Patent Description:
Refrigeration appliances of known types generally include an inner liner disposed within an outer cabinet. The inner liner typically defines one or more compartments, for example a fresh food compartment and a freezer compartment. Each compartment has an open front closed by a door pivotally mounted to the outer cabinet. Compartments are preferably provided with shelves and/or storage drawers to receive items therein.

A refrigeration system is provided to cool the compartments. The refrigeration system typically includes an evaporator which is preferably mounted inside one of the compartments. The evaporator is advantageously mounted to the rear wall of the compartments itself. A protective plate, or cover plate, is usually disposed over the evaporator and towards the interior of the compartment so that a gap is defined between the rear wall and the same cover. A fan is placed in the gap for creating a cooling air stream for the compartment/s. The air passes over the evaporator which cools the air passing therethrough and then the fan conveys the cooled air, coming from the evaporator, inside the compartment/s. One or more air conveying channels comprising air outlet vents opening realized in the cover (and/or above/below the cover) allows conveyance of the cooled air from the fan outlet into the compartment. Conveyance channels are preferably realized in a layer of plastic foam insulation material disposed adjacent to the side wall of the cover and closed to the fan outlet.

During manufacturing process of the appliance, the evaporator is firstly fixed to the rear wall of the inner liner inside the compartment and then the fan, the plastic foam layer and the cover plate are connected together through fasteners, such as screws, bolts, etc., to keep them in place.

A drawback of this known technique derives from the complexity of the mounting method during manufacturing process of the appliance.

The mounting method does not assure the stability of the evaporator fan and often causes undesirable vibration and noise during operation. In instances where the refrigeration appliance is a domestic refrigerator, the noise and vibration can be annoying to consumers and/or give the consumer the impression that the refrigeration appliance is poorly designed and/or poorly manufactured.

<CIT> discloses a refrigerator with a no-frost design.

<CIT> discloses a refrigerator with a force ventilation evaporator.

<CIT> discloses a refrigerator and a duct assembly.

It is an object of the present disclosure to overcome at least some of the problems associated with the prior art.

It is an object of the invention to implement a system apt to simplify manufacturing process of refrigeration appliances compared to known process.

It is another object of the invention to implement a system apt to reduce manufacturing time and/or costs compared to known systems.

It is a further object of the invention to implement a system apt to guarantee a more compact configuration of assembled components compared to known systems.

It is another object of the invention to implement a system apt to reduce noise during operation of the refrigeration appliance.

It is a further object of the invention to implement a system apt to improve reliability of the refrigeration appliances.

The applicant has found that by providing a refrigeration appliance having a compartment receiving an evaporator of a refrigeration system and by providing a pre-assembled fan assembly which is arranged inside the compartment adjacent the evaporator, it is possible to solve the drawbacks of the known systems.

According to the invention there is provided a refrigeration appliance according to claim <NUM>.

For arranged side by side it is meant arranged one laterally of the other and preferably in a lateral order perpendicular to the vertical direction; in other words, each component is at least partially stacked/in contact to the laterally adjacent component.

Preferably, in its installed position, lateral side walls of the outer cabinet are aligned to the vertical direction.

Preferably, the fastening device is apt to fasten the cover plate to the first layer to keep staked, preferably in the following order, the first layer and the fan in their assembled position.

Preferably, the fastening device is apt to fasten the cover plate to the first layer to keep staked, preferably in the following order, the first layer, the fan and the second layer in their assembled position.

The fan is therefore firmly sandwiched between the first layer and the second layer of expanded polystyrene EPS.

Advantageously, the fan assembly with associated fastening device guarantees a compact configuration that avoids/reduces vibrations between them, in particular during activation of the fan.

This results in a reduction of noise during operation of the refrigerator and/or also an improved reliability of the refrigerator.

In a preferred embodiment of the invention, the rotation axis of the rotor is inclined with respect to the lateral side walls of the outer cabinet when the appliance is in its installed position.

Advantageously, inclination of the rotor with respect the vertical direction guarantees a good fluid dynamics efficiency for the fan. Furthermore, inclination of the rotor minimized the space occupied by the assembly fan so that the volume of the compartment is not negatively affected.

According to a preferred embodiment of the invention, the first wall of the compartment is the rear wall of the compartment.

Preferably, the first layer comprises one or more air conveying channels and the cover plate comprises one or more air opening communicating with the one or more air conveying channels when the fan assembly is assembled.

Preferably, in case a second layer is present, also the second layer may comprise one or more air conveying channels.

In a preferred embodiment of the invention, the fastening device comprises snap fit elements.

According to a preferred embodiment of the invention, the fastening device comprises elastic tongues protruding from the cover plate interacting with recesses in the first layer.

Advantageously, the fastening device and the cover plate realize a single body so that there is no need of separated fastening means, thus reducing complexity of the fan assembly and simplifying assembling process steps.

Preferably, the first layer comprises a seat to at least partially receive the fan.

In a preferred embodiment of the invention, the fan assembly comprises a mounting element apt to mount the fan to the first layer.

According to a preferred embodiment of the invention, the mounting element comprises one or more pins apt to be inserted in respective one or more through holes of the first layer and comprising blocking elements connected at the tip of the one or more pins and abutting a surface of the first layer, allowing the constraint of the mounting element to the first layer.

Preferably, vibration dampening elements are interposed between the fan and the mounting element. Advantageously, vibration dampening elements absorb vibrations created by the fan rotation.

In a preferred embodiment of the invention, the fan comprises a frame apt to support the rotor.

According to a preferred embodiment of the invention, the frame is connected to the mounting element through a carrier structure.

Preferably, vibration dampening elements are interposed between the frame of the fan and the mounting element, more preferably interposed between the frame of the fan and carried structure.

In a preferred embodiment of the invention, the fan assembly further comprises a fan mouth where air flows from the evaporator to the fan.

According to a preferred embodiment of the invention, the fan mouth is placed between the first layer and the fan.

Preferably, the fan mouth and the mounting element are integrally made. Advantageously manufacturing time and/cost are reduced.

In a preferred embodiment of the invention, connecting means are apt to connect the fan assembly to the first wall of the compartment.

According to a preferred embodiment of the invention, the fan is a centrifugal fan, preferably a radial fan.

The present invention further relates to a method for manufacturing a refrigeration appliance comprising the steps of:.

In a preferred embodiment of the invention, said fastening steps comprises:.

In a further preferred embodiment, said fan assembly is a pre-assembled assembly obtained by the steps of fastening together, side by side, the following elements:.

In such preferred embodiment, said fastening steps comprises:.

Further characteristics and advantages of the present invention will be highlighted in greater detail in the following detailed description of a preferred embodiment of the invention, provided with reference to the enclosed drawings. In said drawings:.

Referring to <FIG> a refrigeration appliance in the form of a domestic refrigerator is shown, indicated generally as <NUM>. Although the detailed description that follows concerns a domestic stand-alone refrigerator <NUM>, the refrigeration appliance can be embodied by refrigeration appliances other than a domestic refrigerator.

Furthermore, the embodiment described in detail below refers to a bottom mount refrigerator, i.e. of the type including a freezer compartment disposed vertically below a fresh food compartment. However, the refrigerator according to the invention can have any desired configuration, for example a top mount refrigerator wherein the freezer compartment is disposed vertically above the fresh food compartment or a refrigerator comprising only a fresh food compartment or only a freezer compartment.

Furthermore, while the present application is described with reference to a stand-alone refrigerator it has to be noted that also a built-in solution may be contemplated.

The refrigeration appliance <NUM> illustrated in the figures, hereinafter indicated as refrigerator <NUM>, comprises an outer cabinet <NUM> and an inner liner <NUM>, internally received in the outer cabinet <NUM>. The outer cabinet <NUM> and the inner liner <NUM> are separated by a spacing filled with thermal insulation <NUM>, preferably a foam insulation.

The outer cabinet <NUM> preferably extends in a vertical direction V and preferably comprises a base 2A suitable to lay on the ground, a roof 2B and lateral side walls 2C, 2D, 2E connecting the base 2A and the roof 2B, preferably two lateral side walls 2C, 2D and a rear side wall 2E.

In its installed position, lateral side walls 2C, 2D and the rear side wall 2E are preferably aligned to the vertical direction V.

The refrigerator <NUM> according to the embodiment shown in the figures preferably represents a bottom mount type refrigerator. At this purpose, a divider portion <NUM> (<FIG>) is provided which divides inner liner <NUM> into a lower space that is used as a freezer compartment <NUM>, and an upper space that is used as a fresh food compartment <NUM>.

The freezer compartment <NUM> substantially preferably has the form of a cuboid defining a rectangularly shaped front opening <NUM>. A door <NUM> is preferably pivotally mounted to the outer cabinet <NUM> and is movable between an open position and a closed position to cover the front opening <NUM>.

The freezer compartment <NUM> preferably shows a rear wall <NUM> which is defined by a portion of the inner liner <NUM>, more preferably a vertical rear wall <NUM>.

Analogously, the fresh compartment <NUM> substantially and preferably has the form of a cuboid defining a rectangularly shaped front opening <NUM>. A door <NUM> is preferably pivotally mounted to the outer cabinet <NUM> and is movable between an open position and a closed position to cover the front opening <NUM>.

In an alternative embodiment, a single door can be provided to open and close both the front openings <NUM>, <NUM> of the freezer and the fresh compartments <NUM>, <NUM>.

The compartments <NUM>, <NUM> preferably comprise shelves S and/or drawers D for receiving food items.

A refrigeration system <NUM> is preferably provided to cool the compartments <NUM>, <NUM>.

According to the present invention, the refrigeration system <NUM> is apt to cool down air which is circulated inside at least one compartment of refrigerator <NUM>, preferably to cool down air which is circulated inside both compartments <NUM>, <NUM>. In the preferred embodiment of the invention, the refrigeration system <NUM> preferably comprises a closed recirculating system filled with a suitable refrigerant, for example R12 or R134a. The refrigeration system preferably comprises an electric motor-driven compressor <NUM>, a condenser heat exchanger <NUM>, a pressure device such as a capillary tube or a thermostatic valve (not shown) and an evaporator <NUM>.

A collecting tray <NUM> is preferably arranged below the evaporator <NUM> to collect water formed by condensation on the evaporator <NUM>.

The evaporator <NUM> is preferably mounted inside the freezer compartment <NUM>, whereas the compressor <NUM> is mounted external to the freezer compartment <NUM> and preferably arranged in a working chamber <NUM> at the bottom of the refrigerator <NUM>.

The condenser heat exchanger can be a condenser tubing <NUM> that preferably has a serpentine configuration and is preferably externally secured to the rear side wall 2E of the outer cabinet <NUM> so as to form what is commonly known as a "hot wall".

Further features of the refrigeration system <NUM> are not described in detail in the present application since are well known in the art.

The evaporator <NUM> is more preferably mounted to the rear wall <NUM> of the freezer compartment <NUM> towards the interior of the freezer compartment <NUM>.

According to the invention, a pre-assembled fan assembly <NUM> is arranged closed to the evaporator <NUM>. The fan assembly <NUM> is shown isolated from the rest in <FIG>.

The fan assembly <NUM> is advantageously pre-assembled during manufacturing of the refrigerator <NUM> and then it is mounted inside the freezer compartment <NUM> over the evaporator <NUM>.

The fan assembly <NUM> is preferably connected to the rear wall <NUM> of the freezer compartment <NUM> through connecting means <NUM>.

In the preferred embodiment illustrated in the figures, the connecting means <NUM> preferably comprise two lower protruding tabs 61A, 61B with holes for receiving fixing screws (not shown). The fan assembly <NUM> is assembled to the freezer compartment <NUM> by inserting its upper part in position inside the freezer compartment <NUM>, rotating its lower part to bring the fan assembly <NUM> in its final position and finally fixing the fan assembly <NUM> to the inner liner <NUM> with screws inserted in the tabs 61A, 61B.

In different preferred embodiments, the connecting means may comprise other type of fasteners, such as mechanical (e.g. rivets, nuts and bolts, etc.), chemical (e.g. adhesive, epoxy, etc.), or other type of fasteners.

The function of the fan assembly <NUM> is to generate the cooling air stream that is conveyed and recirculated inside the freezer compartment <NUM> and, in the preferred embodiment here illustrated, also inside the fresh food compartment <NUM>. The fan assembly <NUM> is preferably configured to draw air from the evaporator <NUM> and to expel it into the freezer compartment <NUM> and into the fresh food compartment <NUM>.

According to an aspect of the invention, the fan assembly <NUM> preferably comprises a first layer <NUM> of expanded polystyrene, a fan <NUM>, a second layer <NUM> of expanded polystyrene and a cover plate <NUM>.

The first layer <NUM>, the fan <NUM>, the second layer <NUM> and the cover plate <NUM> are preferably arranged side by side, i.e. arranged one laterally of the other and preferably in a lateral order perpendicular to the vertical direction V. In other words, each component <NUM>, <NUM>, <NUM>, <NUM> is at least partially stacked/in contact to the laterally adjacent component.

Preferably, expanded polystyrene used for the layers <NUM>, <NUM>, i.e. EPS, is a lightweight, rigid plastic foam insulation material made of solid polystyrene particles.

The use of EPS enhances thermal isolation of the fan assembly <NUM>, being EPS a high-quality thermal insulator material.

In addition, the use of EPS enhances acoustic isolation of the fan assembly <NUM>, in particular of noise caused by rotation of the fan <NUM> and of the air expelled from it. Furthermore, using of EPS simplifies the fan assembly <NUM> construction as EPS is an easily handled material. Still advantageously, EPS is a cheap material.

Therefore, manufacturing time and/or costs are reduced compared to known systems.

In a further preferred embodiment of the invention, not shown, the second layer of expanded polystyrene may be omitted.

The fan <NUM> preferably comprises a rotor <NUM> with a rotation axis X. The rotor <NUM> is preferably mounted on a supporting frame <NUM>.

The supporting frame <NUM> preferably has a spider shaped structure with arms 80A-80F supporting the rotor <NUM>, as visible in <FIG>.

The fan <NUM> preferably comprises a centrifugal fan, preferably a radial fan. The air flows from a suction side 72A of the fan <NUM> facing the evaporator <NUM>, and the air is then displaced radially, changing its direction (typically by <NUM>°). The rotor <NUM> preferably consists of a rotating arrangement of vanes or blades, rotating around said axis X, which act on the air.

Preferably, a fan mouth <NUM> is arranged at the suction side 72A of the fan <NUM> to convey the air from the evaporator <NUM> to the rotor <NUM>. The fan mouth <NUM> preferably faces the evaporator <NUM> and is preferably placed between the first layer <NUM> and the fan <NUM>.

In different preferred embodiments, the fan mouth may be omitted.

A suction chamber <NUM> is created between the fan <NUM>, preferably the fan mouth <NUM>, and the outlet side 38A of the evaporator <NUM>, as shown in <FIG>. The fan <NUM> draws air from the evaporator <NUM> through the suction chamber <NUM> and expels it outside the fan assembly <NUM>, towards the freezer compartment <NUM> and the fresh food compartment <NUM>, as better described later.

The air preferably flows in the compartments <NUM>, <NUM> to define closed loop circuits and the fan <NUM> is switched on/off according to operational condition, for example the temperature level inside the compartments <NUM>, <NUM> and/or opening of the doors, etc..

According to an aspect of the invention, the rotating axis X of the rotor <NUM> is inclined with respect to a vertical direction V.

Preferably, the rotating axis X is inclined with respect to the rear side wall 2E of the outer cabinet <NUM>.

The rotating axis X is preferably inclined with respect to the vertical direction V of an angle W comprised between <NUM>° and <NUM>°, more preferably inclined of an angle W equal to <NUM>°.

Advantageously, by inclining the rotor <NUM> with respect the vertical direction V the suction chamber <NUM> is shaped to guarantee a good fluid dynamics efficiency and at the same time the space occupied by the fan <NUM> is minimized so that the volume of the freezer compartment <NUM> is not negatively affected.

According to an aspect of the invention, the fan assembly <NUM> comprises a fastening device <NUM> apt to fasten the cover plate <NUM> to the first layer <NUM> to keep elements of the fan assembly <NUM> in the assembled configuration.

Preferably, the fastening device <NUM> is apt to fasten the cover plate <NUM> to the first layer <NUM> to keep staked, preferably in the following order, the first layer <NUM>, the fan <NUM> and the second layer <NUM> in their assembled position.

The fastening device <NUM> keeps the elements of the fan assembly <NUM> firmly together. In particular, preferably, the fan <NUM> is firmly sandwiched between the layers <NUM>, <NUM> of expanded polystyrene EPS.

In case the second layer of expanded polystyrene is omitted, according to an alternative preferred embodiment of the invention, the fastening device is apt to fasten the cover plate to the first layer to keep staked, preferably in the following order, the first layer and the fan in their assembled position.

Preferably, the fastening device <NUM> comprises snap fit elements. In the preferred embodiment illustrated in the figures, the fastening device <NUM> comprises elastic tongues <NUM> protruding from the cover plate <NUM> which interact with respective recesses <NUM> in the first layer <NUM>, as better illustrated in <FIG>. Tongues <NUM> are preferably made in one piece with the cover plate <NUM> to realize a single body.

Advantageously, the fan assembly <NUM> with associated fastening device <NUM> guarantees a compact configuration that avoids/reduces vibrations between them, in particular during activation of the fan.

This results in a reduction of noise during operation of the refrigerator <NUM> and/or also an improved reliability of the refrigerator.

Furthermore, advantageously, the fastening device and the cover plate realize a single body so that there is no need of separated fastening means, thus reducing complexity of the fan assembly and simplifying assembling process steps.

In a preferred embodiment of the invention, the first layer <NUM> comprises one or more air conveying channels 100a-<NUM> for conveying cooled air expelled from the fan <NUM> towards the compartments <NUM>, <NUM>.

Conveying channels 100a-<NUM>, as illustrated in <FIG> and <FIG>, are opened in the direction of the cover plate <NUM>. In the assembled configuration, then, the cover plate <NUM> opportunely closes the conveying channels 100a-<NUM> allowing the air conveyance. The first layer <NUM> with open channels 100a-<NUM> are easily obtained through an injection mould process with EPS.

Nevertheless, in a further preferred embodiment (not shown) air conveying channels may be realized as closed air conveying channels directly on the first layer.

According to the preferred embodiment illustrated in the figures, there are six air conveying channels 100a-100f that are radially arranged around the fan <NUM> for the air to the freezer compartment <NUM> and an upper air conveying channel <NUM> for the air to the fresh food compartment <NUM>.

The cover plate <NUM> preferably comprises one or more air opening 102a-102f communicating with the air conveying channels 100a-100f of the first layer <NUM>. Cooled air advantageously enters the freezer compartment <NUM> through said air openings 102a-102f, which preferably are grated openings.

It is preferably contemplated that the cover plate <NUM> is made from plastic to provide an aesthetically pleasing appearance to a user.

Preferably, an intermediate sheet <NUM> is interposed between the firs layer <NUM> and the cover plate <NUM>. The intermediate sheet <NUM> preferably comprises holes 106a-106f aligned with the air openings 102a-102f of the cover plate <NUM>.

The intermediate sheet <NUM> enhances the closure of the conveying channels 100a-<NUM> of the first layer <NUM>. The intermediate sheet <NUM> improves the sealing effect for the conveying channels 100a-<NUM>, in particular in case the cover plate <NUM> is not perfectly planar.

In a further preferred embodiment, the intermediate sheet may be omitted.

Preferably, the first layer <NUM> comprises a seat <NUM> apt to at least partially receive the fan <NUM>.

A mounting element <NUM> is preferably used to mount the fan <NUM> to the first layer <NUM>, preferably to the seat <NUM>. More preferably, the mounting element <NUM> is preferably used to mount the frame <NUM> of the fan <NUM> to the first layer <NUM>.

In the preferred embodiment illustrated in the figures, the mounting element <NUM> is integrally made with the fan mouth <NUM>. Manufacturing time and/cost are advantageously reduced.

In different preferred embodiments, nevertheless, the mounting element and fan mouth can be two independent elements.

The mounting element <NUM> is arranged in the seat <NUM> of the first layer <NUM> and connected thereto. In the preferred embodiment illustrated in the figures the mounting element <NUM> preferably comprises an annular surface 124A that preferably lays in a plane perpendicular to the axis X of the rotor <NUM>.

The mounting element <NUM> preferably comprises one more pins <NUM> apt to be inserted in respective one or more through holes <NUM> of the first layer <NUM>. The pins <NUM> preferably protrude from the annular surface 124A of the mounting element <NUM>.

The pins <NUM> are axially blocked to the first layer <NUM> with blocking elements <NUM>, for example internal tooth lock washers, connected at the tip of the pins <NUM> and abutting a surface <NUM> of the first layer <NUM>, as better visible in <FIG>. The pins <NUM>, allow the constraint of the mounting element <NUM> to the first layer <NUM>.

More preferably, the frame <NUM> of the fan <NUM> is connected to the mounting element <NUM> through a carrier structure <NUM> preferably comprising ribs <NUM> protruding from the annular surface 124A of the mounting element <NUM>.

In the preferred embodiment illustrated, the ribs <NUM> define connecting points for the frame <NUM> of the fan <NUM>, preferably three connecting points (<FIG>).

In an aspect of the invention, vibration dampening elements <NUM> are interposed between the fan <NUM> and the mounting element <NUM>. Preferably, the vibration dampening elements <NUM> are interposed between the frame <NUM> of the fan <NUM> and the mounting element <NUM>. More preferably the vibration dampening elements <NUM> are interposed between the frame <NUM> of the fan <NUM> and the carrier structure <NUM> of the mounting element <NUM>.

Vibration dampening elements <NUM> preferably comprise rubber washers interposed between three arms 80A, 80C, 80E of the supporting frame <NUM> and corresponding ribs <NUM> of the mounting structure <NUM>.

Vibration dampening elements <NUM> advantageously absorb vibrations created by the fan rotation.

In a preferred embodiment of the invention, the second layer <NUM> comprises a seat/opening <NUM> apt to at least partially receive the fan <NUM>.

The second layer <NUM>, then, preferably comprises protruding pins 222a apt to be received in respective holes 222b of the first layer <NUM> when the fan assembly <NUM> is assembled.

In the assembled configuration, the second layer <NUM> of EPS enhances acoustic isolation of the noise caused by rotation of the fan <NUM> towards the internal volume of the freezer compartment <NUM>.

As said above, the air preferably flows in the compartments <NUM>, <NUM> to define closed loop circuits. Advantageously, the fan assembly <NUM> create an air flow paths inside the fresh food compartment <NUM> and air flow paths in the freezer compartment <NUM>, schematically indicated with FF, F1, F2, F3 in <FIG> and <FIG>.

In particular, air flow path FF is generated by the fan assembly <NUM> and conveyed to the fresh food compartment <NUM> through the upper air conveying channel <NUM> of the first layer <NUM>.

Air flow paths F1, F2, F3 are generated by the fan assembly <NUM> and conveyed to the freezer compartment <NUM> through the six air conveying channels 100a-100f of the first layer <NUM> and air openings 102a-102f of the cover plate <NUM>.

From the inside of the freezer compartment <NUM>, then, the air flows back to the evaporator <NUM> through a gap <NUM> preferably defined between the lower part of the cover plate <NUM> and the lower part of the rear wall <NUM> of the freezer, as indicated in <FIG>.

Main phases for manufacturing the refrigerator <NUM> according to the invention preferably comprises the following steps:.

Main phases for assembling the fan assembly <NUM> comprises the following steps:.

It is clear that in case the second layer of expanded polystyrene is omitted, according to an alternative preferred embodiment of the invention, the above described assembling steps are simplified since the second layer is obviously not used.

Advantageously, from the above description it has been shown that by providing a pre-assembled fan assembly manufacturing process of refrigeration appliances are simplified compared to known process.

Also, noise and vibrations are reduced compared to known appliances since the fan is firmly sandwiched between the layers of expanded polystyrene.

Reduction of vibrations, then, improve reliability of the refrigerator.

Claim 1:
A refrigeration appliance (<NUM>) comprising:
- an outer cabinet (<NUM>) extending in a vertical direction (V) and comprising a base (2A) suitable to lay on the ground, a roof (2B) and lateral side walls (2C, 2D, 2E) connecting said base (2A) and said roof (2B);
- an inner liner (<NUM>), internal to said outer cabinet (<NUM>), defining at least one compartment (<NUM>) for receiving food items;
- a door (<NUM>, <NUM>) apt to open and close said at least one compartment (<NUM>);
- a refrigeration system (<NUM>) comprising an evaporator (<NUM>) to cool down air for said at least one compartment (<NUM>), said evaporator (<NUM>) being arranged inside said at least one compartment (<NUM>) at a first wall (<NUM>) thereof;
- a fan assembly (<NUM>) arranged inside said compartment (<NUM>) and associated to said evaporator (<NUM>) for generating a cooling air stream for said at least one compartment (<NUM>);
wherein said fan assembly (<NUM>) comprises, arranged side by side:
- a first layer (<NUM>) of expanded polystyrene;
- a fan (<NUM>) comprising a rotor (<NUM>) with a rotation axis (X) inclined with respect to a vertical direction (V);
- a cover plate (<NUM>);
and wherein said fan assembly (<NUM>) comprises a fastening device (<NUM>) apt to fasten said cover plate (<NUM>) to said first layer (<NUM>) to keep said fan assembly (<NUM>) in the assembled configuration,
characterized in that said fan assembly (<NUM>) further comprises a second layer (<NUM>) of expanded polystyrene arranged between said fan (<NUM>) and said cover plate (<NUM>).