Technical Field

Embodiments relate to an apparatus for sterilizing a lift and a corresponding kit of parts.

Background

The SARS-CoV-2 virus is creating unprecedented disruption to the world’s economy and causing widespread disease.

Part of the effective management of the virus relates to avoiding infection. This can be particularly difficult in spaces where people mix such as offices, shops, restaurants, and corridors in apartment buildings or any other common space. It has been shown that pathogens such as the SARS-CoV-2 virus are transmitted by touch when a healthy person touches a surface onto which the virus has been deposited by touch or through coughing or sneezing. Viruses deposited on surfaces are able to infect people even after a significant time period has passed, depending on the material and other characteristics of the surface.

It has been shown that the SARS-CoV-2 virus is also spread in the air since it is readily aerosolized. When an infected patient sneezes or coughs, moisture droplets containing the virus are launched into the air. Many of these moisture droplets are small enough that they do not settle under the influence of gravity but remain airborne for extended periods. Aerosols have been proven to facilitate the transmission of tuberculosis, respiratory viruses such as influenza and rhinoviruses, gastrointestinal viruses such as rotavirus, and are suspected of playing a role in the transmission of other pathogens such as norovirus. The half-life of CoV-2 is approximately 2 hours. Some researchers have indicated that the aerosol can survive up to 72 hours in a viable state, and that water droplets of aerosol size (approximately 1 -10 pm) may stay in suspension for over an hour, so transmission in lift cars is a real threat for occupants.

UV-C that operates at a wavelength of 253.7 nm is known as UVGI (ultraviolet germicidal irradiation), and is known to specifically assist in germicidal efficacy by disinfecting the air. Unlike Vacuum UV lamps that operate at 185 nm, UVCI does not generate ozone, which may be harmful if breathed in. Passenger lifts may present a particular difficulty. Due to the small space and large number of people using that space it may be difficult to maintain a sterile environment. Lifts usually include ventilation openings within 300 mm above the floor and higher than 1800 mm above the floor. In addition, lifts often include an extraction fan to expel air from the lift at a high level, with replenishment air being drawn into the lift, in particular conditioned air, when the doors open, to help maintain a comfortable temperature, humidity level and air quality within the lift. When the doors are closed, replenishment air is usually drawn into the lift from the lift shaft through low level grilles in the lift cabin. Often such extraction fans are located in a service space in the ceiling, which means that when the air is drawn into the lift, it will pass the faces of any passengers, potentially increasing the risk that any pathogen in the air will be inhaled by the passengers or deposited onto the various surfaces in the interior of the lift, which may then be touched by the passengers and thereby become a source of infection.

It may be desirable to provide means for disinfecting, or reducing the number of pathogens present, in air and on surfaces in an enclosed space such as a passenger lift.

Summary of the Disclosure

An embodiment provides an apparatus for sterilizing a lift comprising a housing locatable in the lift, the housing comprising a conduit having an inlet and an outlet, the apparatus further comprising: a sterilizing light source located within the conduit and a fan for moving air through the conduit and through illumination provided by the sterilizing light source to thereby sterilize the air, the outlet of the conduit being arranged to direct treated air from a top of the lift downwards when located in the lift, the outlet comprising a plug-flow diffuser.

It is to be realised that the term ‘sterilizing’ and derivates thereof are not used in an absolute sense. Therefore, when for example a light source is referred to as a “sterilizing light source” it is not necessarily the case that the light source is able to provide complete sterility. These terms are used in a relative sense in that they refer to an ability to improve a degree of sterility concerned.

The lift may be a passenger lift.

The housing may be configured for installation at the ceiling of a lift. The outlet may be configured to direct an airflow from the ceiling down towards a floor of the lift.

The outlet may comprise one or more nozzles for directing an airflow. The one or more nozzle may be adjustable so that adjustment variers at least a portion of the airflow from the outlet. The one or more nozzle may be manually adjustable. The one or more nozzle may be remotely adjustable.

The apparatus may be configured so that, when installed in a lift, the inlet of the conduit is located substantially at a ceiling height. The location of both the inlet and/or the outlet at ceiling height may provide an apparatus with a relatively small profile.

Alternatively, or in addition, the inlet may be provided lower than ceiling height, or for multiple inlets, the combination of inlets may all be substantially at ceiling height, lower than ceiling height, or both substantially at ceiling height and lower than ceiling height. For the inlet lower than ceiling height, the housing may comprise a snorkel and the inlet may, in this embodiment, be located at the end of the snorkel. The inlet may be located below head height when installed in the lift. The inlet may be located less than 1 .5 m above a floor of the lift. The inlet may be located less than 1 m above the floor of the lift. The inlet may be located less than 500 mm above the floor of the lift.

More than one inlet may be formed in the snorkel.

The apparatus may comprise turning vanes located in the conduit for assisting a change in air direction. The turning vanes may additionally create a shield for sterilising light.

The turning vanes may be located upstream of the fan or downstream of the fan. The turning vanes may shield the fan from the light source located within the housing.

The apparatus may have a height of less than 1 metre. The apparatus may have a height between 100 mm and 1 metre. In an embodiment, the height of the apparatus is between 100 mm and 500 mm. In a further embodiment, the height of the apparatus is between 100 mm and 300 mm. A small height may contribute to a small profile, potentially making it easier to install and reducing the impact on the existing space in a lift when the apparatus is retrofitted. As discussed here, the height refers to a vertical dimension of the apparatus excluding the snorkel, if present.

At least one of the fans may have a truncated round profile. This may assist in reducing the effective height of the apparatus.

A relatively low profile may allow the apparatus to be retrofitted to existing lifts without significantly reducing the available head space in the lift.

The apparatus may comprise a filter located in the conduit to filter air moving through the conduit. The filter may be located proximate the inlet or proximate the outlet. Where the apparatus has more than one inlet, each inlet may be provided with a filter.

The filter may be irradiated by the sterilising light source to sterilise the filter.

The apparatus may comprise a hatch for accessing an interior of the apparatus. The hatch may be provided in one or more of: a top wall, a bottom wall, a side wall, and an end wall. Where the apparatus includes a snorkel, the hatch may be provided in the snorkel.

The housing may be configured for hinged installation in the lift to provide access to a ceiling of the lift or interior of the housing.

The housing may be configured so that hinged movement of the housing relative to the lift provides access to an interior of the apparatus to provide access for maintenance. The apparatus may comprise a switch configured so that hinged movement of the housing or hatch causes deactivation of each light source.

The apparatus may comprise a switch configured so that opening of the hatch causes any sterilizing light source visible behind that hatch to be deactivated. This may help to avoid injury to maintenance personnel when repairing or maintaining the unit. The switch may deactivate all light sources when the hatch is opened. In addition, or alternatively, the switch may be activated when one or more filters provided in, or proximate to, one or more inlets or outlets is removed.

The apparatus may further comprise a second light source for sterilizing an interior of the lift. The second light source may be attached to an underside of the conduit or housing or an effective ceiling of the lift.

Each light source may comprise an elongate UV light bulb. Each UV light bulb may be a UV-C light bulb. Each light bulb may be of the same size and type. This may assist in maintenance of the apparatus.

Each light source may comprise sets of two elongate light bulbs arranged in an X-formation. Arranging the light bulbs in an X-formation may help to maximise the length of light bulbs, and hence maximise the light intensity and sterilisation effect achieved.

In addition, or alternatively, if the apparatus includes a snorkel, at least one of the light sources may be housed in the snorkel. All sterilizing light sources may be located in the snorkel.

The fans may be located distanced from the sterilizing light source.

The apparatus may comprise an occupant sensor. The occupant sensor may be attached to a side or an underside of the conduit or the housing.

The apparatus may comprise a controller connected to the sensor and connectable to the lift to control the operation of the second light source wherein the controller is configured to: operate the occupant sensor to detect occupants in the lift; if there are no occupants detected in the lift; operate the second light source to sterilize an interior of the lift.

The controller may be further configured to lock the doors while operating the second light source.

In a further embodiment, the apparatus comprises a lift door sensor to determine whether the lift door is open or closed. The lift door sensor may be attached to a side or underside of the housing or the conduit.

The controller may be adapted to operate the second light source under one or more of the following conditions: a predetermined time has passed; the occupant sensor determines that there are no occupants in the lift; the door sensor determines that the lift doors are closed.

The occupant sensor and/or the lift door sensor may be one or more of a passive infrared (PIR) sensor, an ultrasound sensor or a camera. The predetermined period may be 15 minutes, or less. In an embodiment, the predetermined period is 10 minutes, or less. In an alternative embodiment, the predetermined period is 5 minutes, or less. In a further embodiment, the predetermined period is 2 minutes, or less. The predetermined period may depend on the number of bulbs provided.

The outlet may comprise a diffuser.

The diffuser may comprise a plug-flow diffuser. The plug flow diffuser may be substantially horizontally orientated when located in the lift. The plug-flow diffuser may expel airflow with a substantially laminate, low turbulence flow, referred to as a ‘plug airflow’ that substantially displaces lift air in its path. This may tend to minimize mixing thereby potentially avoiding or minimising contaminants in the lift air from reaching head-height for the passengers, or spreading from head-height of one passenger to another, or sweeping them away from head-height of the passengers, or reducing their likelihood of adhering to the walls.

The plug-flow diffuser may comprise a lower plate, and may additionally include an upper plate and a lower plate. The lower and/or the upper plate may be perforated. The upper plate may be of a different thickness to the lower plate. The upper plate may be comprised of an acoustic absorber. A plurality of perforations in the upper plate may be staggered relative to a plurality of perforations in the lower plate. This may prevent direct line of sight from within the lift to the light sources.

In an alternative embodiment, the plug-flow diffuser may comprise a perforated member. The perforated member may comprise a single layer.

In an embodiment, the upper plate may comprise a mat. The mat may comprise a fibrous mat permeable to airflow. The mat may be pleated. The mat may obstruct line of sight to the sterilizing light source from within the lift. The mat may be between 0.5 mm and 5 mm thick. The mat may be between 5 mm and 20 mm thick. The mat may rest directly on an upper surface of the lower plate. The mat may be a filter. The filter may be a HEPA filter.

The housing may additionally comprise a chamfered face where the outlet further comprises an edge diffuser located on the chamfered face for directing air towards walls of the lift, when installed. The edge diffuser may include at least one adjustable element to adjust the direction of the discharged air. The adjustable element may comprise a nozzle. The plug airflow expelled from the plug flow diffuser may not reach the walls of the lift, when the apparatus is installed. In such instances, the edge diffuser, which may be disposed on a chamfered edge, may act to direct airflow towards walls of the lift, away from a high level inlet, and spread the substantial laminate airflow from the plug flow diffuser, thereby potentially minimising turbulence and subsequent mixing from developing between the plug airflow and the walls. This may additionally reduce the contaminants which adhere to the walls of the lift or mix in the facial region of lift occupants.

In a further embodiment, the housing comprises an edge diffuser which is not necessarily disposed on a chamfered edge.

In an alternative embodiment, the outlet may comprise at least one baffle diffuser. The baffle diffuser may comprise a funnel and perforated plate system. The funnel and perforated plate system may be substantially as described in US 2010/0029194 A1 . The baffle diffuser may be arranged to generate a layer of air between the apparatus and the interior of the lift when the apparatus is in use. The layer of air acts as a baffle, preventing air which circulates in the lift from coming into contact with the effective ceiling of the lift (the underside of the apparatus when installed).

A further embodiment extends to a kit of parts for constructing an apparatus as herein described.

Description of the Drawings

Embodiments are herein described, with reference to the accompanying drawings in which:

Figure 1 is a side view of an apparatus for sterilizing a lift;

Figure 2 is a plan cross-sectional view of the apparatus for sterilizing a lift of Figure 1 taken along the line C-C;

Figure 3 is a side cross-section of the apparatus for sterilizing a lift of Figure 2 along line A-A;

Figure 4 is a side cross-section of the apparatus for sterilizing a lift of Figure 2 along line B-B;

Figure 5 is a magnified view of the portion of the apparatus of Figure 3 labelled “X”;

Figure 6 is a side cross-section view along line A-A of Figure 2 illustrating the apparatus of Figure 1 installed in a lift;

Figure 7 is a side view of an apparatus for sterilizing a lift according to a further embodiment;

Figure 8 is a side view of an apparatus for sterilizing a lift according to a further embodiment;

Figure 9 is a side view of an apparatus for sterilizing a lift according to a further embodiment;

Figure 10 is a plan cross-sectional view of the apparatus for sterilizing a lift of Figure 9 taken along the line C-C;

Figure 1 1 is a side cross-section of the apparatus for sterilizing a lift of Figure 10 along line A-A;

Figure 1 1 -1 illustrates a detail of Figure 1 1 ;

Figure 12 is a side cross-section of the apparatus for sterilizing a lift of Figure 10 along line B-B;

Figure 12-1 illustrates a detail of Figure 12;

Figure 13A is a cross-section of an apparatus for sterilizing a lift according to a further embodiment in a first configuration; and

Figure 13B is a cross-section of the apparatus for sterilizing a lift of Figure 13A in a second configuration.

Detailed Description of Specific Embodiment

Figure 1 illustrates an apparatus 10 for sterilizing a lift. The apparatus 10 comprises a housing 12 with air inlets 14 formed therein. In this embodiment, each of the air inlets 14 includes a corresponding filter 16 (see Figure 2) to prevent contaminants from entering the apparatus 10.

The housing 12 defines a conduit 18 through which air flows. The interior of the housing has a number of acoustic baffles 24 and other structures defining the airflow. The apparatus includes four axial fans 20 which, when operational, cause the air to flow within the apparatus in the direction of the arrows 22. It will be apparent to a person skilled in the art that alternative fan types may be used, such as plug fans or tangential fans.

Two elongate UV-C bulbs 26A and 26B are orientated in an X-configuration at the centre of the apparatus 10. As illustrated in Figure 4, as the fans 20 operate, the air is drawn in through the inlets 14 and passes over the bulbs 26A and 26B. The UV-C light emitted by the bulbs helps to sterilize the airflow, rendering pathogens such as viruses unviable. Airflow is then directed, as shown in Figure 3, and exits the apparatus 10 through outlets 30. Furthermore, the filters 16 and bulbs 26A and 26B are situated so that light from the bulbs is incident on the filters. This may help to sterilize and clean the filters.

As illustrated in Figure 3, the apparatus 10 includes two kinds of outlet. A plug-flow diffuser 32 is situated centrally and comprises a perforated plate 40. In the embodiment shown, the plug-flow diffuser 32 additionally incorporates an acoustic absorber or thickened plate 42 (Figure 5) with perforations. A plug-flow diffuser having perforations in both the acoustic absorber or thickened plate, and the perforated plate, which have a diameter of between 4 and 5 mm with centres about 10 mm apart may be suitable. As illustrated in Figure 5, the perforations in the acoustic absorber or thickened plate 42, and perforations in the perforated plate 40, are staggered to prevent direct line of sight (dashed line 62) from within the lift (once the apparatus 10 is installed in the lift) to the light sources within the apparatus. This may help to prevent potentially harmful radiation from these light sources shining directly into occupants’ eyes, thereby potentially avoiding injury.

In an alternative embodiment, plug-flow diffuser 32 comprises a permeable fibrous mat resting on an upper surface of perforated lower plate 40. The fibrous mat permits airflow but blocks direct line of sight to the light sources within the apparatus, thereby potentially avoiding harm to any occupants of the lift.

In a further alternative embodiment, plug-flow diffuser 32 comprises solely the perforated plate 40 provided as a single layer. In this embodiment, the perforated plate may have an extended height, so that the elongate perforations may provide more protection to the lift occupants from the harmful radiation emitted from the UV- C bulbs 26A and 26B, which may additionally, or alternatively, be fitted with light shields 26A’ and 26B’ shown in Figure 3.

The plug-flow diffuser 32 produces an airflow which is substantially laminar as it exists the plug flow diffuser. As illustrated in Figures 1 , 3 and 4, when the apparatus 10 is installed in a lift, the plug-flow diffuser is situated substantially horizontally so that the air flow is directed substantially vertically downwards (i.e. towards the bottom of the page with reference to Figures 1 , 3, 4 and 5).

In addition, the apparatus 10 includes edge diffusers 36. The edge diffuser 36 may be located at the chamfered edge 34 of the housing 12 (Figure 6) as shown, or may be located in a substantially horizontal surface. Furthermore, as illustrated in Figure 4, the apparatus may include edge deflectors 38 located on the edge of the housing 12 proximate the edge diffusers 36.

Figure 6 illustrates the apparatus 10 installed in a lift 50. As illustrated, the apparatus 10 is installed at anchor points 52 and 54. It is to be realised that either of the anchor points 52 or 54 may be provided as a hinge and the other as a latch so that the apparatus may be pivoted relative to the ceiling 56 of the lift to provide access to the ceiling.

The airflow in the lift 50 is illustrated by dashed arrows. Since the plug-flow diffuser 32 is situated substantially horizontal when the apparatus 10 is installed in the lift, the airflow from the plug flow diffuser 32, designated by dashed arrows 64 is substantially vertical and directed towards the floor 58 of the lift 50. Since the airflow from the plug-flow diffuser 32 is substantially downward through the lift, the air provides a ‘wash’ for or between passengers in the lift, particularly in their facial region, potentially helping to ensure that the air which the occupants breathe, and which generally comes into contact with the occupants (in particular, around the head region) is air which has been sterilized by the apparatus 10 or that is screened by plug-flow between adjacent passengers in the lift.

It has been found that the plug-flow diffuser may be particularly well suited to the constraints imposed in a relatively small enclosed space such as a lift. In particular, the relatively laminar airflow produced by the plug-flow diffuser may help to ensure that more air is moved more uniformly downwards relative to other outlets and this may help to reduce eddies, still or turbulent air that traps contaminants in the lift air, in particular at head height of occupants, potentially improving the sterilizing effect. CFD modelling of a lift car sterilising apparatus operating in a lift car in which 1 % of the occupants are infected during the course of a day, and that uses UVGI for both surface and aerosol disinfection, in accordance with particular embodiments, including 10-minute cumulative surface sterilisation every hour has shown substantially reduced infection risk, reducing the infection risk three-fold for occupants not wearing masks in comparison to a lift car in which the occupants do wear masks and the lift car is manually disinfected for ten minutes each hour, in accordance with WHO (World Health Organisation) guide-lines.

Infection risk comprises three components, viz the hazard risk (the community you dwell in), the vulnerability risk (your personal health), and the environment risk (the hygiene of the spaces you are in). For people who have a lifestyle with little hazard risk or vulnerability risk, a lift car sterilising apparatus in accordance with embodiments may continue to protect them as there is also a significantly reduced environment risk. The reasons for this include that there is a disinfection process for aerosols in addition to treating surfaces, the airflow pattern provides a protective air curtain between people, and the UVGI reduces significantly the half-life of the virus (whereas masks lower the risk of aerosol transmission but do not prevent transmission). CFD modelling has shown that the airflow pattern that provides a protective air curtain between people may be of particular importance. For certain embodiments, this aspect alone is shown by the CFD modelling to reduce the environment risk down to a quarter compared to what it would be if the discharged air were mixed into the cabin space.

A further potential advantage for lift cars fitted with an embodiment is that the lift car disinfection system may only have a 10-minute out-of-service period if the car has been constantly occupied. (If the lift car is unoccupied, it will commence surface disinfection, if required, and potentially do so multiple times until the duration required each hour to disinfect the lift car has been reached, cumulatively.) The lift traffic may increase for lift cars fitted with an embodiment. The cars may carry more people and may run for a longer period of time without being out of service, and the costs of manually cleaning the cars may be reduced.

As illustrated in Figure 6, both the inlet 14 and the outlet 30 of the apparatus 10 are located at, or near, the ceiling of the lift. Airflow 22 into the apparatus 10 is drawn at a high level from the lift 50, especially from the four corners of the lift when viewed in plan-view, as per Figure 2. As further illustrated in Figure 6 the apparatus 10 does not extend to the walls 58, 60. Therefore there is a space next to the walls where the airflow from the plug-flow diffuser 32 will not reach. The edge diffuser 36, located on the chamfered edge 34, directs air flow perpendicular to the chamfered edge, when viewed in plan view, towards the walls 58, 60 of the lift, but not towards the four corners of the lift, which is predominantly where an upwards return airflow occurs towards the inlets 14 located at the four corners of the apparatus 10. Each edge diffuser 36 provides additional airflow to that provided by the plug flow diffuser 32 and spreads the plug flow airflow 64 across a greater area, and may help to avoid circulated air from developing between the airflow from the plug flow dispenser 32 and the walls of the lift.

Only two walls 58 and 60 of the lift 50 are illustrated in Figure 6, but it is to be realised that edge diffusers are located on the two edges of the apparatus 10 not illustrated in Figure 6.

Referring back to Figure 5, the perforations of the perforated lower plate 40 are staggered relative the perforations in the acoustic absorber or thickened plate 42 (which here forms an upper plate). This may prevent a line of sight 62 for the occupants of the lift directly into the UV light bulbs, thereby potentially avoiding harm to the occupants. A clear space between acoustic absorber or thickened plate 42 and perforated lower plate 40 allows airflow to pass from one plate to the other despite the offset perforations of the two.

In a further embodiment, the acoustic absorber or thickened plate is replaced with a mat made from a material mesh permeable to airflow. The mat obstructs the line of sight to the sterilizing light source from within the lift whilst still allowing air to pass through. The mat may be pleated. The mat may be a filter. The filter may be a HEPA filter. In an embodiment the mat is about 0.5 mm to 5 mm thick or 5 mm to 20 mm thick and rests directly on an upper surface of the lower plate 40. Figure 8 shows a further embodiment in which mat 196 lies on an upper surface of both lower plate 40 and edge diffuser 36. It is to be realised that the mat may be anywhere between 0.5 mm and 20 mm thick, and further thicknesses may be possible too. The mat may be irradiated by the sterilising light source to sterilise the mat.

As indicated above, in an alternate embodiment, the plug-flow diffuser may be provided by a single layered perforated sheet.

Referring back to Figs. 1 and 2, the apparatus further includes an occupancy sensor or an occupancy and lift door sensor 70, and two further UV-C light bulbs 72 and 74 are provided on an underside of the housing 12, adjacent to two opposing side-walls of the housing 12 (Figure 1 ). The light bulbs 72 and 74 are provided with corresponding reflectors 76 and 78 to increase the amount of light directed from the light bulbs into an interior of the lift. In a further embodiment, two further UV-C light bulbs are provided and located adjacent to the two other opposing side walls of the housing 12.

The occupancy sensor, or occupancy and lift door sensor, 70 is an infra-red sensor, of a known type and uses infra-red radiation to detect if there are any occupants in the lift or if the lift doors are open or closed. In an alternative embodiment, the occupancy and lift door sensor may be an ultra-sound sensor, or a camera using ultra-sound or light rays to detect occupants in the lift and whether a door of a lift is open or closed.

In the embodiment illustrated, the same sensor is used to determine the occupancy state of the lift and the position of the doors. In a further embodiment, different sensors may be used to determine whether the lift is occupied and to determine the position of the doors.

The sensor is connected to a lift control (not shown) which controls the light bulbs 72 and 74, as well as the two further similarly located light bulbs, if present, as well as the lift doors. To help ensure that the interior of the lift remains relatively sterile, the lift control will continuously monitor the occupancy sensor, or occupancy and lift door sensor, 70, or do so at predetermined periods which may be set by the user, to determine if the lift is empty, or if the lift is empty and the doors are closed. Continuous monitoring of the interior of the lift for occupants, may allow the cabin surface sterlising lights to be activated whenever the lift is unoccupied up to the cumulative sterilising period of 10 minutes (or period as set) required each hour. This may be achieved without the need to take the lift out of service.

When the lift control determines that the lift is empty and that the lift doors are closed, or that the lift is empty and the lift doors are locked to prevent the lift from being used, the controller then turns on the light bulbs 72 and 74, as well as the two further similarly located light bulbs, if present, for a cumulative period of ten minutes per hour (or other set period, as determined by the user). Once the period has elapsed, or if the lift doors open or if occupancy is detected the light bulbs 72 and 74, as well as the two further similarly located light bulbs, if present, are turned off and the doors, if locked by the controller are unlocked, allowing the lift to be used in the normal manner.

By bathing the interior of the lift in UV-C light the number of potentially harmful pathogens in the lift, especially on surfaces of the lift, may be reduced. Since pathogens within the lift may be circulated by the air flowing through the interior of the lift, this may help to keep the air flow sterile. Furthermore, since a source of potential infection is pathogens which have been deposited on surfaces such as the interior of the lift, periodically submitting those surfaces to the sterilizing influence of UV-C radiation may help to reduce contagion by touching of these surfaces.

A further potential advantage to having the plug-flow diffuser and/or the edge diffusers is that this airflow may prevent air circulating within the lift from coming into contact with the ceiling defined by the apparatus or discharge surface of the outlet. Since the radiation from the internal light bulbs 72 and 74 does not directly impact the ceiling defined by the apparatus, the sterilizing effect of those light bulbs on the surface of the apparatus ceiling may be reduced. Therefore, by providing an airflow which prevents circulating air from coming into contact with the effective ceiling or discharge surface of the outlet, embodiments may help to keep the effective ceiling and discharge surfaces clean of pathogens which might otherwise be difficult to sterilize.

The apparatus 10 has a height of 200 mm. It is to be realised that the height may vary depending on a number of factors such as the size and shape of the fans. In general, it may be desirable to keep the profile of the apparatus small. The fans 20 provided in the apparatus 10, as best illustrated in Figure 3 have a truncated circular profile in that the top and bottom of the circle defining the outside profile of the fans is provided as two substantially horizontal edges. This may help to reduce the height of the fan without affecting the performance which, in turn, may allow for an apparatus with a reduced height.

A reduced profile or height for the apparatus may be advantageous so that the apparatus, when installed, occupies less of the available space, thereby potentially reducing the impact on the head space for any occupants of the lift.

Two embodiments have been illustrated and described: apparatus 10 with plug-flow diffuser 32. It is to be realised that further embodiments may include both a plug flow-diffuser and a baffle diffuser. Edge diffusers may additionally be provided, and one or more inlets may be ducted to be further located from the apparatus, including located well below face level of occupants beneath the apparatus.

Figure 7 illustrates an alternative embodiment of an apparatus 150 for sterilizing a lift. The apparatus 150 comprises a housing 180 which, in the arrangement illustrated is attached to the ceiling 154 of lift 156.

In this embodiment, the housing 180 comprises an upper housing 152 attached to the ceiling of the lift and a snorkel 160 attached to the upper housing 152. An inlet 162 is located at the end of a snorkel 160 through which air is introduced into the apparatus 150. The snorkel 160 extends down a wall 158 of the lift 156. The inlet 162 is provided with a set of turning vanes 164. The turning vanes 164 may assist with a change in direction of airflow at the inlet 162 and may prevent line-of-sight from within the lift cabin to a sterilising light source 170.

The inlet 162 is located a height H above the floor 166 of the lift 156. The length of the snorkel 160 is provided so that the inlet 162 is generally located below head height for an average lift occupant. In further embodiments, the inlet 162 is provided so that H is less than 1 .5 m, 1 m or 0.5 m. In these embodiments, the dimension H is measured to a middle of the inlet 162 although it is to be realised that benefits of providing a snorkel may be obtained without adhering to the precise measurements provided.

By locating an air inlet to the apparatus below head height, the apparatus may be more effective in drawing down plug-flow air, and may avoid upward flowing air that may pass the facial region of passengers, especially passengers located in the corners of the lift, reducing the likelihood of the spread of infection.

A sterilizing UV-C light bulb 170 is located in the snorkel 160. In this embodiment, the snorkel is orientated vertically. The light bulb is therefore housed within the snorkel in a vertical orientation and, when activated, may act to help sterilize airflow through the snorkel 160.

A fan 172 is located within the upper housing 152 and acts to induce airflow in the snorkel 160, generally through the apparatus 150 and out through the outlet 180 of the apparatus 150. A second set of turning vanes 174 is provided in a junction between the snorkel 160 and the upper housing 152 and may assist in redirecting the airflow between the vertically orientated snorkel 160 and the horizontally orientated upper housing 152. In an alternative embodiment the fan is located in the snorkel 160.

As illustrated in Figure 7, the upper turning vanes 174 are located between the light bulb 170 and the fan 174 and therefore the turning vanes 174 may act as a light shield for the fan 174. In certain embodiments, blades of the fan 174 may be constructed from a plastic which is susceptible to UV radiation which may cause degradation of that plastic. In this case, the turning vanes 174 may act to shield and therefore protect the fans from the effects of the UV-radiation.

In other respects, the apparatus 150 is arranged, and operates, in the same manner as the apparatus 10 illustrated in Figures 1 to 6 and described above. Some aspects and features of the apparatus 150 have been omitted from Figure 6 for the sake of clarity.

In the embodiment illustrated, the apparatus 150 excludes a light source in the upper housing 152. This may provide for an upper housing with a smaller profile when compared to the corresponding housing of the apparatus 10. Furthermore, in such an arrangement, occupants of the lift are protected from potentially harmful effects of the light by the encasing provided by the snorkel, and an arrangement to the plug-flow diffuser to protect the users from the light is unnecessary (e.g. staggered perforations, as described above). In addition, this may reduce the pressure drop of the diffuser, and hence the fan size and noise.

The outlet of the apparatus 150 is provided by a pleated mat 178 and a perforated plate 176. In this embodiment, the pleated mat is a HEPA filter.

The apparatus 150 is provided with a filter 189 proximate inlet 162. The filter may protect the internal components of apparatus 150 from contaminants and may prevent line-of-site from the lift to light source 170. As illustrated, the filters 189 and bulb 170 are situated so that light from the bulbs is incident on the filter. This may help to sterilize and clean the filter.

Figure 8 illustrates an alternate embodiment of an apparatus for sterilizing a lift 190. The apparatus 190 is similar to the apparatus 150 illustrated in Figure 7 and described above, and similar reference numbers are used to denote similar parts. The apparatus 190 of Figure 8 differs from that of apparatus 150 of Figure 7 in that the snorkel 192 comprises an inlet 188 which does not include turning vanes. Furthermore, in this embodiment, the upper housing 186 houses the sterilizing light bulb 194. The provision of a protrusion (e.g. the filter 189 (Figure 8) or turning vanes 164 (Figure 7)) at or near the inlet may help to shield the inlet (and therefore anyone looking in through the inlet) from the harmful effects of the UV radiation.

The outlet in this embodiment is provided by a pleated mat 196 in the form of a HEPA filter provided on top of a perforated plate 198. The pleated mat 196 prevents light rays from being directly emitted from the apparatus into the lift, thereby shielding the eyes of lift occupants from harm. Pleated mat 196 may be sterilised by irradiation from sterlizing light bulb 194.

Figures 9 to 12 illustrate a further embodiment of an apparatus for sterilizing a lift 200. The apparatus 200 is similar to the apparatus 10 illustrated in Figures 1 to 4, and similar reference numbers are used to denote similar parts. The housing 12 incorporates turning vanes 202, 204, 206, 208, 210, 212, 214 and 216 which may act to help redirect airflow within the housing 12. Fans 230, 232, 234, 236, 238, 240 and 242 are located proximate corresponding turning vanes and thereby direct the airflow within the conduit of the housing 12. The turning vanes shield the fans from direct irradiation of potentially damaging rays from light bulbs 220 and 222.

In the embodiment 200, light bulbs 220 and 222 are arranged in a “+’ formation within the housing 12.

Figures 1 1 -1 and 12-1 illustrate details of Figures 1 1 and 12 and show that the outlet, here provided by edge diffuser 250, is provided with adjustable nozzles 252 and 254. Although only two nozzles are shown, it is to be realised that more or fewer than two may be provided. In the embodiment illustrated, the nozzles are manually adjustable, but remotely adjustable nozzles may be provided instead, or as well as. Adjustable nozzles 252 and 254 may allow the spread of air discharged by edge diffuser 36 to be adjusted to suit the lift size.

Figures 13A and 13B illustrate an apparatus 300 according to an alternate embodiment that comprises a tangential fan 20’. The apparatus 300 has a hatch 304 formed in the housing 202. The hatch 204 is attached by a hinge 206 which allows the hatch 304 to pivot between the positions shown in Figures 13A and 13B.

The hatch 204 provides access to the interior of the apparatus 200 and, as illustrated in Figure 10B, when in the open position, provides easy access to the components such as the internal light bulbs 1 14A and 1 14B, when these need to be replaced, for example. ln order to avoid potential harm to maintenance personnel, the housing 102 comprises a switch 140 which is activated when the hatch 204 is opened. Activation of the switch disables the light sources in the apparatus 200, thereby potentially avoiding accidental exposure of maintenance personnel to harmful radiation. The switch 140 is located so that is it also activated if the filter 110 is removed, or omitted when the hatch 304 is closed.

In certain embodiments, where the apparatus has been mounted for pivoting movement relative to the ceiling, the apparatus may also comprise a switch which disables the light sources when the apparatus is pivoted away from the lift ceiling.

As illustrated in all of the above figures, the fans are located at a spaced distance from the sterilizing light source which acts to sterilize the airflow. Having a fan which is too close to the sterilizing light source may cause excessive or spot cooling of the light source, potentially reducing the lifespan of the light source. Furthermore, if the sterilizing light source is too close to the fan, this can affect the airflow, potentially reducing the efficacy of the airflow. Within the apparatus, the airpath and volume of air illuminated by the sterilising light sources may be configured to prolong the contact time between UV-C light and particles in the air as air flows through the apparatus so as to increase the sterilisation effect of the discharged air. Surfaces internal to the apparatus that illumination from the sterilizing light sources reflects off may, furthermore, be reflective, to increase UV-C light intensity, thereby further increasing the sterilisation effect.

Embodiments may provide space for services such as loud speakers, CCTV, lighting or other services which may be provided in the ceiling of a lift. For example, with reference to Figures 2 and 3, four internal cabin lights are provided at 44.

The apparatus 10, 150, 190, 200 illustrated in Figures 1 through 12 are slightly rectangular and this may fit many lifts, in particular with square or slightly rectangular cabin footprints. The apparatuses 10, 150, 190 and 200 may have plan dimensions of approximately 1 .2 m x 0.9 m which may be well suited to fit into most commonly used passenger lift.

However, it is to be realised that further embodiments may be made to lifts having a strongly rectangular cross-section. In particular, a further set of elongate UV-C (or other sterilizing) light bulbs arranged in an X-shape or a “+” shape, or other configurations not shown such as parallel to one another, may be provided and located next-to the light bulbs discussed. A further set of fans and appropriate airflow ducting or conduit may be supplied to direct the air over the light bulbs and out of the appropriate outlets. Therefore, lifts having a different floor plan than substantially square may be accommodated.

Since the apparatus of embodiments may be retrofitted to existing lifts, the apparatus may be provided as a kit of parts. In one embodiment, the kit comprises the apparatus pre-constructed so that it may be installed directly into a lift. Alternatively, the apparatus may be provided as multiple modules. This may be applicable for larger lifts where, for example, two apparatuses similar to the apparatus 10 as illustrated in Figures 1 to 6 or the apparatus 200 in Figures 10 to 12 may be provided next to one another. As a further alternative, the apparatus may be provided as a kit comprising constituent parts, e.g. the housing, fans and light bulbs, which are then assembled and installed on site.

Although the embodiments above have been described with reference to a lift, it is to be understood that further embodiments may be used in any relatively small enclosed space (i.e. where it is practical to cover substantially the whole ceiling with the apparatus). Embodiments may be particularly applicable to any small enclosed space which is communal where the risks of infection are increased. For example, embodiments may be applied to lockers, cold rooms, pantries, bathrooms, kitchens, offices, meeting rooms, gyms, trains, etc. Since it may be necessary to provide the apparatus over almost the entire ceiling area of the space, to potentially ensure that the ‘wash’ provided by the downward air helps to reduce the risk of infection, embodiments, or embodiments per kit, may be limited to enclosed spaces having a floor area of less than 10 m ² .

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments. Similarly, the word “device” is used in a broad sense and is intended to cover the constituent parts provided as an integral whole as well as an instantiation where one or more of the constituent parts are provided separate to one another.