The present invention relates to a blanking panel for a rack in a data center.

BACKGROUND

A data center is, within the purport of the present invention, a facility used to house computer systems and associated components, such as servers, telecommunications and storage systems. A data center can be large, in which case they can be an industrial scale operation which might use as much electricity as a small town. A data center can however also be small, for example a corporate server room.

In data centers, the computer systems and associated components are generally placed in so called racks, and for this reason also called rack mountable equipment modules. The 19- inch (482.6 mm) standard rack arrangement is the most widely used one. The 19-inch rack is widely used throughout the telecommunication, computing, audio, video, entertainment and other industries. Another rack used is the Western Electric 23-inch standard. A 19-inch or 23- inch rack is a standardized frame or enclosure for mounting multiple rack mountable equipment modules, each having a front panel that is 19 inch or 23-inch, respectively, wide (in horizontal direction). According the EIA standard (Electronic Indusries Alliance EIA-310-D, Cabinets, Racks, Panels and Associated Equipment, dated September 1992, called EIA-310- D) as well as according to other similar standards, the 19-inch rack is - in vertical direction - divided in rack units of 1.75 inch (44.5 mm), called the standard U. Also racks with the Western Electric 23-inch standard are - in vertical direction - divided in units of 1.75 inch (44.5 mm). A rack-mountable equipment module is usually designed to occupy some integer number of U. For mounting the equipment module to the rack, the rack is provided with a vertical row of mounting holes provided with a repeating pitch sequence of 15.9 mm, 15.9 mm, 12.7 mm (in total 44.5 mm = 1 .75 inch), i.e. a pitch sequence of 15.9 mm - 15.9 mm - 12.7 mm - 15.9 mm - 15.9 mm - 12.7 mm - 15.9 mm - etcetera In case of a 23- inch rack it is known to use mounting holes having the same pitch sequence as in a 19-inch rack, but in 23-inch racks also a pitch sequence of 1 inch is used. The term 'rack' is within the purport of this invention not limited to the above discussed standard 19-inch rack and standard 23-inch rack. Within the purport of the present invention, the term 'rack' also covers other standardized racks used in data centers.

More in general, the term 'rack' means within the purport of the present invention a rack for housing modules of computer systems and/or associated components, in which the rack has a mounting system defining mounting sections of a predefined 'unitary height' for receiving one or more modules each having an height dimensions occupying some integer number of predefined 'unitary heights', and wherein the rack is especially intended for use in a data center. An example of such a rack is a rack configured in accordance with the EAI-310 standard. It is noted that the term 'rack' within the purport of this invention also encompasses a so called cabinet, which is in fact a rack with two opposing side walls.

In practice, a rack in a data center is frequently not fully occupied with rack mountable equipment modules. If the rack is not fully filled with rack mountable equipment modules - in short also called 'equipment modules'-, there remain one or more open spaces at the front side of the rack where no equipment modules are mounted. In case such open spaces are present, air exhausted from the equipment modules flows back into these equipment modules which suck in again the warm exhausted air. This reuse of warm exhaust air prevents properly cooling of the equipment modules, and heat may accumulate causing malfunctioning or crashing of the equipment modules. In order to prevent this, so called blanking panels are used to fill the open spaces at the front side of the rack. Taking into account the EAI-310 standard, equipment modules as well as blanking panels are in general configured to fit in a vertical rack space of nU, n being an integer larger than zero (i.e. n = 1 , 2, 3 ), and the vertical height of the equipment module respectively blanking panel is according to the EAI-310 standard a little smaller than the respective nU value. This results in a small horizontal gap of 1-2 mm remaining between adjacent equipment modules and blanking panels, which gap contributes as well in exhausted air flowing back and being sucked in again, as already described. The open spaces in the front side of the rack may have various sizes. Consequently, it is known to provide blanking panels of different sizes allowing accommodation in open spaces of correspondingly different size. With respect to racks according to the EAI-310 standard, blanking panels for accommodation in an open space having a vertical height of 1 U, 2 U and 3U are known.

The importance of blanking panels is described in several document, like in "Rack Blanking Panels - To Fill or Not to Fill, a Dell Technical White Paper by David L. Moss and Joyce F. Ruff, february 2011" and "Improving Rack Cooling Performance Using Airflow Management™ Blanking Panels, White Paper 44 revision 4 of Schneider Electric by Neil Rasmussen, 2011".

Many blanking panels have the disadvantage that they do not fill the horizontal gap, which as described above remains due to following the EAI-310 standard and which is in practice in the range of 1 -2 mm. Taking into account that on average a number of 15 blanking panels is frequently used in a rack, the remaining horizontal gaps cause excessive supply of cooling air being required. US 2006/0081545 and its PCT sister WO-2006/044740 of Neil Rasmussen and others, disclose a blanking panel having an oversized height helping to produce an intentional interference with adjacent equipment components and other types of blanking panels when the blanking panel is installed to thereby insure formation of an air seal therebetween. The blanking panel according to WO-2006/044740 is an essentially U-shaped section having two about parallel legs and a closed intermediate body connecting the legs. Mounted in the rack, the open side of the U-shaped section and the free ends of the legs of the U-shaped section are facing to the inside of the rack, and the legs of the U-shaped section extend essentially horizontally. According to WO-2006/044740 the air-seal is obtained by allowing the legs to deflect in vertical direction towards each other. This blanking panel is complex of

construction. Deflection of the legs whilst also maintaining the seal means that the legs have a stiff construction resulting in a large force required for deflecting, which hampers an easy mounting. Further, in practice, the air-sealing of this blanking panel turns out to be

incomplete. US 2009/0178985 discloses a blanking panel similar to the one US 2006/0081545 ^WO- 2006/044740). The blanking panel of US 2009/0178985 also is an essentially U-shaped member having two about parallel legs - in US 2009/0178985 called 'skirt members' - which are allowed to deflect in vertical direction towards each other to provide an air seal. SUMMARY OF THE INVENTION

The present invention has as its object to provide an improved blanking panel for a rack in a data center, which is configured to provide an air-seal with an adjacent blanking panel and/or an adjacent rack mountable equipment module installed in a rack.

A further object of the invention is to provide a blanking panel for a rack in a data center which is easy to mount in a rack in a data center whilst ensuring a good air-seal with an adjacent blanking panel and/or an adjacent rack mountable equipment module already installed in a rack

One or more of the above objects is according to a first aspect of the invention achieved by providing a blanking panel for a rack in a data center,

wherein the blanking panel has an height dimension and length dimension extending transverse to the height dimension;

wherein the blanking panel comprises:

• a panel body delimited by two mutually parallel longitudinal sides extending parallel to the length dimension and two transverse sides extending between the longitudinal sides;

■ at least one resiliently compressible sealing element provided on a said longitudinal side of the panel body and extending over the entire length of this longitudinal side of the panel body;

wherein the at least one sealing element is, over the entire length of the respective longitudinal side, resiliently compressible in the direction of the height dimension such that the blanking panel is, viewed in the direction of the height dimension, compressible from a relaxed state to a compressed state;

wherein, in the relaxed state, the height dimension of the blanking panel is:

H = N x Z + Y , with

H being the height dimension (in mm);

N being an integer larger than zero, i.e. N= 1 , 2, ;

Z being a predefined unitary height of a mounting section in the rack (in mm); N x U being an integer multiple of U; and

Y being a surplus value (in mm)

and

wherein, in the compressed state, the height dimension of the blanking panel is:

H = N x Z. The blanking panel as well as the panel body will according to the invention in general have a rectangular shape delimited by two mutually parallel longitudinal sides and two mutually parallel transverse sides.

According to the invention at least one of the longitudinal sides of the panel body is provided with a resiliently compressible sealing element which is arranged onto (so to say on top of) the longitudinal side of the panel body. The panel body and the at least one compressible sealing element provided on top of a longitudinal side of the panel body form together an about 2 dimensional member, or in other words can be seen as a plate member. The height dimension of the blanking panel is determined by the height of the panel body and the height of the one or two resiliently compressible sealing elements. Due to the at least one sealing element being compressible and being provided on top of a longitudinal side of the panel body, the blanking panel - which basically consists of the panel body and the at least one sealing element - is, viewed in the direction of the height dimension of the blanking panel, compressible from a relaxed state to a compressed state. Due to the resilient compressibility of the at least one resiliently compressible sealing element provided on top of a longitudinal side of the panel body, there is obtained a compressible (2- dimensional) plate-like member formed by the panel body and the at least one sealing element. Due to the resilient compressibility of the at least one resiliently compressible sealing element the compressibility of the blanking panel is a reversible compressibility in the sense that the compression results due to the resilience in a counterforce counter acting the compression. This counter force ensures a good sealing which can be maintained for over very long times. This good sealing can, in case of a resiliently compressible sealing element, be obtained without large forces being required to compress the sealing element. The sealing element could for example be a strip of rubber or a strip of foamed elastomer. This allows an easy mounting of the blanking panel according to the invention. According to a further embodiment of the invention both the longitudinal sides of the panel body may be provided with a said resiliently compressible element extending over the entire length of the respective longitudinal side.

According to a further embodiment of the blanking panel according to the invention, the surplus value is in the range of 2-10 mm. This allows for a good sealing in a wide range of applications. The surplus value might according to a further embodiment be in the range of 4- 6 mm, such as about 5 mm.

According to a further embodiment of the blanking panel according to the invention, the height of a said at least one sealing element is, viewed in the direction of the height dimension, in the range of 6-12 mm, such as in the range of 8-10 mm. This allows cables, like UTP-cables and other cables used in relation to computer systems and associated components, to be passed through between a blanking panel and an adjacent other blanking panel or equipment module. This sealing element according to the invention thus makes separate provisions as known from the prior art to allow passage of cables superfluous. According to a further embodiment of the blanking panel according to the invention, Z is the standard rack unit U of 1.75 inch (=44.45 mm).

According to a further embodiment of the blanking panel according to the invention, the at least one sealing element is a strip of a resiliently compressible material. Using a strip of resiliently compressible material allows the sealing element to deform - under influence of resilient compression - differently at different locations. This results in a better sealing in case of irregularities being present in the area to be sealed. For example in case of a cable to be passed through between adjacent blanking panels or between a blanking panel and an adjacent equipment module, the cable is a local irregularity in the area to be sealed. Due to the cable, the strip of resiliently compressible material will be more compressed at the location of the passing cable, whilst in adjacent locations the compression will be less so that formation of a large gap is counteracted or even prevented. In this respect it is noted that, in WO-2006/044740 the flexing leg - which provides the sealing in WO-2006/044740 - will in case of a cable flex over the total length dimension of the blanking panel so that a gap extending over the entire length of the blanking panel of WO-2006/044740 would be created.

According to a further embodiment of the blanking panel according to the invention, said at least one sealing element might be a strip of a resilient material defining a compressible tubular section. The material of this strip might in itself not be compressible in which case the compressibility is provided by the tubular section which allows deformation. Although this embodiment (a strip of non-compressible material having a tubular section) provides the same advantages as described in relation to the embodiment of claim 7 (the sealing element being a strip of a resiliently compressible material), the material of the strip might according to a preferred embodiment also be a resiliently compressible material (in which case one obtains a combination of claims 7 and 8). The latter embodiment providing a better seal in case of irregularities as a gap due to the irregularity will be smaller or absent.

According to a further embodiment of the blanking panel according to the invention, the tubular section has, viewed in the direction of the height dimension, an internal height in the range of 4-8 mm, such as 5-6 mm. This internal height ensures that the tubular section provides sufficient compressibility in order to allow cables as used in practice to pass.

According to a further embodiment of the blanking panel according to the invention, the strip comprises a rubber or rubber like material, such as an elastomer. Or according to an alternative embodiment of the blanking panel according to the invention, the strip is made from a rubber or rubber like material, such as an elastomer. Elastomeric materials or rubber like materials are resiliently compressible and available in all sorts and kinds, allowing the skilled man to choose a soft or stiffer one, whatever fits best the circumstances.

According to a further embodiment of the blanking panel according to the invention, the sealing element has, in the relaxed state and viewed in a direction perpendicular to the longitudinal sides and to the transverse sides, a thickness of at least 6 mm, such as at least 8 mm or at least 10 mm. This improves the sealing in case of cables passing through the area to be sealed. This because in case a small leak around the passing cable might remain, the length of the leak, viewed in the length direction of the cable, is such that air which might pass through the remaining leak experiences an air-resistance which makes that the seal qualifies in practice as air tight taking into account the pressure differences prevailing in a data center.

According to a further embodiment of the blanking panel according to the invention, the blanking panel further comprises a fastening member provided at the longitudinal ends of the blanking panel. This fastening member might - according to a further embodiment of the blanking panel according to the invention - comprise:

• at least one magnet provided at each of the longitudinal ends of the blanking panel; and/or

· at least one fastening plug provided at each of the longitudinal ends of the blanking panel.

According to a further embodiment of the blanking panel according to the invention, the length dimension of the blanking panel is:

· about 19 inch (=48.26 cm) in conformity with the EIA-310 standard for 19 inch racks; or

• about 23 inch (=58.4 cm) in conformity with the standard for 23 inch racks.

According to a further embodiment of the blanking panel according to the invention, the panel body is essentially solid, and might have, viewed in a direction transverse to the height and width dimension, a thickness of 8-15 mm, like in the range of 10-14 mm, for example about 12 mm thick.

According to a further embodiment of the blanking panel according to the invention, the panel body is made from a plastic. A blanking panel made of plastic is light weight and electrically and thermally insulating. A solid blanking panel of plastic having a thickness of more than 6 mm is also sound-insulating (reducing the sound level in a data center) and has further improved thermally and electrically insulating properties.

According to a further embodiment of the invention, the blanking panel is configured to require a force of at most 100 Newton to reduce the height dimension of the blanking panel with 1 mm. This facilitate easy mounting without excessive force being required for compressing the blanking panel in the direction of its height dimension. The force required to reduce the height dimension of the blanking panel with 1 mm will preferably be lower than said 100 Newton, it might for example be at most 50 Newton. More preferred this force is at most 15 Newton, such as at most 10 Newton.

According to a second aspect, the invention provides a set of blanking panels according to the first aspect of the invention, wherein the set comprises:

• at least one blanking panel having a value N=1 ;

• at least one blanking panel having a value N=5; and

· at least one blanking panel having a value N=9.

According to a further embodiment of the second aspect of the invention, the set further comprises at least one blanking panel having a value N=3. According to a third aspect, the invention provides a data center comprising at least one rack provided with at least one blanking panel according to the first aspect of the invention, such as two or more blanking panels according to the first aspect of the invention.

According to a fourth aspect, the invention provides a data center comprising a row of racks placed with their sides against each other, wherein at least one of the racks comprises at least one blanking panel according to the first aspect of the invention, such as two or more blanking panels according to the first aspect of the invention.

According to a further embodiment of the fourth aspect of the invention, one longitudinal side of the row is a high pressure side and the blanking panels are provided at the high pressure side of the row.

According to a further embodiment of the third and fourth aspect of the invention, the rack has an open front side, a back side and two closed side walls, and wherein the at least one blanking panel is provided at the front side of the rack. According to a fifth aspect, the invention is the use of a blanking panel according to the first aspect of the invention

• in a rack housing modules of a computer system and/or associated components; or

· for filling up an open space in a rack housing modules of a computer system and/or associated components;

or

• in a date center, in a rack housing modules of a computer system and/or associated components;

or

• in a data center for filling up an open space in a rack housing modules of a computer system and/or associated components;

or

• in a rack according to the EIA-310 standard;

or

• for filling up an open space in a rack according to the EIA-310 standard;

or

• in a data center, in a rack according to the EIA-310 standard;

or

· in a data center for filling up an open space in a rack according to the EIA-310

standard.

BRIEF DESCRIPTION OF DRAWINGS Figure 1 shows a very schematic view of an example of a data center.

Figure 2 shows schematically an example of a sequence of mounting holes provided according to the EIA-310 standard in a post of a 19 inch or 23 inch rack. Figure 3 shows three blanking panels according to a first embodiment of the invention; Figure 3A shows a blanking panel for blanking a mounting section having a nominal height of 1 U; ; Figure 3B shows a blanking panel for blanking a mounting section having a nominal height of 5U; and ; and Figure 3C shows a blanking panel for blanking a mounting section having a nominal height of 9U.

Figure 4 shows a side view onto the blanking panel of figure 3A. Figure 5 shows very schematically an example of use of the blanking panel according to the invention.

Figure 6 shows a second embodiment of a blanking panel according to the invention, figure 6A being a perspective front view, figure 6B being a perspective rear view, and figure 6C being a perpendicular rear view.

DESCRIPTION OF EMBODIMENTS

Figure 1 shows by way of example a very schematic view of a data center 1. In a data center so called racks 2 are used for housing computer systems and associated components, here called equipment modules 3. These racks are arranged in rows 4. Figure 1 shows by way of example four such rows 4 each - by way of example - comprising four racks 2. It will be clear that in practice these rows might be much longer, that each row might in theory comprise an infinite number of racks, that the number of rows might be smaller or larger up to in theory an infinite number of rows.

In practice most racks in a data center are 19 inch racks according to the EIA-310 standard. Also 23 inch racks, except for the width of 23 inch, basically according to the EAI-310 standard or according to the Western Electric 23 inch standard are used from time to time.

In general the rows are arranged to form hot aisles 5 and cold aisles 6. In general the front side 7 of the racks 2 faces the cold aisles. The cold aisles 6 are connected to a cold air supply 8 - in this example via a perforated floor - and the hot aisles 5 - in this example having a closed floor - are connected to a warm air discharge 9. The cold air supply 8 and warm air discharge 9 might be connected to a heat exchanger 10 where by means of outside air and/or other cooling means the warm discharge air is cooled down to cooled air before being returned to the cold aisles 6 as cold air. Also other manners of providing cold air and discharging warm air are conceivable. In order to prevent cold air from flowing directly to the hot aisles 5, the hot aisles 5 and cold aisles 6 are physically separated from each other. In figure 1 this physical separation is illustrated, by way of example, by a ceiling 1 1 covering the top of the cold aisles.

In large data centers, the amount of energy required for providing the required cooling is enormous. They might use as much electricity as a small town does.

Figure 2 shows schematically an example of a sequence of mounting holes 12 provided according to the EIA-310 standard in a post 13 of a 19 inch or 23 inch rack. The holes 12 are in figure 2 shown as round. In accordance with the EAI-310 standard these holes might also have a different shape, like a square shape. In accordance with the EAI-310 standard the holes 12 are arranged with a pitch sequence P1 , P1 , P2, which is repeated, see figure 2. P1 is a distance of 0,625 inch (=15.9 mm) and P2 is a distance of 0.5 inch (=12.7 mm). P1 +P1 +P2 gives a total of 1 .75 inch (=44.4 mm), which is the standard U of EAI-310. Taking into this repeated pitch sequence P1 -P1-P2, the rack is divided in rack units U for accommodating equipment modules having a nominal height of nU, n being an integer larger than 0 (i.e. n=1 , 2, 3 ). In other words, the rack defines mounting sections having an height U for accommodating equipment modules having a nominal height of nU, n being an integer larger than 0 (i.e. n=1 , 2, 3, ....).

Now referring to Figure 3, this figures shows an embodiment of a set of three blanking panels according to the invention in their relaxed state. Figure 3A shows a blanking panel 21 according to the invention for blanking a mounting section having a nominal height of 1 U; Figure 3B shows a blanking panel 22 according to the invention for blanking a mounting section having a nominal height of 5U; and ; and Figure 3C shows a blanking panel 23 according to the invention for blanking a mounting section having a nominal height of 9U.

The height dimension H of blanking panel 21 is in the relaxed state:

H1 = 1 U + Y,

the height dimension H of blanking panel 22 is in the relaxed state:

H2 = 5 U + Y, and

the height dimension H of blanking panel 23 is in the relaxed state:

H3 = 9 U + Y,

wherein U is 1.75 inch = 44.4 mm; and Y - the so called surplus value - is, in this

embodiment, 5 mm. This means that, in this embodiment, each blanking panel 21 , 22, 23 has an height which is 5 mm oversized with respect to the height of the mounting section for which it is intended.

In this embodiment each blanking panel has a length dimension L of about 19 inch so that it fits in a 19 inch rack according to the EIA-310 standard. The blanking panel 21 , 22, 24 according to the invention comprises a panel body 24 having, viewed in a direction transvers to the length dimension and transverse to the height direction, a thickness T, which is in this embodiment about 12 mm. The panel body 24 is delimited by two mutually parallel longitudinal sides 25, 26 extending in the direct ion of the length dimension L and by two transverse sides 27, 28 extending between and transverse to the longitudinal sides 25, 26. The blanking panel 21 , 22, 23 according to the invention further comprises at least one sealing element 29 extending over the entire length of one of the longitudinal sides 25, 26. In the embodiment shown in figure 3, each blanking panel 21 , 22, 23 has two such sealing elements 29, one extending over the entire length of the longitudinal side 25 and the other extending over the entire length of the longitudinal sides 26. These sealing elements are, viewed in the direction of the height dimension H, H1 , H2, H3 resiliently compressible such that the height dimension of each blanking panel 21 , 22, 23 can be reduced from the relaxed state - as shown in figure 3 - having an height dimension H which is Y (5 mm) larger than 1 U, 5U and 9U respectively to a compressed state having an height dimension H which is 1 U, 5U and 9U, respectively. This reduction of height dimension H is realised by compression of the blanking panel in the direction of the height dimension.

The surplus value Y is in the embodiment of figure 3 about 5 mm. As earlier discussed, in practice the EAI-310 standard leaves a horizontal gap of 1 -2 mm remaining between adjacent equipment modules and blanking panels. In order to ensure sealing of this gap, the surplus value Y will according to the invention be at least 2 mm, more preferred at least 3 mm. Practically, the surplus value Y will according to the invention have an upper value of 8- 10 mm.

For further explanation of especially the sealing element according to the embodiment of figures 3A, 3B and 3C, Figure 4 shows a side view of the blanking panel of Figure 3A.

As can be seen in figure 4 in more detail, each sealing element 29 is, in the embodiment of figures 3A, 3B and 3C, a tubular section 30 of a resilient material, which resilient material might be compressible as well. In this example, the sealing element 29 is a tubular strip of a rubber like elastomer. Viewed in the direction of the height dimension H, the external height S of the sealing element is in the range of 6-12 mm, in this example S is about 10 mm. Viewed in the same direction of the height dimension H, the internal height R of the tubular section is in the range of 4-8 mm, in this example it is about 6 mm. The cavity 31 within the tubular section provides per sealing element, viewed in the direction of the height dimension H, a freedom for compression over the height R. A value R in the range of 4-8 mm is sufficient to allow sufficient compression for passing most of the cables which are in practice used with computer systems and associated components. Referring to the embodiment shown in figure 6 to be discussed later, it will be clear that the sealing element 29 can also be designed differently.

Referring to figure 4, the panel body 24 is in this example an essentially solid piece of plastic. Notwithstanding the panel body 24 being solid in this example, the panel body might comprise cavities or bores at the longitudinal ends of the panel for accommodating a fastening member like a magnet, a bolt, a nut or a fastening plug. Referring to the

embodiment shown in figure 6 to be discussed later, it will be clear that panel body 24 can also be designed differently.

A magnet as fastening member is shown schematically in figure 3A with dashed lines and indicated with reference number 32. Although not shown, it will be clear that also the blanking panels 22 and 23 as shown in figure 3B and/or figure 3C might be provided with a similar magnet 32 or a plurality of magnets 32 at each longitudinal ends of the respective blanking panel 22, 23.

Fastening plugs are for example known from the car industry for fastening lining plates of the interior of the car. Such fastening plugs allow very easy mounting and demounting. For mounting one just inserts the plug through a bore in the panel and into an opening in the frame of the rack and subsequently the plug or a screw member in the plug is rotated 90 or 180 degrees for establishing the fixation. For demounting one just rotates the plug or screw member 90 or 180 degrees in the back ward direction and pulls away the blanking panel. The rotation of the plug or screw member might be facilitated by providing a knob which can be gripped and operated manually or a slit capable of receiving the edge of a coin or the tip of a screw driver. For illustrative purpose such a fastening plug 33 is shown very schematically in figure 4. This fastening plug 33 comprises a shaft 34, a screw head 36 and a slit 35 large enough for receiving the edge of a coin. When in use, the shaft 34 will project into an opening 12 in a post 13 of the rack. It will be clear that fastening plugs as shown in figure 4 can also be used in one or more of figures 3A, 3B and 3C.

Figure 5 shows, as an example, the use of two blanking panels 21 according to the invention in a rack in a data center. The rack is represented by two post 13 provided with fastening holes 12, as has been explained before with reference to figure 2. In this rack an equipment module 41 and two blanking panels 21 according to the invention have been mounted. The upper blanking panel 21 is arranged with its upper sealing element 29 against the lower edge of the front plate of equipment module 41 ; and with its lower sealing element 29 against the upper sealing element 29 of the lower blanking panel 21. The lower sealing element 29 of the lower blanking panel is in a relaxed state and the upper sealing element 29 of the lower blanking panel 21 is in a compressed state. The sealing elements 29 of the upper blanking panel 21 are both in a compressed state, which has been visualized by means of the heights Hr and He. Reference Hr indicates the height dimension which the upper blanking panel 21 would have in the relaxed state. The reference He indicates the height dimension which the upper blanking panel has in the compressed state, when mounted on the rack as shown in figure 5. Figure 5 also shows that the sealing element 29 of the blanking panel 21 according to the invention is capable of being compressed at a location where a cable 40 passes between an equipment module and a blanking panel according to the invention. This is just a local compression, the cable does not result in additional compression of the entire sealing element which would cause a large gap which in turn would cause leakage of air.

In order to facilitate easy mounting without excessive force being required for compressing the blanking panel in the direction of its height dimension, the blanking panel is according to a further embodiment of the invention configured to require a force of at most 100 Newton to reduce the height dimension of the blanking panel with 1 mm. Thus for example a blanking panel having a length of 19 or 23 inch can, viewed in the direction of the height dimension, be 1 mm compressed by subjecting it to a force of at most 100 N acting in the direction of the height dimension. In order to further facilitate easy mounting, the force required to reduce the height dimension of the blanking panel with 1 mm will be at most 50 N, more preferably at most 15 N, such as at most 10 N.

Figure 6 shows a second embodiment of a blanking panel 51 according to the invention. Figure 6A shows a view of the front side of this blanking panel 51 in a perspective manner, Figure 6B shows a view of the backside this blanking panel 51 in a perspective manner, and Figure 6C shows the backside of the end section of the blanking panel 51 in a perpendicular view according to arrow Vl-c in figure 6B.

The blanking panel 51 of figure 6, is, like blanking panel 21 , a blanking panel for blanking a mounting section having a nominal height of 1 U. Similar as the embodiment of the blanking panels shown in figure 3, it will be clear that the blanking panel 51 of figure 6 can easily be designed for larger mounting sections as well, for example for mounting sections having a nominal height of 2U, 3U, 41), 511 or 911. Like the blanking panels 21 , 22, 23 of figure 3, the blanking panel 51 has two sealing elements 59 and a panel body 54 defined by two opposing longitudinal sides 55, 56 and two transverse sides 57, 58. The blanking panel 51 further has fastening plugs 63, like the fastening plugs 33 of the blanking panel 21 of figure 4. Comparable with the blanking panels 21 -23, the sealing elements 59 of blanking panel 51 have an height S in the range of 6-12 mm.

The blanking panel 51 differs from the blanking panels 21 -23 in that the sealing element 59 the panel body 54 are shaped differently. The sealing element 59 is not a tubular element. It is a solid element 59 of a rubber like material which is, viewed in the direction of the height dimension of the blanking panel, resiliently compressible from a relaxed state to a compressed state. The panel body 54 comprises a plate member 72 having a backside (figure 6B and 6C) which is reinforced with a pattern of diagonal ribs 71. Further, the panel body 54 is provided with a longitudinal flange 70 provided at each longitudinal side 25, 26 and extending about perpendicular to the plate member 72.

The blanking panel 51 can be manufactured in mass production by injection moulding the panel body 54 - being of a non-compressible material - and the resilient elements 59 - being of a resiliently compressible material - integrally in a co-moulding process. With respect to blanking panel 51 as well as blanking panels 21 -23, it is to be noted that these show examples of embodiments and that modifications are very well conceivable. For example the panel body 24 of figures 3A-3C could be replaced by the panel body 54 of figure 6 or by a differently designed panel body. The other way around, one can also replace the panel body 54 of figure 6 by a panel body 24 of figures 3A-3C or by a differently designed panel body.