GB2599940A

GB2599940A - Improvements relating to cladding

Info

Publication number: GB2599940A
Application number: GB2016393.7A
Authority: GB
Inventors: James Wyllie Nicholas
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-10-16
Filing date: 2020-10-16
Publication date: 2022-04-20
Anticipated expiration: 2040-10-16
Also published as: GB202016393D0; GB2599940B

Abstract

Cladding 10 for a wall comprising a first face and a second opposite face. A thermal reservoir is disposed between the first face and the second face. A thermo electric module 14 is disposed between the first face and the reservoir. The cladding may include a second thermoelectric module. Also claimed is a structure, such as a vehicle or building, with two chambers. One chamber is in thermal communication with the external environment by means of a thermoelectric module and the second chamber is in thermal communication with the first chamber by means of a second thermoelectric module.

Description

Improvements relating to cladding Field of the invention [1] The present invention relates to a cladding system for a stmcture, such as a building or a vehicle. In particular, it relates to an active cladding system with 5 means for controlling the environment within a structure.

Background of the invention

[2] Structures such as buildings or vehicles, whether temporary or permanent, orbital or subterranean, are defined by walls or shells. The strength, thickness and material composition of these walls depend on the purpose of the structure They are often composed of several layers, the layers cooperating to provide, for example, the required strength, or particular thermal qualities. It is common for outermost and innermost layers to provide aesthetic qualities as well.

[3] Structures for occupation by humans or animals, and/or for the storage of certain kinds of objects, require an element of environmental control. This may include controlled lighting, humidity, temperature and/or ventilation. The number of systems that have been used and are in use to meet these needs around the world are too many to be counted. Thermal control, for example, is provided by central heating, underfloor heating wood-burning ovens, or air-conditioning units, to name but a few.

[004] Environmental control systems cost energy to run, and energy costs money. Furthermore, most sources of energy used in such systems are finite, and their exploitation is damaging to the environment. The need to reduce the energy cost of running environmental control systems is therefore constantly in the minds of those occupied with their design.

[005] It would be advantageous to combine the walls or shells of structures with a cladding system capable of providing environmental control to the structure which uses less energy than the prior art.

Statement of invention

10061 A first aspect of the invention provides cladding for a wall comprising an first face and an second, opposite face, and having a thermal reservoir disposed between the first face and the second face, wherein a first thermoelectric module is 5 disposed between the thermal reservoir and the first face.

1007] A source of electrical power may be connected across the first thermoelectric module. The source of electrical power may be one of: an electrical energy storage system, a mains supply, a photovoltaic system.

[8] The cladding may further comprise a controller, configured to control the source of electrical power to: apply a voltage of a first polarity across the first thermoelectric module; apply a voltage of a second polarity across the first thermoelectric module; apply no voltage across the first thermoelectric module.

[9] An electrical load may be connected across the first thermoelectric module. The electrical load may be an electrical energy storage system.

[010] The cladding may further comprise a second thermoelectric module disposed between the thermal reservoir and the second face. A source of electrical power may be connected across the second thermoelectric module. An electrical load may be connected across the second thermoelectric module.

[011] The thermal reservoir may comprise a thermally insulated reservoir of fluid.

[012] An airflow path may be provided between the first face and the second face. Airflow through the airflow path may be controllable by means of at least one impeller. The airflow path may be adjacent to and in thermal communication with the thermal reservoir.

[013] A second aspect of the invention provides a structure comprising a first 25 chamber and a second chamber, wherein the first chamber is in thermal communication with the external environment by means of a first thermoelectric module, and the second chamber is in thermal communication with the first chamber by means of a second thermoelectric module.

[14] A source of electrical power may be connected across the first thermoelectric module and the second thermoelectric module. The source of electrical power may be controllable to: apply a voltage of a first polarity across the first thermoelectric module; apply a voltage of a second polarity across the first thermoelectric module; or apply no voltage across the first thermoelectric module. The source of electrical power may be further controllable to apply: a voltage of a first polarity across the second thermoelectric module; apply a voltage of a second polarity across the second thermoelectric module; or apply no voltage across the second thermoelectric module.

[15] The structure may be a building or a vehicle. Brief description of drawings 10161 The invention will now be described, by way of example only, with 15 reference to the following drawings: [17] Figure 1 depicts various cladding elements, some comprising a thermal reservoir according to an embodiment of the invention; [18] Figure 2 depicts a cladding dement comprising a thermal reserve and an air reservoir according to an embodiment of the invention; [01 91 Figure 3 depicts various buildings according to embodiments of the invention; [20] Figure 4 depicts various vehicles according to embodiments of the invention; [21] Figure 5 depicts a thermoelectric module for use in embodiments of the 25 invention; [022] Figure 6 depicts an airflow module for use in embodiments of the invention.

Detailed description

10231 The invention provides a cladding system for a structure. Structures which might make use of the cladding of the invention include both temporary and permanent structures, as well as both static and mobile structures. For example, 5 the cladding of the invention could be used on buildings or vehicles.

10241 Buildings with which the cladding of the invention could be used include accommodation such as houses and flats, storage facilities, offices, factories, medical facilities such as hospitals, and secure installations such as military buildings and prisons.

10251 Vehicles with which the cladding of the invention could be used include cars, trucks, ships, planes, trains, helicopters, submarines, rockets, and spaces stations.

10261 Although in general the invention will be described as being applied to the walls of structures such as buildings, the invention can be used on floors, roofs and 15 ceilings, and any other perimeter of a structure or chamber within a structure.

10271 The cladding system of the invention could be integral to newly built structures, or could be retro-fitted to existing structures. In some embodiments, the cladding of the invention could form the fabric and structure of a complete new building, providing both the fabric of the building and its structural integrity.

In other embodiments, the cladding may form the fabric of the building while being built onto a frame which provides the structural integrity.

10281 When applied to a structure, the various embodiments of the cladding of the invention provide: heating and/or cooling; thermal insulation; air management and ventilation of a structure; and/or air-flow insulation. As will be described below, heating and cooling are provided by thermal reservoirs within the cladding, and thermoelectric modules. Air management and ventilation are provided by air reservoirs, fans, vents and ducts within the cladding.

[29] Examples of claddings systems of the invention can include: thermal cladding incorporating a thermal reservoir, which can insulate, heat, and/or cool a structure; an air management system incorporating an air reservoir, which can insulate and/or ventilate a structure (although such an air system on its own would fall outside the scope of the present invention); a combination of thermal cladding and an air manapFment system.

[30] There are two main aspects to the invention: a cladding panel comprising a thermal reservoir, and a structure comprising at least two chambers in thermal communication. These will be described in turn below, with reference to the figures. Figure la depicts a cladding panel which demonstrates the principles essential to both aspects of the invention, namely the transfer of heat from one side of a panel to the other side by means of a thermoelectric module. Figures lb, lc, 2, 3a and 4a depict embodiments of the first aspect of the invention, in which the thermal reservoir is provided in a cladding panel. Figures 3b, 3c, 4b and 4c depict embodiments of the second aspect of the invention, in which a thermal reservoir is provided by a chamber of the structure.

[31] Figure la depicts a simple cladding panel 10, having a single layer of insulating or barrier material 16, and a thermoelectric module 14. Although this panel lacks a thermal reservoir, it will be described to aid the understanding of the principles of the invention as they apply to the cladding panels of the first aspect of the invention, examples of which are depicted in Figures lb and lc.

[32] The cladding panel 10 can be formed in any conventional way. Cladding fabrics are typically made up of several different materials to provide strength, protection, support, security, weather-proofing, longevity and insulation, among other characteristics. For example, cladding can comprise metalwork, ceramics, brickwork, insulating filling, render, plaster, carbon, canvas, plastic, and various decorative finishes. Often cladding panels are finished both externally and internally to reflect their particular purpose.

[033] Active cladding according to the invention may incorporate insulation, membranes, barriers (e.g. for vapour), and other cladding materials, either on one side of the thermal reservoir or on both sides. Insulation and other elements may be depressurised, pressured, or in a state of vacuum.

[034] In the context of this specification, the term 'cladding' refers to any retrofit cladding panel, curtain wall, or any wall, ceiling, roofing or floor element, or any modular structural element which can be fitted with other elements to create a building or other structure (such as a vehicle). As will become clear, the invention incorporates a thermal reservoir within the cladding, and this can be within a retrofit cladding panel or built in to a wall, floor, ceiling or roof In a vehicle, the thermal reservoir could be between the external skin and the internal skin of the vehicle body.

[35] A preferred embodiment of the thermoelectric module 14 is shown in more detail in Figure 5. It comprises a thermoelectric semiconductor device 26, two 15 thermally conductive plates 28, disposed on respective opposing faces of the thermoelectric semiconductor device 26, and motorised fan impellers 30.

[36] The thermally conductive plates 28 may be made of metal, ceramic, or other thermally conductive material.

[37] The thermoelectric semiconductor 26 and the fan impellers are connected to 20 a source of electrical power, a control system and, preferably, an electrical energy storage system, depicted together at 32.

[38] The thermoelectric semiconductor 26 is capable of transferring heat by the Peltier method, or generating power by the Seebeck method. Such semiconductors are well known and used in a wide variety of fields. Applying a voltage across such a semiconductor creates a heat flux, drawing heat from one side and radiating heat (the radiated heat energy being converted from electrical energy with the semiconductor acting as a resistor). Reversing the polarity of the voltage reverses the direction of heat transfer. The higher the voltage, the greater the rate of heat transfer.

[39] Conversely, when a temperature differential exists across the opposing sides of such a semiconductor, heat energy is conducted from the warmer side to the 5 cooler side and electrical energy is generated in the semiconductor. The greater the temperature differential, the more electrical energy is generated.

[40] The thermally conductive plates 28 aid the transfer of heat to or from the thermoelectric semiconductor 26, acting as heat sinks or heat absorbers. To this end, they can be provided with ridges or fins, or be otherwise configured to increase their surface area exposed to the surrounding air. In some embodiments they could be hollow for fluids to flow within.

[41] The fan impellers 30 increase the transfer of heat between the surrounding air and the thermally conductive plates 28, by increasing the velocity of the surrounding air towards or away from the thermally conductive plates.

[042] In use, the cladding panel 10 will be interposed between a first chamber and a second chamber, or between a first chamber and the external environment. If it is desirable to increase the temperature in the first chamber, the control system can instruct the source of electrical power to cause a voltage to be applied across the thermoelectric semiconductor 26, the voltage having a polarity selected to cause the thermoelectric semiconductor 26 to absorb heat from the external environment or the second chamber, by way of the thermally conducting plate 28 exposed to the air in the external environment or second chamber. The absorbed heat will then be released into the first chamber, by way of the thermally conducting plate 28 exposed to the air in the first chamber. In this way, the temperature in the first chamber will be increased.

[043] It is understood that, due to inevitable inefficiencies in the system, not all heat that is absorbed from a first side will be released to the second side, but this will not be repeated throughout the specification, for the sake of brevity.

[44] Tf it is desirable to decrease the temperature in the first chamber, the system is controlled so that a voltage of opposite polarity is applied across the thermoelectric semiconductor 26, causing it to absorb heat from the first chamber by way of the thermally conducting plate 28 exposed to the air in the first chamber.

This heat will then be released into the second chamber or the external environment by way of the thermally conducting plate 28 exposed to the air in the external environment or second chamber.

[45] These examples illustrate a first aspect of the functioning of the invention. Embodiments of the invention are depicted in Figures lb and lc.

[046] Figure lb depicts a cladding panel 10 according to an embodiment of the invention. It comprises an external skin layer 18 and an internal skin layer 20. In use, and using the terminology of the previous example, the external skin layer 18 faces out into the external environment (or second chamber), and the internal skin layer 20 faces into the first chamber. Sandwiched between the external and internal skin layers 18 and 20 are insulation or barrier layers 16. Sandwiched between the insulation or barrier lavers 16 is a thermal reservoir 12.

[047] The external and internal faces 18,20 may each be formed of a single skin, or may be in the form of casings, which may be with packing material, empty but for air, or in a state of vacuum.

[048] Although the thermal reservoir 12 is depicted as sandwiched between outer layers of cladding 10, in some embodiments the extremities of the thermal reservoir 12 may form the external skin of the cladding 18, 20.

[049] The thermal reservoir 12 preferably extends across most of the area of the cladding panel 10. It provides an additional layer of insulation, wherein the insulation is provided by a layer of air, and the temperature of the air is controllable. Controlling the temperature of the air in the thermal reservoir 12 provides a degree of control over its insulating properties. It also enables the storage of thermal energy in warm air for later use, or the storage of cool air for absorbing heat energy at a later time, which may enable efficiencies which exploit the natural variation in ambient temperature, e.g. between the night and the day. It also enables the more efficient transfer of thermal energy from one side of the cladding panel 10 to the other, by providing an additional step to the heat transfer described in relation to Figure la. A stepped transfer of thermal energy is preferable, because if a thermoelectric module 14 is transferring heat from a cooler environment to a warmer environment, the energy cost of the transfer increases with the temperature difference.

[50] By way of example, an energy efficient stepped heat transfer using active cladding 10 of the invention might provide stepped controlled temperature profiles for the thermal reservoir 12 and the internal environment. In a cold environment, where it is 0 degrees Celsius outside, it might be preferable to control the temperature of the thermal reservoir 12 to be 15 degrees, and the temperature of the internal environment to be 22 degrees. In a warmer environment, where it is 40 degrees outside, it might be preferable to control the temperature of the thermal reservoir 12 to be 25 degrees and the internal environment to be 20 degrees.

[51] The active cladding 10 may incorporate a single thermal reservoir 12 or may incorporate a plurality of thermal reservoirs 12. The thermal reservoirs 12 may have any suitable configuration in the cladding 10, being disposed horizontally, vertically or in any suitable orientation and position. Although depicted as substantially planar and of constant thickness, the thermal reservoirs 12 may have other shapes. They may have varying thickness across length and/or width, they may be tubular or have other shapes, and they may further comprise a plurality of materials and sub-chambers.

[052] In many preferred embodiments, the fluid in the thermal reservoir 12 will be air. This is not necessary, however, since the thermal reservoir 12 does not usually have a fluid inlet/outlet. A different substance, such as a solid, phase-change material, liquid or a gas other than air, may be selected. The substance can be selected according to desired characteristics such as fluidity and specific heat capacity.

[53] Heat transfer between the first chamber and the second chamber or external environment is achieved by way of at least two thermoelectric modules 14 and the thermal reservoir 12. In the embodiment depicted in Figure lb, a single thermoelectric module 14 passes through the external skin 18 and the insulation or barrier material 16, between the external environment or second chamber, and the thermal reservoir 12, and a second single thermoelectric module 14 passes through the internal skin 20 and the insulation or barrier material 16, between the first chamber and the thermal reservoir. It will be clear to the person skilled in the art that more thermoelectric modules can be used, as long as at least one is provided on the internal side and at least one is provided on the external side. In some embodiments, there may only be a single thermoelectric module 14 in a cladding panel 10. This may be on either the internal side or the external side. Such embodiments may be useful, for example, when heat transfer between chambers, or between a chamber and the external environment, is not required, but temperature control of the thermal reservoir 12 is required, for example to control its insulating properties.

[54] The control, power and power storage units 32 are depicted adjacent to their respective thermoelectric modules 14, embedded in the insulation or barrier material 16. Compartments may be provided within the cladding panel 10 to accommodate them. In other embodiments, they may be remote from the thermoelectric modules 14, providing electrical coupling is somehow achieved. In some embodiments, one control, power and power storage unit 32 may be associated with multiple thermoelectric modules 14, or indeed with all thermoelectric modules 14 in a particular structure or system or structures.

[55] A temperature sensor 36 is provided in the thermal reservoir 12. This is in communication with at least one of, and preferably all of, the control, power and power storage units 32 associated with said thermal reservoir 12. In other embodiments, multiple sensors 36 are provided, and in some embodiments each control, power and power storage unit 32 has at least one sensor 36 associated with it. Other kinds of sensor may be used, in different locations and configurations, to feed into aspects of the control of the system according to specific requirements.

10561 In use, if it is desired to increase the temperature of the first chamber, the external side thermoelectric module 14 is controlled to absorb heat energy from the external environment or second chamber. heat energy is then released from the external side thermoelectric module 14 into the thermal reservoir 12, warming the air within the thermal reservoir 12. The internal side thermoelectric module 14 is simultaneously or subsequently controlled to absorb heat energy from the thermal reservoir 12, which is then released into the first chamber to increase the ambient temperature in the first chamber.

10571 In the embodiment depicted in Figure lb, the internal side thermoelectric module 14 and the external side thermoelectric module 14 are placed at opposing ends of the thermal reservoir 12, having individual respective control, power and power storage units 32. In such an embodiment, thermal energy will gradually spread through the thermal reservoir 12 from a first end to the second end by means of convection. The embodiment depicted in Figure lc is different, having the internal side and external side thermoelectric modules 14 placed at the same end of the thermal reservoir 12, sharing a single control, power and power storage unit 32. Thermal energy still gradually spreads from one thermoelectric module to the other by means of convection, because a membrane or baffle is interposed between the thermoelectric modules, bisecting most of the area of the thermal reservoir.

10581 Figure 2 depicts another embodiment of the invention, wherein the active cladding panel 10 comprises both a thermal management system as described above, and an airflow or ventilation management system.

[59] Sandwiched between the external and internal skin layers 18, 20 and the insulation or barrier material layers 16 are two reservoirs: a thermal reservoir 12 and an air reservoir 22. Tt will be appreciated that both reservoirs 12, 22 may contain air, but the thermal reservoir 12 is sealed and therefore not open to airflow 5 from the external environment, but is rather configured to transfer thermal energy to and from the external environment. Any of the thermal reservoirs which are built into the cladding panels of the invention may contain fluids other than air, such as other gases, or liquids. Alternatively, thermal reservoirs may contain solid materials, phase-change materials, or a mixture of materials. The composition of 10 the thermal reservoirs will be selected by the skilled person according to the specific conditions and requirements [60] The air reservoir 22 is similar to the thermal reservoir 12 as described above, insofar as it preferably extends across most of the area of the cladding panel 10, and so provides a thermally insulating barrier within the cladding panel 10. It provides ventilation or changes of air from one side of the cladding panel to the other, as will be explained in more detail below. It may comprise a membrane or baffle, bisecting most of its area, to control its internal airflow.

[61] The active cladding 10 may incorporate a single air reservoir 22 or may incorporate a plurality of air reservoirs 22. The air reservoirs 22 may have any suitable configuration in the cladding 10, being disposed horizontally, vertically or in any suitable orientation and position. Although depicted as substantially planar and of constant thickness, the air reservoirs 22 may have other shapes. They may have varying thickness across length and/or width, they may be tubular or have other shapes, and they may further comprise a plurality of materials and sub-chambers.

[62] A first airflow module 24 is disposed through the external skin 18 and insulation or barrier material 16, connecting the air reservoir 22 with the external environment (or second chanter, to use the exemplary terminology from previous examples). A second airflow module 24 is disposed through the internal skin 20 and the insulation or barrier material 16, connecting the air reservoir 22 with the internal environment on the other side of the panel 10 (or first chamber, to use the exemplary terminology from previous examples). In other embodiments, only one airflow module 24 may be provided.

[63] An example of an airflow module 24 is shown in more detail in Figure 6. The depicted airflow module comprises a duct housing a motorised fan. The impeller of the fan 30 drives airflow in either direction, depending on the direction of rotation of the motor 42. The motor 42 is controlled and powered by a control, power and power storage unit 32. Vents 38 are provided at each end of the duct, allowing air to pass into and out of the duct at each end.

[64] In use, if it is desired to inject fresh air into a first chamber from the external environment, the external side airflow module 24 draws air from the external environment into the air reservoir 22. The internal side airflow module 24 15 simultaneously or subsequently expels air into the chamber.

[65] Alternatively, if it is desirable to remove condensation and/or air from a first chamber to the external environment, the internal side airflow module 24 will draw air into the air reservoir 22. Simultaneously or subsequently, the external side airflow module 24 will expel air from the air reservoir 22 to the external environment.

[66] It will be appreciated that some airflow will occur without the assistance of the impeller 30. This will depend on the air pressure within the air reservoir 22 and on both sides of the cladding 10. It will also depend on the configuration of the vents 38.

[067] It will also be appreciated that, although the described example of an airflow module 24 has a motorised fan and impeller system, there are many other ways of generating airflow. The skilled addressee will understand that any suitable device for causing a change in air pressure or the flow of air can be used with the invention.

[68] The vents may have any conventional configuration. They may be completely open, although this is not a preferred arrangement because of the ingress of debris or even security risks depending on the size of the vents. They may be covered with gratings, or may be louvred, for example Other suitable closure means will be apparent to the skilled person.

[69] At least one airflow sensor 37 is provided within the air reservoir 22. The control, power and power supply unit 32 receives readings from the sensor(s) 37, and these readings may be fed into the control of the airflow modules 24. Humidity sensors and other sensors which may feed into efficient air control may also be provided.

[70] The embodiment depicted in Figure 2 shows the air reservoir 22 and the thermal reservoir 12 adjacent to one another depth-wise through the panel 10. It will be clear that they may have other configurations. For example, they may be adjacent width-wise or height-wise, or be separated by other features such as an additional layer of insulation or barrier material. 'Fhe depicted embodiment is preferable, however, because there are advantages to maximising the surface area of the adjoining surfaces between the two reservoirs 12, 22. Since the adjoining surface cannot be made from a perfect thermal insulator, there will inevitably be some heat exchange between the thermal reservoir 12 and the air reservoir 22. This may provide additional heating or cooling, depending on the circumstances, to the air in the thermal reservoir 12. In some circumstances, for example, it may be desirable to warm or cool the air in the air reservoir 22, for example for purposes related to controlled insulation. It may also be advantageous to have another heat source or heat sink for the therrnal reservoir 12, provided by the air reservoir 22.

[071] Tf it is desired to increase the surface area of the adjoining surfaces of the two reservoirs 12, 22 still further, they can be formed of thinner, interleaved subsections, or otherwise configured to increase their common surface area.

[0721 It may also be desirable to provide a cladding panel 10 with only an air reservoir 22 and airflow modules 24, without a thermal reservoir 12 and thermoelectric modules 14. Such active cladding would be useful in structures which require ventilation but not thermal control, or which have other means to provide thermal control. Cladding of this kind, however, falls outside the scope of the present invention.

[0731 As has been discussed already, the thermoelectric modules 14 and the airflow modules 24 are controlled by control units 32. The control units 32 may be adjacent to or remote from their respective modules 14, 24. The control units 32 may be directly connected to their respective modules 14, 24, or may be in wireless communication. The control units 32 may also provide the power supply and/or power storage circuitry, or this may be housed separately. There may be an individual control unit 32 for each module 14, 24, or a single control unit 32 may control a plurality of modules 14, 24. The active cladding system of a whole structure may be controlled by a single control unit 32. All modules 14, 24 in an active cladding system may be controlled together, or smaller sub-systems of modules 14, 24 may be controlled together, or each module 14, 24 may be controlled independently.

[074] Electrical power supply circuitry is connected to each module 14, 24. The power supply circuitry can be switched to apply voltage across each module 14, 24 with a first polarity or a second polarity, and can also be switched to apply no voltage. The electrical power can be provided from a mains source, from a renewable source such as a photovoltaic panel, or from an energy storage system such as a battery or super-capacitor. The electrical power can be provided from more than one source. The power supply circuitry will include all necessary conversion circuitry.

[075] The power supply circuitry may be remote from the modules 14, 24, or adjacent to each module 14, 24. Multiple modules 14, 24 may be connected to the 5 same power supply circuitry.

10761 Preferably, an electrical energy storage system is connected to some or all of the modules 14, 24. The electrical energy storage systems may be switchable between providing power to the power supply circuitry and receiving power from the modules 14, 24 if the modules 14, 24 are in an electrical energy generating mode. The electrical energy storage systems may also be disconnectable from both the modules 14, 24 and the power supply circuitry. The electrical energy storage systems may be connected to other loads within a structure, such as electric lighting or refrigeration systems. A single energy storage system may be provided for multiple modules 14, 24 and/or multiple power supply circuits. Alternatively, each module 14, 24 and/or each power supply circuit may have its own electrical energy storage system. In systems with a plurality of electrical energy storages systems, control circuitry may be provided to enable the transfer of electrical energy between different electrical energy storage systems. The electrical energy storage system may incorporate at least one battery or super-capacitor. Other electrical energy storage systems are well known to those skilled in the art.

10771 I bach thermoelectric module 14 is controllable in three modes: heat transfer in a first direction by applying a voltage of a first polarity across the thermoelectric semiconductor 26; heat transfer in a second direction by applying a voltage of a second polarity across the thermoelectric semiconductor 26; generation of electrical power by connecting an electrical load, such as battery or super-capacitor, across the thermoelectric semiconductor 26 when a temperature difference exists across the semiconductor 26. This functionality may be used to provide a control strategy in which the thermoelectric modules 14 are switched between different modes to achieve and regulate a desired internal temperature, while reclaiming any excess energy through electrical generation in the presence of a temperature differential. Thermoelectric modules 14 can be programmed manually. Alternatively, switching may be effected by a controller, optionally based on signals received from thermostats or other sensors or input devices. There may be some operating conditions in which some thermoelectric modules 14 are used to transfer heat energy, while others are used to generate electricity, at the same time [78] Each airflow module 24 is controllable in four modes: airflow generation in a first direction by applying a voltage across the motor 42 in a first direction; airflow generation in a second direction by applying a voltage across the motor 42 in a second direction; an inactive mode in which no voltage is applied across the motor 42; and an electrical generation mode in which an electrical load, such as a battery or super-capacitor, is connected across the motor 42 (in embodiments in which the motor is configured to act as a motor/generator) when an air pressure difference exists across the impeller 30.

[79] The embodiments depicted so far provide discrete cladding panels 10 with enclosed reservoir 12, 22 systems. It may be desirable to create an active cladding system for a structure in which the reservoirs 12, 22 of adjacent cladding panels 10 are in fluid communication. Suitable ducts and sealing arrangements can be provided around the edges of such cladding panels, as will be clear to a person skilled in the art.

[80] In some embodiments, cross ventilation can be achieved within a structure by setting some internal side airflow modules 24 to draw air into their respective air reservoirs 22, and setting others to expel air. For example, fresh air may be desired in a living room of a house at the same time as the removal of condensation is desired from a bathroom or kitchen.

[081] In some embodiments, it may be preferable to design a system of active cladding to take advantage of the external conditions particular to the location. In some areas, the external environment surrounding a structure may be relatively cool and/or dry, whereas in other areas the external environment may be relatively warm and/or humid. The purpose of the structure or chamber may also impact the characteristics of the internal environment. A design profile that best achieves one or several goals may be pursued when installing an active cladding system according to the invention.

[82] For example, in a cool environment, it may be preferable for heat to be introduced to structures or chambers within structures by thermoelectric modules at ceiling level, while cooler air is removed by airflow modules at floor level.

Alternatively, in rooms with high humidity, such as bathrooms or kitchens, it may be preferable to introduce heat at a low level and extract air at a higher level.

[83] A coordinated system of temperature management, air management, and insulation, will enable an optimum internal environment. With active cladding warming or cooling the internal environment of a structure and improving the structure's insulation with at least one laver of warm or cool air in the thermal reservoir (and/or air reservoir), the optimtun environment can be maintained at a lower cost due to reduced losses.

[84] The depicted embodiments provide a single thermal reservoir 12, thermally coupled to the environment on either side of the cladding panel by means of thermoelectric modules 14. In some embodiments it may be preferable to have a plurality of depth-wise adjacent thermal reservoirs 12, with additional thermoelectric modules 14 coupling each adjacent reservoir 12. This may provide additional efficiencies by providing additional steps to a stepped heat transfer process.

[085] More examples of the invention, in particular as it applies to buildings, are shown in Figures 3a to 3c.

[086] Figure 3a depicts a simple structure with a single internal chamber, wherein the walls of the chamber are formed by an active cladding system 10 of the first aspect of the invention. Thermoelectric modules 14 transfer air between the external environment and the internal environment by way of a thermal reservoir 12 within the walls. A door is depicted through the walls, providing access to the chamber.

[087] Figure 3b discloses an alternative embodiment for a structure having an inner chamber entirely enclosed within an outer chamber. In this example, the outer chamber forms the thermal reservoir 12, and heat is transferred by means of thermoelectric modules 14 between the external environment, the external chamber 12 and the internal chamber. The chambers can be separated by panels such as that depicted in Figure la, since a thermal reservoir is not needed in the panel, being provided as it is by the chambers themselves.

[88] Figure 3c discloses a different embodiment having two adjacent chambers not connected by a door, wherein the first chamber acts as a thermal reservoir and heat is transferred between the external environment, the first chamber 12, and the second chamber by means of thermoelectric modules 14, which may be provided in panels such as that depicted in Figure la. Both chambers are openable to the external environment by means of respective doors.

[89] Alternative embodiments in buildings are possible, with chambers of any configuration. For example, structures may incorporate the invention with multiple chambers which are either partially or fully enclosed. In some embodiments, chambers may be within other chambers. Depending on the environment and use of a given structure incorporating the invention, the chambers may contain-fluids other than air, or other materials including solids and phase-change materials.

[090] More examples of the invention, in particular as it applies to vehicles, are shown in Figures 4a to 4c.

[091] Figure 4a depicts a simple vehicle structure with a single internal chamber, wherein the walls of the chamber are formed by an active cladding system 10 of the invention. Thermoelectric modules 14 transfer air between the external environment and the internal environment by way of a thermal reservoir 12 within the walls, which may be formed by panels of the first aspect of the invention. This figure might represent an ordinary car, for example, with an inner skin and an outer skin to the walls.

[92] Figure 4b discloses an alternative embodiment for a structure having an inner chamber entirely enclosed within an outer chamber. In this example, the outer chamber forms the thermal reservoir 12, and heat is transferred by means of thermoelectric modules 14 between the external environment, the external chamber 12 and the internal chamber, which may be provided by panels such as that depicted in Figure la.

[93] Figure 4c discloses a different embodiment having two adjacent chambers, wherein the first chamber acts as a thermal reservoir and heat is transferred between the external environment, the first chamber 12, and the second chamber by means of thermoelectric modules 14, which may be provided in panels such as that depicted in Figure la. This figure might represent, for example, a refrigerated lorry.

[94] Alternative embodiments in vehicles are possible, with compartments of any configuration. For example, vehicles may incorporate the invention with multiple compartments which are either partially or fully enclosed. In some embodiments, compartments may be within other compaitments. Depending on the environment and use of a given vehicle incorporating the invention, the compartments may contain fluids other than air, or other materials including solids and phase-change materials.

Ip95] Although the invention has been described with reference to a series of embodiments, the invention is not limited by the embodiments. The scope of the invention is determined by the claims.

Claims

Claims 1. Cladding for a wall comprising a first face and a second, opposite face, and having a thermal reservoir disposed between the first face and the second face, vvherein a first thermoelectric module is disposed between the thermal reservoir and the first face.
2. Cladding for a wall according to claim 1, having a source of electrical power connected across the first thermoelectric module.
3. Cladding for a wall according to claim 2, wherein the source of electrical power is one of: an electrical energy storage system, a mains supply, a photovoltaic 10 system.
4. Cladding for a wall according to claim 2 or claim 3, further comprising a controller, configured to control the source of electrical power to: apply a voltage of a first polarity across the first thermoelectric module; apply a voltage of a second polarity across the first thermoelectric module; apply no voltage across the first thermoelectric module.
5. Cladding for a wall according to any preceding claim, having an electrical load connected across the first thermoelectric module.
6. Cladding for a wall according to claim 5, wherein the electrical load is an electrical energy storage system.
7. Cladding for a wall according to any preceding claim, further comprising a second thermoelectric module disposed between the thermal reservoir and the second face.
8. Cladding for a wall according to claim 7, having a source of electrical power connected across the second thermoelectric module.
9. Cladding for a wall according to claim 7 or claim 8, having an electrical load connected across the second thermoelectric module.
111 Cladding for a wall according to any preceding claim, wherein the thermal reservoir comprises a thermally insulated reservoir of fluid.
11. Cladding for a wall according to any preceding claim, further comprising an airflow path between the first face and the second face.
12. Cladding for a wall according to claim 11, wherein airflow through the airflow path is controllable by means of at least one impeller.
13. Cladding for a wall according to claim 11 or claim 12, wherein the airflow path is adjacent to and in thermal communication with the thermal reservoir.
14. A structure comprising a first chamber and a second chamber, wherein the first chamber is in thermal communication with the external environment by means of a first thermoelectric module, and the second chamber is in thermal communication with the first chamber by means of a second thermoelectric module.
15. A structure according to claim 14 wherein a source of electrical power is 15 connected across the first thermoelectric module and the second thermoelectric module.
16. A structure according to claim 15 wherein the source of electrical power is controllable to: apply a voltage of a first polarity across the first thermoelectric module; apply a voltage of a second polarity across the first thermoelectric module; or apply no voltage across the first thermoelectric module; and wherein the source of electrical power is further controllable to apply: a voltage of a first polarity across the second thermoelectric module; apply a voltage of a second polarity across the second thermoelectric module; or apply no voltage across the second thermoelectric module.
17. A structure according to any one of claims 14 to 16, wherein the structure is a building.
18. A structure according to any one of claims 14 to 16, wherein the structure is a vehicle.