-microbial light source. The light emitting assembly may be directly mounted to the air sterilisation device 110. Alternatively, the light emitting assembly may be provided on a mounting device, such as a shade, mounted to the air sterilisation device 110.

The control system 142 and a sensor (not shown) detect the UV radiation emitted by the UV radiation source 122. The control system 142 and sensor perform substantially the same calculation of the UV radiation dosage required to sterilise air within the receptacle 156 as the embodiment of Figure 1 to 3. The control system 142 may also produce substantially the same output to the embodiment of Figures 1 to 3, as described above. The control system 142 may also be configured to adjust the speed of the impeller to adjust the speed of air flow through the receptacle 156.

For reasons of conciseness and brevity, a number of features present in both embodiments of air sterilisation device 10 have not been described in relation to the air sterilisation device 110. However, it shall be appreciated that any of the following features may be present or omitted in the air sterilisation device 110: the flow meter; the indicator for indicating whether or not the air sterilisation device 110 is functioning correctly; the control system controlling at least one shutter to adjust the flow rate of air through the filters; the display for displaying the quality of air drawn into the inlet and drive out of the outlet; memory for storing information regarding state of the filters, the dosage applied to the air flowing through the receptacle 156, the air quality in and out of the air sterilisation device 110, and all the other information processed by the control system 142; and the heat exchanger.

A method of installing one or more air sterilisation devices 10, 110 in an enclosed space will be discussed. As discussed above, the air sterilisation device 10, 110 may be installed in any suitable enclosed space, such as a room of a building or a vehicle.

Prior to installation of the air sterilisation device 110, one or more areas within the enclosed space are identified. An example of an enclosed space split into discrete positions denoted with an "X" is illustrated in Figure 8. This creates localised areas to be sterilised by each air sterilisation device 110. For example, the room may be split into discrete positions each located 3.5m apart. The discrete positions may form a grid, with each of the discrete positions being spaced apart from adjacent discrete positions in an x-direction and a y-direction. Alternatively, the discrete positions may be at key locations in the enclosed space, for example over desks, over restaurant tables or over workspaces, again creating localised areas to be sterilised.

Air sterilisation devices 10, 110 are provided depending on the number of areas identified within the enclosed space. An air sterilisation device is positioned within the enclosed space a pre-determined distance above each of the one or more identified areas within the enclosed space.

The or each air sterilisation device 10, 100 is configured such that the cross- sectional area of negative pressure generated by the air sterilisation device 10, 110 at the pre-determined distance corresponds to the cross-sectional area of the identified area within the enclosed space. It will be understood that the configuring of the air sterilisation unit 10, 100 may be carried out offsite, or may be carried out within the enclosed space (i.e. on-site)

The control systems of each air sterilisation device 10, 110 are programmed to control the speed of the impeller depending on the spacing between the discrete positions. As discussed above, the adjustment of the speed of the impeller is used to adjust the flow rate of air flow through the housing 12, 112 and therefore the area of negative pressure beneath the air sterilisation device 10, 110. For example, in this example where the discrete positions are 3.5m apart, the impeller, and therefore the flow rate of air flow through the housing, may be adjusted to produce an area of negative pressure with a diameter of up to 3.5m. This ensures that air in the majority of the room is sterilised, without the areas of negative pressure of adjacent air sterilisation units 10, 110 overlapping.

The method of installing an air sterilisation device 10, 110 may also include mounting or connecting an inlet duct to the housing.

Once the control systems 142 have been programmed with the flow rate of the fan assemblies, the air sterilisation devices 110 can be installed at each of the discrete positions. The air sterilisation devices 110 are mounted/secured to a support structure within the enclosed space.

Although the teachings have been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope as defined in the appended claims.