WO2021074637A1

WO2021074637A1 - An air filtration system

Info

Publication number: WO2021074637A1
Application number: PCT/GB2020/052608
Authority: WO
Inventors: Stephen Partridge; Steve HALEY
Original assignee: Stephen Partridge; Haley Steve
Priority date: 2019-10-17
Filing date: 2020-10-16
Publication date: 2021-04-22
Also published as: GB2588386A8; GB2588386A; GB201915052D0

Abstract

The present disclosure relates to an air filtration system comprising a barrier configured to be installed at the side of a road and comprising a duct and at least one inlet. The air filtration system further comprises a filter; an air flow generator; and, an outlet. The duct is configured for fluidly communicating the inlet with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet and through the filter to be expelled from the outlet.

Description

An air filtration system Technical Field

The present disclosure relates to an air filtration system and to a kit of parts for an air filtration system.

Background

Air pollution in urban environments is linked to numerous health problems, including ischaemic heart disease, stroke, chronic obstruction pulmonary disease and lung cancer. A significant contribution to air pollution is vehicle emissions. This includes noxious gases, including nitrogen oxides, and particular matter, including PM 2.5 and PM 10 pollutants.

An object of the present disclosure is to provide an air filtration system and a kit of parts for an air filtration system that reduces the level of one or more of these pollutants in the air.

Summary

According to the present invention, there is provided an air filtration system comprising: a barrier configured to be installed at the side of a road and comprising a duct and at least one inlet; a filter; an air flow generator; and, an outlet, wherein the duct is configured for fluidly communicating the inlet with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet and through the filter to be expelled from the outlet.

In some embodiments, the air filtration system comprises an air treatment unit that comprises the filter, air flow generator and outlet. In some embodiments, the barrier comprises a housing and the air treatment unit comprises a housing. The housing of the barrier may contain the duct. The housing of the air treatment unit may contain the filter. The air treatment unit and barriers may be configured to be installed side by side at the side of the road.

In some embodiments, the air treatment unit is configured to be installed at the side of the road adjacent to the barrier. In some embodiments, the barrier and air treatment unit are distinct and separate components that are configured to be connected to each other.

In some embodiments, the air treatment unit and barrier form a modular air filtration system.

In some embodiments, the air treatment unit comprises a first port for fluidly communicating the air flow generator with the duct of the barrier and a second port for fluidly communicating the air flow generator with a duct of a second barrier.

In some embodiments, the inlet is configured to draw air into a first side of the air filtration system and the outlet is configured to expel air from a second side of the air filtration system. In some embodiments, the barrier has a depth of less than o.8 metres and, preferably, has a depth of less than o.6 metres.

In some embodiments, the barrier has a height of between l and 1.5 metres. In some embodiments, the barrier has a length of at least 10 metres and, preferably, at least 15 metres.

In some embodiment, the barrier unit has a length of at least 3 metres and preferably, at least 4 metres.

In some embodiments, the barrier length has a length of between 3 and 7 metres.

In some embodiments, the air treatment unit has a height of greater than 2 metres and, preferably, greater than 3 metres.

In some embodiments, the barrier is a pedestrian barrier.

In some embodiments, the pedestrian barrier comprises a support structure configured to reinforce the barrier. In some embodiments, the support structure comprises a frame and plurality of support members configured to reinforce the support structure.

In some embodiments, the frame comprises a pair of spaced bars and wherein the support members extend between the bars and, preferably, extend substantially vertically between the spaced bars. In some embodiments, the bars of frame are substantially horizontal.

In some embodiments, the support structure comprises one or more slots that are each configured to receive an inlet such that the inlet is fluidly communicated with the duct.

The frame may surround the duct.

In some embodiments, the air filtration system comprises one or more exterior panels that are mounted to the support structure.

In some embodiments, the barrier is configured to be anchored to the ground and, preferably, the barrier comprises a plurality of legs that are configured to be anchored within holes in the ground.

In some embodiments, the legs are integrally formed with body of frame. In some embodiments, the legs are tubular and have a wall thickness of at least 4 mm and, preferably, at least 5 mm. In some embodiments, one of the depth and width of the legs is at least 40 mm and the other one of the depth and width of the legs is at least 50 mm. The depth and width of the legs may be both perpendicular to the height of the legs.

In some embodiments, the duct is configured to extend substantially the entire length of the barrier.

In some embodiments, the barrier comprises a plurality of barrier units that each has a duct and one or more inlets, wherein the barrier units are configured to be installed by the side of the road adjacent to each other such that the ducts of adjacent barrier units are fluidly communicated and therefore the inlets of the barrier units are fluidly communicated with the outlet. In some embodiments, the air filtration system further comprises a second barrier configured to be installed at the side of a road and comprising a duct and at least one inlet, wherein the duct of the second barrier is configured for fluidly communicating the inlet of the second barrier with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet of the second barrier and through the filter to be expelled from the outlet.

In some embodiments, the second barrier also comprises a plurality of barrier units each comprising ducts and one or more inlets.

In some embodiments, the air filtration system comprises a bicycle rack and/ or a screen configured to display pollution information. In some embodiments, the air flow generator 11 is configured to generate a flow rate through the air flow generator 11 of at least 4 ms/s and, preferably, at least 5 ms/s, at least 7 m3/s, at least 9 ms/s, at least 10 ms/ s, or at least 11 ms/s. A larger flow rate means that more pollutants can be removed from the air by the filters 12, 13. In some embodiments, the air filtration system comprises a moisture sensor configured to detect information indicative of the moisture content of the air and a controller configured such that the airflow generator is powered-off if the information indicative of the moisture content exceeds a predetermined value. In some embodiments, the air filtration system comprises a pollution sensor configured to detect information indicative of pollution.

In some embodiments, the air filtration system may comprise a surveillance system, for instance, one or more CCTV cameras. The surveillance system may be configured to detect passing vehicles on the road and, optionally, may be configured to detect the registration plates or other identifiers of said passing vehicles. Additionally, or alternatively, the surveillance may be configured to monitor the pavement in proximity to the air filtration system. In some embodiments, the air filtration system comprises an ambient air pollution sensor configured to detect information indicative of the ambient pollution levels. For instance, the first pollution sensor may detect pollution in the air at the exterior of the air filtration system. In another embodiment, the first pollution sensor is located within the air filtration system upstream of the filters. Additionally, or alternatively, the air filtration system comprises a filter output pollution sensor configured to detect information indicative of the pollution of the air that has passed through the filter. The filter output pollution sensor may be disposed downstream of the filter. This pollution level detected by the filter output pollution sensor may be used to determine the efficiency of one or more of the filters and thus whether the filters need maintenance and/ or replacing.

In some embodiments there is provided a plurality of air filtration systems each comprising one or more pollution sensors, wherein each air filtration system is configured to transfer information indicative of pollution levels detected by one or more of the pollution sensors of the system to a remote location. The remote location may be a server. In some embodiments, the server is configured to transfer information indicative of pollution levels to a user device, for example, a personal computer, smartphone or tablet. In some embodiments, the server is configured to transmit an alarm signal when the pollution level exceeds a predetermined level. For example, when the ambient pollution exceeds a predetermined level and/ or when the filter output pollution exceeds a predetermined level.

In some embodiments, the air filtration system is a modular air filtration system. In some embodiments, the barrier has a depth of less than 0.8 metres. The depth of the barrier may be measured between first and second sides of the barrier, wherein the first side of the barrier may be on the road side of the barrier and the second side of the barrier may be opposite the first side. In some embodiments, the barrier is configured to separate air on a first side of the barrier from air on a second side of the barrier. The first side of the barrier may be on the road side of the barrier. The second side of the barrier may be opposite the first side, for example, the second side may be on the pavement side of the barrier. In such embodiments, the barrier maybe configured such that polluted air from the side of the road must flow over the top of the barrier to pollute the air on the opposite side of the barrier. The barrier thus reduces pedestrians exposure to polluted air at the road side. In some embodiments, the barrier comprises a shield configured to separate air on a first side of the shield from air on a second side of the shield and, preferably, wherein the shield is transparent or partially transparent.

In some embodiments, the shield is configured such that, in use of the air filtration system, the shield is located above the duct.

In some embodiments, the shield comprises a panel.

In some embodiments, the air filtration system comprises a positioning system configured to determine the location of the air filtration system.

In some embodiments, the air filtration system comprises one or more cameras and, preferably, at least one of the cameras is configured to detect passing vehicles on the road and, preferably, at least one of the cameras is configured to detect the registration plates or one or more other identifiers of said passing vehicles.

According to the present disclosure, there is also provided a kit of parts for an air filtration system comprising: a barrier unit comprising a duct and at least one inlet; and, an air treatment unit comprising a filter, air flow generator and outlet, wherein the barrier unit and air treatment unit are configured to be installed at the side of a road such that the outlet is fluidly communicated with the inlet via the duct such that, in use, the air flow generator is operable to draw air from the road into the inlet and through the filter to be expelled from the outlet. The air filtration system of the kit of parts may have any of the aforementioned features.

In some embodiments, the kit of parts comprises a second barrier unit that comprises a duct and at least one inlet, the second barrier unit configured to be installed at the side of the road such that the inlet and duct of the second barrier unit are fluidly communicated with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet of the second barrier unit and through the filter to be expelled from the outlet. In some embodiments, the barrier units maybe attached together and/or attached to the air treatment unit. In some embodiments, the barrier unit forms or is part of a barrier, for example, a pedestrian barrier. In some embodiments, the kit of parts comprises a plurality of barrier units, for example, at least two, at least three, at least four, at least five or at least six barrier units. Each barrier unit comprises a duct and an inlet. In some embodiments, the kit of parts comprises a plurality of air treatment units that each comprises a filter, air flow generator and outlet.

According to the present disclosure there is also provided a method of installing an air filtration system, method comprising: providing a barrier unit comprising a duct and at least one inlet; providing an air treatment unit that comprises a filter, an air flow generator and an outlet; and, installing the barrier unit and air treatment unit at the side of a road such that the duct fluidly communicates the inlet with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet and through the filter to be expelled from the outlet.

The air filtration system of the method may have any of the aforementioned features.

In some embodiments, the barrier unit forms or is part of a barrier, for example, a pedestrian barrier. In some embodiments, a plurality of barrier units are connected together to form a barrier.

In some embodiments, the method further comprises: providing a second barrier unit comprising a duct and at least one inlet; and, installing the second barrier unit at the side of a road such that the inlet and duct of the second barrier unit are fluidly communicated with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet of the second barrier unit and through the filter to be expelled from the outlet. In some embodiments, the barrier unit is located on an opposite side of the air treatment unit to the second barrier unit. In some embodiments, the second barrier unit is located at an opposite end of the barrier unit to the air treatment unit such that air entering the inlet of the second barrier unit flows into the duct of the second barrier unit and then into the duct of the barrier unit.

In some embodiments, the method comprises providing and installing a plurality of barrier units at the side of the road, for example, at least two, at least three, at least four, at least five or at least six barrier units. Each barrier unit comprises a duct and an inlet. In some embodiments, one or more of the barrier units is installed on the opposite side of the air treatment unit to one or more of the other barrier units. In some embodiments, the method comprises providing and installing a plurality of air treatment units that each comprises a filter, air flow generator and outlet. Brief Description of the Drawings

Embodiments of the invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Fig. l is a perspective view of an air filtration system according to an embodiment; Fig. 2 is a first side view of the air filtration system of Fig. l;

Fig. 3 is a second side view of the air filtration system of Fig. l;

Fig. 4 is a top view of an air treatment unit and first and second barrier units of the air filtration system of Fig. l;

Fig. 5 is a front view of the air treatment unit and first and second barrier units of the air filtration system of Fig. l;

Fig. 6 is a rear view of the air treatment unit and first and second barrier units of the air filtration system of Fig. l;

Fig. 7 is a cross-sectional view of the air treatment unit and first and second barrier units along the line A-A shown in Fig. 4; Fig. 8 is a cross-sectional view of the air treatment unit and first barrier unit along the line B-B shown in Fig. 4, with cover panels of the air treatment unit removed for illustrative purposes;

Fig. 9 is a cross-sectional view of the air treatment unit along the line C-C shown in Fig.

4; Fig. 10 is a cross-sectional view of a first barrier unit along the line D-D in Fig. 4;

Fig. 11 is a front view of a frame of the air treatment unit of the air filtration system of Fig. 1;

Fig. 12 is a rear view of the frame of the air treatment unit;

Fig. 13 is a first side view of the frame of the air treatment unit; Fig. 14 is a second side view of the frame of the air treatment unit;

Fig. 15 is a side view of an upright of the frame of the air treatment unit;

Fig. 16 is a top view of the upright of the frame of the air treatment unit;

Fig. 17 is a front view of a road side section of a frame of a barrier unit of the air filtration system of Fig. 1; Fig. 18 is a rear view of a pavement side section of the frame of the barrier unit;

Fig. 19 is a top view of the frame of the barrier unit; Fig. 20 is a top view of an upright of the road side section of frame shown in Fig. 17;

Fig. 21 is a cross-sectional view of the frame and a duct of the frame of the barrier unit, along the line E-E shown in Fig. 19;

Fig. 22 is a schematic diagram illustrating a controller of the air filtration system of Fig. 1; and,

Fig. 23 is a second configuration of an air filtration system according to an embodiment.

Detailed Description Referring now to Figs. 1 to 22, an air filtration system 1 according to an embodiment is shown. The air filtration system 1 is configured to be installed on a pavement P by the side of a road R. In the present embodiment, the air filtration system 1 is spaced from the edge of the kerb K to avoid collision with the wing mirrors of passing vehicles. The air filtration system 1 comprises an air treatment station or unit 2, used interchangeably hereinafter. The air filtration system 1 further comprises first and second barriers 3, 4. In the present embodiment, the first and second barriers 3, 4 are pedestrian barriers 3, 4. The pedestrian barriers 3, 4 maybe manufactured to meet the requirements of British Standard BS1722 part 9.

The air treatment unit 2 has a front, rear, top, bottom and first and second sides, 2A, 2B, 2C, 2D, 2E, 2F. The front 2A is configured to face towards the road R when the air filtration system 1 is installed by the side of the road R and the rear 2B faces away from the road R. The bottom 2D is configured to be mounted to the pavement P or another surface by the side of the road R. The air treatment unit 2 extends upwardly from the bottom 2D to the top 2C.

The air treatment unit 2 comprises a frame 5 and a housing 6 that covers, or at least partially covers, the frame 5. The air treatment unit 2 further comprises a duct 7 that is disposed within the frame 5 and extends to an outlet 8 in the housing 6. The outlet 8 is located towards the top 2C of the air treatment unit 2 and is configured such that the outlet 8 is directed away from the road R when the air filtration system 1 is installed by the side of the road R. The air treatment unit 2 comprises first and second ports 9, 10 in the first and second sides 2E, 2F respectively of the air treatment unit 2. The first and second ports 9, 10 are fluidly connected with the duct 7 via first and second channels 9A, 10A respectively. In an alternative embodiment (not shown), the first and second channels 9A, 10A are omitted and the duct 7 extends directly to the first and second ports 9, 10. The air treatment unit 2 further comprises an air flow generator 11 and first and second filters 12, 13 that are located within the duct 7. The air flow generator 11 is operable to induce an air flow that draws air into the duct 7 via the first and second ports 9, 10 such that the air travels along the duct 7, through the first and second filters 12, 13 and is then expelled from the outlet 8. In the present embodiment, the air flow generator 11 comprises one or more fans that are powered by an electric motor (not shown). The electric motor is connected to a power source (not shown), for example, at least one of a mains supply (not shown), battery (not shown) or solar panels (not shown).

In some embodiments, the air flow generator 11 is configured to generate a flow rate through the air flow generator 11 of at least 4 m³/s and, preferably, at least 5 m³/s, at least 7 m3/s, at least 9 m³/s, at least 10 m³/ s, or at least 11 m³/s. A larger flow rate means that more pollutants can be removed from the air by the filters 12, 13.

In some embodiments, the air flow generator 11 comprises an inline centrifugal duct fan. However, the skilled person will recognise that other types of air flow generator will be suitable. Optionally, the fan is an Airmover fan manufactured by Nuaire (TM).

The frame 5 is generally cuboidal and comprises first, second, third and fourth uprights 15A, 15B, 15C, 15D. The frame 5 maybe a generally rectangular parallelepiped shape.

The first upright 15A is disposed at the corner of the air treatment unit 2 where the front 2A meets the first side 2C. The second upright 15B is disposed at the corner of the air treatment unit 2 where the front 2A meets the second side 2D. The third upright 15C is disposed at the corner of the air treatment unit 2 where the rear 2B meets the first side 2C. The fourth upright 15D is disposed at the corner of the air treatment unit 2 where the rear 2B meets the second side 2D. The uprights 15A, 15B, 15C, 15D form longitudinal edges of the frame 5.

A top view of the first upright 15A is shown in Fig. 16. A side view of the first upright 15A is shown in Fig. 15. Each upright 15A, 15B, 15C, 15D has the same features, and extends longitudinally and comprises a plurality of slots 16A and a plurality of bolt holes i6B.

The air treatment unit 2 comprises a plurality of front support members 17A, 17B, 17C, 17D, 17E that extend between the first and second uprights 15A, 15B such that opposite ends thereof are received in respective slots 16A of the first and second uprights 15A, 15B.

The air treatment unit 2 comprises a plurality of rear support members 18A, 18B, 18C, 18D, 18E that extend between the third and fourth uprights 15C, 15D such that opposite ends thereof are received in respective slots 16A of the third and fourth uprights 15C, 15D.

The air treatment unit 2 comprises a plurality of first side support members 19A, 19B, 19C, 19D, 19E that extend between the first and third uprights 15A, 15C such that opposite ends thereof are received in respective slots 16A of the first and third uprights 15A, 15C.

The air treatment unit 2 comprises a plurality of second side support members 20A, 20B, 20C, 20D, 20E that extend between the second and fourth uprights 15B, 15D such that opposite ends thereof are received in respective slots 16A of the second and fourth uprights 15B, 15D.

A number of the slots i6Aand corresponding bolt holes 16B of each upright 15A, 15B, 15C, 15D are arranged at substantially ninety degrees to the remaining slots 16A and bolt holes 16B to allow for the support members 17A to 20D to be connected to the respective uprights 15A, 15B, 15C, 15D at ninety degrees to form a generally cuboidal structure. For instance, the front support members 17A, 17B, 17C, 17D will slot into the first upright 15A at ninety degrees to the first side support members 19A, 19B, 19C, 19D.

Each support member 17A to 20D has a generally U-shaped cross-section with closed ends or flanges that each comprise a bolt hole (not shown). In other words, each support member lyAto 20D is generally trough-shaped. A bolt (not shown) extends through the bolt hole 16B of each upright 15A, 15B, 15C, 15D to be secured into the bolt hole (not shown) of a respective support member 17A to 20D to secure the support member 17A to 20D to the upright 15A, 15B, 15C, 15D. However, the skilled person will recognise that other means of securing the components of the frame 5 are possible, for example, screws or welds.

The air treatment unit 2 further comprises diagonal front support members 17F, 17G that extend between the first and second uprights 15A, 15B and have opposing ends that are each secured to the first and second uprights 15A, 15B respectively by, for example, bolts, screws or welds. The air treatment unit 2 also comprises diagonal rear support members 18F, 18G that extend between the third and fourth uprights 15C, 15D and have opposing ends that are each secured to the third and fourth uprights 15C, 15D respectively by, for example, bolts, screws or welds.

The air treatment unit 2 further comprises vertical first side support members 19F, 19G that extend between two or more of the first side support members 19A 19B, 19C, 19D, 19E and are secured thereto. Moreover, the air treatment unit 2 further comprises vertical second side support members 20F, 20G that extend between two or more of the second side support members 20A 20B, 20C, 20D, 20E and are secured thereto.

It should be recognised that in alternative embodiments (not shown), one or more of the support members 17A to 20G may have a different orientation. For instance, one or more of support members 17A to 17E, 18A to 18E, 19A to 19E, or 20A to 20E may extend diagonally between the respective uprights 15A to 15D. Similarly, vertical support members 19F, 19G, 20F, 20G may instead extend diagonally between respective support members i9Ato 19E, 2oAto 20E. Moreover, diagonal support members 17F, 17G, 18F, 18G may instead extend vertically between one or more respective support members 17A to 17E, 18A to 18E.

The housing 6 comprises front and rear panels 22A, 22B and first and second side panels 22C, 22D. The front panel 22A is mounted to the frame 5 at the front 2A of the air treatment unit 2. The rear panel 22B is mounted to the frame 5 at the rear 2B of the air treatment unit 2. The first and second side panels 22C, 22D are mounted to the frame 5 at the first and second sides 2E, 2F respectively of the air treatment unit 2. The front, rear and side panels 22A to 22D together form a generally cuboidal structure, being generally rectangular parallelepiped in shape. In some embodiments, the panels 22A to 22D are configured to slot into guide rails (not shown) mounted to the frame 5 and are then secured into place with fasteners, for example, screws. The housing 6 further comprises a curved hood 23 at the top 2C of the air treatment unit 2.

The outlet 7 is provided in the rear panel 22B, towards the top 2C of the air treatment unit 2.

A first door 24A is provided in the first side panel 22A to allow access to the interior of the air treatment unit 2. A second door 24B is provided in the second side panel 22B to allow access to the interior of the air treatment unit 2. In the present embodiment, the first door 24A provides maintenance access to the filters 12, 13 and the second door 24B provides access to the air flow generator 11 and controller 48.

One or more of the support members 17A, 18A, 19A, 20A at the bottom of the frame 5 of the air treatment unit 2 comprises one or more apertures (not shown) to allow for the air treatment unit 2 to be mounted to the pavement P or other surface. In some embodiments, the air treatment unit 2 is mounted to the pavement P by one or more chemical anchors (not shown) that each through a respective aperture in the support members 17A, 18A, 19A, 20A. The first pedestrian barrier 3 is attached to the first side 2E of the air treatment unit 2 and the second pedestrian barrier 4 is attached to the second side 2F of the air treatment unit 2.

The first and second pedestrian barriers 3, 4 each comprise a plurality of barrier units 3A, 3B, 3C, 4A, 4B, 4C.

In the present embodiment, the first pedestrian barrier 3 comprises three barrier units 3A, 3B, 3C that are connected together to form the first pedestrian barrier 3 and the second pedestrian barrier 4 comprises three barrier units 4A, 4B, 4C that are connected together to form the second pedestrian barrier 4. However, it should be recognised that the number of barrier units 3A to 4C may be varied. This allows for the length L3, L4 of each pedestrian barrier 3, 4 to be easily altered to fit different configurations of pavement with different street furniture layouts. An example of a variation in the configuration of the air filtration system 1 is shown in Fig. 23, wherein the first pedestrian barrier 3 comprises a single barrier unit 3A and the second pedestrian barrier 4 comprises first, second and third barrier units 4A, 4B, 4C. The barrier units 3A, 3B, 3C, 4A, 4B, 4C have the same features unless otherwise stated and therefore, for the sake of brevity, only one of the barrier units 3A will be described in detail hereinafter.

The barrier unit 3A comprises a support structure 25, a housing 26, a duct 27 and one or more inlets 28.

The support structure 25 is configured to reinforce the barrier unit 3A such that, if a road vehicle crashes into the barrier unit 3A, then pedestrians on the pavement P will be protected by the barrier unit 3A.

The support structure 25 comprises a frame 29 and a plurality of support members 30 that are configured to reinforce the frame 29.

The frame 29 comprises first, second, third and fourth uprights 31A, 31B, 31C, 31D that are arranged sequentially in a straight line. The frame 29 further comprises upper and lower front bars 32A, 32B that extend substantially horizontally between the uprights 3iAto 3iD.

The support members 30 extend substantially vertically between the upper and lower front bars 32A, 32B. The support members 30 reinforce the frame 29.

A plurality of slots 33 are provided in the support structure 25 to accommodate each inlet 28. This results in a gap in the support members 30 at each of the slots 33, which could weaken the support structure 25. To prevent such weakening of the support structure 25, the support structure 25 comprises further members 34 that extend substantially horizontally between the free ends of the support members 30 at the edge of the slots 33. The members 34 may be attached to said ends of the support members 30 by welds or other attachment means.

In some embodiments, the support structure 25 comprises at least thirty support members 30 and, preferably, at least forty support members 30. The support structure 25 may comprise at least thirty support members 30 that are each substantially vertical. Each of the uprights 31A to 31D comprises a leg 35A to 35D that extends downwardly past the lower bar 32B. Each leg 35A to 35D is configured to be inserted into a hole in the pavement P and secured in place, for example, with cement. The legs 35A to 35D are shown in dashed lines in Figs. 17 to depict that the legs 35Ato 35D are received in the pavement P.

In some embodiments, each leg 35A to 35D has a height Hi of at least about 250 mm and preferably, at least about 300 mm. This has been found to provide a more secure anchoring to the pavement P.

In some embodiments, each leg 35A to 35D is integrally formed with the remainder of the upright 31A to 31D, which has been found to increase the strength of the support structure 25. In other words, each leg 35A to 35D and respective upright 31A to 31D is formed form a single piece of material, for instance, a longitudinal bar.

In some embodiments, one of the depth Di or width Wi of each upright 31A to 31D is at least about 25 mm and the other one of the depth Di or width Wi of each upright 31A to 31D is at least about 45 mm. Preferably, one of the width Wi or depth Di of each upright 31A to 31D is at least about 30 mm and the other one of the width Wi or depth Di of each upright 31A to 31D is at least about 50 mm. In the present embodiment, the uprights 31A to 31D are tubular and may have a wall thickness that is at least about 4 mm thick and, preferably, at least about 5 mm thick.

The depth Di of each upright 31A to 31D may be measured perpendicular to the road R, in a direction from the road R to the pavement P. The width Wi may extend parallel to the road R, in a direction perpendicular to the depth Di.

In some embodiments, the uprights 3iAto 31D, support members 30 and/or upper and/or lower front bars 32A, 32B are manufactured from metal, for example, steel.

The frame 29 further comprises upper and lower rear bars 32C, 32D. A plurality of rear uprights 36A to 36F extend between the upper and lower rear bars 32C, 32D. Rear support members 37A extend diagonally or horizontally between adjacent uprights 36A to 36F. The front uprights 3iAto 31D and upper and lower front bars 32A, 32B are connected to the rear uprights 35A to 35E and upper and lower rear bars 32C, 32D by a plurality of connecting members 38. In the present embodiment, the connecting members 38 comprise longitudinal bars that are connected to the respective components by bolts or welds.

In the present embodiment, the connecting members 38 each have a generally U- shaped cross-section with closed ends or flanges that each comprise a bolt hole (not shown). In other words, each connecting members 38 is generally trough-shaped. A bolt (not shown) extends through the bolt hole (not shown) in each upright 31A to 31D, rear upright 36A to 36F and/or the upper and lower bars 32A to 32D such that these components are secured to the connecting members 38. However, the skilled person will recognise that other means of securing the components of the frame 5 are possible, for example, screws or welds.

The frame 29 may additionally, or alternatively, comprise brackets 39 that help to secure the connecting members 38 to the components of the frame 29. The brackets 39 improve the rigidity of the structure 25. The lower connecting members 38 comprise one or more apertures (not shown), for example, bolt holes, to facilitate securing of the frame 29 to the pavement P. For instance, chemical anchors 40 may be used to attach the frame 29 to the pavement P via the apertures in the lower connecting members 38. In some embodiments, the barrier unit 3A has a length L2 of at least 3 metres, at least 4 metres or at least 5 metres. In some embodiments, the barrier unit 3A has a length L2 of between 3 and 7 metres and, preferably, between 4 and 6 metres. In one embodiment, the barrier unit 3A has a length L2 of about 5 metres. The length L2 of the barrier unit 3A refers to the distance between opposing first and second ends 43A, 43B of the barrier unit 3A. The road R extends longitudinally parallel to the length L2 of the barrier unit 3A when the barrier unit 3A is installed by the side of the road R.

The length L2 of the barrier unit 3A means that the barrier unit 3A is able to draw in polluted air into the inlets 28 from a relatively larger section of the roadside than if the frame 29 had a smaller length L2. Each barrier unit 3A to 4C also acts as a barrier between pedestrians on the pavement P and polluted air at the road R, thus helping to protect the pedestrians from the polluted air. In some embodiments, the frame 29 has a height H2 of at least 1 metre, measured including the height Hi of the legs 35A to 35D. The height H2 of the frame 29 may be at least 1.3 or 1.5 metres.

In some embodiments, the frame 29 has a height H3 of at least 0.7 metres, not including the height Hi of the legs 35A to 35D. That is, height H3 is the height of the top of the frame 29 from the ground when the frame 29 is installed at the side of the road such that the legs 35A to 35D are installed in apertures in the pavement P. Preferably, height H3 is at least 1 metre and, preferably, at least 1.2 metres. In the present embodiment, the height H3 of the frame 29 is the distance between the upper and lower front bars 32A to 32B. Height H2 is the sum of height Hi and height H3.

In some embodiments, the frame 29 has a depth D2 of less than 0.6 metres and, preferably, less than 0.5 metres. The depth D2 of the frame 29 is measured perpendicular to the longitudinal direction of the road R. Thus, depth Di and D2 are perpendicular to both directions of vehicle travel on the road. The smaller the depth D2, the less space that the frame 29 takes up on the pavement P. In one embodiment, the frame 29 has a depth of about 0.4 metres.

The barrier unit 3A further comprises front, rear and top panels 41A, 41B, 41C that are attached to the frame 29. The panels 41A to 41C form a housing of the barrier unit 3A.

The front panel 41A comprise a plurality of slots 42 that align with respective slots 33 in the frame 29. The inlets 28 extend through the slots 42 and slots 33 to fluidly communicate the ambient air at the roadside R with a duct 27 that is located within the frame 29.

The barrier unit 3A comprises opposite first and second ends 43A, 43B. The duct 27 extends the length L2 of the frame 29 between the first and second ends 43A, 43B. The first and second ends 43A, 43B of the barrier unit 3A are open such that the barrier unit 3A comprises a first port 44A at the first end 43A and a second port (not shown) at the second end 44B. The first and second ports 44A are configured to allow the duct 27 of the barrier unit 3A to be fluidly connected to the duct 27 of an adjacent barrier unit 3B via a respective port on said adjacent barrier unit 3B. The first and second ports 44A are also configured to allow the duct 27 of the barrier unit 3A to be fluidly connected to the duct 7 of the air treatment unit 2 via the first or second port 9, 10 of the air treatment unit 2. In some embodiments, one or both ports 9, 10, 44A of the air treatment unit 2 and/ or barrier units 3A to 4C may comprise a connecting member and/ or sealing member (not shown), for example, a rubber gasket, to facilitate a sealed connection to the port 9, 10, 44A of an adjacent sealing unit 2 or barrier unit 3A to 4C. However, it should be recognised that in alternative embodiments the sealing member maybe omitted. For instance, the ports 44A of the barrier units 3A to 4C may simply comprise the open ends 43A, 43B with the duct 27 extending to said open ends 43A, 43B.

The barrier unit 3A to 4C that is furthest from the air treatment unit 2 has an end panel 45 that seals, or substantially seals, the end 43A, 43B of said barrier unit 3A to 4C that is furthest from the air treatment unit 2 and thus is not connected to an adjacent barrier unit 3A to 4C.

In use of the air filtration system 1, the air flow generator 11 is operated to draw air from the roadside into the inlets 28 of the barrier units 3A to 4C such that the air is drawn along the ducts 27 and into the first and second channels 9A, 10A of the air treatment unit 2 via the first and second ports 9, 10. The air then travels through the first and second channels 9A, 10A and into the duct 7 of the air treatment unit 2 wherein the air is drawn through the first and second filters 12, 13 and is then expelled from the outlet 8.

The first and second filters 12, 13 are configured to remove pollutants from the air such that the air expelled from the outlet 8 is cleaner than the air from the roadside drawn into the inlets 28. Therefore, the air filtration system 1 helps to reduce levels of pollutants in the air. In some embodiments, the outlet 8 is directed towards rear 2B of the air treatment unit 2 such that the cleaner air expelled from the outlet 8 mixes with the air on the pavement P that is breathed by pedestrians. In some embodiments, the outlet is at least 1.8 metres above the ground and, preferably, is at least 2 metres, 2.2 metres or 2.4 metres above the ground. This helps to prevent the outlet 8 from blowing the air directly on to passing pedestrians, which may otherwise be disruptive. In some embodiments, the outlet 8 is configured to expel the air substantially horizontally. If the air was directed downwards, then it may disrupt passing pedestrians.

In some embodiments, the height of the outlet 8 from the ground is greater than the height of the inlets 27 from the ground. This allows for polluted air to be drawn into the air filtration system 1 at a height proximate to the height of a vehicle exhaust, and to be expelled at a height that is more readily breathed in by pedestrians.

In the present embodiment, the first filter 12 is configured to remove particulates, for example, PM 10 or PM 2.5. The first filter 12 may be a HEPA filter. The second filter 13 is configured to remove one or more gases, for example, nitrogen oxides such as nitrogen monoxide and/ or nitrogen dioxide. The first filter 12 may comprise an adsorbent. The first filter 12 may comprise activated carbon. However, it should be recognised that both of the filters 12, 13 may be configured to remove particulates or gases. Alternatively, one of the filters 12, 13 maybe omitted. In yet another embodiment, both filters 12, 13 may be combined. In one such embodiment (not shown), the system 1 may comprise a single filter that filters both particulates and pollutant gases and may comprise, for example, a HEPA filter impregnated with an adsorbent such as activated carbon.

The air filtration system 1 is configured to be mounted next to the kerb K and thus is in close proximity to the road R. This improves the effectiveness of the air filtration system 1 at filtering pollutants. This is because it has been found that pollutants will dissipate from the source, such as a vehicle exhaust, and thus the closer the air filtration system 1 is to the source the greater the proportion of the pollutants that will be drawn into the inlets 28 and removed from the air by the filters 12, 13. Advantageously, the pedestrian barriers 3, 4 can be fitted in place of existing pedestrian barriers to save room on the pavement P. In the embodiment shown in Figs l to 22, the first pedestrian barrier 3 comprises first, second and third barrier units 3A, 3B, 3C and the second pedestrian barrier 4 comprises first, second and third barrier units 4A, 4B, 4C. However, the modular nature of the air filtration system 1, with the barrier units 3A to 4C and air treatment unit 2 each being provided as a separate unit, means that the number and arrangement of the barrier unit(s) 3A to 4C and air treatment unit(s) 2 can easily be modified depending on filtration requirements, expected pollution levels, and the layout of the street and street furniture. For example, an alternative configuration is shown in Fig. 23 wherein the first pedestrian barrier 3 instead comprises a single barrier unit 3A.

In another alternative arrangement (not shown), a plurality of air treatment units 2 maybe provided. In one such arrangement, air treatment units 2 are provided at opposite ends of one of the pedestrian barriers 3, 4 to increase the airflow through the air filtration system 1 and thus the amount of pollutants that are removed. This may be particularly advantageous if said pedestrian barrier 3, 4 is particularly long in length L3, L4. In an alternative, two air treatment units 2 may be located adjacent to each other such that the ducts 27 of the first pedestrian barrier 3 are fluidly connected to one of the air treatment units 2 and the ducts 27 of the second pedestrian barrier 4 are fluidly connected to the other one of the air treatment units 2.

In one embodiment, gaps can be provided between adjacent pedestrian barriers 3, 4 that are each fluidly connected to different air treatment units 2 so that pedestrians can walk through the gap to access the road R.

In one embodiment, the length L3 of the first pedestrian barrier 3 and/or the length L4 of the second pedestrian barrier 4, is at least 5 metres, at least 7 metres, at least 10 metres, at least 12 metres or at least 15 metres. That is, the first and/or second pedestrian barrier 3, 4 may extend by said length L3, L4 along the side of the road R. An increased length L3, L4 has been found to increase the amount of pollutants that are drawn into the air filtration system 1 and filtered.

The air filtration system 1 may comprise one or more pollution sensors to detect the pollution level of the air entering or leaving the air filtration system 1. In the embodiment of Figs. 1 to 23, the air filtration system 1 comprises a first pollution sensor 46 that is configured to detect the pollution level of the air at the roadside and a second pollution sensor 47 that is configured to detect the pollution level of the air after is has passed through the filters 12, 13.

In some embodiments, the first pollution sensor 46 may be mounted on the rear of the air treatment unit 2 or pedestrian barriers 3, 4 to monitor pollution levels in proximity to the pavement P or the first pollution sensor 46 may be mounted on the front of the air treatment unit 2 or pedestrian barriers 3, 4 to monitor pollution levels in proximity to the road R. The pollution sensors 46, 47 may be connected to a controller 48 comprising a processor 49 and a memory 50. A schematic block diagram of the controller 48 is shown in Fig. 22. The memory 50 may be configured to store instructions for execution by the processor 49. The memory 50 may also be configured to store data from one or more of the pollution sensors 46, 47 and or moisture sensors 54, 55.

The pollution sensors 46, 47 may detect information indicative of the pollution level, for example, the level of particulate detected in the air or the level of one or more pollutant gases, and send the information to the controller 48. In some embodiments, the controller 48 is connected to a data output 51, for example, a wireless transmitter, that transmits the pollution information to a remote location such as a server. Thus, the pollution information, for example, the pollution level detected by the first pollution sensor 46 may be monitored remotely. The pollution information may be transmitted to a separate device, for example, a computer or smartphone, either directly or indirectly.

Monitoring the information detected by the second pollution sensor 47 means that it can be determined when the filters 12, 13 have stopped operating effectively and need to be replaced, namely when the pollution level detected by the second pollution sensor 47 exceeds a predetermined level. In some embodiment, this may cause an alarm or a notification to be sent to a remote device. In some embodiments, the second pollution sensor 47 detects one or more gas pollutants and a third pollution sensor (not shown) is provided downstream of the first filter 12 to detect particulate pollutants. Thus, it can be determined whether the first and/or second filter 12, 13 has stopped working depending on whether gas or particulate pollutants exceed corresponding predetermined levels. In one embodiment (not shown), a plurality of air filtration systems are provided that each comprises one or more pollution sensors. Thus, it is possible to monitor the pollution at each of the different locations that the air filtration systems are installed. In some embodiments, each air filtration system comprises a positioning system that is configured to detect the location of the corresponding air filtration system. This positioning system maybe a satellite based positioning system, for example, based on the Global Position System (G.P.S) or the Galileo system. Alternatively, or additionally, the positioning system may be of an alternative configuration, for example, using location data based on the cellular network and/ or wireless (Wi-Fi) network data. The location data determined by the positioning system may be used in conjunction with the pollution data detected by the pollution sensor(s) to determine the environmental pollution level at each location and/or the filter 12, 13 status at each location such that a maintenance engineer can be sent to the location of a filter 12, 13 that needs to be replaced.

Alternatively, the location of each air filtration system may be recorded, for example, during instillation. For instance, the location of each air filtration system may be recorded on a map, grid, or based on the address of the air filtration system such that the pollution data and/or filter maintenance status can be mapped to a corresponding air filtration system.

The air filtration system 1 may comprise one or more screens 51, 52, 53 to display the pollution level detected by the first and/or second pollution sensors 46, 47. For example, the screens 51, 52, 53 may display the pollution levels detected by the first pollution sensor 46 to provide information on the local pollution level, or the pollution level detected at nearby locations by other air filtration systems 1. Additionally, the screens 51, 52, 53 may display the pollution levels detected by the second pollution sensor 47 to demonstrate that the air expelled from the air filtration system 1 is cleaner that the air entering the system 1.

In some embodiments, the sensors for detecting pollution include one or more of metal oxide sensors, electrochemical sensors, photo ionization detectors, optical particle counters, and/or optical sensors, for instance, measuring the adsorption of light such as infrared. In some embodiments, the first and second pollutions sensors are manufactured by Plume Labs (TM).

In one embodiment, the first screen 51 is located on the first pedestrian barrier 3 on the pavement P side of the barrier 3 such that it may be viewed by pedestrians. The second screen 52 is located on the second pedestrian barrier 4 on the pavement P side of the barrier 4 such that it may be viewed by pedestrians. The first and second screens 51, 52 maybe mounted to the rear panels 40B of the respective pedestrian barriers 3, 4. The screens 51, 52 maybe angled upwards to aid viewing by pedestrians. The first and/or second screen 51, 52 could alternatively be located on the air treatment unit 2.

The third screen 53 is located on the front 2A of the air treatment unit 2 such that it can be viewed by motorists. In other embodiments, the third screen 53 may be located on the front of one of the barriers 3, 4.

In some embodiments, the air filtration system 1 is spaced less than 0.5 metres from the road R and, preferably less than about 0.4 metres from the road R. In one embodiment, the air filtration system 1 is spaced 0.3 metres or less from the road R. The air filtration system 1 may further comprise one or more moisture sensors 54, 55 configured to detect the moisture level in the air. In the present embodiment, a first moisture sensor 54 is located at the first port 9 of the air treatment unit 2 and the second moisture sensor 55 is located at the second port 10 of the air treatment unit 2.

In other embodiments, the moisture sensors 54, 55 may be located in the ducts 27 of the pedestrian barriers 3, 4 or on the exterior of the air filtration system 1.

The controller 48 may be configured to power-off the airflow generator 11 if the detected moisture in the air exceeds a predetermined value. This helps to prevent the ingress of water into the system 1 if it starts to rain, which may otherwise damage the filters 12, 13.

In some embodiment, each pedestrian barrier 3, 4 comprises a shield 56 that helps to separate the polluted roadside air from the cleaner air on the pavement P side of the air filtration system 1. The shields 56 may be transparent, or partially transparent, so that pedestrians can view the road R through the shields 56. The shield 56 may be manufactured from, for example, acrylic or polycarbonate. In some embodiments, the pedestrian barriers 3, 4 includes one or more bicycle storage racks (not shown) so that bicycles can be secured to the pedestrian barriers 3, 4. The air filtration system 1 may further comprise one or more alarms that are activated if attempts are made to forcibly remove the bicycles from the bicycle racks. For example, the or each alarm may comprise a motion detector such as an accelerometer or switch that is attached to the barriers 3, 4 and detects shaking of the barriers 3, 4.

In the above described embodiments the air filtration system 1 comprises an air treatment unit 2 and first and second barriers 3, 4. Advantageously, this means that the air treatment unit 2 houses the air flow generator 11 and filters 12, 13 which are relatively expensive and bulky. Therefore, the size of the barriers 3, 4 can be reduced to take up less space on the pavement P. Furthermore, the length of the air filtration system 1 can be altered to different configurations of pavement P by duplicating the relatively inexpensive barriers. However, it should be recognised that in alternative embodiments (not shown), the air treatment unit 2 maybe omitted and instead one of the barriers may comprise the components such as the air flow generator, filters and controller. In some embodiments, the air flow generator, filters and controller may be may be housed in the housing of one or more of the barriers, for example, within the housing of one or more of the barrier units.

In some embodiments, the air filtration system 1 may comprise a surveillance system (not shown), for instance, one or more CCTV cameras. The surveillance system may be configured to detect passing vehicles on the road R and, optionally, may be configured to detect the registration plates (for instance, the number plate) or other identifiers of said passing vehicles. Additionally, or alternatively, the surveillance may be configured to monitor the pavement P in proximity to the air filtration system.

In the above described embodiment, the barriers 3, 4 comprise pedestrian barriers. In alternative embodiments (not shown), the barriers 3, 4 may be of a different type. For example, the barriers 3, 4 may be motorway crash barriers.

In the above described embodiments the air treatment unit 2 is a separate component to the first and second barriers 3, 4. However, in an alternative embodiment (not shown) the air treatment unit and the first and/or second barriers are a single unit and may be integrally formed. Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware, and application logic. The software, application logic and/or hardware may reside on memory, or any computer media. In an example embodiment, the application software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a “memory” or “computer-readable medium” maybe any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration various embodiments in which the claimed invention(s) maybe practiced and provide for a superior air filtration system, kit of parts for an air filtration system and method of installing an air filtration system. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/ or exclusive. They are presented only to assist in understanding and teach the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications maybe made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future.

Claims

1. An air filtration system comprising: a barrier configured to be installed at the side of a road and comprising a duct and at least one inlet; a filter; an air flow generator; and, an outlet, wherein the duct is configured for fluidly communicating the inlet with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet and through the filter to be expelled from the outlet.

2. An air filtration system according to claim l, wherein the system comprises an air treatment unit that comprises the filter, air flow generator and outlet.

3. An air filtration system according to claim 2, wherein the air treatment unit is configured to be installed at the side of the road such that the air treatment unit is adjacent to the barrier.

4. An air filtration system according to claim 2 or claim 3, wherein the air treatment unit comprises a first port for fluidly communicating the air flow generator with the duct of the barrier and a second port for fluidly communicating the air flow generator with a duct of a second barrier.

5. An air filtration system according to any one of the preceding claims, wherein the inlet is configured to draw air into a first side of the air filtration system and the outlet is configured to expel air from a second side of the air filtration system.

6. An air filtration system according to any one of the preceding claims, wherein the barrier has a depth of less than 0.8 metres and, preferably, has a depth of less than

0.6 metres.

7. An air filtration system according to any one of the preceding claims, wherein the barrier is a pedestrian barrier.

8. An air filtration system according to any one of the preceding claims, wherein the barrier comprises a support structure configured to reinforce the barrier.

9. An air filtration system according to claim 8, wherein the support structure comprises a frame and plurality of support members configured to reinforce the support structure.

10. An air filtration system according to claim 9, wherein the frame comprises a pair of spaced bars and wherein the support members extend between the bars and, preferably, extend substantially vertically between the spaced bars.

11. An air filtration system according to any one claims 8 to 10, comprising one or more exterior panels that are mounted to the support structure.

12. An air filtration system according to any one of the preceding claims, wherein the barrier is configured to be anchored to the ground and, preferably, the barrier comprises a plurality of legs that are configured to be anchored within holes in the ground.

13. An air filtration system according to any one of the preceding claims, wherein the duct is configured to extend substantially the entire length of the barrier.

14. An air filtration system according to any one of the preceding claims, wherein the barrier comprises a plurality of barrier units that each has a duct and one or more inlets, wherein the barrier units are configured to be installed by the side of the road adjacent to each other such that the ducts of adjacent barrier units are fluidly communicated and therefore the inlets of the barrier units are fluidly communicated with the outlet.

15. An air filtration system according to any one of the preceding claims, further comprising a second barrier configured to be installed at the side of a road and comprising a duct and at least one inlet, wherein the duct of the second barrier is configured for fluidly communicating the inlet of the second barrier with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet of the second barrier and through the filter to be expelled from the outlet.

16. An air filtration system according to any one of the preceding claims, further comprising a bicycle rack and/or a screen configured to display pollution information.

17. An air filtration system according to any one of the preceding claims, comprising a moisture sensor configured to detect information indicative of the moisture content of the air and a controller configured such that the airflow generator is powered-off if the information indicative of the moisture content exceeds a predetermined value.

18. An air filtration system according to any one of the preceding claims, wherein the barrier has a depth of less than 0.8 metres.

19. An air filtration system according to any one of the preceding claims, wherein the barrier is configured to separate air on a first side of the barrier from air on a second side of the barrier.

20. An air filtration system according to any one of the preceding claims, wherein the barrier comprises a shield configured to separate air on a first side of the shield from air on a second side of the shield and, preferably, wherein the shield is transparent or partially transparent.

21. An air filtration system according to claim 20, wherein the shield is configured such that, in use of the air filtration system, the shield is located above the duct.

22. An air filtration system according to claim 20 or claim 21, wherein the shield comprises a panel.

23. An air filtration system according to any one of the preceding claims, comprising a positioning system configured to determine the location of the air filtration system.

24. An air filtration system according to any one of the preceding claims, comprising one or more cameras and, preferably, wherein at least one of the cameras is configured to detect passing vehicles on the road and, preferably, wherein at least one of the cameras is configured to detect the registration plates or one or more other identifiers of said passing vehicles.

25. An air filtration system according to any one of the preceding claims comprising a pollution sensor configured to detect information indicative of pollution.

26. A network of air filtration systems according to claim 25, wherein each air filtration system is configured to transfer information indicative of pollution levels detected by the one or more pollution sensors of said system to a remote location.

27. A kit of parts for an air filtration system comprising: a barrier unit comprising a duct and at least one inlet; and, an air treatment unit comprising a filter, air flow generator and outlet, wherein the barrier unit and air treatment unit are configured to be installed at the side of a road such that the outlet is fluidly communicated with the inlet via the duct such that, in use, the air flow generator is operable to draw air from the road into the inlet and through the filter to be expelled from the outlet.

28. A kit of parts according to claim 27, further comprising a second barrier unit that comprises a duct and at least one inlet, the second barrier unit configured to be installed at the side of the road such that the inlet and duct of the second barrier unit are fluidly communicated with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet of the second barrier unit and through the filter to be expelled from the outlet.

29. A kit of parts according to claim 27 or claim 28, wherein the air filtration system has the features of any one of claims 1 to 25.

30. A method of installing an air filtration system, the method comprising: providing a barrier unit comprising a duct and at least one inlet; providing an air treatment unit that comprises a filter, an air flow generator and an outlet; and, installing the barrier unit and air treatment unit at the side of a road such that the duct fluidly communicates the inlet with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet and through the filter to be expelled from the outlet.

31. A method according to claim 30, wherein the method further comprises: providing a second barrier unit comprising a duct and at least one inlet; and, installing the second barrier unit at the side of a road such that the inlet and duct of the second barrier unit are fluidly communicated with the outlet such that, in use, the air flow generator is operable to draw air from the road into the inlet of the second barrier unit and through the filter to be expelled from the outlet.