GB2521450A

GB2521450A - A system for conditioning air and a filtering apparatus therefor

Info

Publication number: GB2521450A
Application number: GB1322709.5A
Authority: GB
Inventors: Neil Beloe
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2013-12-20
Filing date: 2013-12-20
Publication date: 2015-06-24
Anticipated expiration: 2033-12-20
Also published as: GB201322709D0; GB2521450B

Abstract

A system for conditioning a substantially enclosed and re-circulated volume of air such as from a passenger cabin of a vehicle comprises a filtering apparatus 100 having at least two filtering sections F1,F2. Each section has material that cleans and/or dehumidifies air, e.g. activated carbon and/or a desiccant. At least one section can be deactivated from cleaning and/or dehumidifying to be regenerated whilst another is activated for cleaning and/or dehumidifying. The system may receive cabin air 45 through a first inlet 40 that is cleaned and dehumidified by a first section F1 whilst a second section F2 receives ambient air 35 through a second inlet 30 for regeneration, with clean, dry air 47 being supplied back to the cabin through a first outlet 42 and purged dirty air 37 passing back out to ambient via a second outlet 32. Switching elements 34,36,44,46 can be used to direct air through the apparatus to permit: regeneration of the first or second section while the other cleans; or deactivation of one of the sections without regeneration (figure 5). Regeneration of the sections can be undertaken by respective heating sources 50,60. A method of ventilating an enclosed space is also claimed.

Description

A SYSTEM FOR CONDITIONING AIR AND A FILTERING APPARATUS THEREFOR

TECHNICAL FIELD

The present invention relates to a system for conditioning air and to a filtering apparatus therefor. More particularly, but not exclusively, to an air cleaning and drying system having at least two filters. The invention finds advantageous application in vehicles, but may be used in other enclosed spaces, for example rooms of buildings and the like.

Aspects of the invention relate to a system for conditioning air, to a filtering apparatus, to a vehicle and to a method.

BACKGROUND

In motor vehicles it is typical to provide a ventilation system in which air flows into and out of the vehicle cabin to provide fresh or cleaned air into the vehicle cabin for the occupants.

Fresh clean air is required for example for control of humidity, for controlling CO2 levels and intake of fresh clean air should be controlled for pollutants. Typically an air inlet is provided proximate to a front end of the vehicle with an air filter which cleans air flowing into the vehicle. This filtered air may then be passed through an air chilling unit for controlling the temperature and humidity of the air. The cleaned and chilled air is then blown into the vehicle cabin and flows out of the vehicle cabin through an outlet. Such systems may be referred to as full-flow" systems.

Such ventilation systems use large quantities of air sourced from outside the cabin. Warming or cooling this ventilation air uses a large amount of energy at high and low ambient temperatures. Such systems may clean in the region of 100 litres of air per second and depending upon the temperature requirements of the occupants of the vehicle cabin, a significant amount of energy may be consumed by the air conditioning unit. For example, if the ambient temperature is 30°C and the required temperature in the vehicle cabin is 20°C, a condensing air conditioning unit may reduce the temperature of the ambient air to about 2°C in order to dehumidify the air and then heat the dried air to the required temperature of 20°C. In doing this, in the region of about 5 to about 7kWh of energy may be used, a significant amount of which (in the region of about 3 to about 4kWh) is wasted as the cleaned, dried and cooled cabin air flows out of the vehicle.

It is desirable therefore to reduce the energy used in conditioning ventilation air by recirculating the cabin air. However recirculation of the cabin air means recirculating odours, moisture and CO2 that would otherwise be expelled from the cabin. Recirculation of moisture means that moisture can build up, and can condense on cold surfaces such as glass windows and screens.

The present invention seeks to provide an improvement in the field of air cleaning and drying systems that has particular application for vehicles. The invention may be utilised in applications other than for vehicles; for example, it is foreseen that the invention may have application in buildings, for example houses.

SUMMARY OF THE INVENTION

Aspects of the invention provide a system for conditioning air, a filtering apparatus and a vehicle as claimed in the appended claims.

According to an aspect of the invention for which protection is sought, there is provided a system for conditioning a substantially enclosed and recirculated volume of air, the system comprising a filtering apparatus having at least two filtering sections, each filtering section comprising material suitable for cleaning and/or dehumidifying air from said substantially enclosed and recirculated volume of air, the filtering apparatus being configured and arranged such that at least one filtering section can be deactivated from cleaning and/or dehumidifying such that said at least one filtering section can be regenerated in situ, whilst another of said at least two filtering sections is activated for cleaning and/or dehumidifying air from said substantially enclosed and recirculated volume of air. In this way a recirculation-type ventilation system is provided in which additional air is typically or only very occasionally drawn in and for the most part, the same air is scrubbed, dehumidified and recirculated about the cabin.

According to another aspect of the invention for which protection is sought, there is provided a filtering apparatus comprising at least two filtering sections, each filtering section comprising material suitable for cleaning and/or dehumidifying air from a substantially enclosed and recirculated volume of air, the filtering apparatus being configured and arranged such that at least one filtering section can be deactivated from cleaning and/or dehumidifying such that said at least one filtering section can be regenerated in situ, whilst another of said at least two filtering sections is activated for cleaning and/or dehumidifying air from said substantially enclosed and recirculated volume of air.

Optionally, each of said at least two filtering sections has a heating source associated therewith for use during regeneration of said at least one filtering section.

Optionally, the filtering apparatus comprises a first filtering section and a second filtering section and is configured and arranged such that, when the first filtering section is deactivated from cleaning and/or dehumidifying such that said first filtering section can be regenerated in situ, the first filtering section is isolated from the substantially enclosed and recirculated volume of air and opened to ambient air external to the substantially enclosed and recirculated volume of air; and wherein the filtering apparatus is configured and arranged such that when the second filtering section is deactivated from cleaning and/or dehumidifying such that said second filtering section can be regenerated in situ the second filtering section is isolated from the substantially enclosed and recirculated volume of air and opened to said ambient air.

Optionally, the filtering apparatus is configured and arranged such that, when the first filtering section is activated for cleaning and/or dehumidifying, the first filtering section is isolated from the ambient air external to the substantially enclosed and recirculated volume of air; and wherein the filtering apparatus is configured and arranged such that when the second filtering section is activated for cleaning and/or dehumidifying the second filtering section is isolated isolated from the ambient air external to the substantially enclosed and recirculated volume of air.

Optionally, said first filtering section has a first heating source associated therewith that is controllable and wherein said second filtering section has a second heating source associated therewith that is controllable, the first and second heating sources being operable independently of one another.

Optionally, the filtering apparatus comprises: a first inlet from the substantially enclosed and recirculated volume of air into the filtering apparatus; ii. a first outlet from the filtering apparatus into the substantially enclosed and recirculated volume of air; üi. a second inlet from said ambient air into the filtering apparatus; and iv. a second outlet from the filtering apparatus to said ambient air.

Optionally, the filtering apparatus comprises switching elements for controlling whether air from the enclosed volume routed through the first inlet and out of the first outlet is additionally routed through the first filtering section or the second filtering section; and wherein the filtering apparatus comprises switching elements for controlling whether ambient air routed through the second inlet and out of the second outlet is additionally routed through the second filtering section or the first filtering section.

Said switching elements may be controllable by a control unit such that in dependence upon one or more control parameters, the control unit is operable to deactivate the first or second filtering section from cleaning and/or dehumidifying for regenerating operation, and activate the first or second filtering section for cleaning and/or dehumidifying operation respectively.

Said switching elements may comprise: a first switching element disposed proximate to said first inlet operable between first and second positions, where in the first position the first switching element causes air from the substantially enclosed and recirculated volume of air to be routed through the first filtering section and where in the second position, the first switching element causes air from the substantially enclosed and recirculated volume of air to be routed through the second filtering section; and a second switching element disposed proximate to said second inlet operable between first and second positions, where in the first position the second switching element causes ambient air to be routed through the second filtering section and where in the second position, the second switching element causes air from the enclosed volume to be routed through the first filtering section.

Additionally or alternatively said switching elements may comprise: a third switching element disposed proximate to said first outlet operable between first and second positions, where in the first position the third switching element causes air from first filtering section to be routed into the substantially enclosed and recirculated volume of air and where in the second position, the third switching element causes air from the second filtering section to be routed into the enclosed volume; and a fourth switching element disposed proximate to said second inlet operable between first and second positions, where in the first position the fourth switching element causes air from the second filtering section to be routed to ambient air and where in the second position, the fourth switching element causes air from the first filtering section to be routed into the substantially enclosed and recirculated volume of air.

Optionally, the system is for a vehicle and said substantially enclosed and recirculated volume of air is contained at least in pad by a cabin of the vehicle, and wherein one or more control parameters includes one or more or a combination of: the time period a filtering section has been cleaning and/or dehumidifying; ii. the time period another filtering section has been regenerating; iii. a number of occupants within the cabin of the vehicle; iv. ambient temperature; v. cabin size; vi. cabin arrangement; vu. ambient air conditions, including the pollution quality of the ambient air; viii. cabin air conditions including the pollution quality of the substantially enclosed and recirculated volume of air within the cabin; ix. cabin occupant required or system required temperature; x. actual cabin air temperature; i xi. size, capacity, configuration, composition, age and quality of each filtering section; xii. vehicle location; xiii. vehicle speed; xiv. filtering section remaining capacity; xv. pressure difference detected across the filtering sections; xvi. filter weight; xvii. filter discolouration; and xviii. filter conductivity.

Optionally, said composition of material comprised in each filtering section comprises activated carbon or a similar material designed to selectively capture pollutants and a desiccant material such that each filtering section is configured to clean and dehumidify air from said substantially enclosed and recirculated volume of air.

Additionally, the system may comprise a sensor for monitoring CO2 and/or 02 concentrations within the substantially enclosed and recirculated volume of air and wherein in dependence upon said monitored concentrations, the system is configured to draw in samples of ambient air in order to increase 02 concentration or to decrease CO2 concentration.

According to another aspect of the invention for which protection is sought, there is provided a vehicle complising the system of any preceding, relevant, paragraph.

Optionally, the vehicle comprises an in vehicle cabin HMI display comprising a graphical representation of a pollutant metric. The pollutant metric may comprise a comparison between the pollution quality of the cabin air and the pollution quality of the ambient air.

According to yet another aspect of the invention for which protection is sought, there is provided a method of ventilating an enclosed space, the method comprising: routing air from a volume of air contained substantially within the enclosed space through a first filtering section for cleaning and/or dehumidifying the air from the volume of air; ü. deactivating a first filtering section from cleaning and/or dehumidifying; iii. in situ, regenerating said first filtering section; and iv. activating a second filtering section for cleaning and/or dehumidifying air from said volume of air.

As used herein the terms "air conditioning" and "conditioning of air" may, as appropriate given the context, be used to refer to air cleaning or scrubbing (which may refer to the removal of air pollutants, allergens, odours and the like) and/or air drying (dehumidifying) and/or temperature control of air and/or management of the composition of the gases within the air (for example reduction of 002). In other words, the terms "air conditioning" and "conditioning of air" may not necessarily refer to temperature control of air.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, may be taken independently or in any combination thereof. For example, features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 is a side view of a vehicle shown without doors to schematically illustrate an air cleaning and drying system according to an embodiment of the invention; FIGURE 2 is a plan view of the vehicle of Figure 1 showing schematically the air cleaning and drying system of Figure 1; FIGURE 3 is schematic illustration of a filtering apparatus used in the air cleaning and drying system of Figures 1 and 2 in a first air filtering and filter regeneration cycle; FIGURE 4 is schematic illustration of the filtering apparatus of Figure 3 in a second air filtering and filter regeneration cycle; and FIGURE 5 is schematic illustration of the filtering apparatus of Figure 3 during an air filtering only period wherein a second regenerated filtering section is isolated from the atmosphere external to the vehicle.

DETAILED DESCRIPTION

Detailed descriptions of specific embodiments of the systems for conditioning air, filtering apparatus and vehicles of the present invention are disclosed herein. It will be understood that the disclosed embodiments are merely examples of the way in which certain aspects of the invention can be implemented and do not represent an exhaustive list of all of the ways the invention may be embodied. Indeed, it will be understood that the systems for conditioning aft, filtering apparatus and vehicles described herein may be embodied in various and alternative forms. The Figures are not necessarily to scale and some features may be exaggerated or minimised to show details of particular components. Well-known components, materials or methods are not necessarily described in great detail in order to avoid obscuring the present disclosure. Any specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the invention.

In Figure 1 there is shown a side view of a vehicle 10. The vehicle 10 is illustrated without doors in order to show schematically a system 90 for conditioning air 45/47 within a cabin 14 of the vehicle 10. In contrast to the prior art, the system 90 operates by recirculating air 45/47 within the cabin 14. The air is cleaned (also referred to as scrubbed) by the system 90 and is recirculated back into the cabin 14. In this way, the system 90 is required to condition a significantly lower volume or flow of air. Additionally, recirculation of the air 45147 and repeated filtration for scrubbing, and optionally humidity and temperature control, may improve the quality of air 45/47 and improve the distribution of clean air 47 within the cabin 14 compared with prior art systems where ambient air 35 (which may contain pollutants, for example allergens and odours) is filtered quickly and briefly and the cabin is continually being "refreshed" with air that has only been lightly filtered or scrubbed. The system 90 of the present disclosure may therefore be referred to as a recirculation system or a closed loop system. Further benefits and features of the system 90 will be described with reference to Figures 1 to 5. Ambient air 35 is the air that is outside of the substantially enclosed volume of air 45/47 within the cabin 14.

The system 90 optionally additionally comprises an air movement device such as an air fan or blower. This has been omitted from the illustrations for simplicity and to avoid obscuring the illustration of a filtering apparatus 100.

The system 90 comprises a filtering apparatus 100 which is shown in more detail in Figures 3 and 4. In Figure 3, the filtering apparatus 100 is depicted in a first air filtering and filter regeneration cycle. In Figure 4, the filtering apparatus 100 is depicted in a second air filtering and filter regeneration cycle. As depicted in Figures 1 and 2, the filtering apparatus 100 may be disposed substantially centrally of the vehicle 10 and optionally beneath and partly within the cabin 14 of the vehicle 10. The filtering apparatus 100 comprises a first inlet 40 (which may optionally comprise more than one inlet opening into the vehicle cabin 14) which provides for the passage of cabin air 45 into the filtering apparatus 100. The filtering apparatus 100 comprises a first outlet 42 (which may optionally comprise more than one outlet opening into the vehicle cabin 14) which provides for the passage of cleaned and optionally dried air 47 back into the vehicle cabin 14. The cleaned and optionally dried air 47 circulates within the cabin 14 and over time the volume of air 45/47 within the cabin 14 is repeatedly conditioned by the filtering apparatus 100.

To achieve continual scrubbing of the cabin air 45/47, the filtering apparatus 100 comprises at least two separate filtering sections Fl, F2. In the present arrangement, the filtering apparatus 100 comprises two separate filtering sections Fl, F2 which are disposed in distinct and controllably selectable first and second filtering channels 52, 62 respectively. At least one of the filtering sections Fl, F2 is preferably continually in operation to scrub the cabin air 45/47. This filtering section Fl, F2 may be referred to as the active filtering section Fl, F2. In Figure 3, the first filtering section Fl is being used to scrub the cabin air 45/47 and as such in Figure 3, the first filtering section Fl is the active filtering section. In Figure 4, the second filtering section F2 is being used to scrub the cabin air 45/47 and as such in Figure 4, the second filtering section F2 is the active filtering section.

The provision of at least two filtering sections Fl, F2 that are disposed in at least two distinct and controllably selectable first and second filtering channels 52, 62, enables one or more filtering sections Fl, F2 to be deactivated from scrubbing the cabin air 45/47 and

S

regenerated whilst continual cleaning of the cabin air 45 continues using the active filtering section Fl, F2. The filtering section Fl, F2 being regenerated may be referred to as the regenerating filtering section Fl, F2 or may be referred to as the deactivated filtering section because it has been made available for regeneration and has been deactivated from cleaning. In Figure 3, the second filtering section F2 is being purged using heat and ambient air flow and as such in Figure 3, the second filtering section F2 is the regenerating filtering section. In Figure 4, the first filtering section Fl is being purged using heat and ambient air flow and as such in Figure 4, the first filtering section Fl is the regenerating filtering section.

The filtering apparatus 100 additionally comprises a second inlet 30 (which may optionally comprise more than one inlet opening) which provides for the passage of ambient air 35 into the filtering apparatus 100 from the atmosphere exterior to the vehicle 10. The filtering apparatus 100 also comprises a second outlet 32 (which may optionally comprise more than one outlet) which provides for the passage of purged air 37 back out into the atmosphere to the exterior of the vehicle 10. The ambient air flow 35 is used in conjunction with heat 95 provided by heating sources 50, 60 to regenerate the regenerating filtering sections Fl, F2 and to purge the regenerating filtering sections Fl, F2 of pollutants and moisture collected (which may have been collected by adsorption dependent upon the nature of the pollutant and/or the nature of the filtering material contained within the filtering section Fl, F2; or absorbed by the desiccant). The purged "dirty air" 37 is output to the atmosphere to the exterior of the vehicle 10.

In the present arrangement, heat 95 is provided by two electrically powered heating elements 50, 60. In other embodiments, the heating sources 50, 60 may not be identical in form and/or size. For example, in other embodiments the heating sources may be configured and arranged such that heat 95 is provided by any one or any suitable combination of: an electrically powered heating element; a fuel powered heater; hot water; and/or pumped refrigerant (which may be pumped from a vehicle cooling system to provide heat to the present system). Optionally, the heating sources 50, 60 are suitable for generating heat 95 of an appropriate temperature, which optionally may be about 80°C to about 100°C in some embodiments, in order to promote the regenerating filtering section (F2 in Figure 3; Fl in Figure 4) to "give-up" the adsorbed pollutants and absorbed moisture.

Regeneration may occur over a shorter time period than an active filtering section may be active in conditioning air and as such a filtering section Fl, F2 may have a status of inactive.

In Figure 5 the first filtering section Fl has been regenerated and is inactive. The first filtering section Fl is no longer being purged and is not coupled to the cabin 14 for cleaning cabin air 45. When regeneration of a regenerating filtering section (F2 in Figure 3; Fl in Figure 4) is no longer being conducted, the inactive filtering section (Fl in Figure 5) (and therefore to some extent the filtering apparatus 100) is optionally isolated from the atmosphere by closing the second inlet 30 and second outlet 32. This is illustrated in Figure 5, wherein after regeneration of the first filtering section Fl (in Figure 4), the first filtering section is clean and inactive. It is not being regenerated nor is it being actively used for filtering cabin air 45. The second inlet 30 and second outlet 32 are blanked off by additional switching elements 48, 38.

Returning now to Figure 3 it is schematically depicted therein how incoming cabin air 45 is passed through the first inlet 40, into the first filtering channel 52 by means of an open switching element 44, and into the first active filtering section Fl. The first filtering section Fl may comprise one or more sections or canisters of filtering material, such as activated carbon. The composition, size and configuration of the first filtering section Fl is optionally the same as the second filtering section F2. In other embodiments, however, the second filtering section F2 has a smaller volume of filtering material. In such an embodiment the second filtering section F2 can only operate as the active filtering section for a shorter time period compared to the larger capacity first filtering section, but the second filtering section F2 can also be regenerated in a shorter time period; and the second filtering section F2 can operate as the active filtering section for a sufficient period of time to enable the larger first filtering section to be regenerated. Optionally in such an arrangement, the larger filter may be operable in an active state for several hours, optionally including about 1 to 2 or more hours, and may take in the region of a few minutes (optionally between about 2 minutes to about 10 minutes) to regenerate. As such, the smaller filtering section F2 may be operable in an active state for about only a few minutes longer than the time taken to regenerate the larger first filtering section Fl, so that the smaller filtering section F2 only takes over active conditioning whilst the primary larger filtering section Fl regenerates.

A further beneficial aspect of the disclosure is that one or more volumes of one or more desiccant materials are optionally provided within each of the filtering sections Fl, F2. The desiccant material may absorb moisture from the cabin air 45 such that during active conditioning of the cabin air 45 using the first or second filtering sections (Fl in Figure 3; F2 in Figure 4) the humidity of the filtered air 47 is controlled and problems associated with moisture condensing on the glass windows and screens of the cabin 14 are avoided.

In the present embodiment, the filtering apparatus 100 is configured to perform conditioning (cleaning and optionally drying) of cabin air 45 using only one of the two separate filtering sections Fl, F2 at any given time. The filtering apparatus 100 is configured to perform regeneration or purging of the other filtering section F2, Fl during a period when that other filtering section F2, Fl is not being used for cleaning and optionally drying of cabin air 45. It will be appreciated, however, that in other embodiments other arrangements of filtering apparatus may be used to provide continual (or at least substantially continual) conditioning (cleaning and optionally drying) of cabin air 45 using one or more active filtering sections whilst permifting one or more additional filtering sections to be regenerated.

The use of two of more filtering sections Fl, F2 providing at least one active (Fl in Figure 3; F2 in Figure 4) and one regenerating filtering section (F2 in Figure 3; Fl in Figure 4) provides a variety of options for control strategies for determining how to operate the filtering apparatus 100. A control unit 70 (see Figure 2) is optionally coupled to one or more sensors 2 (see Figure 2) associated with the filtering sections Fl, F2, and thereby the control unit 70 monitors the status of the active filtering section (Fl in Figure 3; F2 in Figure 4) in order to determine when that active filtering section (Fl in Figure 3; F2 in Figure 4) should be withdrawn from an air filtering cycle and replaced" with a regenerated filtering section (F2 in Figure 3; Fl in Figure 4). Similarly, the control unit 70 via said one or more sensors 2 may monitor the status of a regenerated filtering section (F2 in Figure 3; Fl in Figure 4) in order to determine, in real time, when regeneration of the regenerated filtering section has been fully completed.

The filtering channels 52 and 62, in the absence of the switching elements, are fluidly connected to both the first and second inlets 40, 30 and the first and second outlets 42, 32.

In Figures 3 and 4 the current position of a controllable switching element 44, 34, 46, 36 is shown by a bold line and the other position that the controllable switching element 44, 34, 46, 36 can be moved into is shown by a dotted line.

The controllable switching elements 44, 34, 46, 36 are each moveable between two positions in order to control the flow paths for cabin air flow 45/47 and ambient air flow 35/37. The switching elements 44, 34 work in conjunction to prevent the non-desired flow paths from the inlets 40, 30 to the filtering sections Fl, F2. Likewise, the switching elements 46, 36 work in conjunction to prevent the non-desired flow paths from the filtering sections Fl, F2 to the outlets 42, 32.

For example, in the switch positions of the configuration of Figure 3, the switching element 44 allows fluid communication between the first inlet 40 and the first filtering section Fl, but also acts to prevent fluid communication between the second inlet 30 and the first filtering section Fl and between the second inlet 30 and the first filtering section Fl; the switching element 34 allows fluid communication between the second inlet 30 and the second filtering section F2, but also acts to prevent fluid communication between the first inlet 40 and the second filtering section F2 and between the second inlet and the first filtering section Fl; the switching element 46 allows fluid communication between the first filtering section Fl and the first outlet 42, but also acts to prevent fluid communication between the first filtering section Fl and the second outlet 32 and between the second filtering section F2 and the first outlet 42; and the switching element 36 allows fluid communication between the second filtering section F2 and the second outlet 32, but also acts to prevent fluid communication between the second filtering section F2 and the first outlet 42 and between the first filtering section Fl and the second outlet 32.

In Figure 4, the switches are in their alternative positions, and fluid communication is allowed/prevented at each switching element in the opposite sense to the configuration of Figure 3.

It will be appreciated that the provision of controllable switching elements 44, 34, 46, 36 to control the respective flow paths between the first inlet 40 and first outlet 42, and between the second inlet 30 and second outlet 32 respectively, enables a filtering section Fl, F2 to be withdrawn from active service and swapped for a regenerated filtering section Fl, F2 without necessitating actual movement of the respective filtering sections Fl, F2.

The control strategy carried out by the control unit 70 may be selected in dependence upon a number of factors which may include one or more or a combination of: vehicle type; cabin size; cabin arrangement; ambient air conditions; cabin air conditions; ambient temperature; cabin occupant required temperature; actual cabin air temperature; the size, capacity, configuration, composition, age and quality of each filtering section; vehicle location; and/or vehicle speed. For example, purging of the regenerating filtering section (F2 in Figure 3; Fl in Figure 4) causes "dirty air" 37 to be vented into the atmosphere proximate to the exterior of the vehicle 10. It is therefore preferred to vent "dirty air' 37 when the vehicle 10 is moving or when occupants of the vehicle have alighted the vehicle and are some distance away. In a control strategy according to one aspect of the disclosure therefore, priority is given to regenerating a filter section (F2 in Figure 3; Fl in Figure 4) when the vehicle is moving or under static conditions only if the vehicle has been locked for a predetermined amount of time (which may indicate that the passengers have alighted the vehicle and moved away from it).

The system 90 optionally additionally comprises a specific mechanism for enabling the system 90 to draw ambient air into the system 90 and hence into the cabin 14. As such, whereas the system 90 has been described as a recirculating or closed-loop system, it may not be a recirculating system all of the time, but only for a significant percentage of the time it is in use. It may be desirable (or necessary) to draw in additional samples of ambient air into the system 90 to refresh the air and/or to increase oxygen (02) levels within the cabin 14. The recirculated air within the cabin 14 is being inhaled by the occupants and some carbon dioxide (002) is being exhaled. Over time, and in dependence upon the number of occupants and the duration of their journey, the level of 002 within the cabin air 45/47 may increase and the level of 02 within the cabin 14 may decrease. To ensure that the cabin air remains not only within safe limits, but preferably of a high quality, the system 90 in the present embodiment optionally comprises a sensor 6 for monitoring one or both of the level of 002 within the cabin 14 and/or the level of 02 within the cabin 14. The sensor 6 may monitor the concentration of 002 and/or 02 within the cabin 14 and may output a data signal via communications link 4 to the control unit 70 indicative of the concentration of 002. In dependence upon said data signal, the control unit 70 may determine whether ambient air should be drawn in. The control unit 70 is optionally also configured to determine when ambient air should be drawn in, for example to avoid the drawing in of ambient air coinciding with the venting of air purged through a regenerating filter (F2 in Figure 3; Fl in Figure 4).

The control unit 70 is optionally also configured to determine how much ambient air should be drawn in. In other embodiments other sensor arrangements, detected parameters and formats of data signal may be used in the monitoring of the cabin air and in the determination of whether ambient air should be drawn in.

In the present embodiment, the specific mechanism for enabling the system 90 to draw ambient air into the system 90 optionally involves the use of the switching element 48.

During a period when no regeneration of any filtering sections Fl, F2 is occurring and preferably once the inactive filtering section (Fl in Figure 5) has been regenerated, the switching element 48 may be opened (by virtue of a command signal issued by the control unit 70). In this way, ambient air 35 can be drawn into the system 90.

In some embodiments, the specific mechanism for enabling the system 90 to draw ambient air into the system 90 utilises only the arrangement of controllable switching elements 44, 34, 46, 36 and no additional switching element 48 is required. The controllable switching elements 44, 34, 46, 36 can be controlled and set such that external air 35 is drawn into the system 90 via the first or second filtering section Fl, F2 and into the cabin 14 through the first outlet 42. Such an arrangement benefits from the fact that at no point is outside air 35 introduced into the cabin 14 or the system 90 without first being filtered.

In other embodiments, the specific mechanism for enabling the system 90 to draw in ambient air may comprise an auxiliary route (not shown) arranged to permit ambient air to flow into the active filtering section.

Optionally a pollutant metric may be displayed to the occupants of the vehicle to illustrate the quality of the air within the cabin. Optionally the pollutant metric may be shown by using Front Control Display Interface Modules (FCDIM) or other HMI apparatus. Optionally the pollutant metric may comprise a comparison between the cabin air and ambient air to demonstrate clearly to the occupants the improved quality of the cabin air. Such a display may be particularly beneficial in much polluted climates, where the ambient air is much polluted and a significant difference in the quality of the cabin air and ambient air can be shown.

It can be appreciated that the system 90 of the present disclosure allows for a high rate of filtration of recirculated air because the filters and desiccant used to scrub and dry samples of the cabin air can be regenerated in situ and during real time use of the system 90. In this way a high quality of clean air is recirculated within the cabin, using less energy than known full-flow-type systems. Indeed, depending upon cabin size, the system 90 may be required to only condition about 2 -3 cubic metres of air. By regenerating the filtering sections frequently, and optionally before they become saturated or too dirty, the working lifetime of the filtering sections can be prolonged compared to filters that are not regenerated and are continually used in the aforementioned "full-flow" type systems. Yet a further benefit is that the use of desiccant material in particular contributes to solving the problem associated with air chilling systems, wherein condensate collected in the air chilling systems can be released into the cabin when the air chilling system is off, generating moisture within the cabin that then causes condensation and poor visibility.

It can be appreciated that various changes may be made within the scope of the present invention. For example, in other embodiments of the invention it is envisaged that a temperature control system may be incorporated into the system for heating or cooling the air before it is recirculated back into the cabin 14. Alternatively, existing heaters and coolers may be configured to function with the present system which may supply a flow of cabin air thereto for heating or cooling prior to being filtered and recirculated back into the cabin 14.

Optionally some embodiments include the use of a reclaiming means for reclaiming thermal energy from the system 90 which, for example, is used for the purpose of regeneration in the exhausted air path.

Whereas the filtering apparatus 100 has been illustrated as being located substantially centrally of the floor of the vehicle cabin 14, other locations for the filtering apparatus may be suitable. Beneficially though, locating the filtering apparatus 100, air intake 40 and outlet 42 substantially centrally may permit good recirculation of the cabin air 45. The recirculation of clean and dry cabin air 45 offered by the system of the present disclosure is further beneficial because it can avoid a short circuit of cabin air being drawn in and pumped out in the region of the front footwell. Such a short circuit often occurs in known systems, in which ventilation air does not always circulate well within the cabin.

Optionally in some envisaged embodiments, biocidal chemicals may be provided within the system 90, in particular within the filtering sections Fl, F2, to mitigate against the growth of bacteria and mould. However, it is envisaged that the use of heat 95 of sufficient temperature to purge the filtering sections Fl, F2 may substantially sterilise the filters and prevent or reduce the growth of bacteria and mould.

In other embodiments, desiccant material and material for selectively capturing pollutants, such as activated carbon, may be contained in separate filtering sections. In such an arrangement, more than two filtering sections are provided.

In some envisaged arrangements, the air flow direction used during regeneration is not in the same direction as the air flow direction used during filtering. Advantageously in such embodiments, regeneration efficiency may be improved by reversing the direction of air flow during regeneration.

The following numbered paragraphs contain statements of invention: 1. A system for conditioning a substantially enclosed and recirculated volume of air, the system comprising a filtering apparatus having at least two filtering sections, each filtering section comprising material suitable for cleaning and/or dehumidifying samples of said substantially enclosed and recirculated volume of air, the filtering apparatus being configured and arranged such that at least one filtering section can be deactivated from cleaning and/or dehumidifying such that said at least one filtering section can be regenerated in situ, whilst another of said at least two filtering sections is activated for cleaning and/or dehumidifying samples of said substantially enclosed and recirculated volume of air.

2. A system according to paragraph 1 wherein each of said at least two filtering sections has a heating source associated therewith for use during regeneration of said at least one filtering section.

3. A system according to paragraph 2 wherein the filtering apparatus comprises a first filtering section and a second filtering section and is configured and arranged such that, when the first filtering section is deactivated from cleaning and/or dehumidifying for being regenerated in situ, the first filtering section is isolated from the substantially enclosed and recirculated volume of air and opened to ambient air external to the substantially enclosed and recirculated volume of air; and wherein the filtering apparatus is configured and arranged such that when the second filtering section is deactivated from cleaning and/or dehumidifying for being regenerated in situ, the second filtering section is isolated from the substantially enclosed and recirculated volume of air and opened to ambient air.

4. A system according to paragraph 3 wherein said first filtering section has a first heating source associated therewith that is controllable and wherein said second filtering section has a second heating source associated therewith that is controllable, the first and second heating sources being operable independently of one another.

5. A system according to paragraph 4 wherein the filtering apparatus comprises: i. a first inlet from the substantially enclosed and recirculated volume of air into the filtering apparatus; ii. a first outlet from the filtering apparatus into the substantially enclosed and recirculated volume of air; Hi. a second inlet from said ambient air into the filtering apparatus; and iv. a second outlet from the filtering apparatus to said ambient air.

6. A system according to paragraph 5 wherein the filtering apparatus comprises switching elements for controlling whether air from the enclosed volume routed through the first inlet and out of the first outlet is additionally routed through the first filtering section or the second filtering section; and wherein the filtering apparatus comprises switching elements for controlling whether ambient air is routed through the second inlet and out of the second outlet is additionally routed through the second filtering section or the first filtering section.

7. A system according to paragraph 6 wherein said switching elements are controllable by a control unit such that, in dependence upon one or more control parameters, the control unit is operable to deactivate the first or second filtering section from cleaning and/or dehumidifying for regenerating operation, and activate the first or second filtering section for cleaning and/or dehumidifying respectively.

8. A system according to claim 6 or 7 wherein said switching elements comprise: (i) a first switching element disposed proximate to said first inlet operable between first and second positions, where in the first position the first switching element causes air from the substantially enclosed and recirculated volume of air to be routed through the first filtering section and where in the second position, the first switching element causes air from the substantially enclosed and recirculated volume of air to be routed through the second filtering section; (ii) a second switching element disposed proximate to said second inlet operable between first and second positions, where in the first position the second switching element causes ambient air to be routed through the second filtering section and where in the second position, the second switching element causes air from the enclosed volume to be routed through the first filtering section; (iH) a third switching element disposed proximate to said first outlet operable between first and second positions, where in the first position the third switching element causes air from first filtering section to be routed into the substantially enclosed and recirculated volume of air and whele in the second position, the third switching element causes air from the second filtering section to be routed into the enclosed volume; and (iv) a fourth switching element disposed proximate to said second inlet operable between first and second positions, where in the first position the fourth switching element causes air from the second filtering section to be routed to ambient air and where in the second position, the fourth switching element causes air from the first filtering section to be routed into the substantially enclosed and recirculated volume of air.

9. A system according to paragraph 7 wherein the system is for a vehicle and said substantially enclosed and recirculated volume of air is contained within a cabin of the vehicle, and wherein one or more control parameters includes one or more or a combination of: i. the time period a filtering section has been cleaning and/or dehumidifying; ii. the time period another filtering section has been regenerating; a number of occupants within the cabin of the vehicle; iv. ambient temperature; v. cabin size; vi. cabin arrangement; vii. ambient air conditions, including the pollution quality of the ambient air; viii. cabin air conditions including the pollution quality of the substantially enclosed and recirculated volume of air within the cabin; ix. cabin occupant required or system required temperature; x. actual cabin air temperature; xi. size, capacity, configuration, composition, age and quality of each filtering section; xii. vehicle location; xiii. vehicle speed xix. filtering section remaining capacity; xx. pressure difference detected across the filtering sections; xxi. filter weight; xxii. filter discolouration; and xxiii. filter conductivity.

10. A system according to paragraph 1 wherein said material comprised in each filtering section comprises activated carbon or similar material suitable for air cleaning or scrubbing and a desiccant material such that each filtering section is configured to clean and dehumidify air from said substantially enclosed and recirculated volume of air.

11. A system according to paragraph 1 wherein the system comprises a sensor for monitoring 002 and/or 02 concentrations within the substantially enclosed and recirculated volume of air and wherein in dependence upon said monitored concentrations, the system is configured to draw in samples of ambient air in order to increase 02 concentration or to decrease CO2 concentration.

12. A vehicle comprising the system of paragraph 1.

13. A vehicle comprising the system of paragraph 1 additionally comprising an in vehicle cabin HMI display comprising a graphical representation of a pollutant metric.

14. A vehicle according to paragraph 12 wherein the pollutant metric comprises a comparison between the pollution quality of the cabin air and the pollution quality of the ambient air.

15. A filtering apparatus for use in the system of paragraph 1, the filtering apparatus comprising at least two filtering sections, each filtering section comprising material suitable for cleaning and/or dehumidifying samples of substantially enclosed and recirculated volume of air, the filtering apparatus being configured and arranged such that at least one filtering section can be deactivated from cleaning and/or dehumidifying such that said at least one filtering section can be regenerated in situ, whilst another of said at least two filtering sections is activated for cleaning and/or dehumidifying samples of said substantially enclosed and recirculated volume of air.

16. A filtering apparatus for use in the system of paragraph 1, the filtering apparatus comprising at least two filtering sections, each filtering section comprising material suitable for cleaning and/or dehumidifying samples of substantially enclosed and recirculated volume of air, the filtering apparatus being configured and arranged such that at least one filtering section can be deactivated from cleaning and/or dehumidifying such that said at least one filtering section can be regenerated in situ, whilst another of said at least two filtering sections is activated for cleaning and/or dehumidifying samples of said substantially enclosed and recirculated volume of air.

17. A filtering apparatus according to paragraph 16 wherein each of said at least two filtering sections has a heating source associated therewith for use during regeneration of said at least one filtering section.

18. A filtering apparatus according to paragraph 17 wherein said at least two filtering sections comprise a first filtering section and a second filtering section wherein the filtering apparatus comprises: a first inlet from the substantially enclosed and recirculated volume of air into the filtering apparatus; H. a first outlet from the filtering apparatus into the substantially enclosed and recirculated volume of air; Hi. a second inlet from ambient air into the filtering apparatus; and iv. a second outlet from the filtering apparatus to said ambient air.

19. A filtering apparatus according to paragraph 18 wherein said composition of material comprised in each filtering section comprises activated carbon and a desiccant such that each filtering section is configured to clean and dehumidify samples of said substantially enclosed and recirculated volume of air.

20. A method of ventilating an enclosed space, the method comprising: i. routing samples of a volume of air contained substantially within the enclosed space through a first filtering section for cleaning and/or dehumidifying the samples of the volume of air; ii. deactivating a first filtering section from cleaning and/or dehumidifying; in situ, regenerating said first filtering section; and iv. activating a second filtering section for cleaning and/or dehumidifying samples of said volume of air.

Claims

CLAIMS1. A system for conditioning a substantially enclosed and recirculated volume of air, the system comprising a filtering apparatus having at least two filtering sections, each filtering section comprising material suitable for cleaning and/or dehumidifying air from said substantially enclosed and recirculated volume of air, the filtering apparatus being configured and arranged such that at least one filtering section can be deactivated from cleaning and/or dehumidifying such that said at least one filtering section can be regenerated in situ, whilst another of said at least two filtering sections is activated for cleaning and/or dehumidifying air from said substantially enclosed and recirculated volume of air.
2. A system according to claim 1 wherein each of said at least two filtering sections has a heating source associated therewith for use during regeneration of said at least one filtering section.
3. A system according to claim 1 or 2 wherein the filtering apparatus comprises a first filtering section and a second filtering section and is configured and arranged such that, when the first filtering section is deactivated from cleaning and/or dehumidifying such that said first filtering section can be regenerated in situ, the first filtering section is isolated from the substantially enclosed and recirculated volume of air and open to ambient air external to the substantially enclosed and recirculated volume of air; and wherein the filtering apparatus is configured and arranged such that when the second filtering section is deactivated from cleaning and/or dehumidifying such that said second filtering section can be regenerated in situ, the second filtering section is isolated from the substantially enclosed and recirculated volume of air and opened to said ambient air.
4. A system according to claim 3 wherein said first filtering section has a first heating source associated therewith that is controllable and wherein said second filtering section has a second heating source associated therewith that is controllable, the first and second heating sources being operable independently of one another.
5. A system according to any of claims 3 to 4 wherein the filtering apparatus comprises: a first inlet from the substantially enclosed and recirculated volume of air into the filtering apparatus; ii. a first outlet from the filtering apparatus into the substantially enclosed and recirculated volume of air; a second inlet from said ambient air into the filtering apparatus; and iv. a second outlet from the filtering apparatus to said ambient air.
6. A system according to claim 5 wherein the filtering apparatus comprises switching elements for controlling whether air from the enclosed volume routed through the first inlet and out of the first outlet is additionally routed through the first filtering section or the second filtering section; and wherein the filtering apparatus comprises switching elements for controlling whether ambient air is routed through the second inlet and out of the second outlet is additionally routed through the second filtering section or the first filtering section.
7. A system according to claim 6 wherein said switching elements are controllable by a control unit such that, in dependence upon one or more control parameters, the control unit is operable to deactivate the first or second filtering section from cleaning and/or dehumidifying for regenerating operation, and activate the first or second filtering section for cleaning and/or dehumidifying operation, respectively.
8. A system according to claim 6 or 7 wherein said switching elements comprise: a first switching element disposed proximate to said first inlet operable between first and second positions, where in the first position the first switching element causes air from the substantially enclosed and recirculated volume of air to be routed through the first filtering section and where in the second position, the first switching element causes air from the substantially enclosed and recirculated volume of air to be routed through the second filtering section; and a second switching element disposed proximate to said second inlet operable between first and second positions, where in the first position the second switching element causes ambient air to be routed through the second filtering section and where in the second position, the second switching element causes air from the enclosed volume to be routed through the first filtering section.
9. A system according to claim 6, 7 or 8 wherein said switching elements comprise: a third switching element disposed proximate to said first outlet operable between first and second positions, where in the first position the third switching element causes air from first filtering section to be routed into the substantially enclosed and recirculated volume of air and where in the second position, the third switching element causes air from the second filtering section to be routed into the enclosed volume; and a fourth switching element disposed proximate to said second inlet operable between first and second positions, where in the first position the fourth switching element causes air from the second filtering section to be routed to ambient air and where in the second position, the fourth switching element causes air from the first filtering section to be routed into the substantially enclosed and recirculated volume of air.
10. A system according to claim 7 wherein the system is for a vehicle and said substantially enclosed and recirculated volume of air is contained within a cabin of the vehicle, and wherein one or more control parameters includes one or more or a combination of: i. the time period a filtering section has been cleaning and/or dehumidifying; ii. the time period another filtering section has been regenerating; iU. a number of occupants within the cabin of the vehicle; iv. ambient temperature; v. cabin size; vi. cabin arrangement; vii. ambient air conditions, including the pollution quality of the ambient air; viii. cabin air conditions including the pollution quality of the substantially enclosed and recirculated volume of air within the cabin; ix. cabin occupant required or system required temperature; x. actual cabin air temperature; xi. size, capacity, configuration, composition, age and quality of each filtering section; xü. vehicle location; xiii. vehicle speed xiv. filtering section remaining capacity; xv. pressure difference detected across the filtering sections; xvi. filter weight; xvh. filter discolouration; and xvhi. filter conductivity.
11. A system according to any preceding claim wherein said material comprised in each filtering section comprises activated carbon or similar material suitable for air cleaning or scrubbing and a desiccant material such that each filtering section is configured to clean and dehumidify air from said substantially enclosed and recirculated volume of air.
12. A system according to any preceding claim wherein the system comprises a sensor for monitoring CO2 and/or 02 concentrations within the substantially enclosed and recirculated volume of air and wherein in dependence upon said monitored concentiations, the system is configured to draw in samples of ambient air in order to increase 02 concentration or to decrease CO2 concentration.
13. A vehicle comprising the system of any preceding claim.
14. A vehicle according to claim 13 comprising an in vehicle cabin HMI display comprising a graphical representation of a pollutant metric.
15. A vehicle according to claim 14 wherein the pollutant metric comprises a comparison between the pollution quality of the cabin air and the pollution quality of the ambient air.
16. A filtering apparatus for use in the system or vehicle of any preceding claim, the filtering apparatus comprising at least two filtering sections, each filtering section comprising material suitable for cleaning and/or dehumidifying air from a substantially enclosed and recirculated volume of air, the filtering apparatus being configured and arranged such that at least one filtering section can be deactivated from cleaning and/or dehumidifying such that said at least one filtering section can be regenerated in situ, whilst another of said at least two filtering sections is activated for cleaning and/or dehumidifying air from said substantially enclosed and recirculated volume of air.
17. A filtering apparatus according to claim 16 wherein each of said at least two filtering sections has a heating source associated therewith for use during regeneration of said at least one filtering section.
18. A filtering apparatus according to claim 17 wherein said at least two filtering sections comprise a first filtering section and a second filtering section wherein the filtering apparatus comprises: a first inlet from the substantially enclosed and recirculated volume of air into the filtering apparatus; ii. a first outlet from the filtering apparatus into the substantially enclosed and recirculated volume of air; a second inlet from ambient air into the filtering apparatus; and iv. a second outlet from the filtering apparatus to said ambient air.
19. A filtering apparatus according to claim 18 wherein said material comprised in each filtering section comprises activated carbon or similar material suitable for air cleaning or scrubbing and a desiccant material such that each filtering section is configured to clean and dehumidify air from said substantially enclosed and recirculated volume of air.
20. A method of ventilating an enclosed space, the method comprising: routing air from a volume of air contained substantially within the enclosed space through a first filtering section for cleaning and/or dehumidifying the air from the volume of air; ii. deactivating a first filtering section from cleaning and/or dehumidifying; iii. in situ, regenerating said first filtering section; and iv. activating a second filtering section for cleaning and/or dehumidifying air from said volume of air.
21. A system, vehicle, filtering apparatus or method substantially as described herein with reference to and/or as illustrated by the accompanying Figures.