Technical field

The present application relates to a frame mounted filter assembly holder in a ventilation arrangement and a ventilation arrangement particle filter unit comprising such a frame mounted filter assembly holder.

Background

Over the last decades there has been significant progress within the field of ventilation filters. Ventilation filters are commonly used in houses, offices or warehouses that have an air heating system or a heat exchanger. They are used to clean the air from particles such as dust, pollen, bacteria or mould spores or to get rid of unpleasant odours and gases from tobacco smoke, garbage or garages.

It is common that such ventilation filters use frame mounted ready-to-install filters. Ready-to- install filters commonly comprise one or more filters that are secured to relatively stiff rectangular frames, e.g. having a frame edge height of 25 mm. One type of such ventilation arrangement particle filter unit uses a frame mounted ready-to-install bag filter assembly in order to filter an air-flow passed there through. Such frame mounted bag filter assemblies, sometimes also referred to as multi sack bag filters, are usually composed of several filter bags, made of synthteic filter media, such as polymer fibers, or micro glass-fibre fleece, of different thickness or number of layers, depending on the required filter performance. Bag Filter media efficiency varies from very low, coarse filters, to very high, fine filters. The individual bags will then usually have been shaped so as to provide wedge-shaped filter bags, possibly with spacers in the individual filter bags to ensure complete utilization of the full bag depth and, in turn, of the entire filter surface. A typical frame mounted bag filter assembly may consist of 4 to 12 parallel bags. A width and height of a bag filter assembly frame may vary, e.g. from 300 mm up to 900 mm, in dependence on the required capacity of an associated ventilation arrangement particle filter unit.

A typical ventilation arrangement particle filter unit using such frame mounted filter assemblies will comprise a box shaped filter housing having an air inlet opening at a first side of the filter assembly, e.g. at a first end wall, and an air outlet opening at a second side of the filter assembly, e.g. at a second end wall, such that a filter assembly may be interposed there between. The box shaped filter housing will further usually have a first and a second end wall, as exemplified above, where the first and second end walls are joined by four closed side panels, one of which is at least partly openable. The side panels adjacent the openable panel has a filter assembly holder consisting of a respective pair of first and second mutually facing inwardly protruding flanges, extending across its respective panel parallel to the first and second end walls. The respective flanges in each pair of parallel flanges arranged at a distance from each other allowing a perpendicular edge of a filter assembly frame to be received and held there between. The width of the first and second flanges is usually such that corresponds to at least part of a frame face width of a filter assembly frame to be held thereby.

Replacement of a used frame mounted filter assembly with a new one is performed through opening the openable panel of the box shaped filter housing and pulling the used filter assembly frame straight out of the holder provided by the respective pair of first and second mutually facing inwardly protruding flanges. Once the frame is pulled fully out of the respective pair of first and second mutually facing inwardly protruding flanges it is possible to remove the frame mounted filter assembly. Replacement of the thus removed frame mounted filter assembly with a new one is performed conversely, i.e. by placing the frame of the new filter assembly outside an extension of the respective pair of first and second mutually facing inwardly protruding flanges and aligned therewith, and thereafter inserting the frame of the new filter assembly fully between the flanges in the respective pair of first and second mutually facing inwardly protruding flanges.

From the above it will be evident that replacement of a used frame mounted filter assembly with a new one in such typical ventilation arrangement particle filter units will require a free- space outside the respective pair of first and second mutually facing inwardly protruding flanges at least corresponding to the length of the filter assembly frame side to be inserted between the flanges in the respective pair of first and second mutually facing inwardly protruding flanges. However, the above free-space requirement may limit the applicability of ventilation arrangement particle filter unit using such frame mounted filter assemblies. This especially is true in the confined or inaccessible spaces where it is often desirable to place ventilation arrangement filter units, such as e.g. in ceilings or attics.

Thus, there is a need for ventilation arrangement particle filter units that can use frame mounted filter assemblies and can be used in such confined or inaccessible spaces where it is often desirable to place ventilation arrangement filter units, such as e.g. in ceilings or attics. Summary

Embodiments herein aim to provide an improved frame mounted filter assembly holder in a ventilation arrangement.

This is provided through a frame mounted filter assembly holder in a ventilation arrangement, the ventilation arrangement comprising a box shaped filter housing having at least one air inlet opening at a first side of the holder and at least one air outlet opening at a second side of the holder, a first and a second end wall, the first and second end walls being joined by four closed side panels, one of which is at least partly openable, where the side panels adjacent the openable panel has a respective first and second mutually facing inwardly protruding frame support element extending across its respective panel parallel to the first and second end walls the width of which first and second frame support element

corresponds to at least part of a frame face width of a filter assembly frame to be held thereby, characterized in that at least one third frame support element is arranged such that it protrudes inwardly from the closed side panel facing the openable panel up to 10% of their extension in parallel to the first and second frame support elements at a distance there from allowing a perpendicular edge of a filter assembly frame to be received there between, and that at least one fourth frame support element is arranged such that it protrudes at least part of the frame face with inwardly from the openable side panel such that it, when the openable side panel is closed, extends parallel to the first and second frame support elements at a distance there from allowing a perpendicular edge of a filter assembly frame to be received there between.

The provision of at least one third frame support element and at least one fourth frame support element, as above, provides for improved accessibility to a frame mounted filter assembly, especially for facilitating mounting and removal thereof in ventilation arrangements having limited surrounding free-space, such that frame mounted filter assemblies can be used in such confined or inaccessible spaces where it is often desirable to place ventilation arrangement filter units, such as e.g. in ceilings or attics.

According to a second aspect is provided that a respective third frame support element is provided as two mutually facing inwardly protruding flanges the width of which flanges corresponds to at least part of a frame face width of a filter assembly frame to be supported thereby.

The provision of the respective third frame support elements, as above, provides a first alternative for supporting a frame mounted filter assembly such that its frame only requires a limited distance translation along the first and second frame support elements for mounting and removal of the frame adjacent the first and second frame support elements.

According to a third aspect is provided that the two mutually facing inwardly protruding flanges of the third frame support element at their respective ends facing the openable panel has a respective canted end portion, which respective canted end portion has an extension slanting away from the first and second frame support elements.

The provision of a respective canted end portion, as above, facilitates mounting of a filter assembly frame between the first and second frame support elements and the respective third frame support elements as the canted end portions will serve to guide the filter assembly frame into the gap between the first and second frame support elements and the respective third frame support elements upon mounting thereof.

According to a fourth aspect is provided that the third frame support element is provided as an inwardly protruding flange extending across the closed side panel facing the openable panel the width of which third frame support element flange corresponds to at least part of a frame face width of a filter assembly frame to be supported thereby.

The provision of the third frame support element, as above, provides a second alternative for supporting a frame mounted filter assembly such that its frame only requires a limited distance translation along the first and second frame support elements for mounting and removal of the frame adjacent the first and second frame support elements. According to a fifth aspect is provided that the flange of the third frame support element at its end facing the openable panel has a canted end portion, which canted end portion has an extension slanting away from the first and second frame support elements.

The provision of a canted end portion, as above, facilitates mounting of a filter assembly frame between the first and second frame support elements and the third frame support element as the canted end portion will serve to guide the filter assembly frame into the gap between the first and second frame support elements and the third frame support element upon mounting thereof.

According to a sixth aspect is provided that a respective fourth frame support element is provided as two mutually facing flanges the width of which fourth frame support element flanges corresponds to at least part of a frame face width of a filter assembly frame to be supported thereby.

The provision of a respective fourth frame support element, as above, provides a first alternative for supporting a frame mounted filter assembly such that its frame will become supported for mounting adjacent the first and second frame support elements upon closing of the openable side panel and released for removal upon opening of the openable side panel.

According to a seventh aspect is provided that that the flanges of the fourth frame support element at their respective ends facing away from the openable panel has a respective canted end portion, which respective canted end portion has an extension slanting away from the first and second frame support elements.

The provision of a respective canted end portion, as above, facilitates mounting of a filter assembly frame between the first and second frame support elements and the respective fourth frame support elements as the canted end portions will serve to guide the filter assembly frame into the gap between the first and second frame support elements and the respective fourth frame support elements upon mounting thereof.

According to an eight aspect is provided that the fourth frame support element is provided as an inwardly protruding flange extending across the openable panel the width of which flange corresponds to at least part of a frame face width of a filter assembly frame to be supported thereby.

The provision of the fourth frame support element, as above, provides a second alternative for supporting a frame mounted filter assembly such that its frame will become supported for mounting adjacent the first and second frame support elements upon closing of the openable side panel and released for removal upon opening of the openable side panel. According to a ninth aspect is provided that the fourth frame support element flange at its end facing away from the openable panel has a canted end portion, which canted end portion has an extension slanted away from the first and second frame support elements.

The provision of a canted end portion, as above, facilitates mounting of a filter assembly frame between the first and second frame support elements and the fourth frame support elements as the canted end portion will serve to guide the filter assembly frame into the gap between the first and second frame support elements and the fourth frame support element upon mounting thereof.

According to a tenth aspect is provided that that each respective first and second frame support element has a respective first sealing strip adjacent its associated side panel at a side of the respective first and second frame support element facing the third and fourth frame support elements.

The provision of a respective first sealing strip, as above, provides for improved sealing of a potential leakage by an air-flow past a frame mounted filter assembly held by the holder and thus also for ensuring an air-flow through such a frame mounted filter assembly held by the holder.

According to an eleventh aspect is provided that a respective second sealing strip is arranged in parallel with the respective first sealing strips at a distance there from allowing a respective perpendicular side edge of a filter assembly frame to be received there between.

The provision of a respective second sealing strip, as above, provides for further improved sealing of a potential leakage by an air-flow past a frame mounted filter assembly held by the holder and thus also for ensuring an air-flow through such a frame mounted filter assembly held by the holder. According to a twelfth aspect is provided that the third frame support element flange has a third sealing strip adjacent the closed side panel facing the openable panel at a side thereof facing the first and second frame support elements.

The provision of a third sealing strip, as above, provides for even further improved sealing of a potential leakage by an air-flow past a frame mounted filter assembly held by the holder and thus also for ensuring an air-flow through such a frame mounted filter assembly held by the holder.

According to a thirteenth aspect is provided that the fourth frame support element flange has a fourth sealing strip adjacent the openable panel at a side thereof facing the first and second frame support elements. The provision of a fourth sealing strip, as above, provides for still further improved sealing of a potential leakage by an air-flow past a frame mounted filter assembly held by the holder and thus also for ensuring an air-flow through such a frame mounted filter assembly held by the holder.

According to a fourteenth aspect is provided a ventilation arrangement particle filter unit, the ventilation arrangement comprising a box shaped filter housing having at least one air inlet opening at a first side of a filter holder and at least one air outlet opening at a second side of the filter holder, a first and a second end wall, the first and second end walls being joined by four closed side panels, one of which is at least partly openable, where the side panels adjacent the openable panel has a respective first and second mutually facing inwardly protruding frame support element extending across its respective panel parallel to the first and second end walls the width of which first and second frame support element

corresponds to at least part of a frame face width of a filter assembly frame to be held thereby, the ventilation arrangement particle filter unit comprising a frame mounted filter assembly holder as described herein.

According to a fourteenth aspect is provided a ventilation arrangement particle filter unit, as above, that comprises an arrangement for ionizing air particles arranged in the at least one air inlet opening.

The provision of an arrangement for ionizing air particles arranged in the at least one air inlet opening provides for an exceptional cleaning capacity when combined with e.g. Active ION HEPA frame mounted bag filters which will allow for high airflow at very low energy consumption and noise levels. Brief description of the drawings

In the following, embodiments herein will be described in greater detail by way of example only with reference to attached drawings, in which

Fig. 1 is a schematic illustration of a ventilation arrangement comprising a box shaped filter housing having an air inlet opening at a first end wall and a facing air outlet opening at a second end wall.

Fig. 2 is a schematic illustration of how an openable side panel of the box shaped filter housing of fig. 1 is fully opened to expose a frame of a bag filter assembly.

Fig.3 is a schematic illustration, non-openable side panels removed for providing a clear view, of how the frame of the bag filter assembly is supported by the first, second and third frame support elements according to fig. 2.

Fig. 4 is a schematic illustration of how the frame of the bag filter assembly is translated slightly, upwards in the figure, to release the frame of the bag filter assembly from being held between the first, second and third frame support elements.

Fig. 5 is a schematic illustration, non-openable side panels removed for providing a clear view, of how the frame of the bag filter assembly has been released from being held between the first, second and third frame support elements according to fig. 4.

Fig. 6 is a schematic illustration of rotation of the released frame mounted bag filter assembly within the box shaped filter housing.

Fig. 7 is a schematic illustration of collapsing of the filter bags of the rotated frame mounted bag filter assembly such that the filter bags lie essentially in parallel to the extension of the frame. Fig. 8 is a schematic illustration of a third frame support element provided as an inwardly protruding flange extending across the closed side panel facing the openable panel and having a canted end portion at its end facing the openable panel.

Fig. 9 is a schematic illustration of a fourth frame support element provided as an inwardly protruding flange extending across the openable panel and having a canted end portion at its end facing away from the openable panel.

Fig. 10 is a schematic illustration of how each respective first and second frame support element has a respective first sealing strip and a respective second sealing strip in parallel with the respective first sealing strips. Still other objects and features of embodiments herein will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits hereof, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.

Description of embodiments

This disclosure is based on the realization that in order to provide for improved accessibility to a frame 1 mounted filter assembly, especially for facilitating mounting and removal thereof in ventilation arrangements 3 having limited surrounding free-space, such that frame 1 mounted filter assemblies can be used in such confined or inaccessible spaces where it is often desirable to place ventilation arrangement 3 filter units, such as e.g. in ceilings or attics, it would be preferable if mounting and removal of the frame 1 mounted filter assembly can be performed without having to pull the frame 1 fully out of an associated holder having the full length of a corresponding frame 1 side.

This has been provided through a frame 1 mounted filter assembly holder 2 in a ventilation arrangement 3 as illustrated in figure 1 . The illustrated ventilation arrangement 3 comprises a box shaped filter housing 4 having an air inlet opening 5 at a first end wall and a facing air outlet opening 6 at a second end wall. However, it will be evident to the person skilled in the art that the filter housing 4 may have a plurality of air inlet openings 5 and also a plurality of air outlet openings 6, which do not necessarily have to be facing, although air inlet and outlet openings 5, 6 should respectively be located such that air inlet openings 5 are placed at a first side of the holder 2 and air outlet openings 6 at a second side of the holder 2. This, of course, to ensure that air to be filtered is passed through a filter held by the holder 2.

As illustrated in figure 1 , the first and second end walls 4a, 4b are joined by four closed side panels 4c, 4d, 4e, 4f, one of which 4f is at least partly openable. The side panels 4c, 4e adjacent the openable panel 4f has a respective first and second mutually facing inwardly protruding frame support element 2a, 2b, e.g. a respective first and second flange, extending across its respective panel 4c, 4e parallel to the first and second end walls 4a, 4b. The width of the respective first and second frame support element 2a, 2b corresponds to at least part of a frame 1 face width of a filter assembly frame 1 to be held thereby. At least one third frame support element 7 is arranged such that it protrudes inwardly from the closed side panel 4d facing the openable panel 4f. The at least one third frame support element 7 suitably protrudes up to 10% of the extension of the first and second frame support elements 2a, 2b in parallel to the first and second frame support elements 2a, 2b. The at least one third frame support element 7 is arranged at a distance from the first and second frame support elements 2a, 2b allowing a perpendicular edge of a filter assembly frame 1 to be received there between.

Furthermore, at least one fourth frame support element 8 is arranged such that it protrudes at least part of the frame 1 face with inwardly from the openable side panel 4f such that it, when the openable side panel 4f is closed, extends parallel to the first and second frame support elements 2a, 2b. The at least one fourth frame support element 8 is arranged at a distance from the first and second frame support elements 2a, 2b allowing a perpendicular edge of a filter assembly frame 1 to be received there between.

Hence the at least one third frame support element 7 and at least one fourth frame support element 8, as above, provides for improved accessibility to a frame 1 mounted filter assembly, especially for facilitating mounting and removal thereof in ventilation arrangements 3 having limited surrounding free-space, such that frame 1 mounted filter assemblies can be used in such confined or inaccessible spaces where it is often desirable to place ventilation arrangement 3 filter units, such as e.g. in ceilings or attics.

Figs. 2-7 illustrate the process of removing a used frame 1 mounted bag filter assembly from the holder 2 according to embodiments herein. Mounting of a new frame 1 mounted filter assembly can be performed in the reversed order. Although the figures illustrates the frame 1 mounted filter assembly as comprising bag filters it should be clear to the person skilled in the art that the illustrated process is suitable for any type of frame 1 mounted filter or set of filters. As illustrated in figure 2, the openable side panel 4f is fully opened to expose the frame 1 of the bag filter assembly.

Figure 3 illustrates, non-openable side panels 4c, 4d, 4e removed for providing a clear view, how the frame 1 of the bag filter assembly is supported by the first and second frame support elements 2a, 2b and the third frame support element 7. The fourth frame support element 8 has been removed through the opening of the openable side panel 4f. As further illustrated schematically in figure 3, the holder 2 at least comprises the first and second frame support elements 2a, 2b and the third and fourth frame support elements 7, 8.

Figure 4 illustrates how the frame 1 of the bag filter assembly is translated slightly out of the box shaped filter housing 4, upwards in the figure, to release the frame 1 of the bag filter assembly from being held between the first and second frame support elements 2a, 2b and the third frame support element 7.

Figure 5 illustrates, non-openable side panels 4c, 4d, 4e removed for providing a clear view, how the frame 1 of the bag filter assembly has been released from being held between the first and second frame support elements 2a, 2b and the third frame support element 7.

Figure 6 illustrates how the now released frame 1 mounted bag filter assembly can be rotated within the box shaped filter housing 4, such that the frame 1 of the bag filter assembly protrudes at an angle therefrom.

Figure 7 illustrates how the filter bags of the rotated frame 1 mounted bag filter assembly can be collapsed to lie essentially in parallel to the extension of the frame 1 of the bag filter assembly. In this way the frame 1 mounted bag filter assembly is positioned such that removal or mounting thereof can be achieved with only a limited amount of free-space outside the opened box shaped filter housing 4, especially as compared to the requirement of free-space of the prior art holder corresponding to the full extension of the frame 1 of the bag filter assembly.

In some embodiments, not shown, a respective third frame support element 7 is provided as two mutually facing inwardly protruding flanges the width of which flanges corresponds to at least part of a frame 1 face width of a filter assembly frame 1 to be supported thereby. This provides a first alternative for supporting a frame 1 mounted filter assembly such that its frame 1 only requires a limited distance translation along the first and second frame support elements 2a, 2b for mounting and removal of the frame 1 adjacent the first and second frame support elements 2a, 2b. In order to facilitate mounting of a filter assembly frame 1 between the first and second frame support elements 2a, 2b and the respective third frame support elements 7 the two mutually facing inwardly protruding flanges of the third frame support element 7, at their respective ends facing the openable panel 4f, in some further embodiments based on the first alternative embodiment above has a respective canted end portion, c.f. the fig. 8

embodiment, which respective canted end portion has an extension slanting away from the first and second frame support elements 2a, 2b. The canted end portions will serve to guide the filter assembly frame 1 into the gap between the first and second frame support elements 2a, 2b and the respective third frame support elements 7 upon mounting thereof. In other embodiments, as illustrated in figure 8, the third frame support element 7 is provided as an inwardly protruding flange 7a extending across the closed side panel 4d facing the openable panel 4f the width of which third frame support element 7 flange 7a corresponds to at least part of a frame 1 face width of a filter assembly frame 1 to be supported thereby. This provides a second alternative for supporting a frame 1 mounted filter assembly such that its frame 1 only requires a limited distance translation along the first and second frame support elements 2a, 2b for mounting and removal of the frame 1 adjacent the first and second frame support elements 2a, 2b.

In further embodiments based on the second alternative embodiment above, as illustrated in figure 8, the flange 7a of the third frame support element 7 at its end facing the openable panel 4f has a canted end portion 7b, which canted end portion 7b has an extension slanting away from the first and second frame support elements 2a, 2b. This facilitates mounting of a filter assembly frame 1 between the first and second frame support elements 2a, 2b and the third frame support element 7 as the canted end portion 7b will serve to guide the filter assembly frame 1 into the gap between the first and second frame support elements 2a, 2b and the third frame support element 7 upon mounting thereof.

In still further embodiments, not shown, a respective fourth frame support element 8 is provided as two mutually facing flanges the width of which fourth frame support element 8 flanges corresponds to at least part of a frame 1 face width of a filter assembly frame 1 to be supported thereby. This provides a first alternative for supporting a frame 1 mounted filter assembly such that its frame 1 will become supported for mounting adjacent the first and second frame support elements 2a, 2b upon closing of the openable side panel 4f and released for removal upon opening of the openable side panel 4f.

In order to facilitate mounting of a filter assembly frame 1 between the first and second frame support elements 2a, 2b and the respective fourth frame support elements 8, in further embodiments, the flanges of the fourth frame support element 8 at their respective ends facing away from the openable panel 4f has a respective canted end portion, c.f. the fig. 9 embodiment, which respective canted end portion has an extension slanting away from the first and second frame support elements 2a, 2b. The canted end portions will serve to guide the filter assembly frame 1 into the gap between the first and second frame support elements 2a, 2b and the respective fourth frame support elements 8 upon mounting thereof.

In another embodiment, as illustrated in figure 9, the fourth frame support element 8 is provided as an inwardly protruding flange 8a extending across the openable panel 4f the width of which flange 8a corresponds to at least part of a frame 1 face width of a filter assembly frame 1 to be supported thereby. This provides a second alternative for supporting a frame 1 mounted filter assembly such that its frame 1 will become supported for mounting adjacent the first and second frame support elements 2a, 2b upon closing of the openable side panel 4f and released for removal upon opening of the openable side panel 4f.

In some still further embodiments, as also illustrated in figure 9, the fourth frame support element 8 flange 8a at its end facing away from the openable panel 4f has a canted end portion 8b, which canted end portion 8b has an extension slanted away from the first and second frame support elements 2a, 2b. This facilitates mounting of a filter assembly frame 1 between the first and second frame support elements 2a, 2b and the fourth frame support elements 8 as the canted end portion 8b will serve to guide the filter assembly frame 1 into the gap between the first and second frame support elements 2a, 2b and the fourth frame support element 8 upon mounting thereof.

In order to provide for improved sealing of a potential leakage by an air-flow past a frame 1 mounted filter assembly held by the holder 2 and thus also for ensuring an air-flow through such a frame 1 mounted filter assembly held by the holder 2, according to some

embodiments, as illustrated in figure 10, each respective first and second frame support element 2a, 2b has a respective first sealing strip 2c adjacent its associated side panel 4c, 4e at a side of the respective first and second frame support element 2a, 2b facing the third and fourth frame support elements 7, 8.

In order to provide for further improved sealing of a potential leakage by an air-flow past a frame 1 mounted filter assembly held by the holder 2 and thus also for ensuring an air-flow through such a frame 1 mounted filter assembly held by the holder 2, according to yet some further embodiments, as also illustrated in figure 10, a respective second sealing strip 2d is arranged in parallel with the respective first sealing strips 2c at a distance there from allowing a respective perpendicular side edge of a filter assembly frame 1 to be received there between. In still some further embodiments, in order to provide for even further improved sealing of a potential leakage by an air-flow past a frame 1 mounted filter assembly held by the holder 2 and thus also for ensuring an air-flow through such a frame 1 mounted filter assembly held by the holder 2, the third frame support element 7 flange 7a has a third sealing strip, not shown, adjacent the closed side panel 4d facing the openable panel 4f at a side thereof facing the first and second frame support elements 2a, 2b.

In yet some further embodiments the fourth frame support element 8 flange 8a has a fourth sealing strip, not shown, adjacent the openable panel 4f at a side thereof facing the first and second frame support elements 2a, 2b. This provides for still further improved sealing of a potential leakage by an air-flow past a frame 1 mounted filter assembly held by the holder 2 and thus also for ensuring an air-flow through such a frame 1 mounted filter assembly held by the holder 2.

It is further envisaged herein a ventilation arrangement 3 particle filter unit, the ventilation arrangement 3 comprising a box shaped filter housing 4 having at least one air inlet opening 5 at a first side of a filter holder 2 and at least one air outlet opening 6 at a second side of the filter holder 2, a first and a second end wall 4a, 4b, the first and second end walls 4a, 4b being joined by four closed side panels 4c, 4d, 4e, 4f, one of which 4f is at least partly openable, where the side panels 4c, 4e adjacent the openable panel 4f has a respective first and second mutually facing inwardly protruding frame support element 2a, 2b extending across its respective panel 4c, 4e parallel to the first and second end walls 4a, 4b the width of which first and second frame support element 2a, 2b corresponds to at least part of a frame 1 face width of a filter assembly frame 1 to be held thereby, the ventilation

arrangement 3 particle filter unit comprising a frame 1 mounted filter assembly holder 2 as described herein.

The ventilation arrangement 3 particle filter unit described above may be provided with an arrangement for ionizing air particles 9 as they enter the one or more air inlet openings 5. Such an arrangement for ionizing air particles 9 will be well known to a person skilled in the art and is therefore not described in further detail herein. By ionizing air particles as they enter the ventilation arrangement 3 particle filter unit, they can be given a light negative charge. This will make the air particles attracted to oppositely charged surfaces, which e.g. means that they will stick to filters such as Active ION HEPA frame 1 mounted bag filters.

Apart from exceptional cleaning capacity, Active ION HEPA frame 1 mounted bag filters will allow for high airflow at very low energy consumption and noise levels. Active ION HEPA frame 1 mounted bag filters are pre-ionized and can therefore be much sparser than traditional filters. This allows the air to flow almost freely through the filter and still come out free from particles, in fact it has the potential of removing 95-100% of all pollen, dust, bacteria, radon daughters, mould spores and other harmful particles from the air.

Thus, in accordance with the present application is also envisaged a ventilation arrangement 3 particle filter unit comprising an arrangement, not shown in detail, for ionizing air particles arranged in the at least one air inlet opening 5 as described in the foregoing.

The above-described embodiments may be varied within the scope of the following claims.

Thus, while there have been shown and described and pointed out fundamental novel features of the embodiments herein, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are equivalent. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment herein may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice.