WO2021187989A1

WO2021187989A1 - A face mask, an air treatment unit and a protection system comprising the face mask and the air treatment unit

Info

Publication number: WO2021187989A1
Application number: PCT/NO2021/050066
Authority: WO
Inventors: Hans Kotthaus
Original assignee: Ccd As
Priority date: 2020-03-18
Filing date: 2021-03-17
Publication date: 2021-09-23
Also published as: NO20200326A1

Abstract

Described herein is a face mask (2), an air treatment unit (3) for a face mask (2) and a protection system (1) comprising the face mask (2) and the air treatment unit (3). The face mask (2) comprises a screen (21) arranged to at least cover a user's mouth and nose, wherein the screen (21) is provided with a fastening device (22) for fastening the face mask (2) to the user's head. A frame (24) designed in an elastic material, is fastened to the screen (21) for resting against a part of the user's face and delimit a cavity (241) between the user's face, the screen (21) and the frame (24) wherein the user can breathe. The screen (21) is provided with an air intake (23) for letting air into the delimited cavity (241), and the air intake (23) is arranged for attachment of an air treatment unit (3) for treatment of the air before it is let into the delimited cavity (241). The face mask (2) comprises a ventilation opening (242) for ventilating the delimited cavity (241). The air treatment unit (3) comprises a housing which delimits an air treatment chamber (34), wherein the housing is provided with an air inlet (36) and an air outlet (32). The air treatment unit (3) is further provided with at least one air treatment element (33, 35) and a fan (31) for driving air from the air inlet (36), through the air treatment chamber (34) and to the air outlet (32).

Description

A FACE MASK, AN AIR TREATMENT UNIT AND A PROTECTION SYSTEM COMPRISING THE FACE MASK AND THE AIR TREATMENT UNIT

The invention concerns a protection system for protecting a user from breathing in harm ful particles and/or pathogenic microorganisms. The invention further concerns a face mask and an air treatment unit, wherein the face mask and the air treatment unit are arranged so that they can be coupled together to make up the protection system. The face mask is arranged to receive the air treatment unit, and the air treatment unit can be detachably fastened to the face mask.

The need for various types of protection masks is great, and there are masks for different purposes. A variety of face masks and mouth coverings are known both from the industry, where the need for protection against e.g. dust and harmful aerosols is great, and from the health sector, where this need often concerns protection against pathogenic mi crobes. In addition to protection masks, there are masks for other medical uses, such as respiratory masks where a patient receives oxygen through a port in a tight-fitting mask. One type of mask according to prior art, is a mask fitted with a filter and supported by a fan that creates overpressure. Such masks are offered e.g. as protective equipment for sandblasters, painters and other craftsmen. The patent publication US 5655527 A de scribes a mask of this type.

Medical staff often use a fibre-based mask in combination with glasses or a basic face shield or visor in the form of a thin, curved and transparent plastic screen.

Known solutions can be divided into two main categories: tight-fitting masks with ports for inhalation and exhalation, and loose-fitting masks or screens. A disadvantage of tight- fitting masks is that they can put an uncomfortable pressure on parts of the skin of the face, which can lead to discomfort for the user. Loose-fitting masks have the disadvantage of providing poorer protection due to leaks around the nose and the mouth. In addition, masks of prior art are suitable for filtering out certain types of particle aerosols and drop let aerosols, but may be not very suitable for stopping viruses and dispersed aerosols. Viruses infect via droplet infection and as single aerosols which can find their way in through mucous membranes in the nose, eyes and mouth.

The purpose of the invention is to remedy or reduce at least one of the disadvantages of prior art, or at least provide a useful alternative to prior art. A further purpose of the in vention is to provide a mask that provides effective protection against viruses and dis- persed aerosols, and that at the same time is comfortable to wear over a prolonged peri od of time. Another further purpose of the invention is to provide a type of face mask that is flexible in that it can be adapted to different areas of application and needs for protection.

The purpose is fulfilled by the features specified in the description below and the subse quent patent claims.

The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

In a first aspect, the invention concerns more specifically a face mask that comprises:

- a screen arranged to at least cover a user's mouth and nose, the screen having an inter- nal side and an external side;

- a fastening device for fastening the screen to the user's head so that the screen's inter nal side faces the user's face;

- a frame comprising an elastic material, wherein the frame is fastened to the screen's internal side to rest against a part of the user's face to delimit a cavity between the user's face, the screen and the frame wherein the user can breathe; the screen further being provided with an air intake for letting air into the delimited cavi ty, and wherein the air intake is arranged for attachment of an air treatment unit for treatment of the air before it is let into the delimited cavity; and wherein the face mask further comprises a ventilation opening for ventilating the delim- ited cavity.

In its smallest version, the face mask's screen can cover the mouth and the nose, while in a larger version, it can also cover the eyes. The purpose of the face mask is to protect the user against inhalation of unwanted substances. What unwanted substances are, de- pends on in which environment the face mask is to be used. The face mask can be a mask for infection control and its function may be to protect against pathogenic and infectious substances like viruses and bacteria. Further, the face mask may in the same or a differ ent embodiment protect the user against aerosols that are hazardous to health.

The frame of the face mask is made of a material that is comfortable against the skin. The frame can have encased or surface-mounted reinforcements, preferably arranged so that they do not come into contact with the user's skin. It is important that a face mask that perhaps is to be worn throughout an entire workday is comfortable to wear and at the same time safe and effective. The frame can for example be made of a material that is soft and elastic, kind to the skin and compatible with human skin. Further, it would be advantageous for the material to be washable and suitable for multiple use. The frame can for example be made of a silicone material or a thermoplastic elastomer, polyure thane or latex.

The air intake can be arranged for detachable attachment of the air treatment unit. It would be advantageous if the air treatment unit and the face mask can be fastened de- tachably to each other. Cleaning of both parts will become easier, and additionally the face mask can be used with different air treatment units, depending on the area of appli cation.

The screen can be provided with two or more air intakes. In an embodiment with several, preferably two, air intakes, the air intakes can be arranged for receiving one air treatment unit each. In another embodiment, the air intakes can be arranged for receiving one common air treatment unit.

At least a portion of the screen can be made of a transparent material. The screen can for example be made of clear plastic like polycarbonate. The screen can be arranged to cover the user's entire face.

In embodiments where the screen of the face mask covers the mouth, nose and eyes, at least the portion that covers the eyes is made of a transparent material so that the user can see through the screen. Further, it would be advantageous if the screen is also trans- parent in the area that covers the mouth to make communication easier. This will be par ticularly advantageous when communicating with persons who are hearing-impaired or other persons who need to be able to read lips.

It can be advantageous if the air intake arranged for attachment of the air treatment unit is placed on the screen in such a way that the user's mouth is still visible for other people while the air treatment unit is coupled to the face mask.

The ventilation opening can comprise at least one recess in the frame.

There must be ventilation from the face mask, but this can be achieved in several ways. In one embodiment, the face mask can be arranged so that is does not rest against the skin of the face in a fully sealed manner, but at a small distance so that fan air with overpres- sure and exhaled air can escape through this narrow gap. In another embodiment, the ventilation can as mentioned happen through a recess in the frame. Alternatively, there can be several recesses in the frame, there can be one or several recesses in the screen of the face mask, or there can be a combination of the aforementioned possible ventilation forms. In embodiments wherein the ventilation opening comprises at least one recess in the frame, this at least one recess can be placed in an upper portion of the frame in the usage position.

It should be understood that the concept "in the usage position" in this connection means the position the face mask is in when a person has put it on and the person is standing or sitting upright. An upper portion of the frame will as such, in the usage position, be in the area next to the user's nose, under or to the side of the eyes. It can be advantageous if the recess is placed towards the sides of the face mask, so that the air the user is breath ing out, is not blown straight into the user's eyes, but out to the side of the eyes. The fastening device can comprise a band to be fastened around the user's head.

The band can be elastic. The band can be fastened to the screen, and there are several alternative ways to fasten the band. An example of a way of fastening, is that the band can be threaded through recesses in the screen. Another way of fastening could be gluing the band to the screen. Yet another way of fastening could be to provide the screen with two pins or other elements that project out from the screen, and fasten the band to these. It should be understood that other ways of fastening are also possible. The band may be provided with a tightening mechanism for adjusting the band to different users. The fastening device can in an alternative embodiment comprise arms or bows, for ex- ample corresponding to the temples of a spectacle frame, to be placed over the user's ears.

In a second aspect, the invention concerns more specifically an air treatment unit for a face mask, wherein the air treatment unit comprises:

- a housing which delimits an air treatment chamber, wherein the housing is provided with an air inlet and an air outlet;

- at least one air treatment element; and

- a fan for driving air from the air inlet, through the air treatment chamber and to the air outlet.

The fan contributes to the creation of an overpressure in the delimited cavity of the face mask when the air treatment unit is coupled to a face mask according to the first aspect of the invention. An effect of the fan is thus that it contributes to making it easier to breathe than if there was no fan in the air treatment unit.

The air treatment unit can be provided with one or more further fans. Using more than one fan in the air treatment unit can increase the air capacity of the air treatment unit. Alternatively, two smaller fans could be used instead of one larger fan, and thereby retain the same capacity but ensure greater freedom in the design of the air treatment unit.

The air treatment unit can be fastened to the face mask in such a way that the air inlet is facing the user of the face mask when the user has the face mask in the usage position. The air inlet will then typically be able to face the user under or next to the user's chin. Alternatively, the air inlet can, in the usage position, when the user is standing or sitting upright, face downwards.

It is advantageous to place the air inlet so that it, in use, is facing the user. At least, it is advantageous if the air inlet does not face directly away from the user so as to avoid air that is being exhaled by a person standing across from the user, entering the air inlet di rectly. Even though the air treatment unit purifies the air before the user breathes it in, it would be advantageous for the air to be as clean as possible before it reaches the air treatment chamber. The air treatment unit's at least one air treatment element can comprise an air filter.

A variety of different air treatment units can be produced, wherein these are adapted to different areas of application. For example, a basic air treatment unit can comprise an air filter as the only purifying device. While another embodiment of the air treatment unit can comprise both a filter and a radiation source. In this way, air treatment units can be adapted to area of application and requirements, and different air treatment units can be used in conjunction with the same face mask according to the first aspect of the inven tion.

The air treatment element can comprise a UVC radiation source for irradiation of air lo cated in the air treatment chamber. The UVC radiation source, herein also referred to as light source, can treat the air in the air treatment chamber before it is inhaled. The UVC radiation source can be disposed in its entirety inside the air treatment chamber. Alternatively, the UVC radiation source can be placed so that it irradiates into the air treatment chamber from another, adjacent chamber or from the outside, e.g. through a window made of a suitable material. The light source can for example be connected to a control unit and sensors so that the radia tion can be turned on at inhalation and off at exhalation. The control unit can also be ar ranged so that it facilitates increasing the light intensity from the light source. Alternative ly, the light source can emit a pulsating light. A pulsating light has the effect of conserving power compared to a continuous light. The UVC radiation inactivates viruses and bacteria, including the corona virus.

The air treatment element can comprise several UVC radiation sources. The one or more UVC radiation source(s) can be placed so that their direction of radiation in the air treat- ment chamber is against or at a sharp angle, meaning 0-90 degrees, relative to the air flow.

The UVC radiation source is preferably a light-emitting diode / LED.

The UVC radiation source can irradiate the air in the air treatment chamber with a radia tion having a wavelength in the range of 220-280 nm. In one embodiment, the UVC radia- tion source can irradiate the air with a UVC radiation having a wavelength in the range of 260-280 nm. UVC radiation in the range 260-280 nm has been shown to be effective against viruses. In another embodiment, the UVC radiation source can irradiate the air with a UVC radiation having a wavelength in the range of 220-240 nm. Radiation in this range kills bacteria. At least a portion of the air treatment chamber's wall can comprise a reflective material for reflecting UVC radiation.

Herein, reflective material means a material that is particularly suitable for reflecting UVC radiation. It should be understood that any material will reflect some radiation, but that the reflective material used here, is particularly well suited to reflect UVC radiation. The effect of reflective material is both a more effective purification of the air in the air treatment chamber and that the walls of the air treatment chamber are protected against the radiation. The air treatment chamber can be designed in plastic, but a challenge of common household plastics is that they will over time be broken down by the UVC radia tion. It is therefore advantageous to use specially treated plastics or cover with a reflec- tive material, as mentioned. The reflective material can be metal, but this has the disad vantage of making the air treatment unit heavier. Another example of reflective material well suited for this purpose is a material comprising fluoropolymer.

Since UVC radiation can cause damage to a person's skin and mucous membranes, the air treatment chamber is designed so that the UVC radiation is contained within the air treatment chamber. This means that in an embodiment of the air treatment unit that comprises a UVC radiation source, the UVC radiation source is placed in the air treatment chamber in such a way that radiation cannot escape through the air inlet or the air outlet. Air inlets and air outlets can for example be shielded with internal walls in the air treat ment chamber. Alternatively or additionally, the UVC radiation source can be placed in such a way that radiation does not hit the air inlet or the air outlet. Yet another alterna tive is that the air inlet or air outlet itself is designed so that any radiation hitting the opening internally in the air treatment chamber, does not exit the air treatment unit fully. For example, the air inlet and the air outlet can comprise a channel which is curved. The above-mentioned alternatives are intended to be examples, and a skilled person will be able to combine these, or in other ways stop the UVC radiation from leaving the air treatment chamber.

The UVC light source is arranged in such a way that the air that passes through the air treatment chamber receives an effective exposure of UVC radiation without the user or other persons being exposed to radiation.

In a third aspect, the invention more specifically concerns a protection system for protect ing a user from breathing in harmful particles or pathogenic microorganisms, wherein the protection system comprises: - a face mask according to the first aspect of the invention; and

- an air treatment unit according to the second aspect of the invention, wherein the air treatment unit is arranged for detachable attachment to the face mask, so that treated air flowing out of the air treatment unit's air outlet is supplied to the de limited cavity between the screen and the user's face via the screen's air intake. As described above, the mask is designed so that it does not rest against the wearer's face in a sealed manner, but allows a small ventilation. The fan contributes to the creation of an overpressure in the delimited cavity that the user is breathing in.

The protection system can further comprise an energy source arranged to at least provide the fan with electric energy. The air treatment unit can further comprise a UVC radiation source for radiation of air located in the air treatment chamber and the energy source can be arranged to provide energy to the UVC radiation source. The UVC radiation source can be a light-emitting di ode. One embodiment of the protection system can in this manner comprise a protective shield, also referred to as screen herein, an air treatment unit comprising an electrically controlled fan, a filter unit and a UVC chamber with an electric light source. Further, the protection system can comprise a control unit with sensors for the UVC radiation source and the fan. The energy source can be a power source, e.g. a battery. The control unit and/or the energy source can be integrated into the face mask, attached to the face mask, or carried as a separate container on the body, e.g. on a string around the neck, or with a buckle on a belt or in another suitable manner.

The energy source can be a battery, e.g. a rechargeable battery.

Another embodiment of the protection system can comprise a protective shield, meaning screen, and an air treatment unit comprising two or more electrically controlled fans with filter units coupled thereto and an air treatment chamber with an electrical UVC radiation source.

It would be advantageous if all the parts of the protection system, including the face mask and the air treatment unit, are made of materials which are durable and washable, so that the protection system can be used several times.

In the following, examples are described of preferred embodiments which are illustrated in the attached drawings, wherein:

Fig. 1 shows an embodiment of a protection system seen from the side, where the protection system comprises a face mask and an air treat ment unit;

Fig. 2 shows the protection system from Fig. 1 seen from the front;

Fig. 3 shows one embodiment of an air treatment unit; Fig. 4 shows a sketch in perspective of another embodiment of the protec tion system;

Fig. 5a and 5b show the protection system from Fig. 4 seen from the front and from the side respectively; Fig. 6 shows the protection system from Fig. 4 in perspective seen from be hind at an angle;

Fig. 7 shows a face mask without an air treatment unit connected;

Fig. 8 shows an embodiment of an air treatment unit;

Fig. 9 shows an example of an energy source for the protection system; Fig. 10a and 10b show an embodiment of the protection system wherein the air treat ment unit is provided with two fans; and

Fig. 11a and lib show an embodiment of the protection system wherein the face mask is provided with two air intakes and is arranged to receive two air treatment units. The figures are shown in a simplified and schematic manner, and details that are not im portant for highlighting what is new with the invention, may have been left out of the figures. The different elements in the figures are not necessarily shown in correct scale in relation to each other. Similar and corresponding elements will be specified using the same reference numbers in the figures. Any indicators of position such as "over" and "under" refer to positions shown on the figures.

Reference is first made to figure 1, which shows an example of a protection system 1 that comprises a face mask 2 and an air treatment unit 3. The face mask 2 is here shown com prising a transparent screen 21 and with a fastening device 22 in the form of bows 221 for resting over a user's ears. The air treatment unit 3 is here shown with a placement just below the user's mouth. In the shown embodiment, the face mask 2 covers the mouth, nose and eyes. It is also made clear that the face mask 2 does not rest in a completely sealed manner against the user's face. The face mask's 2 screen 21 is provided with an air intake 23 and the air treatment unit 3 is provided with an air inlet 36.

In figure 2, the protection system 1 is shown from the front. The air treatment unit 3 is here shown provided with a fan 31 disposed in connection to the air inlet 36 and thereby the air intake 23. In the shown embodiment, the face mask 2 is arranged so that the air treatment unit 3 can be disposed on the inside of the face mask 2, meaning inside of the screen 21. The fan 31 creates an overpressure on the inside of the face mask 2. The air treatment unit 3 is further provided with at least one air outlet 32 where air that is fully treated in the air treatment unit 3 is released and supplies treated air to the user of the protection system 1.

Figure 3 shows the air treatment unit 3 in further detail. The air treatment unit 3 is shown here comprising a filter 33 arranged downstream of the fan 31, so that the air is filtered before it reaches an air treatment chamber 34 provided with an UVC light source 35 in the form of a light-emitting diode. The filter 33 can comprise a porous filter material. The protection system 1 is further provided with an energy source 4, and in the shown em bodiment the energy source 4 is disposed integrated into the air treatment unit 3. The energy source 4 can be a battery that supplies energy to both the fan 31 and the UVC light source 35. Further, the energy source 4 can be provided with a control unit 41.

The fan 31 sucks fresh air from the environment and blows the air in through the filter 33 and further into the air treatment chamber 34 where it is irradiated with UVC radiation.

Figure 4 shows another embodiment of the protection system 1 wherein the air treat ment unit 3 is arranged to be fastened onto the outside of the face mask 2 and send treated air in through the face mask's 2 air intake 23. The fastening device 22 is here shown as a band 222 or a strap with a tightening mechanism 223 for tightening the band 222 around the user's head. It should be understood that the fastening device 22 could also be bows 221 in this embodiment, in the same way that the embodiment of the pro tection system 1 shown in figure 1 could be provided with a band 222 as a fastening de vice 22. The figures 5a, 5b and 6 are referenced together, since they show the same embodiment of the protection system as shown in figure 4. In these figures it is however made clearer that the face mask 2 further comprises a frame 24. The frame 24 is at least partially formed in an elastic material for making the face mask 2 comfortable for a user to wear against their face. In the shown embodiment, it is made clear that the frame 24 can be fastened to the inside of the screen 21 and shaped so that it can fit nicely over the user's nose and rest against the user's cheeks. A cavity 241 will be delimited between the frame 24, the screen 21 and the user's face when the user is wearing the face mask 2. In the shown embodiment, a ventilation opening 242 is provided in the frame 24. It should be understood that the ventilation opening 242 or several ventilation openings 242 can be provided elsewhere in the frame 24 and/or in the screen 21. Alternatively, ventilation can happen by the ventilation opening 242 being provided as a groove in towards the user's face, and not as a hole/opening through the frame 24.

Figure 7 shows the face mask 2 without an air treatment unit connected. The air intake 23 is here shown as an opening with a flange for coupling to the air treatment unit. The air treatment unit 3 and the face mask 2 can be connected in per se known ways like by a screw, clamp or bayonet coupling.

Figure 8 shows an embodiment of the air treatment unit 3. With air inlet 36, filter 33, air treatment chamber 34, UVC light source 35 and air outlet 32. The fan 31 is not shown, but is disposed upstream of the filter 33. The inside of the air treatment chamber 34 is pro vided with a reflective material 37.

Figure 9 shows an example of an energy source 4 that in this embodiment is not integrat ed in the air treatment unit 3, but is suitable for connection via e.g. a not shown cord to the air treatment unit 3 for supplying the fan 31 and the UVC light source 35 with power. The shown energy source 4 is provided with a switch 42 for turning it on and off, a cable outlet 43 for connection to a cable/cord, and a fastening 44 for e.g. fastening a string that the user can wear around the neck. The energy source 4 can alternatively be fastened to the user in another manner, for example the fastening 44 can be made so that the energy source can be fastened to a belt, or it can comprise a clip that can be hooked onto a pocket.

Figures 10a and 10b show an embodiment of the protection system 1 wherein the air treatment unit 3 is provided with two fans 31. Figures 11a and lib show an embodiment of the protection system 1 wherein the face mask 2 is provided with two air intakes 23 and wherein the protection system 1 comprises two air treatment units 3 coupled to the face mask 2.

It should be noted that all embodiments mentioned above illustrate the invention, but do not delimit it, and experts on the area will be able to design many alternative embodi ments without deviating from the scope of the attached claims. In the claims, the refer- ence numbers in parenthesis shall not be considered delimiting.

The use of the verb "to comprise" and its different forms does not exclude the presence of elements or steps not mentioned in the claims. The indefinite articles "a" or "an" be fore an element do not exclude the presence of more such elements.

Claims

P a t e n t c l a i m s

1. Face mask (2) comprising:

- a screen (21) arranged to at least cover a user's mouth and nose, the screen (21) having an internal side and an external side;

- a fastening device (22) for fastening the screen (21) to the user's head so that the screen's (21) internal side faces the user's face;

- a frame (24) comprising an elastic material, wherein the frame (24) is fastened to the screen's (21) internal side to rest against a part of the user's face to delim it a cavity (241) between the user's face, the screen (21) and the frame (24) wherein the user can breathe; the screen (21) further being provided with an air intake (23) for letting air into the delimited cavity (241), and wherein the air intake (23) is arranged for at tachment of an air treatment unit (3) for treatment of the air before it is let into the delimited cavity (241); and wherein the face mask (2) further comprises a ventilation opening (242) for ven tilating the delimited cavity (241).

2. Face mask (2) according to claim 1, wherein the air intake (23) is arranged for de tachable attachment of the air treatment unit (3).

3. Face mask (2) according to any of the preceding claims, wherein at least a por tion of the screen (21) is made of a transparent material.

4. Face mask (2) according to any of the preceding claims, wherein the screen (21) is arranged to cover the user's entire face.

5. Face mask (2) according to any of the preceding claims, wherein the ventilation opening (242) comprises at least one recess in the frame (24).

6. Face mask (2) according to claim 5, wherein the at least one recess is placed in an upper portion of the frame (24), in the usage position.

7. Face mask (2) according to any of the preceding claims, wherein the fastening device (22) comprises a band (222) for fastening around the user's head.

8. Air treatment unit (3) for a face mask (2), wherein the air treatment unit (3) comprises: - a housing which delimits an air treatment chamber (34), wherein the housing is provided with an air inlet (36) and an air outlet (32);

- at least one air treatment element (33, 35); and

- a fan (31) for driving air from the air inlet (36), through the air treatment cham ber (34) and to the air outlet (32).

9. Air treatment unit (3) according to claim 8, wherein, when the air treatment unit (3) is fastened to the face mask (2), the air inlet (36) is facing towards the user of the face mask.

10. Air treatment unit (3) according to claim 8 or 9, wherein the at least one air treatment element (33, 35) comprises an air filter (33).

11. Air treatment unit (3) according to any of the claims 8-10, wherein the air treat ment element (33, 35) comprises a UVC radiation source (35) for radiation of air located in the air treatment chamber (34).

12. Air treatment unit (3) according to claim 11, wherein the UVC radiation source (35) irradiates the air in the air treatment chamber (34) with a radiation having a wavelength in the range of 260-280 nm.

13. Air treatment unit (3) according to claim 11 or 12, wherein at least a portion of the air treatment chamber's (34) wall comprises a reflective material for reflect ing UVC radiation.

14. Protection system (1) for protecting a user from breathing in harmful particles or pathogenic microorganisms, wherein the protection system (1) comprises:

- a face mask (2) according to claim 1; and

- an air treatment unit (3) according to claim 8, wherein the air treatment unit (3) is arranged for detachable attachment to the face mask (2), so that treated air flowing out of the air treatment unit's (3) air outlet (32) is supplied to the delimited cavity (241) between the screen (21) and the user's face via the screen's (21) air intake (23).

15. Protection system (1) according to claim 14, wherein the protection system (1) further comprises an energy source (4) arranged to at least provide the fan (31) with electric energy.

16. Protection system (1) according to claim 15, wherein the air treatment unit (3) further comprises a UVC radiation source (35) for radiation of air located in the air treatment chamber (34) and wherein the energy source (4) is arranged to provide energy to the UVC radiation source (35).