WO2023232501A1

WO2023232501A1 - An assembly of a housing and a drawer for heating water in a building

Info

Publication number: WO2023232501A1
Application number: PCT/EP2023/063545
Authority: WO
Inventors: Florian ANTOINE; Dominique Bastien; Arnaud Bichler
Original assignee: Bdr Thermea Group B.V.
Priority date: 2022-05-30
Filing date: 2023-05-22
Publication date: 2023-12-07
Also published as: WO2023232509A1; WO2023232503A1; WO2023232505A1; WO2023232508A1; WO2023232506A1; WO2023232502A1; WO2023232504A1

Abstract

Providing an assembly for heating water in a building, in particular a heat pump, wherein the assembly comprises a casing, a housing for accepting a drawer, and a drawer for holding a heat exchanging circuit. The drawer may be inserted, removed or replaced upon installation or maintenance of the assembly without the need for an installer or operator to handle the heat exchanging circuit. The heat exchanging circuit may comprise a refrigerant loop.

Description

An assembly of a housing and a drawer for heating water in a building

The invention relates to an assembly for heating water in a building, in particular a heat pump, wherein the assembly comprises a casing, a housing for a drawer inside the case and a drawer positioned within the housing. Additionally, the invention relates to a heat pump with the housing for a drawer. Also, the invention relates to a drawer for use in a heat pump comprising the housing.

Heating of water in buildings, such as heating water of a central heating system or heating of water for domestic use, may be accomplished by means of a heat pump system. Such a heat pump system may either be a ground source to water heat pump (GSHP) system or an air source to water heat pump (AWHP) system. In a GSHP system, calories are exchanged between the ground and the water. The calories in the ground may be extracted by capturing calories in a water table or by circulating a water-based circuit in the ground. In an AWHP system calories are exchanged between the air and the water. Heat pump systems may be further divided into so-called ‘split’ systems or ‘monobloc’ systems.

A heat pump system typically comprises at least one first heat exchanger for capturing calories from a first source, at least one second heat exchanger for transferring captured calories to a second source, and a refrigerant loop between both heat exchangers to transport the captured calories from the at least one first heat exchanger to the at least one second heat exchanger. The at least one first and second heat exchangers together with the refrigerant loop form, at least a part of, a heat exchanging circuit. The heat exchanging circuit may be connected to a hydraulic group. Said hydraulic group may be a liquid loop such as a water loop or a loop comprising water and an antifreeze additive such as glycol. The hydraulic group may be connected to, or be a part of, a water-based central heating system, a heated domestic water supply system, a water boiler for heating and storing domestic water, or a combination thereof. Thus the hydraulic group may transport the captures calories from within the heat pump system to a water source outside the heat pump system, either directly or indirectly.

In a heat pump ‘monobloc’ system, the heat exchanging circuit may be comprised within a single indoor or outdoor unit. In a GSHP ‘monobloc’ system, the at least one first heat exchanger is connected to a ground loop capturing calories from a ground source. In a AWHP ‘monobloc’ system, the at least one first heat exchanger captures calories from the outside air. Said calories are then transported via the refrigerant loop to the at least one second heat exchanger. This at least one second heat exchanger then transfers the captured calories to a hydraulic group. The refrigerant loop therefore typically comprises a compressor and an expansion valve to allow the refrigerant in the refrigerant loop to compress upstream of one heat exchanger and to expand upstream of the other heat exchanger thereby enabling the heat exchanging circuit to exchange and transfer calories between the outside air and the hydraulic group.

In a heat pump ‘split’ system, the heat exchanging circuit may be split over an outdoor and an indoor unit. In a GSHP ‘split’ system, the at least one first heat exchanger is present in an outdoor unit an connected to a ground loop capturing calories from a ground source. In a AWHP ‘split’ system, the at least one first heat exchanger is present in an outdoor unit capturing calories from the air. The calories are then transported via the refrigerant loop, usually crossing a wall of a building, to the at least one second heat exchanger which is present in an indoor unit. This at least one second heat exchanger then transfers the captured calories to a hydraulic group. The indoor unit is separate from the outdoor unit, while the components of the heat exchanging circuit are thus distributed over both the indoor and outdoor unit. Hence, the heat exchanging circuit is split over the outdoor and indoor unit.

Classically, hydrofluorocarbon (HFC) refrigerants were used in such a refrigerant loop. Now, natural refrigerants such as propane are used as an ecological alternative to HFC refrigerants. Natural refrigerants such as propane, however, are flammable. This creates a risk of explosion in the event of a leak present in the refrigerant loop. As the heat pump system is an electric appliance, upon leakage of the natural refrigerant an electric spark may potentially ignite the natural refrigerant and create an explosion. Thus there is a risk of a residential or commercial building to explode or to burn. These risks need to be mitigated as much as possible.

Leakage is most likely to occur at a joint within the refrigerant loop. At any joint, two parts of the loop come together and have to be connected securely and tightly in order to prevent any leakage. A major potential risk of a bad connection at a joint within the refrigerant loop may occur upon installation or during maintenance of the heat pump system. Especially when handling the heat exchanger circuit as a whole, misalignment of connections can occur upon installing or reinstalling during maintenance. This can lead to bad connections and as such pose a risk of leakage. The heat exchanger circuit comprising the refrigerant loop, however, usually does not require much or any maintenance. Maintenance typically takes place with other parts of the heat pump system such as with the hydraulic group or the electronic system, including sensors and probes. In the situation that the heat exchanger circuit comprising the refrigerant loop requires maintenance, it involves emptying the heat exchanger circuit of its refrigerant, changing the component without polluting the system and refiling it again while ensuring that there are no leaks. When replacing a component, the circuit needs to be brazed using fire to ensure no refrigerant is present anymore. Usually this requires a trained and authorized installer and operator to perform the maintenance. Also, this kind of maintenance can take about approximately one day of maintenance. Thus it is often more worthwhile and safer to replace the entire heat exchanging circuit as a whole.

It is therefore desired to obtain an assembly for heating water in a building, in particular a heat pump, wherein the heat exchanger circuit comprising a refrigerant loop may be installed, removed and/or replaced as a whole without the need of assembly, disassembly and/or reassembly of the refrigerant loop. With such an assembly, the risk of misalignment of joints within the refrigerant loop by an installer or operator is reduced or even removed due to the fact that the installer or operator does not have to couple or connect any of the joints upon installation or during maintenance of the assembly. Furthermore, the heat exchanger circuit may thus be installed, removed and/or replaced within a very short time without the requirement of special training or authorization.

The object of the invention is obtained by providing an assembly for heating water in a building, in particular a heat pump, wherein the assembly comprises a casing, a housing for a drawer, the housing being fixed inside the case, at least one primary hydraulic pipe arranged at the inside of the casing and arranged next to the housing, a first end of the primary hydraulic pipe being connected to the outside of the casing and a second end of the primary hydraulic pipe arranged inside the casing, a drawer for carrying a heat exchanging circuit, the drawer being positioned within the housing, wherein the drawer comprises at least two heat exchangers, at least one refrigerant loop comprising a compressor, an expansion valve and a refrigerant and the refrigerant loop being connected to the at least two heat exchangers, and at least one secondary hydraulic pipe wherein a first end of the secondary hydraulic pipe is connected to at least one of the two heat exchangers and a second end of the secondary hydraulic pipe is reversibly connected to the second end of the primary hydraulic pipe by means of a connection interface. The drawer thereby comprising at least one heat exchanging circuit suitable for an indoor or outdoor unit of a heat pump system. By proving such a drawer with the at least one heat exchanging circuit, the drawer may be easily installed, removed or replaced upon installation or maintenance without the requirement of assembling, disassembling or reassembling the refrigerant loop as the whole drawer is inserted and removed as one single part of the assembly. Thus a quick and safe insertion, removal and/or replacement of the heat exchanging circuit is provided.

The assembly for heating water in a building may be a heat pump or heat pump system such as a GSHP or AWHP system. The assembly comprises a casing of metal, plastic or a combination of both. The casing may hold and protect all functional parts of the heat pump. The casing comprises at least one housing for a drawer. The housing is being fixed inside the casing and has an opening on at least one side for accepting a drawer wherein the opening is situated in at least one side of the casing so that a drawer can be inserted through the casing into the housing. The housing may be made of metal, plastic or a combination of both.

Within the casing, more preferably between the housing and the casing, at least one primary hydraulic pipe is arranged. A first end of the primary hydraulic pipe is connected to the outside of the casing. At this connection, a first connection interface may be present to allow for a reversible connection between the primary hydraulic pipe and one or more external pipes or hoses via the first connection interface. A second end of the primary hydraulic pipe is arranged inside the casing. The second end of the primary hydraulic pipe may be situated closely behind the housing, be part of the housing or extend through the housing. At this second end of the primary hydraulic pipe, a second connection interface may be present to allow for a reversible connection between the primary hydraulic pipe and a secondary hydraulic pipe situated in drawer via the second connection interface. Both the first and second connection interface may be, for example, a pipe fitting, or a part thereof, such as a coupling or adaptor. Both connection interfaces may be threaded, comprise at least a part of a quick-release system or a combination thereof. When the connection interfaces is a threaded interface, the connection interface is preferably situated within the casing and behind the housing to allow easy access for an installer or operator to tighten or loosen the threaded connection. The drawer for carrying a heat exchanging circuit may be made of metal, plastic or a combination of both. The drawer may have at least a front panel that, when positioned into the housing, closes off the casing of the assembly for heating water in a building. Also, the drawer may have at least a bottom panel to support the components comprised within the drawer. Preferably, the drawer has a front panel, a back panel, two side panels, a bottom panel, and a top panel to enclose the entire drawer and prevent access to the components comprised within the drawer. The drawer comprises at least one heat exchanging circuit. A first end of the secondary hydraulic pipe is connected to at least one heat exchanger within the heat exchanging circuit and a second end of the secondary hydraulic pipe is reversibly connected to the second end of the primary hydraulic pipe via the second connection interface when the drawer is positioned within the housing. The drawer preferably does not comprise any hydraulic piping that does not require direct contact with any of the components present within the drawer and preferably the drawer does not comprise any ignition source such as a hot point or electronic device that can create an electrical spark.

With the drawer positioned within the housing, and the primary and secondary hydraulic pipe reversibly connected, a part of an hydraulic group is formed which exchanges calories between the at least one heat exchanger in the drawer and a liquid such as water within the hydraulic group and transporting the calories via the liquid to the outside of the heat pump. By using a reversible connection, the part of the hydraulic group may be separated by taking out the drawer without having to interact with the heat exchanging circuit, more particular without having to interact with the refrigerant loop, present in the drawer as the drawer may be taken out as a whole. This leaves an assembly of a casing and housing which may be easily and quickly installed or maintained by an installer or operator without any risk of misalignment of joints of the refrigerant loop present in the drawer. As such, the casing with the housing including all functional parts may be installed or maintained without the heat exchanging circuit present within the casing and housing. Furthermore, if the second end of the at least one primary hydraulic pipe is part of to the housing, the connection interface at the second end of the primary hydraulic pipe is stabilized which makes it easier for an installer or operator to place or replace the drawer without any misalignment at said connection interface for the hydraulic group.

The assembly for heating water in a building may further comprise electrical wiring, in particular power or electrical signal cables for controlling various components or measuring various temperature and/or pressure probes present in the assembly. The electrical wiring may be situated in the casing, the housing and/or the drawer. There may also be an electrical connection interface present between the casing and the drawer or between the housing and the drawer.

Furthermore, all connection interfaces of the hydraulic pipes present in the assembly may be sealed using flexible seals such as foam or elastomeric seals. This supports the hydraulic pipes without transmitting vibration to any parts of the assembly.

In an embodiment, the housing is sealed along the edges of the housing. In case of any leakage of the refrigerant due to the aging of the joints within the heat exchanging circuit in the drawer, the seal along the edges of the housing prevent any refrigerant gas to escape through the housing and into the casing where electrical circuits may be present. As such, the seal acts as another barrier to reduce risk of explosion.

In an embodiment, the drawer is sealed along the edges of the drawer. In case of any leakage of the refrigerant due to the aging of the joints within the heat exchanging circuit in the drawer, the seal along the edges of the drawer prevent any refrigerant gas to escape through the drawing and into the housing and casing where electrical circuits may be present. As such, the seal acts as another barrier to reduce risk of explosion.

In an embodiment, the drawer further comprises an air duct. In case of any leakage of the refrigerant due to the aging of the joints within the heat exchanging circuit in the drawer, the refrigerant gas can be expelled through the air duct. As the refrigerant gas typically is heavier than air, the air duct should be positioned below any connection interface to allow any refrigerant gas to escape from the casing before it reaches any of the connection interfaces. The air duct is preferably situated at the bottom half of the drawer. It is also preferred that the air duct is faced outwards and away from the casing to expel and direct the refrigerant gas away from the casing. Furthermore, it is preferred that the opening of the air duct on the outer surface of the drawer comprises a grid or a grille to prevent solid objects entering the air duct from the outside. This prevents, for instance, a user accidentally sticking their finger into the air duct.

In an embodiment, the drawer further comprises a fan. This fan may assist in expelling the refrigerant gas through the air duct by accelerating the flow of the refrigerant gas out and away from the entire assembly. Preferably, the fan comprises a brushless motor to reduce any risk of igniting the refrigerant gas through an electric spark. In an embodiment, the assembly further comprises a guide rail system between the drawer and the housing. By providing a guide rail system, the drawer can be positioned onto a guide rail which improves access and visibility during positioning. The drawer is then guided directly by the guide rail into the housing ensuring a proper positioning of the drawer into the housing and thus an improved connection of the hydraulic pipes.

In an aspect of the invention, a casing is provided for an above mentioned assembly wherein the casing comprises a housing for a drawer, the housing being fixed inside the casing, and at least one primary hydraulic pipe arranged at the inside of the casing and arranged next to the housing, a first end of the primary hydraulic pipe being connected to the outside of the casing and a second end of the primary hydraulic pipe (5b) arranged inside the casing (2) wherein the second end of the primary hydraulic pipe (5b) comprises a connection interface for reversibly connecting the second end of the primary hydraulic pipe to a second end of a secondary hydraulic pipe.

The casing may hold and protect all functional parts of the heat pump. The casing comprises at least one housing for a drawer. The housing is being fixed inside the casing and has an opening on at least one side for accepting a drawer wherein the opening is situated in at least one side of the casing so that a drawer can be inserted through the casing into the housing. The housing may be made of metal, plastic or a combination of both.

Within the casing, more preferably between the housing and the casing, at least one primary hydraulic pipe is arranged. A first end of the primary hydraulic pipe is connected to the outside of the casing. At this connection, a first connection interface may be present to allow for a reversible connection between the primary hydraulic pipe and one or more external pipes or hoses via the first connection interface. A second end of the primary hydraulic pipe is arranged inside the casing. The second end of the primary hydraulic pipe may be situated closely behind the housing, be part of the housing or extend through the housing. At this second end of the primary hydraulic pipe, a second connection interface may be present to allow for a reversible connection between the primary hydraulic pipe and a secondary hydraulic pipe situated in a drawer via the second connection interface. Both the first and second connection interface may be, for example, a pipe fitting such as a coupling or adaptor. Both connection interfaces may be threaded, comprise at least a part of a quick-release system or a combination thereof. Such a casing allows for accepting a drawer comprising a heat exchanging circuit and as such allows installation and maintenance of the casing with the housing including all functional parts may be installed or maintained without the heat exchanging circuit present within the casing and housing.

In an embodiment, the casing is made of metal, plastic or a combination thereof. This allows for a sturdy casing that is suitable to protect all functional parts within the casing.

In an embodiment the housing situated in the casing is sealed along the edges of the housing. In case of any leakage of the refrigerant due to the aging of the joints within the heat exchanging circuit in a drawer that could be inserted into the housing, the seal along the edges of the housing prevent any refrigerant gas to escape through the housing and into the casing where electrical circuits may be present. As such, the seal acts as a barrier to reduce risk of explosion when a drawer is inserted into the housing and when the refrigerants leaks at the joints due to aging of the joints.

In an embodiment, a seal is fitted between the housing and the casing. The seal between the housing and the casing prevents direct contact between the panels of the housing and the casing, thereby reducing any vibrations between the housing and the casing.

In an embodiment, wherein the housing comprises a guide rail system. By providing a guide rail system, a drawer may be accepted and positioned onto a guide rail improving access and visibility during positioning. Such a drawer is then guided directly by the guide rail into the housing ensuring a proper positioning of the drawer into the housing and thus an improved connection of the hydraulic pipes.

In another aspect of the invention, a drawer is provided for an above mentioned assembly and placement in an above mentioned casing with a housing where the drawer comprises at least two heat exchangers, at least a part of a refrigerant loop comprising a compressor, an expansion valve and a refrigerant and the refrigerant loop being connected to the at least two heat exchangers, and at least one secondary hydraulic pipe, wherein a first end of the secondary hydraulic pipe is connected to at least one of the two heat exchangers and wherein a second end of the secondary hydraulic pipe may be reversibly connected to a second end of a primary hydraulic pipe through a connection interface when the drawer is inserted into an assembly for heating water in a building. The drawer for carrying a heat exchanging circuit may be made of metal, plastic or a combination of both. The drawer comprises a heat exchanging circuit. A first end of the secondary hydraulic pipe is connected to at least one heat exchanger within the heat exchanging circuit and a second end of the secondary hydraulic pipe is reversibly connected to the second end of the primary hydraulic pipe via the second connection interface when the drawer is positioned within the housing.

Such a drawer can be inserted, removed or replaced within an assembly or casing as mentioned above without having to interact with the heat exchanging circuit present in the drawer as the drawer may be taken out as a whole. As such, the joints of the refrigerant loop cannot be misaligned upon installation or maintenance of the assembly or casing mentioned above.

In an embodiment, the drawer is sealed along the edges of the drawer. In case of any leakage of the refrigerant due to the aging of the joints within the heat exchanging circuit in the drawer, the refrigerant gas can be expelled through the air duct. As the refrigerant gas typically is heavier than air, the air duct is preferably situated at the bottom half of the drawer. It is also preferred that, when inserted into a housing inside a casing, the air duct is faced outwards and away from the casing to expel and direct the refrigerant gas away from the casing.

In an embodiment, the drawer further comprises a fan. This fan may assist in expelling the refrigerant gas through the air duct by accelerating the flow of the refrigerant gas out and away from the entire assembly. Preferably, the fan comprises a brushless motor to reduce any risk of igniting the refrigerant gas through an electric spark.

In the figures, the subject-matter of the invention is schematically shown, wherein identical or similarly acting elements are usually provided with the same reference signs.

Figure 1 shows a schematic representation of an assembly according to the present invention.

Figure 2 shows a schematic representation of an assembly according to the present invention.

Figure 3 shows a side view of an assembly according to the present invention. Figure 4 shows a schematic representation of an assembly according to the present invention.

With reference to Figure 1 , an assembly 1 according to the present invention is shown. The assembly 1 is an example of a GSHP. The assembly 1 comprises a casing 2 with a housing 3 situated inside casing 2 and having an opening in the same plane as one of the sides of the casing 2. On top of the casing 2, a first end of the primary hydraulic pipe 5a can be seen. Furthermore, a drawer 4 is shown having a fan 10. The drawer 4 may be inserted into the opening of the housing 3.

In Figure 2, the same assembly 1 is shown as in Figure 1 where a side panel of the casing 2 is removed and drawer 4 has only a front panel. In this Figure 2, a primary hydraulic pipe 5 is arranged inside the casing 2. In particular, the primary hydraulic pipe 5 is arranged between the housing 3 and the outside of the casing 2. Furthermore, it is shown that the drawer 4 comprises a secondary hydraulic pipe 6 with a second end of the secondary hydraulic pipe 6b together with a first heat exchanger 7a and a second heat exchanger 7b.

Figure 3 is a side view of the same assembly 1 as shown in Figures 1 and 2. In this particular figure, a second end of the primary hydraulic pipe 5b can be seen inside the casing 2 right behind the housing 3. As shown, a second end of the secondary hydraulic pipe 6b is lined up at the same height as the second end of the primary hydraulic pipe 5b. Also, it is shown that the drawer 4 comprises a refrigerant loop 8 connected to the first heat exchanger 7a and the second heat exchanger 7b (not shown) both situated on the drawer 4. Furthermore, it can be seen that a first end of the secondary hydraulic pipe 6a is connected to the first heat exchanger 7a. Lastly, an airduct 9 and a fan 10 are situated at the bottom of drawer 4. The refrigerant loop 8 further comprises a compressor, an expansion valve and a refrigerant (all not shown).

Figure 4 shows the assembly 1 according to the previous figures wherein the drawer 4 is inserted and arranged within the housing 3. The side panel of the casing 2 and of the housing 3 is removed. As can be seen in this figure, the second end of the primary hydraulic pipe 5b and the second end of the secondary hydraulic pipe 6b are again lined up with each other to be connected to each other. Furthermore, an airduct 9 and a fan 10 are shown at the bottom of the drawer 4. Reference Signs

1 assembly for heating water in a building

2 casing 3 housing

4 drawer

5 primary hydraulic pipe

5a first end of the primary hydraulic pipe

5b second end of the primary hydraulic pipe 6 secondary hydraulic pipe

6a first end of the secondary hydraulic pipe

6b second end of the secondary hydraulic pipe

7a first heat exchanger

7b second heat exchanger 8 refrigerant loop

9 air duct

10 fan

11 guide rail system

Claims

PATENT CLAIMS

1. An assembly (1) for heating water in a building, in particular a heat pump, the assembly comprising:

- a casing (2);

- a housing (3) for a drawer, the housing being fixed inside the casing (2);

- at least one primary hydraulic pipe (5) arranged at the inside of the casing (2) and arranged next to the housing (3), a first end of the primary hydraulic pipe (5a) being connected to the outside of the casing (2) and a second end of the primary hydraulic pipe (5b) arranged inside the casing (2); and

- a drawer (4) for carrying a heat exchanging circuit, the drawer (4) being positioned within the housing (3); wherein the drawer (3) comprises at least two heat exchangers (7a, 7b), at least one refrigerant loop (8) comprising a compressor, an expansion valve and a refrigerant and the refrigerant loop (8) being connected to the at least two heat exchangers (7a, 7b), and at least one part of a secondary hydraulic pipe (6) wherein a first end of the secondary hydraulic pipe (6a) is connected to at least one of the two heat exchangers (7a, 7b) and a second end of the secondary hydraulic pipe (6b) is reversibly connected to the second end of the primary hydraulic pipe (5b) by means of a connection interface.

2. The assembly (1) according to claim 1 , wherein the housing is sealed along the edges of the housing.

3. The assembly (1) according to claim 1 or 2, wherein the drawer is sealed along the edges of the drawer.

4. The assembly (1) according to any of the preceding claims, wherein the drawer further comprises an air duct (9).

5. The assembly (1) according to claim 4, wherein the drawer further comprises a fan (10).

6. The assembly (1) according to any of the preceding claims, wherein the assembly (1) further comprises a guide rail system (11) between the drawer (4) and the housing (3).

7. A casing (2) for an assembly (1) according to claim 1 , wherein the casing (2) comprises:

- a housing (3) for a drawer (4), the housing (3) being fixed inside the casing (4); and

- at least one primary hydraulic pipe (5) arranged at the inside of the casing (2) and arranged next to the housing (3), a first end of the primary hydraulic pipe (5a) being connected to the outside of the casing (2) and a second end of the primary hydraulic pipe (5b) arranged inside the casing (2); wherein the a second end of the primary hydraulic pipe (5b) comprises a connection interface for reversibly connecting the second end of the primary hydraulic pipe (5b) to a second end of a secondary hydraulic pipe (6b).

8. The casing (2) according to claim 7, wherein the casing (2) is made of metal, plastic or a combination thereof.

9. The casing (2) according to claim 7 or 8, wherein the housing (3) is sealed along the edges of the housing (3).

10. The casing (2) according to any of claims 7 to 9, wherein a seal is fitted between the housing (3) and the casing (2).

11 . The casing (2) according to any of claims 7 to 10, wherein the housing (3) comprises a guide rail system (11).

12. A drawer (4) for use in an assembly (1) according to claim 1 , wherein the drawer (4) comprises:

- at least two heat exchangers (7a, 7b);

- at least a part of a refrigerant loop (8) comprising a compressor, an expansion valve and a refrigerant and the refrigerant loop (8) being connected to the at least two heat exchangers (7a, 7b); and

- at least one secondary hydraulic pipe (6); wherein a first end of the secondary hydraulic pipe (6a) is connected to at least one of the two heat exchangers (7a, 7b) and wherein a second end of the secondary hydraulic pipe (6b) may be reversibly connected to a second end of a primary hydraulic pipe (5b) through a connection interface when the drawer (4) is inserted into an assembly (1) for heating water in a building.

13. The drawer (4) according to claim 12, wherein the drawer (4) is sealed along the edges of the drawer (4).

14. The drawer (4) according to claims 12 or 13, wherein the drawer (4) further comprises an air duct (9).

15. The drawer (4) according to claim 14, wherein the drawer (4) further comprises a fan (10).