Heat exchanger panel for tempering building rooms

Abstract

According to the invention, a heat exchanger panel is provided for controlling the temperature of building spaces. The heat exchanger panel comprises a heat exchanger having a medium line for conducting a heat exchange medium and a heat exchanger wall that is in thermal contact with the medium line. The heat exchanger wall has an interface facing the building space to be temperature-controlled, which interface can be brought to a lower temperature compared to a heat load or a higher temperature compared to a cold load. The heat exchanger panel further comprises a layer made of a polymer material that is arranged on the interface of the heat exchanger, wherein the layer has gas bubbles or gas chambers so that it is at least partially permeable to thermal radiation. The heat exchanger panel is characterized in that the layer made of polymer material has a transparency with respect to thermal radiation of no more than 30%.

Description

The invention relates to a heat exchanger panel for tempering rooms of buildings and to a method for tempering rooms of buildings with such a heat exchanger panel.It is known for tempering buildings, i.e. for heating and cooling, to heat or cool a component of the building, e.g. by means of a heated or cooled pipe register. Thus, the component can release heat to the room air and surrounding areas by radiation exchange or absorb heat from the room air and surrounding areas and thermal loads located in the room and thereby influence the interior climate. As components, frequently ceiling panels, wall panels or floor heating systems are provided with a water-guided pipe register or electrically operated heating wire. This can be installed directly during the construction of the building or can be retrofitted in an existing building.For example, DE 10 2008 053 192 A1 relates to a solar collector having a cooling function, wherein solar radiation incident on the one hand can be converted into heat by the solar collector and thermal energy, for example from a building, can be dissipated on the other hand. For this purpose, the solar collector comprises a device through which a first heat transfer fluid can flow, which device is in contact with an absorber. By means of the absorber, incident solar radiation is converted into heat and is dissipated from the first heat transfer fluid. The solar collector also comprises a device through which a second heat transfer fluid can flow, which device leads to an outer surface. By means of the second heat transfer fluid, heat is conducted to the outer surface, where it is released to the environment.Furthermore, DE 20 2008 014 419 U1 discloses a solar-operated collective collector for simultaneously generating electric current and thermal heat, and also a solar cooling unit. The collective collector comprises a light inlet panel, at least one photovoltaic cell, at least one light absorber layer and at least one pipe filled with a fluid, wherein the fluid is heated. Sunlight passes through the light inlet panel and reaches the light absorber layer through a passage of the photovoltaic cell, which absorbs the sunlight and is thus heated. The light absorber layer is in thermal contact with the tubing, thereby heating the fluid in the tubing. The collective collector is suitable in particular for use with a refrigerating machine.CN 107606824 A shows an evaporator and an air conditioner refrigeration system. The evaporator includes a heat exchange member and a heat-resistant permeable plate, the heat-resistant permeable plate being disposed on at least one side of the heat exchange member at the surface thereof and being in contact with room air. The heat-resistant permeable plate is heat-insulating and at least partially permeable to heat radiation. The material of the heat resistant permeable plate may be polyethylene. The heat exchanger element further comprises a tube through which a cooling medium can be conducted. By means of the evaporator, heat can thus be dissipated from a space in which the thermal radiation arising therein is absorbed.Proceeding from the prior art, the object of the present invention is thus to provide a heat exchanger panel for tempering building rooms, which heat exchanger panel temperatures the building rooms in an energy-efficient manner and in particular has a good cooling effect with a very low convection component.A further object of the present invention is to provide a heat exchanger panel for tempering rooms of buildings, which heat exchanger panel has a high heat radiation exchange over a broad temperature spectrum.A further object of the present invention is to provide a heat exchanger panel for tempering rooms of buildings, which almost prevents the formation of condensate on the heat exchanger panel.It is a further object of the present invention to provide a heat exchanger panel for tempering rooms of buildings, which has a high mechanical stability, wherein the heat radiation exchange is hardly influenced thereby.In addition, it is an object of the present invention to provide a heat exchanger panel for tempering rooms of buildings, which is designed to be visually appealing without significantly influencing the heat radiation exchange in the process.One or more of these objects are achieved by the features of the independent claim. Advantageous embodiments are specified in the dependent claims dependent thereon.According to a first aspect of the invention, a heat exchanger panel for tempering rooms of buildings is provided. The heat exchanger panel comprises a heat exchanger having a medium line for guiding a heat exchanger medium and a heat exchanger wall which is in thermal contact with the medium line. The heat exchanger wall has an interface facing the building room to be temperature-controlled, which can be brought to a temperature lower than a heat load or higher than a cold load. The heat exchanger panel further comprises a layer of a polymer material arranged on the boundary surface of the heat exchanger, wherein the layer has gas bubbles or gas chambers, so that it is at least partially permeable to thermal radiation. The heat exchanger panel is characterized in that the layer of polymer material has a transparency of not more than 30% in a wavelength range of thermal radiation between 9 μm and 11 μm.Thermal radiation is electromagnetic radiation of the infrared wavelength range, which at least partially penetrates the layer of polymer material. The wavelength range of thermal radiation (infrared radiation) typically extends from 780 nm to 1 mm. For the spectral range of 4 μm to 12 μm, the term room temperature radiation can also be used. This spectral range contains a major part of the energy of the thermal radiation of a black body radiator at approximately room temperature. If the heat exchanger panel is to be used for cooling in a warmer climate, this spectral range can be slightly shifted. Likewise, shorter wavelengths can occur if the building room has special heat sources, for example electrical devices. The spectral range from about 2 μm to about 100 μm contains almost the entire energy of the thermal radiation of a black body radiator at about room temperature.The wavelength range between 9 μm and 11 μm comprises the maximum of room temperature radiation, for which reason this range is also the most important for the assessment of the transparency.The layer of polymer material has a transparency of not more than 30% in the wavelength range of thermal radiation between 9 μm and 11 μm. Although this means that the layer has a transparency of not more than 30% in this wavelength range, the layer likewise has a certain transparency in the remaining wavelength range between 780 nm and 1 mm, in particular in the range between 2 μm and 100 μm. This transparency can also be higher than 30% at individual wavelengths, but the layer has an average transparency of not more than 30% over the wavelength range of 780 nm and 1 mm, in particular between 2 μm and 100 μm. As a rule, the layer has even a substantially higher absorption at individual specific wavelengths, so that the transparency is lower at individual specific wavelengths.The layer of polymeric material has a transparency of not more than 30% to thermal radiation in the wavelength range between 9 μm and 11 μm over the entire local mean of the volume of the layer. For the remaining wavelengths of the thermal radiation, the layer of polymer material generally has the same property.Such a layer is preferably a foam layer. A foam layer is not homogeneous, i.e. there is a different amount of material at different locations in the cross section. A transparency of the layer made of polymer material of not more than 30% with respect to the thermal radiation in a wavelength range between 9 μm and 11 μm thus means that, viewed over the entire volume of the layer, on the local average not more than 30% of the total thermal radiation between 9 μm and 11 μm impinging on a surface of the layer facing the building room reaches the interface. In this case, a transparency of more than 30%, but typically only of somewhat more than 30%, may be present at individual locations of the layer. 70% of the thermal radiation is absorbed between 9 μm and 11 μm over the entire volume of the layer or is reflected to a small extent. Depending on the material selection and solid angle, a proportion of 1% to 15% of the thermal radiation between 9 μm and 11 μm is reflected. Polymers typically have a physically unavoidable reflection in the range of 5% to 15%. For the remaining wavelengths of the thermal radiation, the layer of polymer material can have the same properties.The transparency of the layer of polymer material is determined by means of FTIR spectroscopy (Fourier transform infrared spectroscopy), which falls under the term infrared spectroscopy, in a corresponding FTIR spectrometer. A sample of the layer is introduced into the spectrometer in the form which is also formed on the heat exchanger panel. The layer is placed in the spectrometer without any change, such as would be carried out by pressing the layer. In the spectrometer, the layer is irradiated with infrared radiation of the wavelength 9 μm to 11 μm perpendicular (at a 90° angle) to the surface of the foam layer. The intensity of the radiation (energy density) after the layer is measured and compared with the intensity of the input radiation. A transparency of the layer made of polymer material of not more than 30% in a wavelength range of the thermal radiation between 9 μm and 11 μm means that the measured intensity of the radiation in the range 9 μm and 11 μm after the layer is not more than 30% of the intensity of the input radiation. This measuring method can be carried out, for example, with the FTIR spectrometer INVENIO ® from Bruker.Unless stated otherwise, the term "thermal radiation" hereinafter comprises the wavelength range between 2 μm and 100 μm.The layer of a polymer material has gas bubbles or gas chambers. The gas filling of the gas bubbles or gas chambers is largely permeable to thermal radiation. The gas bubbles or bubbles are respectively separated from the gas bubbles.Gas chambers are preferably filled with air. The gas filling preferably compensates for the pressure conditions in the layer. The gas filling of the layer thus preferably has an almost equal pressure level to the surrounding air. The layer is referred to as "foam layer" below.The foam layer can be viewed as a barrier to air and water vapor from the space that cannot pass through the foam layer to the interface. As a result, no convective heat exchange can take place between the air and the boundary surface.The foam layer is connected on the one hand to the heat exchanger at the boundary surface and on the other hand has a free surface, which is referred to below as "surface of the foam layer" or merely as "surface".The term building room is understood to mean both closed and open rooms. A closed space is a space closed on all sides. An open space comprises all kinds of spaces which are open at least to one side. This can be, for example, a bus-holding-point housing or a covered outer surface. Hereinafter, all of these spaces will be referred to as "space".The heat exchanger panel can be provided for cooling a room (cooling case). A thermal load is then present in the space. In this case, the heat exchange medium in the medium line is a cooling medium. The room temperature is typically about 20° C. to 30° C. in the case of a thermal load in the room (at a relative humidity of 60%), and the temperature of the heat exchange medium is typically about 6° C. to 20° C.The heat exchanger panel can likewise be provided for heating a room (heating case). A cold load is then located in the space. In this case, the heat exchange medium is a heating medium. The room temperature is typically about 10°C in the case of a room cold load and the temperature of the heat exchange medium is typically about 35°C to 50°C.The foam layer is formed to have transparency of not more than 30% in a wavelength range of thermal radiation between 9 μm and 11 μm.In principle, the transparency should be as high as possible for the functional principle of the heat exchanger panel, so that heat radiation can be absorbed as completely as possible at the temperature-controlled boundary surface. However, a high transparency of, for example, more than 60% requires very little polymer material to be applied to the interface. This results in a very thin or very sensitive foam layer. A thin foam layer provides only a low thermal insulation against heat conduction so that the surface of the foam layer rapidly approaches the temperature of the interface.The inventor has found that a maximum transparency of 10% is already sufficient, since then approximately 10% of the heat radiation impinges directly on the boundary surface, but a further considerable part of the heat radiation is absorbed in the region of the boundary surface by the temperature-controlled foam layer via the material thickness itself and the heat is supplied to the boundary surface by means of heat conduction in the material.In addition, a lower transparency allows more polymer material or a thicker foam layer to be provided. A foam layer with a certain minimum thickness of, for example, 0.5 cm to 1.5 cm brings about good thermal insulation, so that the surface of the foam layer can be kept above the dew point, even if the interface is also kept below the dew point.It has been found that such a foam layer having a maximum transparency of not more than 40%, of not more than 30%, of not more than 20%, in a wavelength range between 9 μm and 11 μm, is formed with sufficient thermal insulation to achieve the desired functions of dissipating the heat introduced by means of thermal radiation and of insulating the surface of the foam layer, such that the temperature of the surface is above the dew point.In addition, in the case of a thicker foam layer, more heat is introduced from the space into the foam layer and is also stored there and dissipated. This heat input takes place on the one hand by means of heat conduction in the region of the surface of the foam layer, wherein heat is transferred from the room air to the surface by convection. On the other hand, the heat input takes place in the entire volume of the foam layer by an increased absorption capacity of the foam layer (due to the low transparency of the total layer thickness, but considerable transparency in the heat radiation spectrum over a part of the material thickness). The heat input into the foam layer exceeds the heat flow from the (constantly) cool interface to the surface and prevents the surface from cooling below the dew point temperature of the room air to a defined point. According to the principle, this is close to the medium room temperature of the room.A surface of the foam layer having a temperature below the average room temperature would lead to the formation of condensate by the room air on the surface from the point of reaching the dew point temperature of the room air, which is to be positively avoided. This effect is also supported by heat gains from hot room air flowing past (in the typical use of a ceiling sail or wall panel). Warm room air rises and impinges on the slightly cooler surface. Consequently, the room air cools down easily but simultaneously warms up the surface and falls down again.At the same time, a heat flow by thermal radiation acts on the boundary surface from the room surfaces visible from the surface, so that the boundary surface aims at an equilibrium temperature corresponding to the mean radiation temperature.If the foam layer is formed too thin, a heat flow from the (constantly) cool interface to the surface of the foam layer exceeds the heat contained in the foam layer from the space, which leads to a cool surface and thus to condensate formation.In order to achieve a transparency of the foam layer, in particular over the entire layer thickness, of 30% in a wavelength range between 9 μm and 11 μm, it must already be formed very thin. In this case, with the density of gas bubbles or gas chambers in the foam layer remaining the same, the thinner the layer, the higher the transparency. However, if the film is formed so thin as to have transparency of over 30%, it becomes unstable.On the other hand, the transparency of the foam layer can be increased to more than 30%, in particular more than 50%, by providing larger gas bubbles or gas chambers in the foam layer with the same thickness of the layer and number of gas bubbles or gas chambers, or by forming the walls of the gas bubbles with very thin walls. However, this then leads to a low amount of material being present in the foam layer, as a result of which the foam layer becomes very unstable. If there is little material in the layer to absorb heat in the form of thermal radiation and convection from the room air, then the heat flow from the (constantly) cool interface again exceeds the heat present in the foam layer.The inventor has recognized that, in the case of a foam layer having a transparency of not more than 30%, an equilibrium is established in a wavelength range between 9 μm and 11 μm, which equilibrium allows the most effective possible heat input of heat from the space to the interface (by means of thermal radiation and thermal conduction through the foam layer), wherein at the same time sufficient heat is absorbed by the foam layer such that no (or only a very low) heat flow from the interface reaches the surface of the foam layer.In the case of a cold load in the room, a foam layer having a transparency of not more than 30% balances in a wavelength range between 9 μm and 11 μm in the same manner, in which heat is emitted from the interface (by means of thermal radiation through the foam layer) into the room, while at the same time no heat flow from the interface reaches the surface of the foam layer, whereby the foam layer on the surface remains cool enough, so that the loss of convection heat on the surface is kept low. This convection heat would be completely lost, especially when heating outdoor rooms, since it is carried by moving air outside it.There is only a small portion of heat lost by convective heat. This is the part of the thermal radiation from the interface which is absorbed by the foam layer in a region close to the surface of the foam layer and then reaches the surface by means of thermal conduction.The radiant heat generated by the heat exchanger panel provides for relatively low-loss heating. Thus, the temperature of the heat exchanger medium can be relatively low and an effective heating of an outer space is nevertheless possible. Since the temperature level of the heat exchange medium may be relatively low, the use of heat pumps to heat the medium is possible. The heat exchanger panel thus offers the possibility of energy-efficient heating even in external areas.Since the foam layer only allows a conditional heat conduction from the tempered interface towards the surface of the foam layer and prevents a convective heat exchange between the interface and the room air, a large temperature difference may form between the interface and the surface. Thus, in the case of a thermal load in the room, the interface can be cooled to a temperature below the dew point and the surface maintains a temperature above the dew point temperature of the room air, which leads to effective cooling via the absorption of heat radiation from room surfaces or heat sources. Due to the effect of the foam layer that is insulating from the boundary surface to the surface, the boundary surface can also be cooled down particularly quickly.At the same time, preventing convective heat exchange between the interface and the room air results in moisture from the room air not being able to condense on the interface even though the interface has a radiation temperature below the dew point.If the heat exchanger panel is arranged over a large area in a space, it can be cooled very efficiently and quickly and moisture can nevertheless be prevented from precipitating at the boundary surface. This prevents the room or the surface of the foam layer or the heat exchanger panel from being contaminated, or prevents appliances or devices from being damaged, annoying persons, causing structural damage and / or adversely affecting the room climate.In the case of a cold load in the room, the interface can be heated to a high temperature and the interface can be rapidly heated.With the arrangement of the foam layer permeable to thermal radiation on the cooled or heated interface, the actual surface temperature (corresponding substantially to the average room temperature) of the foam layer is decoupled from the radiation temperature at the surface of the foam layer. The radiation temperature at the surface of the foam layer can consequently be lower than the material temperature of the surface in the case of cooling. The radiation temperature at the surface corresponds to a value which depends on the transparency, thermal conductivity and surface condition of the foam layer and approaches the radiation temperature of the interface more and more with increasing transparency. A higher thermal conductivity of the foam layer leads to the material surface temperature approaching that of the boundary surface The heat input from convective and radiation-physical conditions can be influenced by the surface condition due to, for example, a surface enlargement by a rough surface. An example would be a intentionally groove-like or uneven structure.The additional possible temperature difference leads to a higher power density and less convective losses in the case of a heat load or a cold load in the room than in the case of an exposed interface. By an exposed interface is meant the direct contact between the room air and the interface. Consequently, the degree of utilization of the heat radiation is increased by the foam layer. In particular, the additional possible temperature difference between the mean flow temperature ((flow temperature+return temperature) / 2) leads to a higher power density over a broad temperature range than in the case of an exposed boundary surface which is thus in direct contact with the room air.While with dew point limitation of the interface the temperature difference and consequently the absorption power is limited, a dew point independent interface can be operated constantly with high temperature difference and low radiation temperatures.The inventor has recognized, on the one hand, that a transparency of more than 30% in a wavelength range between 9 μm and 11 μm is not necessary in the case of a foam layer in order to meet the desired thermal properties, and, on the other hand, a mechanically stable foam layer is possible with a transparency of not more than 30% in a wavelength range between 9 μm and 11 μm, which permits permanent operation.The foam layer may be firmly bonded to the interface. The foam layer may also be a body applied to and bonded to the interface. It is also possible for the foam layer to be placed only on the boundary surface and to be braced with the latter. For this purpose, a circumferential seal can be provided by adhesive bonding or a dry seal on the boundary surface on which the foam layer is placed. Thus, the foam layer can be separated from the boundary surface again, as required.Enclosures may be provided laterally on the heat exchanger panel. These may be firmly connected to the heat exchanger panel and / or to the foam layer. In the case of a firm connection to the heat exchanger panel and to the foam layer, the foam layer can thus be additionally fixed. The enclosures may therefore serve optical and / or static purposes.It can also be provided that the foam layer completely surrounds the medium lines of the heat exchanger. The medium lines run within the foam layer. This ensures better heat transfer. In this case, the foam layer is not arranged on the boundary surface, but on a surface of the ceiling or wall panel. Nevertheless, a heat-conducting layer can be provided, which connects the medium lines to one another within the foam layer and thus forms a large surface.The layer of polymer material can have a transparency of not more than 25% or of not more than 20% or of not more than 15% or of not more than 10% or of not more than 5% in the wavelength range of the thermal radiation between 9 μm and 11 μm.In a wavelength range of the thermal radiation between about 2 μm and about 20 μm or between about 2 μm and about 100 μm, the layer of polymer material can have a transparency of not more than 30%, of not more than 25%, of not more than 20%, of not more than 15%, of not more than 10%, of not more than 5%.The layer of polymer material can have a thickness of at least 2 mm or at least 3 mm or at least 4 mm or at least 5 mm or at least 6 mm or at least 7 mm or at least 8 mm and / or a thickness of at most 150 mm or at most 75 mm or at most 50 mm or at most 28 mm or at most 27 mm or at most 26 mm or at most 25 mm or at most 24 mm or at most 23 mm or at most 22 mm. The layer can have a thickness of 10 mm to 14 mm.The layer thickness of the foam layer can be adjusted based on the individual requirements of the ambient climate and the operating temperature of the interface.The polymer material of the layer can be formed from a polyolefin, preferably from polyethylene or from polypropylene, or a mixture thereof.The polymer material can be formed from any material combination of the polyolefins. Furthermore, the polymer material can be provided with various additives, such as flame retardants, inhibitors, UV protection or special reflective or absorbing particles or heat transport layers. The surface of the foam layer can be front-coated and / or back-coated.The foam layer can have a transmission of 20% to 80% for radiation with a wavelength in the range from 4 μm to 12 μm at a thickness between 2 mm 10 and 20 mm. Therefore, these materials are suitable for forming the foam layer. Preferably, a flame retardant, closed cell polyethylene foam having a low density is used. Alternatively, polypropylene, or a copolymer of both or more polymers, or a polyolefin foam is used.The layer of polymer material can be a layer of a foam, in particular with closed cells, or a bubble film or hollow chamber film. The layer may completely cover the interface.Foams and bubble films are suitable as materials for the foam layer since they have cells filled with a gas, by means of which the foam layer acquires a certain transparency to thermal radiation. At the same time, the foam layer can thereby be formed relatively easily, so that the total weight of the heat exchanger panel is hardly increased. Since the gas in the cells usually constitutes a good heat insulator, the remaining material of the foam layer preferably has heat conducting properties.The material of the foam layer may be admixed with materials which have a high absorption with respect to thermal radiation. The heat input of thermal radiation into the material can thus be improved. Additionally or alternatively, the material of the foam layer can be mixed with materials which have a high thermal conductivity. Thus, the heat input of convection heat from the room and the thermal conductivity of the foam layer can be increased.The foam layer is preferably formed and arranged at the boundary surface in such a way that moisture introduction at the boundary surface is excluded. Nevertheless, capillary channels can be provided in the foam layer in order to remove moisture to the room. The capillary channels run as directly as possible from the boundary surface in the direction of the space and lead the moisture which arises back into the space. This ensures a permanent functionality of the heat exchanger panel.The capillary channels may be formed of the same material as the foam layer or of another capillary active material.It can be provided that the foam layer is additionally arranged laterally circumferentially on the heat exchanger panel. The foam layer can have a different thickness in the lateral regions of the heat exchanger panel than on the side facing the space.The heat exchanger has medium lines through which a cold or hot heat exchanger medium (preferably a fluid) can flow. The heat exchanger is a body which comprises these medium lines or in which these medium lines are embedded and in which the heat is predominantly distributed by heat conduction. In the extreme case, the heat exchanger can consist only of the medium lines. As a rule, however, the heat exchanger has a body in which the medium lines are embedded and in which the heat is distributed predominantly by heat conduction and not by heat radiation.In the simplest case, the heat exchanger can be formed only from a tube carrying hot or cool medium and the connected foam layer. The supporting structure in the ceiling or wall region can then be ensured, for example, by pipe clamps or a clamping structure.Thermal radiation is generally radiated from the boundary surface both into the space and into the interior of the heat exchanger. However, the thermal radiation can only propagate in the interior of the heat exchanger if the heat exchanger has a material with low density or high transparency, in particular in the infrared spectrum. The higher the density, the lower the spread of heat by thermal radiation and the more the transfer by thermal conduction.The heat exchanger can have at least one straight or meandering tube and / or can be a plate heat exchanger.The heat exchanger can also be a body with lines that is geometrically free of a flat plane, or can be formed directly from a line.In a preferred embodiment of the heat exchanger panel, the heat exchanger has at least two parallel straight tubes which are connected to one another by a plurality of thinner tubes which in turn run parallel. The heat exchanger can also be a tube system with capillary tubes or a capillary tube mat. In this case, the tubes are preferably integrated into a ceiling or wall panel, so that the material of the ceiling or wall panel fills the interstices between the tubes. However, the tubes can also be applied exposed to the ceiling or wall panel.The surface of the tubes is particularly relevant for the temperature control of the room. These surfaces may be smooth or rough in order to influence their absorption or reflection behavior. The surfaces may also contain or consist of a metal or an alloy. Due to the high thermal conductivity and / or high heat capacity of the surfaces and high absorption in the radiation range of the temperature radiation of 2 μm to 20 μm or 2 μm to 100 μm wavelength, the performance of the device according to the invention can be increased. By means of a low or high heat capacity of the surfaces, or by means of additionally introduced or attached latent storage materials (PCM), on the other hand, the response behavior of the heat exchanger panel can be specifically influenced.The heat exchanger and / or the ceiling or wall panel can be made of the same material as the foam layer or consist thereof. This reduces the diversity of materials and improves the recycling capability. Thus, the heat exchanger can also be a capillary tube mat which is made completely from a polymer material.It can be provided to add highly radiation-absorbing particles, such as carbon particles, to the material of the heat exchanger and / or of the ceiling or wall panel. These particles absorb heat radiation coming from the room and also radiation emanating from the heat exchanger itself. Any thermal radiation is absorbed very quickly by the particles without it being able to penetrate deeply into the material. The absorbed thermal radiation is converted into heat and contributes to the heating of the heat exchanger by thermal conduction. It can also be provided to mix the foam layer with such radiation-absorbing particles.As radiation-absorbing particles, any particles having good absorptivity may be provided. These may be, for example, polymer or metal particles. However, metal generally has high reflectance to IR radiation. If the heat exchanger and / or the ceiling or wall panel and the foam layer consist of a polymer material, carbon particles or particles of a radiation-absorbing carbon compound are suitable for this purpose. Thus, polymer materials are also carbon compounds from a chemical point of view, which keeps the material diversity low and keeps the recycleability high.An additional heat-conducting layer can be provided between the heat exchanger and the foam layer.The heat-conducting layer can be introduced between the heat exchanger and the foam layer in such a way that the surfaces of the individual lines of the heat exchanger are additionally connected to one another in a heat-conducting manner. The heat-conducting layer is, for example, a layer made of a metal. In particular, the thermally conductive layer can be an optically functional layer, the layer applied by a printing method or other coating methods. This creates a large overall surface area of the heat exchanger, which has a uniform temperature distribution. In the case of a heating load in the room, a large cooling surface is thus formed, which absorbs thermal radiation over its entire area and conducts it to the tubes. In the case of a cold load in the room, on the other hand, a large heating surface is formed, which gives off heat radiation to the room over a large surface area.Between the heat exchanger and the foam layer, a moisture-removing layer can be provided, which is, for example, a capillary-active nonwoven.Instead of or in addition to the capillary channels in the foam layer, a moisture-removing layer can be provided at the boundary surface. This moisture-removing layer is preferably a capillary-active nonwoven. The nonwoven is preferably formed from highly absorbent, biologically resistant synthetic fibers. With the fleece, possibly occurring moisture should be buffered and discharged into a region of the fleece which can dry, for example, in the ambient air.Electronic components, such as sensors, semiconductors, LEDs and / or other active or passive components or thermal storage materials, can be arranged between the heat exchanger and the foam layer.The components can also be electrothermal components, such as Peltier elements. In embodiments, a PCM material may also be introduced for thermal buffering.Electronic components such as LEDs may be provided for decorative and technical purposes. Thus, the heat exchanger panel can not only serve for tempering a room, but at the same time contribute to the optical design and workplace illumination of the room with light elements. In warehouses or laboratories, where a constant temperature and / or a constant humidity are very important, sensors can be provided that permanently monitor these values.The foam layer may be applied to a portion of the interface such that a portion of the interface is exposed to condense moisture thereon.In this embodiment, the heat exchanger panel, in addition to cooling a room, also allows dehumidifying the room. Since the boundary surface for cooling the room is cooled according to the invention to a temperature below the dew point, a strong condensation of moisture from the room air takes place at the exposed partial areas. This condensate is preferably discharged from a capillary-active fleece applied to the boundary surface into an outer edge region of the heat exchanger panel and collected there. In the edge region, a collecting channel is preferably provided in order to collect and drain the moisture. The dehumidifying of the room can thus be additionally achieved in a simple manner. This likewise takes place with a lower air flow than in typical air-conditioning devices, but at the same time offers the advantage of the system combination.On a side of the heat exchanger facing away from the building space to be tempered, a heat-insulating and / or sound-absorbing layer and / or a layer diffusion-proof with respect to water vapor can be provided.The heat-insulating layer can reduce, for example, energy losses from the room to the outside or into volumes and areas not to be heated.The sound-absorbing layer reduces the sound level in the space by absorbing sound waves. This improves inter alia the speech intelligibility in rooms. The sound-absorbing layer is, for example, an acoustic foam and is preferably formed from the same material as the diffusion-tight thermal insulation material. The acoustic foam has a more open-pored surface than the heat insulation material.The layer which is diffusion-proof with respect to water vapor prevents moisture from entering the ceiling and / or the wall of the room or on the surface of the heat exchanger.The heat exchanger panel may be a solid component of a building, such as a solid building ceiling or wall. If the heat exchanger panel is integrated into a ceiling panel, a ceiling sail or into a wall panel, it can also be introduced subsequently together with the panels into an existing building. By installing such panels, a large surface is obtained for exchanging heat radiation which is used for tempering a room. As a result, rapid cooling or heating is possible on the one hand, and the temperature control of the room is carried out in a pleasant manner on the other hand, since no air currents are generated as in the case of a conventional air-conditioning system. The material of the panels is preferably a water vapor diffusion-proof heat insulation material.During operation of the heat exchanger panel, the boundary surface facing the space is brought to a temperature lower than a heat load (cooling case) or to a temperature higher than a cold load (heating case). This can be effected, for example, by a refrigerant or a heating medium. The cooling or heating medium can be, for example, water, which is cooled or heated by means of a heat pump. Thus, either the temperature of the interface can be lowered to remove heat from the thermal load or the temperature of the interface can be raised to supply heat to the cold load. By means of the foam layer, these effects can thus be achieved in a simple and particularly cost-effective manner.The thermal load can be solar radiation, for example, or can arise in the room by electrical devices or persons. Usually, the warm room surfaces radiate more heat radiation than the cooling surface of the heat exchanger panel, so that an energy transport from the warm room surfaces to the cooled boundary surface occurs. The thermal radiation (infrared) emanating from the thermal load is absorbed by the cold interface and the foam layer and removed from the space by the refrigerant.The cold load is usually produced by cool room surfaces, by cool surfaces of objects in the room or by persons who have a lower radiation temperature than the radiation temperature of the surface of the heat exchanger panel. The room surfaces then receive more heat from the warm interface than they release. The heating means heats the interface by thermal conduction, from which the (infrared) thermal radiation is then emitted to the space. The heat is additionally supplied to the space via the foam layer, which conducts it to the surface.According to a second aspect of the invention, a heat exchanger panel for tempering rooms of buildings is provided. The heat exchanger panel comprises a heat exchanger having a medium line for guiding a heat exchanger medium and a heat exchanger wall which is in thermal contact with the medium line. The heat exchanger wall has an interface facing the building room to be temperature-controlled, which can be brought to a temperature lower than a heat load or higher than a cold load. The heat exchanger panel further comprises a layer of a polymer material arranged on the boundary surface of the heat exchanger, wherein the layer has gas bubbles or gas chambers, so that it is at least partially permeable to thermal radiation. In addition, the heat exchanger panel has a covering layer which is arranged on the layer of polymer material and is at least partially permeable to thermal radiation.The heat exchange panel of the first aspect of the invention corresponds to the heat exchange panel of the second aspect of the invention except for the covering layer.Also in the second aspect of the invention, the layer of a polymer material is referred to as "foam layer", the free surface of the foam layer as "surface", and the building room as "room".The cover layer may be a hole supporting structure having a plurality of through holes so as to be almost transparent to heat radiation.The hole supporting structure may be a substantially plate-shaped body having a plurality of through holes.The hole supporting structure is an open structure for air. The air can pass through the through-holes of the hole-supporting structure virtually unimpeded to the foam layer. The same applies to thermal radiation. The number and size of the through-holes can be selected such that the hole supporting structure overall has the greatest possible opening width, as a result of which heat radiation can pass predominantly through.The hole support structure gives the heat exchanger mechanical stability. At the same time, the hole supporting structure protects the heat exchanger on the side facing the space. These may be, for example, impacts against the heat exchanger. Such impacts would quickly lead to damage if they were directly incident on the foam layer. Due to the largest possible opening width of the hole supporting structure, it can itself have a low dead weight, but a high stability.Due to the mechanical stability imparted by the hole support structure, the other structures of the heat exchanger can in turn be configured to be less stable and thus weight-saving or material-saving and cost-effective.In addition to the mechanical stability, the hole support structure can be used to make the appearance of the heat exchanger visually appealing. Thus, a fully functional heat exchanger can be provided with the hole supporting structure, which heat exchanger can additionally be designed to be decent or to optically enhance a space, depending on the configuration of the hole supporting structure.Thus, the hole supporting structure enables the provision of a light, functional and yet mechanically stable heat exchanger, in which the heat exchanger properties are hardly influenced by the hole supporting structure and which at the same time can have a visually appealing design by means of the hole supporting structure.The hole support structure may be supportedly connected to the foam layer. The hole supporting structure can be glued onto the foam layer or connected to an edge composite running laterally on the heat exchanger panel.It can also be provided that the hole supporting structure is arranged at a distance from the foam layer. In this case, edge elements can be provided, which engage laterally on the heat exchanger panel and on the hole support structure, respectively, and thus couple the hole support structure to the heat exchanger panel.In the case of the hole supporting structure arranged at a distance from the foam layer, a film transparent to thermal radiation can additionally be provided between the foam layer and the hole supporting structure. The film can in turn lie on the foam layer and be connected thereto, in particular bonded thereto. By means of the film, the diffusion tightness towards the boundary surface can be further improved without excessively influencing the heat conducting properties.The hole supporting structure can have a distance of 5 mm or of 50 mm or of 100 mm or of 200 mm or of 300 mm from the foam layer.The hole supporting structure can be attached subsequently to the heat exchanger panel or to the foam layer. The purpose of this is to be able to alter the heat exchanger panel visually later, to make the components more recyclable and to separate them in a single type, and to be able to correct damage more easily and cost-effectively.By means of the hole supporting structure, it can be configured to be sound-absorbing. For this purpose, the hole supporting structure can have a microperforation and / or targeted hole sizes. This has the purpose of attenuating reverberation times in the room and improving thermal comfort or feel in the room.An edge of each through-hole can have a distance from the edges of the respectively adjacent through-holes of at most 3 mm or of at most 2 mm or of at most 1 mm or of at most 0.5 mm or of at most 0.2 mm.The through holes can have a center distance of a maximum of 10 mm or a maximum of 8 mm or a maximum of 6 mm or a maximum of 4 mm or a maximum of 2 mm from one another.The through holes may each have a round shape or a polygonal, preferably a hexagonal, shape.A hexagonal shape for the through-holes is preferred because they can be so placed directly adjacent to each of the adjacent through-holes. The through holes can be arranged so close to each other that only a thin web is present between them. Thus, the hole supporting structure has a very large opening width.In a plan view, the through-holes can each have an area of not more than 1.5*10 3 mm 2 or of not more than 750 mm 2 or of not more than 100 mm 2 or of not more than 10 mm 2 or of not more than 1 mm 2 or of not more than 0.1 mm 2 or of not more than 0.01 mm 2 or of not more than 1*10 3 μm 2 or of not more than 100 μm2.The larger the area of the through holes in a plan view, the larger the opening width. If large through-holes are selected, which in particular have a hexagonal shape, the opening width can be maximized.The through-holes can have a depth running substantially perpendicular to the boundary surface of at least 1 cm or of at least 2 cm or of at least 4 cm or of at least 6 cm or of at least 8 cm or of at least 10 cm.The hole supporting structure can in particular be a structure in the form of an expanded metal.Surface sections of the hole support structure running essentially perpendicular to the boundary surface can have an absorption with respect to thermal radiation of at least 50% or of at least 60% or of at least 70% or of at least 80% or of at least 90% or an absorption of at most 50% or of at most 40% or of at most 30% or of at most 20% or of at most 10%.The surface sections of the hole supporting structure running perpendicular to the boundary surface mean all those sections which form side walls of the through-holes.The hole supporting structure may be a perforated or perforated metal foil or ceramic foil or foil of a carbon fiber composite material, the perforations forming the through holes.The film can have a thickness of at least 10 μm or of at least 100 μm or of at least 200 μm or of at least 300 μm or of at least 400 μm or of at least 500 μm and / or a thickness of at most 1000 μm or of at most 900 μm or of at most 800 μm or of at most 700 μm or of at most 600 μm.The hole support structure may be a metal grid having grid openings, the grid openings forming the through holes.The metal grid can have a thickness of at least 0.01 mm or of at least 0.1 mm or of at least 0.5 mm or of at least 1 mm and / or a thickness of at most 5 mm or of at most 4 mm or of at most 3 mm or of at most 2 mm.The hole supporting structure may be a mesh of a fiber-reinforced polymer composite material or may be formed of fibers of a fiber composite material or fibers of an inorganic material, with mesh openings of the mesh forming the through holes.The grid can have a thickness of at least 10 μm or of at least 100 μm or of at least 500 μm or of at least 1000 μm or of at least 2500 μm and / or a thickness of at most 10 mm or of at most 8 mm or of at most 6 mm or of at most 4 mm.The covering layer can be a surface element, in particular a film, which is at least partially permeable to thermal radiation.The film can be flexible or designed as a rigid plate-shaped body.The film can lie on the foam layer and be firmly connected thereto, in particular glued thereto.By means of the film on the foam layer, a smooth surface can be imparted to the latter. Such a smooth surface is easier to clean than a typically rough surface of such a foam layer. The film can also serve as a mechanical protective layer in order to prevent or at least mitigate direct physical effects on the foam layer. The film can additionally ensure that the combination of foam layer and film is completely air-impermeable, as a result of which no air can pass from the space to the interface. The film can also be used to form the heat exchanger panel in a more visually appealing manner.It is also possible for the foam layer to have a film-like layer on the front side and / or on the rear side, which layer is firmly connected to the latter. It is also possible to provide a plurality of layers of polymer material and film-like layers in any desired lamination. For decorative purposes, it may be by means of a printing process or physical reasons for adjusting the specific radiation or surface properties.The surface element can have a thickness of at least 2 mm or at least 4 mm or at least 6 mm and a thickness of at most 20 mm or at most 15 mm or at most 10 mm.The surface element can have a transmission of more than about 50% or of more than about 70% or of more than about 90% at a wavelength between about 2 μm and about 20 μm or between about 2 μm and about 100 μm at least in a partial region.The advantages described above with reference to the first aspect of the invention apply analogously to the second aspect of the invention. The different features of the aspects can be combined as desired, provided they are not technically exclusive.Furthermore, a method according to the invention for producing a heat exchanger panel explained above on the basis of the first aspect of the invention is provided. The method comprises the following steps:providing a layer of a polymer material and a heat exchanger having at least one metal surface,heating a hot melt adhesive film made of polyurethane,pressing the hot melt adhesive film of polyurethane onto a surface of the layer of a polymer material,cooling the polyurethane hot melt adhesive film on the surface of the layer of a polymer material,applying an adhesive to the cooled polyurethane hot melt adhesive film on the surface of the layer of a polymer material; andconnecting the layer of a polymer material to the at least one metal surface of the heat exchanger by means of the adhesive.The method can also produce a heat exchanger panel according to the second aspect of the invention, apart from the covering layer.By means of the method according to the invention, a method for adhering or producing a firm connection between a layer of a polymer material and a thermally conductive metal surface is provided.The coating process is chosen to obtain a permanent bond between a generally low energy polyolefin surface and a metal surface (heat exchanger). Other methods are possible only for small surfaces, are implementable only at high cost or do not form a long-term resistant composite. For example, a compound decomposes and dissolves by means of cyanoacrylate adhesives and primers through exposure to moisture for the years. With the material composite according to the invention, a permanently fixed connection is created.The layer of polymer material (foam layer) can be a thin, substantially plate-shaped solid body. The polymeric material may be an IR transparent foamable polymer. The polymeric material is preferably a polyolefin such as polyethylene or polypropylene.It is technically difficult to firmly bond such a foam layer to a smooth metal surface. One reason is that polyethylene or polypropylene is low-energy (nonpolar) materials to which conventional adhesives adhere only poorly or not at room temperature. Moreover, such a foam layer typically has a rough and non-uniform surface, so that it cannot be applied to a smooth surface over the entire surface. A cost-effective and reliable surface connection is thus hardly possible with a conventional method.Other methods such as thermal pressing or direct melt bonds or thermal welds are likewise hardly possible due to a typical construction of a heat exchanger with single tubes which offer only a small surface area on one side.Therefore, a method is provided by which a permanent bond can be achieved between a layer of a low energy polyethylene or polypropylene and a metal surface.A hot melt adhesive film made of polyurethane is provided. The polyurethane of the hot-melt adhesive film has high-energy (strongly polar) properties in the heated state, as a result of which it bonds very well to the low-energy (nonpolar) polyethylene of the foam layer. Thus, with the hot-melt adhesive film made of polyurethane, a surface can be produced on the foam layer, to which a further adhesive can be applied well. By means of this, the foam layer can be well connected to the at least one metal surface of the heat exchanger in a further step.Since both polymers have a matched melting point, the low energy surface of the polyolefin of the foam layer and the high energy polyurethane of the hot melt adhesive film bond to one another at the molecular level in the molten boundary layer.The polyurethane hot melt adhesive sheet may be applied as a film to the surface of the foam layer. The hot-melt adhesive film made of polyurethane can have a thickness of not more than 250 μm or of not more than 150 μm or of not more than 50 μm or of not more than 5 μm.Metal particles may be provided in the polyurethane hot melt adhesive film. With such metal particles having good thermal conductivity, the hot-melt adhesive foil can be heated quickly and homogeneously, since the metal particles distribute the heat in the adhesive material (inductive heat bonding).By means of the methods, it is possible to connect the IR-transparent foam layer to the heat exchanger surface made of metal in large numbers in a cost-effective, high-adhesion and large-surface manner.The adhesive which is applied to the cooled hot-melt adhesive film made of polyurethane is in particular a liquid adhesive.As an embodiment, the heat exchanger can be directly a concrete ceiling, in particular a diffusion-tight concrete ceiling, for example. The medium line can be a pipe system which is applied, for example, directly to the (raw) concrete ceiling. The tube system can be designed as a capillary mat. The transparent layer of polymer material, in particular foam layer, is applied or bonded to the pipe system. This results in the same principle with the advantage of saving overall height, material and taking into account individual circumstances. The disadvantage is on-site production.Optionally, a diffusion-tight insulation layer, for example in the form of a paint or water vapor diffusion-tight insulation layer, can be applied to the concrete floor in order to allow the existing construction for the construction. The "panel" is thus formed directly as a surface on the cover wall. The panel can thus also be firmly connected to the structural body or be applied as a structure directly to a ceiling and wall construction.The heat exchanger can likewise also be manufactured directly as a medium-carrying pipe with a foam layer. This eliminates the need for the separate heat exchanger and the product can be produced continuously as a tube. The pipe is then suspended from the ceiling, for example, with clamps, or fastened to it. A cladding can be formed, for example, from a perforated metal sheet, such as, for example, an expanded metal sheet, which are transparent to thermal radiation.Thus, the term "panel" can also mean bodies with non-planar surfaces, wherein, however, a panel is generally an approximately planar, plate-shaped component. A non-planar panel may be, for example, a tube or a curved surface. Regardless of the mold, a panel according to the invention has a heat exchanger layer and a polymer layer, which is generally foamed.Instead of the hot melt adhesive film made of polyurethane, a mass of hot melt polyurethane adhesive can also be provided, which is heated and, in the heated state, is applied to the surface of the layer made of polymer material and smoothened. Thereafter, the mass is also cooled and an adhesive is applied to the cooled mass. The composition of polyurethane hot melt adhesive has the same properties as the hot melt adhesive film of polyurethane mentioned above.The descriptions of the features of the heat exchanger panel listed above and the associated advantages also apply equally to the heat exchanger panel produced by means of the method described above.Other objects, features and advantages of the present invention will become apparent from the description and exemplary embodiment illustrated in the accompanying drawings. These show in: FIG. 1 shows a schematic sectional illustration of a heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a first exemplary embodiment of the invention, in FIG. 2 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to the first exemplary embodiment of the invention with arrow representations for the heat exchange, in FIG. 3 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a preferred embodiment of the first exemplary embodiment of the invention, in FIG. 4 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a further preferred embodiment of the first exemplary embodiment of the invention, in FIG. 5 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a further embodiment of the first exemplary embodiment of the invention, in FIG. 6 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a further embodiment of the first exemplary embodiment of the invention, in FIG. 7 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a further embodiment of the first exemplary embodiment of the invention, in FIG. 8 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a further embodiment of the first exemplary embodiment of the invention, in FIG. 9 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a first embodiment of a second embodiment of the invention, in FIG. 10 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a further embodiment of the second exemplary embodiment of the invention, in FIG. 11 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a second embodiment of the second embodiment of the invention, in FIG. 12 shows a schematic sectional illustration of the heat exchanger panel according to the invention, integrated into a ceiling or wall panel, according to a third exemplary embodiment of the invention, in FIG. 13 shows an exemplary graph for the cooling capacity of a cooling surface in space with and without dew point limitation at 60% relative humidity, and in FIG. 14 shows some (additional) numerical values to the graph according to FIG. 13.In the following, a heat exchanger panel 1 according to the invention for tempering building rooms 2 is described in more detail by way of example with reference to a first exemplary embodiment (first aspect of the invention) (FIGS. 1 to 9 ). The building rooms 2 will be referred to as "room" hereinafter. The space 2 has either a heat load (cooling case) or a cold load (heating case).The heat exchanger panel 1 comprises a heat exchanger 3. the heat exchanger 3 is integrated into a ceiling or wall panel 4.The heat exchanger 3 has at least two parallel straight tubes which are connected to one another by a plurality of thinner tubes which in turn run parallel. The heat exchanger 3 can also be a pipe system with capillary tubes or a capillary tube mat or can have at least one meandering pipe. The tubes can be formed from metal or from plastic and are designed for conducting a heat exchanger medium.The heat exchanger medium can be a refrigerant (cooling case) or a heating medium (heating case) in the form of a fluid which serves for absorbing heat or emitting heat. The cooling or heating medium can be, for example, cooled or heated water.The heat exchanger 3 can be formed from the same material as the ceiling or wall panel 4. A refrigerant, for example R32 or R290, can also flow directly through the heat exchanger 3, but preferably water or a water-glycol mixture.A heat pump (not shown) is provided for supplying cooled or heated water to the heat exchanger 3 via a pipe (not shown). The water is fed from the pipeline directly into the at least one pipe of the heat exchanger 3. The heat pump and the heat exchanger 3 form a circuit.For example, a single heat pump can be provided in a building, which is connected by means of a plurality of pipelines to a plurality of heat exchanger panels 1 on different floors and provides the cooled or heated water to the heat exchangers 3 of the heat exchanger panels 1. Alternatively, any cooling and heat sink can be incorporated into the circuit. Thus, installations with solar cooling, geothermal probes or groundwater cooling and consequently regenerative cold sources are also possible.The tubes of the heat exchanger 3 are introduced into the ceiling or wall panel 4 in such a way that a material of the ceiling or wall panel 4 fills the intermediate spaces between the tubes of the heat exchanger 3. The material is preferably a diffusion-proof heat insulation material.The heat exchanger 3 has an interface 5. The boundary surface 5 is the surface of the heat exchanger 3 facing the space 2.At the interface 5, there is substantially the temperature exchange between the space 2 and the heat exchange medium which flows through the tubes of the heat exchanger 3.Thermal radiation 8 is radiated from the boundary surface 5 basically both into the space 2 and into the interior of the heat exchanger 3. However, the heat radiation 8 can only propagate inside the heat exchanger 3 if the heat exchanger 3 comprises a material with a low density. The higher the density, the lower the propagation of the heat by means of the thermal radiation 8 and the stronger the transmission by means of the thermal conduction 9.On the side of the boundary surface 5 facing the space 2, a layer 6 made of a polymer material is arranged over the entire surface. The layer 6 made of a polymer material is referred to below as "foam layer".The foam layer 6 is bonded to the boundary surface 5. The adhesive is configured to be heat-conducting and at least partially permeable to thermal radiation 8.On the one hand, the foam layer 6 is connected to the heat exchanger 3 at the boundary surface 5 and on the other hand has a free surface 7 facing the space 2, which is referred to below as "surface of the foam layer" or merely as "surface".The foam layer 6 is formed from a polyolefin, such as polyethylene or from polypropylene, and has gas bubbles or gas chambers, so that it is at least partially permeable to the thermal radiation 8.With respect to the thermal radiation 8, the foam layer 6 has a transparency of not more than 30% in a wavelength range between 9 μm and 11 μm.The foam layer 6 has a thickness in the range from 2 mm to 25 mm.A density of gas bubbles or gas chambers in the foam layer 6 and the thickness of the foam layer 6 are selected such that a transparency of the foam layer 6 is achieved at a wavelength between 9 μm and 11 μm of not more than 30%.A foam layer 6 made of a polyolefin having such transparency has a relatively high material density.If the cooling case is considered, despite the relatively low transparency, sufficient heat passes from the space 2 through the foam layer 6 to the boundary surface 5 in order to achieve efficient cooling of the space 2. The heat reaches the interface 5 through a combination of a permeability of the foam layer 6 for the thermal radiation 8 and thermal conduction 9 in the region of the interface 5.At the same time, the foam layer 6 with a transparency of not more than 30% in a wavelength range between 9 μm and 11 μm absorbs sufficient heat from the space 2 so that no heat flow takes place from the interface 5 to the surface 7, which reaches the surface 7 and cools below an average room temperature of the space 2. This would lead to the formation of condensate by the room air at the surface 7.The heat is transferred from the room air at the surface 7 to the latter on the one hand by convection 10 (convective heat exchange) and then introduced into the material of the foam layer 6 in a region of the surface 7 by means of heat conduction 9. On the other hand, heat is introduced into the volume of the foam layer 6 by means of thermal radiation 8 as a result of an increased absorptive capacity (due to the low transparency).Considering the heating case, with a foam layer 6 having a transparency of not more than 30% in a wavelength range between 9 μm and 11 μm, heat is emitted from the interface 5 into the space 2, while at the same time no heat flow from the interface 5 reaches the surface 7, whereby the foam layer 6 at the surface 7 remains cool enough so that the loss of convection heat at the surface 7 is kept low.In a preferred embodiment (FIG. 3 ), an additional heat-conducting layer 11 is applied between the heat exchanger 3 and the foam layer 6. By means of the heat-conducting layer 11, the surfaces of the tubes of the heat exchanger 3 are connected to one another in a heat-conducting manner. This produces a large total surface area which has a uniform temperature distribution.In a further preferred embodiment (FIG. 4 ), the material of the heat exchanger 3 and / or of the ceiling or wall panel 4 is mixed with highly radiation-absorbing particles 12, such as carbon particles, for example. The particles 12 absorb heat radiation 8 coming from the space 2 and also heat radiation 8 coming from the heat exchanger 2 itself. Any thermal radiation 8 is absorbed very quickly by the particles 11 without it being able to penetrate deeply into the material. The absorbed thermal radiation 8 is converted into heat and contributes to the heating of the heat exchanger 3 by thermal conduction 9.As the radiation absorbing particles 12, any particles having good absorptivity may be provided. These can also be metal particles, for example. If the heat exchanger 3 and / or the ceiling or wall panel 4 and the foam layer 6 consist of a polymer material, carbon particles or particles of a radiation-absorbing carbon compound are suitable for this purpose. Thus, polymer materials are also carbon compounds from a chemical point of view, which keeps the material diversity low and keeps the recycleability high.According to a further embodiment (FIG. 5 ), a sound-absorbing layer 13 is introduced into the material of the ceiling or wall panel 4. The sound-absorbing layer 13 is preferably an acoustic foam and is preferably formed from the same material as the diffusion-tight thermal insulation material of the ceiling or wall panel 4. The acoustic foam has a more open-pored surface than the heat insulation material. The sound-absorbing layer 13 reduces the sound level and the reverberation time in the room 2.According to a further embodiment (FIG. 6 ), a moisture-removing layer 14 is provided between the boundary surface 5 and the foam layer 6. The moisture-removing layer 14 is substantially thinner than the foam layer 6 and bears both directly on the boundary surface 5 and on the foam layer 6. The moisture-removing layer 14 is, for example, a capillary-active nonwoven with which moisture which is not completely excluded can be removed. It extends into an edge region of the heat exchanger panel 1 in such a way that it protrudes at the boundary surface 5 and can dry the discharged moisture in the room air.According to a further embodiment (FIG. 7 ), a selective coating 15 is provided on the surface 7 of the foam layer 6. The selective coating 15 is a polymer membrane made of polyethylene or polypropylene which is transparent to thermal radiation 13. It is preferably provided for decorative reasons, but can also fulfil technical purposes.According to a further embodiment (FIG. 8 ), lighting elements 16 are provided between the boundary surface 5 and the foam layer 6. The illumination elements 16 can be, for example, LEDs which are mounted on the boundary surface 5 in a manner spaced apart from one another. Thus, a ceiling or wall panel 4 can not only serve for tempering the room 2, but at the same time contribute to the optical and technical configuration of the room 2 with lighting elements 16.A method for tempering a building room (room) 2 with a heat exchanger panel 1 according to the invention is explained below.In the case of cooling, an interface 5 of the heat exchanger panel 1 facing the space 2 is brought to a temperature which is lowered with respect to a heat load or the room temperature. For this purpose, a refrigerant is used as the heat exchanger medium, which flows through at least one tube of a heat exchanger 3 of the heat exchanger panel 1.The refrigerant, for example, in the form of cooled water, is supplied to the heat exchanger 3 by means of a heat pump (not shown) and supplied to the tube of the heat exchanger 3 via a pipe line (not shown).A layer 6 made of a polymer material (foam layer) is arranged on the interface 5.The foam layer 6 ensures, on the one hand, that no room air can reach the cool interface 5 directly, as a result of which no moisture can form a condensate from the room air of the room 2 at the interface 5.On the other hand, the foam layer 6 ensures that no heat flow takes place from the cool interface 5 to a warm surface 7 of the foam layer 6. Thus, no condensate can form even on the surface 7 of the foam layer 6.Thus, the interface 5 can be brought to a temperature below the dew point and the surface 7 of the foam layer 6 facing the space 2 nevertheless remains at a surface temperature above the dew point (medium room temperature).By means of the interface 5, heat can thus be extracted from the heat load in the space 2. The heat removal is effected by means of thermal radiation 8, which can emit at least partially through the foam layer 6 to the interface 5 and is absorbed by the foam layer 6 in a region of the interface 5 and then reaches the interface 5 by means of thermal conduction 9.At the same time, the foam layer 6 absorbs sufficient heat from the space 2 (by means of heat conduction 9 of convection heat 10 in a region of the surface 7 and by means of heat radiation 8 in the entire volume of the foam layer 6) so that this heat exceeds the heat flow from the boundary surface 5 to the surface 7, whereby it cannot pass to the surface 7 in order to cool it down.In the case of heating, on the other hand, the boundary surface 5 of the heat exchanger panel 1 facing the space 2 is brought to a temperature that is elevated with respect to a cold load. A heating medium is used as the heat exchanger medium.The heating medium, for example, in the form of heated water, is provided to the heat exchanger 3 by means of the heat pump and is supplied to the pipe of the heat exchanger 3 via the piping.The foam layer 6 ensures that no heat flow takes place from the warm interface 5 to the cool surface 7 of the foam layer 6. Thus, the loss of convection heat at the surface 7 is avoided.Heat can thus be supplied to the cold load by means of the interface 5. Since the foam layer 6 is at least partially transparent to 15 thermal radiation 13, the space 2 is heated by means of thermal radiation 13.A second embodiment (second aspect of the invention) will be explained below (FIGS. 9 to 11 ). Identical parts have the same reference numerals as in the previous exemplary embodiment. In addition, the above explanations apply equally to the corresponding parts of the second embodiment. The second embodiment differs from the first embodiment in that a covering layer 17 is arranged on the surface 7 of the layer 6 made of a polymer material. The cover layer 17 is at least partially permeable to thermal radiation 8.In a first embodiment of the second embodiment (FIG. 9 ), the cover layer 17 is a hole support structure 18.The hole supporting structure 18 is bonded to the foam layer 6.The hole supporting structure 18 has a plurality of through holes 19 arranged substantially perpendicular to the surface 7 of the foam layer 6. The through-holes 19 thus extend from a surface of the hole supporting structure 18 facing the space 2 to the foam layer 6.The through-holes 19 have a depth of 1 cm to 10 cm running perpendicular to the boundary surface.By means of the hole supporting structure 18, the heat exchanger panel 1 is given an increased stability. At the same time, the hole supporting structure 18 is intended to impart a visually appealing appearance to a side of the heat exchanger panel 1 facing the space 2.A distance of the through-holes 19 from one another and an area of the through-holes 19 in a plan view are selected such that the hole supporting structure 18 has an opening width which is as large as possible. Thus, the hole supporting structure 18 is almost permeable to thermal radiation 8.The hole supporting structure 18 is formed of metal so as to be highly thermally conductive. Thus, it conducts a heat flow from the space 2 to the surface 7.The through-holes 19 each have surface sections 20 running perpendicular to the boundary surface 5. These surface portions 20 form the walls of the through holes 19.The surface sections 20 are preferably formed or provided with a coating such that they have a high degree of reflection for thermal radiation 8. Thus, the thermal radiation 8 is reflected through it as free of losses as possible.Due to the through-holes 19 and the large opening width of the through-holes 19, air from the space 2 can pass almost unimpeded to the foam layer 6. By means of the hole supporting structure 18, additional stability is thus imparted to the heat exchanger panel 1 without significantly disturbing the properties of the heat exchanger panel 1 mentioned in the first exemplary embodiment.In a further embodiment (FIG. 10 ), the hole supporting structure 18 can also be arranged at a distance from the foam layer 6. In this case, at least one edge element 24 can be provided, which engages laterally on the heat exchanger panel 1 and on the hole support structure 18 and thus couples the hole support structure 18 to the heat exchanger panel 1.According to a second embodiment of the second embodiment (FIG. 11 ), the cover layer 17 is a surface element in the form of a film 21.The film 21 is bonded to the foam layer 6. The adhesive is configured to be heat-conducting and at least partially permeable to thermal radiation.The film 21 is formed from a polymer material, in particular the same material as the foam layer 6. The film 21 is thus at least partially permeable to thermal radiation 8.The film 21 has a thickness of between 2 mm and 20 mm. At a wavelength between about 2 μm and about 20 μm or between about 2 μm and about 100 μm, the film 21 has a transmission of more than about 50% or of more than about 70% or of more than about 90%, at least in a partial region.The thickness and transmission of the film 21 are selected such that sufficient thermal radiation 8 can emit therethrough and sufficient heat reaches the foam layer 6 by means of thermal conduction 9 such that the latter retains the properties mentioned in the first exemplary embodiment.By means of the film 21 on the foam layer 6, a smooth surface is imparted to the latter. Such a smooth surface is easier to clean than a typically rough surface of such a foam layer 6.The film 21 also serves as a mechanical protective layer in order to prevent or at least mitigate direct physical effects on the foam layer 6.The film 21 additionally ensures that the combination of foam layer 6 and film 21 is completely air-impermeable, as a result of which no air can pass from the space 2 to the interface 5.The elements mentioned in the first exemplary embodiment on the basis of the further embodiments (heat-conducting layer 11, radiation-absorbing particles 12, sound-absorbing layer 13, moisture-removing layer 14, selective coating 15 and illumination element 16) can also be provided for the second exemplary embodiment.A method for producing a heat exchanger panel 1 explained above with reference to the first exemplary embodiment is provided below.The method can also be used to produce a heat exchanger panel 1 according to the second exemplary embodiment, apart from the covering layer 17.A layer 6 of a polymer material (foam layer) and a heat exchanger 3 with a metal tube are provided.The metal tube of the heat exchanger 3 is arranged such that a plurality of parallel running surfaces of the metal tube are present on one side of the heat exchanger 3. The foam layer 6 is intended to be firmly connected to these surfaces of the metal tube.The foam layer 6 is a thin, substantially plate-shaped solid body made of an IR-transparent foamable polymer material. The polymeric material is a polyolefin such as polyethylene or polypropylene.A hot melt adhesive film of polyurethane is heated. The heated hot melt adhesive film is hot pressed onto a surface of the foam layer 6 in the heated state.After the hot-melt adhesive film made of polyurethane has cooled on the surface of the foam layer 6, an adhesive, in particular a liquid adhesive, is applied to the cooled mass.The foam layer 6 is pressed onto the surfaces of the heat exchanger 3 and adhesively bonded to the surfaces by means of the adhesive.The method achieves a permanent bond between a layer of a low energy polyethylene or polypropylene and a metal surface.The hot-melt adhesive film made of polyurethane has high-energy (strongly polar) properties in the heated state, as a result of which it bonds very well to the low-energy (nonpolar) polyethylene of the foam layer 6. The bonding is then effected by melting the two polymers which bond to one another at the molecular level and thus form a solid bond. The melting points are matched in such a way that they are close to one another.The hot melt adhesive film can produce a surface on the foam layer 6, to which a further adhesive can be applied well. By means of this, the foam layer 6 can be well connected to the metal surfaces of the heat exchanger 3 in a further step.A third exemplary embodiment is explained below (FIG. 12 ). Identical parts have the same reference numerals as in the preceding exemplary embodiments. In addition, the above explanations apply equally to the corresponding parts of the third embodiment.The heat exchanger panel 1 including the heat exchanger 3 is provided. The heat exchanger 3 has the interface 5.A surface element 23 is provided between the boundary surface 5 and the space 2, so that an intermediate space 22 is enclosed between the boundary surface 5 and the surface element 23. The surface element 23 is arranged substantially parallel to the boundary surface 5.The intermediate space 22 is bounded laterally by a completely encircling edge element 24. The edge element 24 is firmly connected to the heat exchanger panel 1 and protrudes beyond the boundary surface 5 into the space 2.The surface element 23 is a film and is at least partially permeable to thermal radiation 8. The film is flexible and is connected and tensioned to the edge element 24 in a diffusion-tight manner at an edge thereof. The surface element 23 can also be a rigid plate-shaped body which is connected to the edge element 24 at the edge thereof. The surface element 23 can be glued to the edge element 24.The surface element 23 is formed from a polymer material.The surface element 23 has a thickness of at least 2 mm or at least 4 mm or at least 6 mm and a thickness of at most 20 mm or at most 15 mm or at most 10 mm.At a wavelength between about 2 μm and about 20 μm or between about 2 μm and about 100 μm, the surface element 23 has a transmission of more than about 50% or of more than about 70% or of more than about 90%, at least in a partial region.The space 22 is filled with air. Thus, the surface element 23 can be formed to be particularly thin. If a vacuum were to be drawn in the intermediate space 22, an excessively thin surface element 23 would be sucked into the intermediate space 22. A protective gas can also be provided in the intermediate space 22.The intermediate space 22 can also be almost air-less with a corresponding thickness of the surface element 23.Due to the intermediate space 22 and the surface element 23, no room air can reach the boundary surface 5 and condense there. The temperature exchange between the boundary surface 5 and the space 2 takes place almost exclusively via thermal radiation 8.On a side 25 of the surface element 23 facing the space 2, a hole supporting structure 14 is arranged.The hole supporting structure 14 is laterally fixedly connected to the edge element 24. The hole support structure 14 may be adhesively bonded to the rim member 24.The hole supporting structure 14 can be arranged lying against the surface element 23 or somewhat spaced apart from the surface element 23.It can also be provided that the surface element 23 is not connected to the edge element 24, but is only connected, in particular glued, to the hole supporting structure 14. A diffusion-tightness towards the edge element 24 is important in this case.With the hole supporting structure 14, the structure of the heat exchange panel 1 according to the third embodiment is also given increased stability. Since the hole supporting structure 14 ensures the stability of the heat exchanger panel 1 and protects the surface element 23 from the space 2, the surface element 23 can be formed to be particularly thin. Thus, it is particularly transparent to thermal radiation 8, as a result of which the heat exchange of the heat exchanger panel 1 is very effective.List of reference characters1 Heat exchanger panel 2 Building room 3 Heat exchanger 4 Ceiling or wall panel 5 Boundary surface 6 Layer of polymer material 7 Surface of the layer 8 Thermal radiation 9 Thermal conduction 10 Convective heat exchange 11 Thermally conductive layer 12 Radiation-absorbing particles 13 Sound-absorbing layer 14 Moisture-removing layer 15 Selective coating 16 Lighting element 17 Covering layer (hole supporting structure / film) 18 Hole supporting structure 19 Through hole 20 Surface section 21 Film 22 Intermediate space 23 Surface element 24 Edge element 25 Room-facing sideReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2008 053 192 A1

[0003] DE 20 2008 014 419 U1

[0004] CN10760682 A

[0005]

Claims

Heat exchanger panel for tempering building rooms, comprising - a heat exchanger which has a medium line for guiding a heat exchanger medium and a heat exchanger wall which is in thermal contact with the medium line, wherein the heat exchanger wall has an interface facing the building room to be tempered, which interface can be brought to a temperature lower than a thermal load or higher than a cold load, and - a layer of a polymer material which is arranged on the interface of the heat exchanger, wherein the layer has a multiplicity of gas bubbles or a multiplicity of gas chambers, so that it is at least partially permeable to thermal radiation, characterized in that the layer of polymer material has a transparency of not more than 30% in a wavelength range of the thermal radiation between 9 μm and 11 μm.Heat exchanger panel according to claim 1, characterised in that the layer of polymer material has a transparency of not more than 25% or of not more than 20% or of not more than 15% or of not more than 10% or of not more than 5% in the wavelength range of the thermal radiation between 9 μm and 11 μm.Heat exchanger panel according to claim 1 or 2, characterised in that the layer of polymer material has a transparency of not more than 30% or of not more than 25% or of not more than 20% or of not more than 15% or of not more than 10% or of not more than 5% in a wavelength range of the thermal radiation of between about 2 μm and about 20 μm or between about 2 μm and about 100 μm.Heat exchanger panel according to one of claims 1 to 3, characterised in that the layer of polymer material has a thickness of at least 2 mm or at least 3 mm or at least 4 mm or at least 5 mm or at least 6 mm or at least 7 mm or at least 8 mm and / or a thickness of at most 28 mm or of at most 27 mm or of at most 26 mm or of at most 25 mm or of at most 24 mm or of at most 23 mm or of at most 22 mm or respectively.Heat exchanger panel according to one of claims 1 to 4, characterised in that the polymer material of the layer is formed from a polyolefin, preferably from polyethylene or from polypropylene, or a mixture thereof.Heat exchanger panel according to one of claims 1 to 5, characterised in that the layer of polymer material is a layer of a foam, in particular with closed cells, or a bubble film or hollow chamber film and / or the layer completely covers the boundary surface.Heat exchanger panel according to one of claims 1 to 6, characterised in that the heat exchanger has at least one straight or meandering tube and / or is a plate heat exchanger.Heat exchanger panel according to one of Claims 1 to 7, characterized in that a heat-insulating and / or sound-absorbing layer and / or a layer which is diffusion-proof with respect to water vapor is provided on a side of the heat exchanger which faces away from the building space to be temperature-controlled.Heat exchanger panel for tempering rooms of buildings, in particular according to one of claims 1 to 8, comprising - a heat exchanger which has a medium line for guiding a heat exchanger medium and a heat exchanger wall which is in thermal contact with the medium line, wherein the heat exchanger wall has an interface facing the room of buildings to be tempered, which interface can be brought to a temperature lower than a thermal load or a temperature higher than a cold load, - a layer of a polymer material which is arranged on the interface of the heat exchanger, wherein the layer has gas bubbles or gas chambers, so that it is at least partially permeable to thermal radiation, and - a covering layer which is arranged on the layer of polymer material and is at least partially permeable to thermal radiation.The heat exchanger panel according to claim 9, characterized in that the cover layer is a hole supporting structure having a plurality of through holes so as to be almost permeable to heat radiation.Heat exchanger panel according to claim 10, characterised in that an edge of each through-hole is at a distance from the edges of the respectively adjacent through-holes of at most 3 mm or of at most 2 mm or at most 1 mm or at most 0.5 mm or at most 0.2 mm.Heat exchanger panel according to claim 10 or 11, characterised in that the through-holes have a centre distance of at most 10 mm or at most 8 mm or at most 6 mm or at most 4 mm or at most 2 mm from one another.Heat exchanger panel according to one of Claims 10 to 12, characterized in that the through-holes each have a round shape or a polygonal, preferably a hexagonal, shape.Heat exchanger panel according to one of Claims 10 to 13, characterized in that, in a plan view, the through-holes each have an area of not more than 1.5*10 3 mm 2 or of not more than 750 mm 2 or of not more than 100 mm 2 or of not more than 10 mm 2 or of not more than 1 mm 2 or of not more than 0.1 mm 2 or of not more than 0.01 mm 2 or of not more than 1*10 3 μm 2 or of not more than 100 μm2.Heat exchanger panel according to one of Claims 10 to 14, characterized in that the through-holes have a depth running substantially perpendicularly to the boundary surface of at least 1 cm or of at least 2 cm or of at least 4 cm or of at least 6 cm or of at least 8 cm or of at least 10 cm.Heat exchanger panel according to one of Claims 10 to 15, characterized in that surface sections of the hole supporting structure running substantially perpendicular to the boundary surface have an absorption with respect to thermal radiation of at least 50% or of at least 60% or of at least 70% or of at least 80% or of at least 90% or an absorption of at most 50% or of at most 40% or of at most 30% or of at most 20% or of at most 10%.Heat exchanger panel according to one of claims 10 to 16, characterised in that the hole supporting structure is a perforated or perforated metal foil or ceramic foil or foil made of a carbon fibre composite material, wherein the perforations or perforations form the through-holes.Heat exchanger panel according to one of claims 10 to 16, characterized in that the hole supporting structure is a metal grid with grid openings, wherein the grid openings form the through holes.Heat exchanger panel according to one of claims 10 to 16, characterised in that the hole supporting structure is a grid made of a fibre-reinforced polymer composite material or is formed from fibres made of a fibre composite material or from fibres made of an inorganic material, wherein grid openings of the grid form the through-holes.Heat exchanger panel according to Claim 9, characterized in that the covering layer is a planar element, in particular a film, which is at least partially permeable to thermal radiation.Heat exchanger panel according to claim 20, characterised in that the surface element has a thickness of at least 2 mm or at least 4 mm or at least 6 mm and a thickness of at most 20 mm or at most 15 mm or at most 10 mm.Heat exchanger panel according to Claim 20 or 21, characterized in that the planar element has a transmission of more than approximately 50% or of more than approximately 70% or of more than approximately 90% at a wavelength of between approximately 2 μm and approximately 20 μm or between approximately 2 μm and approximately 100 μm at least in a partial region.Method for producing a heat exchanger panel according to one of claims 1 to 8, comprising - providing a layer of a polymer material and a heat exchanger with at least one metal surface, - heating a hot-melt adhesive film of polyurethane, - pressing the hot-melt adhesive film of polyurethane onto a surface of the layer of a polymer material, - cooling the hot-melt adhesive film of polyurethane on the surface of the layer of a polymer material, - applying an adhesive to the cooled hot-melt adhesive film of polyurethane on the surface of the layer of a polymer material, and - connecting the layer of a polymer material to the at least one metal surface of the heat exchanger by means of the adhesive.

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