Heat exchanger element and method for its manufacture; building panel and method for dehumidifying air

Abstract

A heat exchanger element has a heat-conducting body and a heat-transfer fluid pipe embedded in ducts having a channel-shaped locating section and two tabs connected flat to the heat-conducting body. To produce the heat exchanger element, foil strips are pressed into grooves so that they each form a section pressed into the grooves in a channel-like manner and laterally projecting tabs. A building panel has a heat exchanger element with a heat exchange surface, a cooling device and a collecting device, the cooling device being designed to cool the heat exchange surface in contact with the ambient air to a temperature below the dew point of the water vapour in the ambient air.

Claims

1. A method of manufacturing a heat exchanger element comprising a heat-conducting body with a heat transfer surface and being made of a flexible foil of aluminum, copper or an alloy thereof, and a heat-transfer fluid pipe comprising sections arranged with a spacing of 1 to 5 cm between each other, the heat-transfer fluid pipe made of a capillary plastic tube and being heat-conductively connected to the heat conducting body, wherein the method comprises: arranging a heat-conductive foil on a template having grooves such that the grooves are covered by the heat-conductive foil; covering the grooves of the heat-conductive foil with foil strips; pressing the foil strips into respective grooves in a single pull, the foil strips being configured in width so that, after pressing in, each of the foil strips form a channel-shaped section pressed into the grooves; said foil strips comprising tabs projecting laterally at longitudinal edges of the grooves; inserting the sections of the heat-transfer fluid pipe into the channel-shaped sections of the foil strips pressed into the grooves; and connecting the tabs flatly with the heat-conducting body, wherein the foil strips are formed when pressed into the grooves in said single pull by the heat-conductive foil tearing longitudinally between the grooves at predefined locations, the predefined locations being formed by a weakening produced in the heat-conductive foil before the heat-conductive foil is arranged on the template, or the foil strips are formed in the heat-conductive foil arranged on the template by a cutting tool.

2. The method according to claim 1, wherein the heat-conductive foil is carried by a pressing tool for pressing the foil strips into the grooves, wherein the pressing tool is arranged on the template, and then pressed into the grooves in said single pull.

3. The method according to claim 1, wherein the tabs are connected to the heat-conducting body via a heat-conducting adhesive or a heat-conducting bonding agent, the adhesive or the bonding agent being applied to the heat-conducting body in advance.

4. The method according to claim 1, wherein the template is made of an elastically flexible material and wherein an opening width of the channel-shaped portions of the foil strips pressed into the grooves is smaller than an outer diameter of the heat-transfer fluid pipe.

5. The method according to claim 1, wherein the template is made of a heat and/or sound insulating material and lies on the heat exchanger element as an insulation board, wherein the heat conductive foil is provided with an adhesive or a bonding agent on a surface facing the template prior to being arranged on the template, thereby forming a connection with the template after the foil strips have been pressed into the respective grooves.

6. The method according to claim 1, wherein the heat-conducting body and/or the foil or foil strips are made of a material selected from the group consisting of: aluminium, copper, an alloy, and composite material.

Description

(1) In the following, the invention is explained using the embodiments shown in the drawings as examples. The drawings show schematically:

(2) FIG. 1 a section of a heat exchanger element according to an embodiment of the invention in a cross-sectional view,

(3) FIGS. 2A to 2G steps of a manufacturing process of a heat exchanger element according to an embodiment of the invention in cross-sectional views,

(4) FIGS. 3A and 3B a step of a manufacturing process of a heat exchanger element and a heat exchanger element according to an embodiment of the invention in cross-sectional views,

(5) FIGS. 4A and 4B a step of a manufacturing process of a heat exchanger element and a heat exchanger element according to an embodiment of the invention in cross-sectional views,

(6) FIGS. 5A and 5B a step of a manufacturing process of a heat exchanger element and a heat exchanger element according to an embodiment of the invention in cross-sectional views,

(7) FIGS. 6A and 6B a heat conductor for a heat exchanger element and a heat exchanger element according to an embodiment of the invention in a perspective or cross-sectional view,

(8) FIG. 7 a heat exchanger element according to an embodiment of the invention in a cross-sectional view,

(9) FIG. 8 a heat exchanger element according to an embodiment of the invention in a cross-sectional view,

(10) FIG. 9 a heat exchanger element according to an embodiment of the invention in a cross-sectional view,

(11) FIG. 10 a heat exchanger element according to an embodiment of the invention in a plan view,

(12) FIG. 11 a heat exchanger element according to an embodiment of the invention in a plan view,

(13) FIG. 12 a heat exchanger element according to an embodiment of the invention in a plan view,

(14) FIG. 13a a building panel according to an embodiment of the invention in a plan view,

(15) FIG. 13b a building panel according to an embodiment of the invention in a cross-sectional view,

(16) FIG. 14 a functional principle of a building panel according to an embodiment of the invention in a cross-sectional view, and

(17) FIG. 15 the Magnus formula.

(18) An embodiment of a heat exchanger element is explained below (FIG. 1).

(19) A heat exchanger element 1 has a heat conducting body 2. In this embodiment, the heat conductor 2 is a homogeneous aluminium part with a high thermal conductivity of, for example, approx. 235 W/m*K. However, the invention is not limited to this. In this embodiment, the heat conductor 2 is plate-shaped and rectangular, especially in plan view, and thus has two main surfaces and four edge sides. A main surface of the heat conductor 2 is defined as a heat transfer surface 14, the opposite main surface as a mounting surface 15. A coating 3 is arranged on the heat transfer surface 14 of the heat conductor 2. In this embodiment, the coating 3 is a black colour and thermally highly emissive. A duct 5 with a heat transfer fluid pipe 8 embedded in it is arranged on the mounting surface 15 of the heat conductor 2 by means of a heat-conducting adhesive 4. The duct 5 is approximately Ω-shaped in cross-section and has a channel-shaped locating section 7 as well as two tabs 6 connected to the side of the locating section 7. In this embodiment, duct 5 is also a homogeneous aluminium part. The heat transfer fluid pipe 8 is circular in cross-section. The heat transfer fluid pipe 8 has an interior space 9 which is filled with a heat transfer medium during operation. The heat transfer medium is a gas or a liquid and in particular water or water mixed with an antifreeze agent such as glycol. Antifreeze agents usually not only have the property that they lower the melting point, but also raise the boiling point, which extends the range of application of such a fluid both in the cold and in the hot area.

(20) FIG. 1 shows heat or cold flows 11, 12, 13 in such a way that heat or cold is removed from the heat transfer medium (fluid) in the heat transfer fluid pipe 8 and transferred to the surroundings of the heat exchanger element 1. A cold flow is a heat flow in the opposite direction. The heat exchanger element 1 can thus be used as a heating element or a cooling element. If the heat exchanger element 1 is used as a cooling element, heat from the surroundings of the heat exchanger element 1 is dissipated via the heat transfer medium in the heat transfer fluid pipe 8.

(21) As shown above, the heat transfer fluid pipe 8 is embedded in heat-conducting contact in the locating section 7 of duct 5. Heat-conducting contact with the heat-conducting body 2 is also provided via the heat-conducting adhesive 4 as well as the proximity to the heat-conducting body 2. Thus, the heat transfer fluid pipe 8 is surrounded on all sides by a heat contact surface 10, which enables a directly conducting heat transfer from the heat transfer fluid pipe 8 to the locating section 7 of the duct 5 as well as to the heat transfer body 2.

(22) Furthermore, a convective heat flow 11 can take place via the surfaces adjacent to the side of the locating section 7 and the heat thus transported can be absorbed at these surfaces. Heat absorbed via the wall of the locating section 7 is also conducted into the tabs 6 of the duct 5 and directly conductively transferred by these tabs into the heat conducting body 2 (conductive heat flow 12). Via the thermally highly emissive coating 3, the heat absorbed from the mounting side 15 and conducted through the heat conduction body 2 to the heat transfer surface 14 is transferred to the environment in the form of heat rays 13.

(23) On the other hand, a warm area, for example, which on the side of the coating 3 is connected to the heat transfer fluid pipe 8 via the mounting surface 15, can be cooled via the heat exchanger element 1 by absorbing excess heat from the environment at the heat transfer surface 14.

(24) In this embodiment, the heat transfer fluid pipe 8 is made of plastic, preferably cross-linked polyethylene (PEX). In this embodiment, the heat transfer fluid pipe 8 is designed as a capillary tube with a wall thickness of approx. 0.8 mm and an inside diameter of approx. 2.5 mm to 3.0 mm, and in particular approx. 2.9 mm.

(25) It goes without saying that the heat exchanger element 1 is not only limited to the cut-out shown in FIG. 1, but can also have a large number of adjacent ducts 5 distributed over the mounting surface 15 with a heat transfer fluid pipe 8 embedded in them (FIGS. 8 to 12).

(26) In one embodiment, the heat transfer fluid pipe 8 has a large number of straight, parallel sections 102 which are connected to one another by reverse sections 103 in order to form a serpentine or meander-shaped heat transfer fluid pipe 8 (FIG. 10). The first and last straight section 102 is provided with a flow connection piece 100 for a heat transfer fluid flow 104 and a return connection piece 101 for a heat transfer fluid return 105. The straight sections 102 are included in the ducts 5 described above (not shown in FIG. 10), while the reverse sections 103 lie freely above the mounting surface of the heat-conducting body 2. In this embodiment, the straight sections 102 are designed in one piece with the reversing sections 103 as well as the flow connection piece 100 and the return connection piece 101. This allows the heat transfer fluid pipe 8 to be preformed and ensures the tightness of the heat transfer fluid pipe 8 over its entire length.

(27) As a variant to this embodiment, curved duct sections can also be optionally provided for the reverse section 103 in order to further optimise the heat transfer.

(28) In another variant, the straight sections 102 and reverse sections 103 can be designed separately. This type of design can also enable compact transport of the individual parts.

(29) In another variant, the straight sections 102 can be connected at one end to a flow distributor section 110 and at another end to a return distributor section 111 (FIG. 11).

(30) In another variant, the heat transfer fluid pipe 8 can also run helically on the mounting surface 15 of the heat conductor 2 (FIG. 12).

(31) In another variant, the heat conductor 2 can have a heat transfer fluid pipe 8 on both sides (FIG. 9). In this variant, both main sides of the heat conductor 2 have both a heat transfer surface 14 and a mounting surface 15.

(32) In design variants, the heat conductor 2 can be made of a different material such as another metal and can also be non-homogeneous. For example, the heat conductor can also be made of copper, steel or another metal or an alloy. Preferably, however, the heat conduction body is made of a highly thermally conductive material.

(33) In design variants, the coating 3 can also be a fleece, an electrochemical or other coating or can also be omitted, as the requirements of the application dictate. The coating 3, however, is preferably thermally highly emissive, i.e. it has a high radiant or absorptive capacity for heat transferred from the heat conduction body 2.

(34) In design variants, the thermally conductive adhesive 4 may be replaced by another adhesive or another type of connection. For example, the connection between the tabs 6 of the duct 5 and the heat-conducting body 2 can be made in a form-fitting manner using connecting elements such as rivets, pins or the like, by soldering, spot welding or friction welding.

(35) The heat transfer fluid pipe 8 can also be square ring-shaped, hexagonal ring-shaped, octagonal ring-shaped or similar in cross-section. In other versions, the heat transfer medium can also be a refrigerant, an oil or another fluid.

(36) In a method for manufacturing a heat exchanger element, a foil 20 is first provided in a first step (FIG. 2A). The foil 20, for example, can be made of aluminium.

(37) In a second step, the foil 20 is provided with a perforation 21 (FIG. 2B). The perforation 21 forms parallel lines of dot or line shaped holes and can be produced, for example, by a punching process or by a rolling die.

(38) In a further step, the foil 20 provided with perforation 21 is placed on a template 22, which is arranged opposite a punch 24 with a pressing direction 26 (FIG. 2C). Different sequences are possible: the foil 20 can be placed on the template 22 arranged opposite the punch 24, or the template 22 can be moved into a machine frame under the punch 24 after the foil 20 has been placed, or the punch 24 can be moved over the template 22 after the foil 20 has been placed. The template 22 has parallel grooves 23 of approximately rectangular cross-section. The grooves 23 have the same distance from each other as the lines of the perforation 21 of the foil 20. The foil 20 is placed on the template 22 in such a way that the lines of the perforation 21 run approximately in the middle between the grooves 23. The punch 24 has projections 25 which are shaped and arranged to complement the grooves. In this embodiment, the projections 25 have a roughly rectangular cross-section. They are arranged exactly above the grooves 23. The projections 25 are slightly smaller in cross-section than the grooves 23.

(39) In a further step, the punch 24 is closed in the pressing direction 26 and retracted again (FIG. 2D). When closing the punch 24, the projections 25 of the punch 24 dip into the grooves 23 of the template 22 and take the foil 20 with them in such a way that the foil 20 tears at the perforation 21 so that foil strips form. A central part of the foil strips is pulled into the grooves 23, while lateral parts of the foil strips slide on the template 22 (sliding direction 27). The foil strips formed in this way form the later ducts 5 of the heat exchanger element, with the parts drawn into the grooves 23 each forming the locating section 7 and the parts remaining on the surface of the template 22 forming the tabs 6. This step gives the locating sections 7 an opening width w.

(40) In a further step, a heat transfer fluid pipe 8 is pressed into the locating sections 7 (FIG. 2E, pressing direction 28). The heat transfer fluid pipe 8 is made of plastic or metal (e.g. aluminium, copper or an alloy). In this step, the heat transfer fluid pipe 8 can have individual pipe sections or be a continuous line with reverse or distributor sections at the ends, as described in embodiments above (FIGS. 10, 11, 12). A wall thickness t8 of the heat transfer fluid pipes 8 may correspond to a wall thickness t5 of the ducts 5, or may be slightly or significantly larger (FIG. 2E). However, wall thicknesses can also be measured using suitable design criteria such as, but not limited to, heat transfer, heat conduction, weight and strength. Preferably, the wall thickness t5 of the ducts is about 50 μm. An outer diameter d of the heat transfer fluid pipes 8 can correspond to the opening width w of the ducts 5 or be slightly larger in order to achieve a certain clamping effect in such a way that the heat transfer fluid pipe 8 is held in the locating sections 7.

(41) In a further step, a thermally conductive adhesive 4 is applied to the exposed surfaces of the heat transfer fluid pipes 8, ducts 5 and template 22 and a heat conductor 2 of wall thickness t2 is pressed on (FIG. 2F).

(42) Then a coating 3 is applied to the exposed surface of the heat conductor (heat transfer surface 14 in FIG. 2F) and the template 22 is removed (FIG. 2G). This completes the heat exchanger element 1.

(43) The template 22 can be a carrier component 29 which remains on the heat exchanger element. However, the finished heat exchanger element can also be separated from the template 22 later, whereby the template 22 can be a lost auxiliary component or a permanent part of a tool device.

(44) In one variant of the method, after the ducts 5 have been formed, the template 22 is removed and replaced by a second template. In this state, the heat transfer fluid pipe 8 is then pressed in. In this variant, the template 22 may be made of a hard material, such as steel or hard plastic, and the second template may be made of a soft or at least softer material, such as a foam plate or a rubber-elastic material. In this variant, if the opening width w of the locating section 7 of the duct 5 is smaller than the outer diameter d of the heat transfer fluid pipe 8, the second template can yield when the heat transfer fluid pipe 8 is pressed in and return to the previous shape at the point of the opening so that the heat transfer fluid pipe 8 is elastically clamped in the duct 5. It goes without saying that in this case the second template can remain on the heat exchanger element 1 as carrier component 29.

(45) As an alternative to perforating the foil 20, foil strips can also be produced by cutting the foil 20 placed on the template 22 into strips or punching it (using the punch 24 if necessary). Alternatively, foil strips can be prepared in advance and placed on the template 22. As an alternative to placing on the template 22, the foil 20 or prepared foil strips can also be picked up by the punch 24 (e.g. by vacuum, electrostatic effect, fluid adhesion or the like) and placed over the template 22. With the latter alternative, suitable means must be used to ensure that the punch 24 is easily detached from the foil 20 after the ducts 5 have been formed, without moving or damaging it.

(46) The explanations given in FIG. 1 for the heat exchanger element 1 can be accepted for heat conductor 2 and coating 3 as well as for all other components of the heat exchanger element 1. All other modifications, variants, alternatives and options described above or further below can also be applied, unless excluded for physical reasons.

(47) The heat conductor body 2 was described above as a homogeneous aluminium component. However, other metals such as copper or an alloy can also be used. The heat conductor 2 is preferably in the form of foil.

(48) In another embodiment, which is a variant of the embodiment described first, the heat conductor body 2 is designed in such a way that it is permeable to media such as air or liquids, for example as a metal or plastic grid. In the manufacturing process, the heat conduction body 2 can be pressed onto the ducts 5 and heat transfer fluid pipe 8 in the template 22 (FIG. 3A, pressing direction 30). After removing the template 22, a convective heat flow 31 can occur through the grid of the heat conductor 2 (FIG. 3B). The convective portion can be increased by the free spaces. In this variant, the heat exchanger element 1 can be used, for example, but not only, with thermally activated expanded metal grid ceilings or for flat heat exchangers in water, soil, liquid media, façade areas, etc. In addition to heat supply and discharge, the grid can also be used to maintain the distance under the pipes and offers the possibility of acoustic improvement through acoustic absorbers behind it. The grid can also be a subsequently or previously perforated or punched, heat conducting or non heat conducting sheet metal or plastic part. If the template 22 is also permeable for a medium, it can also remain on the heat exchanger element 1 as carrier component 29.

(49) In a further embodiment, which is a variant of the embodiment described first, the heat conduction element 2 is designed as a micro- or coarsely-perforated metal sheet. In the manufacturing process, the heat conduction body 2 can be pressed onto the ducts 5 and heat transfer fluid pipe 8 in the template 22 (FIG. 4A, pressing direction 40). After removing the template 22, a convective heat flow 31 can occur through hole 41 of the heat conductor 2 (FIG. 4B). The convective portion can be increased by the ventilated spaces and enlargement of the surface. In this variant the heat exchanger element 1 can be used, for example, but not only, for thermally activated pipes in facade constructions or in ice reservoirs, ceiling areas or plastered or cast into walls or ceilings (e.g. in concrete). If the template 22 is also permeable for a medium, it can also remain on the heat exchanger element 1 as carrier component 29.

(50) In a further embodiment, which is a variant of the embodiment described first, the heat conduction element 2 is joined in the manufacturing process without adhesive to the ducts 5 and heat transfer fluid pipe 8 in the template 22 (FIG. 5A, pressing direction 50, FIG. 5B). Bypassing the adhesive can be achieved, for example, but not only, by press joining or forming the aluminium. Optionally an adhesive heat conducting paste can be applied. The adhesive as a potential source of failure can be avoided by force-locking and/or form-fit joining.

(51) In another embodiment, which is a variant of the embodiment described first, the heat conductor body 2 has a perforation 60 (FIG. 5A). The perforation 60 can, for example, be a cross perforation in rectangular or otherwise useful form for free forms of the heat transfer fluid pipe 8 (FIG. 5B). This also allows or facilitates individual shapes.

(52) In another embodiment, which is a variant of the embodiment first described, the heat conductor 2 has a selective coating 3 (FIG. 7). The coating 3 can, for example, be applied by adhesive, sputter or other coating methods. The coating 3 can be applied with adsorbent or absorbent materials such as zeolite or silica gel to use heat or cold. This makes it possible, for example, to implement cost-effective, e.g. heat-driven cooling machines. The coating 3 can also be designed to selectively influence physical properties of the surface, such as the emission behaviour of resistance to substances or aggressive atmospheres.

(53) Due to large pipe cross-sections and a physical limitation of the thermal conductivity of the materials, it was necessary in previous systems to select high material thicknesses.

(54) The approach of the present invention is to reduce the pipe cross-section by using cost-efficient capillary tube mats. Thus the material thickness of the heat conduction plates can be reduced from approx. 2 mm down to 0.05 mm, and heat dissipation can be considerably improved by the small spacing of the tubes (heat transfer fluid pipe 8) of 1-5 cm. Due to the small distance between the capillary tubes, a physical and material optimum of heat conduction and material input is achieved.

(55) For the production of the heat exchanger element 1, the metal or foil-like material can be coated on both sides or on one side with an adhesive in order to achieve an optimum thermal coupling between the capillary tube and the surface later on. The adhesive layer fills any gaps that may occur and optimises the heat transfer through the connection with the capillary tubes. The foil material can be coated with adhesive, which increases the degree of prefabrication and simplifies processability and reliability in the production process.

(56) The use of a relatively thin aluminium or metal layer makes it possible to use material and cost-effective, foil-like and easy-to-process material. To shape the sheet metal strips, an additional processing step is carried out by pressing them directly onto an insulating element of an insulating or separating material or a template (22, 29 in FIGS. 2C-2F and others) into a foamed, slotted or pre-formed groove (23 in FIG. 2C). This is done with a defined counter press mould (punch 24 in FIGS. 2C, 2D). In order to compensate for the resulting elongation and thus prevent uncontrolled tearing of the material, the separating layer is perforated at the crack point. The perforation is selected so that the material tears apart in a defined manner during the pressing and forming process.

(57) The adhesive-coated foil material is perforated at the middle distance of the capillary tubes. The material tears through the perforation in a controlled manner and can be formed into the grooves required for the capillary tubes. The result is that the approx. 15-1000 μm thick aluminium sheets, coated on both sides with thermally conductive adhesive, are optimally adapted to the grooves and capillary tubes. As an option, the pressed component can then be removed from the counter-press mould without the composite element described.

(58) The capillary tube mat (heat transfer fluid pipe 8) is then pressed into the grooves. In a new pressing process, this is optimally formed on the preformed metal heat-conducting sheet strips. These are located within the previously defined grooves and are therefore optimally coated with a top layer and thermally coupled thereto.

(59) The capillary mats are pulled in, bringing the tubes into position for optimum thermal coupling and bonding.

(60) The tubes pressed into the grooves are then coated on the front with a metal sheet (heat conductor 2). This ensures an almost complete enclosure of the capillary tube by an extremely resource-saving and cost-effective process.

(61) Pressing the drawn-in capillary mat with the adhesive-coated heat-conducting sheets with a heat-conducting plate can create a complete metal sheathing of the slim pipe cross-sections. This process ensures an almost complete enclosure of the slender capillary tubes. This results in a high increase in heat transfer efficiency, especially for flat systems. In combination with a suitable insulating material, a composite component with low weight and low material and cost input can be created.

(62) The metal foil on the surface side can have a thickness of approx. 15-1000 μm. Alternatively, the use of non-woven or organic materials, such as wood, is possible.

(63) The new heat exchanger element can form a heat transfer system containing at least one heat distribution pipe system and heat conduction plates which create a thermal coupling and planar distribution between the fluid carrying system and the heat conduction plate which are coupled together and connected to the pipe system by a separation process during forming. For this purpose, an initial workpiece, such as a foil, can have a perforation for the heat conduction plates before pressing, which tears in a controlled manner during pressing. The heat conduction plates can be glued or welded. Post-forming processes are also possible. The heat exchanger element can be subsequently coated with optical or technical elements. Here, the use of thermally conductive adhesives is advantageous. Combinations with selective absorption and reflection materials are also possible. The heat exchanger element is suitable for integration into solar collector systems as well as into thermal storage concepts.

(64) The heat exchanger element according to the invention has the following advantages, among others: Low weight: Instead of several mm thick heat conduction plates, a foil about 50 μm thick for example, is sufficient for high efficiency. In this context, high efficiency means low cost and material costs for exchanging heat between a large area and a fluid. Low material input: The low material thickness causes only little waste. Fast processing: The adhesive pre-coating and perforation achieve a high degree of prefabrication and a simple technical implementation. Easy processing: The easy to cut and form sheets are easy to handle and process. Fast reaction time: The low weight and complete enclosure of the tube surface ensures high transfer efficiency and rapid reaction. Variable application areas: Large heat transfer surfaces are becoming increasingly important. Conventional systems reach their limits, especially with small temperature differences. The best possible coupling creates a cost-effective and highly efficient system.

(65) The new heat exchanger element can be used in areas where an even and flat heat distribution with high cooling or heating capacity and low difference between fluid and surface temperature is particularly important. The following areas of application are particularly noteworthy: Solar thermal or PV/solar hybrid modules—for dissipating heat input to the surface; Cooling and heating blankets for optimum distribution of heat and cold to large surfaces; Temperature control systems integrated into components, e.g. in concrete components or insulation structures; Object cooling of batteries, furniture, switch cabinets, computer centres etc.; High-performance surface cooling of climatic chambers and warehouses; Heat input and output from thermal, e.g. ice storage or latent heat storage with e.g. paraffin with particularly high power density at low temperature difference; Waste heat recovery from industrial processes or environmental heat; Areas in which an efficient, uniform and large-area heat distribution and heat transfer is required.

(66) In the following, a further embodiment is described, where the same elements are provided with the same reference symbols as in the previous embodiment (FIGS. 13a, 13b, 14). The explanations given above apply to the same elements, unless otherwise stated below.

(67) In this embodiment, the present invention comprises a building panel 70, which is mounted on walls of buildings over a large area. The building panel 70 has a heat exchanger element 1, as described in one of the embodiments above, a thermally separated edge bond 71 and a collecting device 73.

(68) The heat exchanger element 1, on which the air humidity is to be condensed, has a coating 3, a heat conductor 2, an adhesive 4, a tab 6 and a heat transfer fluid pipe 8. The coating 3 on the heat conductor 2 is surrounded in the building panel 70 by the thermally separated edge bond 71. The building panel 70 is mounted on a house wall at this edge bond 71. The building panel 70 is vertically aligned, while a slight tilt does not significantly restrict function. The collecting device 73 is located below the thermally activated surface 72 and collects the condensed water.

(69) The heat transfer fluid pipe 8 is connected to a heat transfer fluid flow 104 and to a heat transfer fluid return 105. The individual forms and embodiments of this heat transfer fluid pipe 8 have been described in detail above.

(70) The heat transfer surface of the heat conductor 2 is preferably made of a durable material. This can be glass or metal, for example. In this embodiment, the coating 3 has a super-hydrophobic surface due to micro- and nano-structuring. Furthermore, the surface is preferably formed with antibacterial properties, such as a coating with titanium oxide.

(71) The collecting device 73 is designed in such a way that it flows as a channel into a collecting container 74. This collecting container 74 is designed in such a way that the collected water can flow off from there either into a domestic water drain or a water recovery system, or is equipped with a carrier system in such a way that it can be easily transported away and poured out. The collecting container 74 preferably has a capacity of not more than 20 litres, in particular not more than 10 litres and in particular not more than 5 litres.

(72) Preferably, the heat conducting body 2 has three-dimensional structures. This is provided, for example, by a corrugated or zigzag-shaped heat conductor 2.

(73) In a further embodiment, which is a variant of the previously described embodiment, the building panel 70 has a facing wall 75. Preferably, this facing wall 75 is made of gypsum plasterboard. However, it can also consist of an air-permeable fabric stretched over a frame. In order for the room air to reach the heat conduction body 2, there are preferably 2 slots at the top and bottom of the facing wall 75, which is connected to the building in the usual way.

(74) In order to dehumidify the room air, the contact surface is cooled to a temperature below the dew point of the water vapour in the surrounding air by the coolant having a corresponding temperature. It must be ensured that the dew point is dependent on the relative humidity and temperature of the air. In one embodiment, the air is led through the air slots between the facing wall and the heat conductor 2 by convection currents in the air. The water vapour in the air then condenses on the surface 10 of the heat conductor 2. If sufficient water condenses, drops of water form which, from a certain size, run down and thus take even more water with them. Dust particles, bacteria and fungal spores are carried along by the water droplets. The water then collects in a collecting device 73. The temperature of the heat conductor 2 is additionally distributed by the course of the water droplets on the surface. The water in the collecting device 73 then flows off into a collecting container 74 and from there into the water drain of the building.

(75) The invention can be briefly summarised as follows: A heat exchanger element (1) has a heat-conducting body (2) and a heat-transfer fluid pipe (8) which is connected to the heat-conducting body (2) for heat conduction, the heat-transfer fluid pipe (8) being embedded in sections in preferably parallel ducts (5) of heat-conducting material in heat-conducting contact, the ducts (5) having a channel-shaped locating section (7) and two tabs (6) which are connected to the locating section (7), so that the ducts (5) are approximately Ω-shaped in cross-section, and the tabs (6) are connected flat to the heat-conducting body (2) in order to establish the heat-conducting connection of the heat-conducting fluid pipe (8) to the heat-conducting body (2). A method of manufacturing the heat exchanger element (1) is given. Furthermore, a building panel and a method for dehumidifying air are specified.

LIST OF REFERENCE NUMBERS

(76) 1 heat exchanger element 2 heat conduction element 3 coating 4 adhesive 5 duct 6 tab 7 locating section 8 heat transfer fluid pipe 9 interior (fluid) 10 heat contact area 11 convective heat flow 12 conductive heat flow 13 emissive heat flow 14 heat transfer surface 15 mounting surface 20 foil 21 perforation 22 template 23 groove 24 punch 25 projection 26 pressing direction 27 sliding direction 28 pressing-in direction 29 carrier component 30 pressing direction 31 heat flow 40 pressing direction 41 perforation 42 heat flow 50 pressing direction 60 perforation 70 building panel 71 edge bond 72 thermally activated area 73 collecting device 74 collecting container 75 facing wall 100 flow connection section 101 return flow connection section 102 straight section 103 reversal/connector section 104 heat transfer flow 105 heat transfer return flow 110 flow distribution section 111 return flow distribution section d outer diameter of heat transfer fluid pipe t2 wall thickness heat conductor body t5 wall thickness duct t8 wall thickness heat transfer fluid pipe w opening width duct S1 Humid air at room heat comes into contact with the cooled surface and drops on to the element. S2 The air cools to below the dew point temperature. S3 Absorption of radiant heat S4 The cooled air flows into the room and the condensate is discharged.