The invention relates to an air treatment device for treating the air entering, leaving or within a vehicle.

People are frequently at risk of being infected by airborne pathogens. These include common cold virus, such as rhinoviruses and influenza virus. Additionally there are a number of bacterial pathogens such as methicillin resistant Staphylococcus aureus (MRSA) or Mycobacterium tuberculosis (TB). There are a number of current methods for preventing infections, including vaccination, the wearing of personal protective equipment, such as face masks, and the disinfection of surfaces.

There are drawbacks associated with vaccinating populations, such as variations in the pathogen and the inability to vaccination, for example, immune-suppressed individuals.

Current personal protective equipment includes face masks, such as those containing filters.

W02008/120005 describes a protective device utilising a face mask and an ultraviolet source. Whilst these are useful for patients or medical professionals, they require the device to be fitted to the individual.

The Applicant has now realised that it would be useful to be able to treat the air passing in or out of a vehicle or into a vehicle. Air passing out of a vehicle, where the vehicle contains for example a patient with a suspected infectious disease, means that it is often difficult to contain the disease or requires the subject to be placed within a separate bubble tent within the vehicle. Additionally, there may be a desire to treat air coming into or from within the vehicle to protect passengers within the vehicle from infection.

There are a number of different sources of ultraviolet light available. However, the major problem with existing ultraviolet light sources, such as U.V. LEDs, is that they produce a lot of heat. For example, U.V.c light LEDs are relatively inefficient. Only 2% of input energy is converted into U.V.c.. Accordingly, for 2 watts of U.V.c., 98 watts of heat is needed to be dissipated. This produces a problem in the ability to cool devices.

Accordingly, a first aspect of the invention provides a vehicle air treatment device, comprising : (i) An air treatment zone comprising a wall defining the air treatment zone and an air inlet and air outlet;

(ii) A plurality of ultraviolet light emitting diodes (U.V. LEDs) mounted on or adjacent to the wall and arranged to treat air passing through the air treatment zone with U.V. light; and

(iii) A cooling zone comprising a fluid for cooling the U.V. LEDs.

Typically, the LED is a U.V.c LED that emits U.V.c. light. U.V.c. is typically in the region of 200-800 nanometers.

The U.V. is used to inactivate microorganisms in the air passing through the air treatment zone. That is, the microorganisms may be disabled to prevent the microorganism infecting a person. Alternatively, the microorganism may be killed. The term "disabled" includes reduction of pathogenicity and/or the ability to replicate. The microorganism may include viruses, bacteria, algae, protozoa, fungi, mycobacterium and spores thereof. Where the virus is treated with the U.V., it may form a so-called DI virus. DI viruses are no longer capable of producing an infectious disease, but still remain a level of immunogenicity which allows an immune response to be produced against the virus.

The device may be arranged so that air passing from the vehicle interior passes through the air inlet into the air treatment zone, and out of the air outlet to the exterior of the vehicle. That is, it prevents the release of infectious pathogens into the environment. Alternatively, air from the exterior or interior of the vehicle may be passed through the air inlet into the air treatment zone and out of the air outlet into the interior of the vehicle. This can be used to protect the passengers within a vehicle from pathogens from outside of the vehicle, or indeed alternatively to treat the air within the vehicle to prevent transmission of diseases from one passengers to another within the vehicle.

Air from the air outlet may pass through the cooling zone to cool the U.V. LEDs.

Alternatively, a separate coolant fluid may be provided to cool the U.V. LEDs and the coolant is a liquid or gas that has not been passed through the air treatment zone. For example, air may be drawn from the outside of the vehicle through a vehicle air inlet into the cooling zone and then expelled from the cooling zone into the exterior of the vehicle. A cooling liquid, such as water, may alternatively be passed through an inlet of the cooling zone into the cooling zone and pass out of the cooling zone. The fluid from the cooling zone may be passed through a heat exchanger to heat air passing into the vehicle, but not released directly into the air passing into the vehicle. It therefore recovers some heat of the U.V. light sources and is used to heat the vehicle.

The cooling zone is typically provided with a wall defining the cooling zone with an inlet and outlet for the fluid and may be provided, for example, as an annular chamber around the exterior of the air treatment zone, or alternatively simply provided around an exterior part of the air treatment zone where the light emitting diodes have been provided.

U.V. LEDs may be mounted on the wall of the air treatment zone where the U.V. LEDs are mounted.

U.V. LEDs may also be each mounted at a respective aperture in the wall of the air treatment zone, optionally where the aperture comprises a substantially U.V. transparent window to allow U.V. from the U.V. LEDs into an interior of the treatment zone, where air can be treated with the U.V. Alternatively, at least a portion of the wall of the air treatment zone may be substantially transparent to the U.V.

U.V. LEDs may comprise one or more heat sinks to increase the surface area of the LEDs to be cooled.

The interior wall of the air treatment zone may comprise a U.V. reflective layer on at least a portion of the wall facing the interior of the air treatment zone. This increases the effect of the U.V. from the U.V. LEDs, by reflecting the U.V. back into the interior of the air treatment zone. Such reflective surfaces include a polytetrafluoroethylene such as EPTFE.

The device may be provided with a filter, such as a pollen filter, in order to remove particulates, such as pollen, prior to passage of the air through the air treatment zone. This has the additional advantage that it helps to prevent the build-up of dust on the surface of, for example, the reflective surface of the wall of the air treatment zone, or the U.V. LEDs.

Typically, the device does not comprise a photocatalyst such as titanium dioxide.

The air from the air treatment zone may be passed to one or more vents into the interior of the vehicle. Alternatively, each vent may have its own air treatment device. The typical maximum volume of air entering is less than 170 litres/second with approximately 30 litres/second at each vent. The vehicle may be a space, land, air, or water vehicle. Such vehicle may be selected from, for example, an automobile, a bus, a lorry, a van, a train, a tram, a cable car, an aeroplane, a ship and a spacecraft. Typically, the vehicles are able to transport passengers and may comprise a compartment for a driver.

The U.V. LEDs are typically U.V.c. LEDs, which emit ultraviolet light at the U.V.c. wavelength. U.V. LEDs are generally known in the art. The device may comprise a regulator to regulate the amount of U.V. light emitted by the U.V. LEDs into the air treatment zone. This may be in the form of a simple on/off switch or alternatively a control to regulate the amount of U.V. light emitted. For example, the amount of U.V. light used to treat the air may vary depending on the flow of air through the system. Accordingly, there may be provided a sensor to detect the amount of U.V. emitted into the air treatment zone and a detector to detect the flow of air through the air treatment zone. The amount of U.V. may be varied depending upon the amount of air passing through the air treatment zone.

A vehicle comprising a device according to the invention is also provided, wherein the vehicle is preferably defined as above.

The invention will now be described by way of invention only with reference to the following figures:

Figure 1 shows an arrangement according to one aspect of the invention in which air is treating with ultraviolet light, prior to being used to cool the LEDs.

Figure 2 shows an alternative arrangement of the invention, in which a separate cooling system is provided.

Figure 3 shows an alternative arrangement of the LED light mounted on the wall of the device.

In Figure 1 air is taken in through an intake (11) into the air treatment zone (12). The air may be from the outside of the vehicle, in which case the device is used to pre-treat the air prior to entering into the vehicle, or alternatively it is from within the vehicle, and may be used to treat air leaving the vehicle. Illustratively, air is passed through a tube. One end of the tube then passes into an air treatment zone (12) before leaving the air treatment zone at an air outlet (13). The treated air then passes into a cooling zone (14) where it passes LEDs (16) and cools excess heat from the LEDs, prior to exiting the device. The internals walls of the air treatment zone may be covered with a reflective lining such as EPTFE. This increases the amount of U.V. light transmitted into the interior of the air treatment zone and increases the efficiency. U.V.s may be mounted on the wall of the air treatment zone (12).

A wall (20) of the cooling zone (14) may comprise a non reflective or absorbent material such as a U.V. absorbent paint, in order to prevent escape of U.V. light from the air treatment zone (12). Figure 1 illustratively shows the U.V.c. emitted by one of the LEDs (22) into the air treatment zone (12).

Figure 2 shows an alternative arrangement in which there is provided an air inlet (11) to an air treatment zone (12), which also has an air outlet (13).

The cooling zone (14) has a separate fluid inlet (15) and outlet (17). Fluid, which may be a coolant liquid such as water, optionally with additives such as antifreeze or alternatively a gas, such as air or a refrigerant, may pass in the same direction as, or indeed in a counter direction to, the air flowing through the coolant chamber (12). The air treatment zone may have a substantially circular cross section, with the air treatment zone providing an annular cooling zone around the air treatment zone (12). In the example shown in Figure 2, the U.V. LED (16) is mounted on the wall of the air treatment zone (12). The wall itself may act as a heat sink, with it being cooled by fluid passing through the cooling zone (14).

Figure 3 shows an alternative arrangement of the LED. In Figure 3, there is provided a wall (24) which separates the air treatment zone (12) from the cooling zone (14). The LED (16) is mounted adjacent to a transparent window (26). This allows the transmission of U.V. light into the air treatment chamber (12). Alternatively, instead of a transparent window, there may simply be an aperture within the wall (24) and the LED is air sealed to the aperture by means of a suitable seal.

As discussed above, the amount of U.V. may be variable according to the amount of air passing through the air treatment zone. This may be varied, for example, by switching one or more LEDs on or off, or increasing the output from one or more of the LEDs. Accordingly, a control circuit may be provided.

The walls of the device may comprise any suitable material including metal and plastic materials.