WO2025149674A1

WO2025149674A1 - Switchable building component

Info

Publication number: WO2025149674A1
Application number: PCT/EP2025/050696
Authority: WO
Inventors: Mervyn Smyth; Adrian PUGSLEY
Original assignee: Ulster University
Current assignee: Ulster University
Priority date: 2024-01-11
Filing date: 2025-01-13
Publication date: 2025-07-17
Anticipated expiration: 2026-07-11
Also published as: GB202400423D0

Abstract

A building component comprises: a first chamber locatable on or adjacent to an outer surface of a building or building element; a second chamber locatable on or adjacent to an inner surface of the building or building element; a two-phase working fluid comprising a gas-phase and a liquid-phase contained within the first chamber and/or the second chamber; at least one conduit configured to provide a path for the gas-phase of the working fluid to move between the first chamber and the second chamber; and at least one fluid transfer means configured to control transfer of the liquid-phase and/or the gas phase of the working fluid between the first chamber and the second chamber. The building component comprises an insulating configuration in which latent heat transfer between the first and second chambers is prevented or substantially prevented by the at least one fluid transfer means and at least one thermally conductive configuration in which latent heat transfer between the first and second chambers is permitted or substantially permitted by the at least one fluid transfer means. The at least one fluid transfer means has an inactive state in which transfer of the working fluid between the first and second chambers is prevented or substantially prevented and an active state in which transfer of the working fluid between the first and second chambers is permitted or substantially permitted. Switching the at least one fluid transfer means from the inactive state to the active state causes the building component to switch from the insulating configuration to the at least one thermally conductive configuration.

Description

SWITCHABLE BUILDING COMPONENT

The present application relates to a building component, particularly a switchable building component that has an insulating configuration and at least one thermally conductive configuration.

Background

The energy efficiency of a building determines the rate at which energy is lost through the building envelope. Buildings having lower energy efficiencies often require greater amounts of energy to ensure the physical comfort of the occupants. Many contemporary buildings exhibit low energy efficiency such that heating and cooling systems can often represent between 50% and 75% of the total energy demand. In many countries, increasing the energy efficiency of buildings forms an important part of efforts to combat climate change and achieve ‘net zero’ emissions.

Conventional approaches to reducing heat loss from buildings include providing appropriate insulation and/or making building envelopes more airtight. While such approaches can help to reduce heat loss during spells of colder weather, such approaches can lead to “trapped heat”, especially in buildings with large sun-facing windows or those having spaces used to host heat-generating occupant activities (e.g. gyms, kitchens, and densely occupied meeting rooms). In periods of warmer weather, such trapped heat can increase the energy demands on cooling systems and make buildings excessively warm and uninhabitable. This adverse effect can be referred to as “anti-insulation”, whereby increasing insulation performance of a building has the perverse effect of increasing (instead of reducing) the overall energy demand.

While the provision of shading, cooling, and ventilation systems in buildings can help to overcome overheating problems, such solutions will often significantly increase capital costs, increase overall energy demands, reduce the available space for other utilities, and increase the complexity of a building’s operation and maintenance. There exists a need for a way to effectively and appropriately control the transfer of heat by or through buildings. Summary of the Invention

According to a first aspect of the invention there is provided a building component comprising: a first chamber locatable on or adjacent to an outer surface of a building or building element; a second chamber locatable on or adjacent to an inner surface of the building or building element; a two-phase working fluid comprising a gasphase and a liquid-phase contained within the first chamber and/or the second chamber; at least one conduit configured to provide a path for the gas-phase of the working fluid to move between the first chamber and the second chamber; and at least one fluid transfer means configured to control transfer of the liquid-phase and/or the gas phase of the working fluid between the first chamber and the second chamber, wherein the building component comprises an insulating configuration in which latent heat transfer between the first and second chambers is prevented or substantially prevented by the at least one fluid transfer means, and wherein the building component comprises at least one thermally conductive configuration in which latent heat transfer between the first and second chambers is permitted or substantially permitted by the at least one fluid transfer means. Advantageously, the building component has a plurality of configurations with contrasting heat conducting properties, allowing selective transfer of heat, for example between the interior and exterior of a building.

Optionally the at least one fluid transfer means has an inactive state in which transfer of the working fluid between the first and second chambers is prevented or substantially prevented.

Optionally the at least one fluid transfer means has an active state in which transfer of the working fluid between the first and second chambers is permitted or substantially permitted.

Optionally switching the at least one fluid transfer means from the inactive state to the active state causes the building component to switch from the insulating configuration to the at least one thermally conductive configuration.

Optionally the first chamber and/or the second chamber comprises at least one planar surface. Advantageously, the or each planar surface can support further components to increase the effectiveness or utility of the building component, such as insulation or photovoltaic cells.

Optionally the or each planar surface is located on an outer surface of the building component. Advantageously, the or each planar surface is located in an accessible position.

Optionally at least one planar surface comprises a heat-absorber material.

Advantageously, the heat-absorber material can be used to absorb heat and/or solar radiation incident on a surface of the building component.

Optionally at least one planar surface comprises an evaporative capillary surface. Advantageously, the evaporative capillary surface can be used to insulate a surface of the building component.

Optionally at least one planar surface comprises one or more photovoltaic cells.

Advantageously, the photovoltaic cells can be used to generate electricity from solar radiation incident on the building component.

Optionally the first chamber and/or second chamber is formed of a first member and a second member.

Optionally at least one of the first member and the second member comprises a thermally conductive material, such as metal. Advantageously, the use of a thermally conductive material to form at least one of the first member and the second member ensures good thermal conductance of the first member and/or second member.

Optionally the first chamber and/or second chamber is formed of a first member and a second member, wherein at least one of the first member and the second member is a metal tray.

Optionally the second member is a metal tray or plate.

Optionally the first chamber and/or the second chamber comprises two pressed- metal trays sealably joined around the perimeters thereof. Advantageously, pressed- metal trays allow simple manufacture of the first and/or second members.

Optionally the second member is formed of a sheet of tempered glass or a glassglass encapsulated photovoltaic panel.

Optionally the first chamber and/or the second chamber comprise internal support means. Advantageously, the internal support means are configured to prevent collapse of the first and/or second chambers, in use.

Optionally the internal support means comprise pillar arrays, porous infill, interlocking lattice plates or mesh frameworks. Optionally the building component comprises fixing points for attaching the building component to a substrate or structure. Advantageously, the fixing points allow the building component to be easily attached to a substrate or structure.

Optionally a cavity is located between the first chamber and the second chamber. Advantageously, the cavity reduces the thermal coupling between the first chamber and the second chamber.

Optionally the building component comprises insulation means located in the cavity. Advantageously, the insulation means minimises the transfer of heat between the adjacent inner surfaces of the first chamber and the second chamber.

Optionally the cavity is partially or entirely filled with insulation means.

Optionally the working fluid is a saturatable fluid.

Optionally the working fluid is a non-toxic working fluid, such as a non-toxic working fluid comprising water and water vapour. Advantageously, the use of a non-toxic working fluid reduces the risk of contamination in the area immediately surrounding the building component, in use.

Optionally the building component is an enclosed system. Advantageously, the use of an enclosed system ensures that the amount of working fluid in the building component does not need to be adjusted, in use.

Optionally the building component is sealed or substantially sealed to prevent egress of the working fluid. Advantageously, sealing the building component provides an enclosed system which can support an evaporation-condensation cycle of the working fluid within the building component.

Optionally the building component comprises, or is in communication with, one or more sensing means. Advantageously, the operation of the building component can be based on the output of the sensing means.

Optionally the sensing means comprises one or more temperature sensors.

Advantageously, temperature sensors can be used to measure temperatures near the building component and/or the performance of the building component.

Optionally the sensing means comprises one or more optical sensors.

Advantageously, optical sensors can be used to measure the amount of light incident on the building component.

Optionally the sensing means comprises a plurality of sensors configured to measure temperature on opposing sides of the building component. Advantageously, a plurality of sensing means can be used to measure thermal conduction through the building component.

Optionally the sensing means comprises one or more optical sensors.

Optionally the sensors comprise at least one sensor configured to measure temperature at or adjacent to the first chamber.

Optionally the sensors comprise at least one sensor configured to measure temperature at or adjacent to the second chamber.

Optionally the at least one conduit comprises at least one pipe or plenum. Advantageously, the pipe or plenum is configured to allow vapour to pass between the first and second chambers.

Optionally the at least one conduit comprises a plurality of pipes.

Optionally the first and/or second chamber comprises a reservoir for the liquid-phase of the working fluid. Advantageously, working fluid can be stored one or both chambers, in use.

Optionally the lower part of each chamber functions as a reservoir for the liquid working fluid. By ‘lower’ it is meant lowermost, in use.

Optionally the lower part of the first and/or second chamber features a sloped section configured to collect condensed working fluid. Advantageously, condensed working fluid in the lower part of the chamber can be drained towards the fluid transfer means by the or each sloped section.

Optionally the fluid transfer means comprises a valving and/or pumping means. Advantageously, the valving and/or pumping means allows the amount of condensed working fluid in each chamber to be controlled.

Optionally the fluid transfer means comprises a bi-directional valving and/or pumping means. Advantageously, the bi-directional nature of the valving and/or pumping means allows condensed working fluid to be transferred from the first chamber to the second chamber, and vice versa, in use.

Optionally the building component comprises a plurality of thermally conductive configurations.

Optionally the building component comprises a first thermally conductive configuration in which heat is transferred from the first chamber to the second chamber. Advantageously, in the first thermally conductive configuration the building component is able to transfer heat from e.g. the outside of a building to the inside of a building. Optionally the building component comprises a second thermally conductive configuration in which heat is transferred from the second chamber to the first chamber. Advantageously, in the second thermally conductive configuration the building component is able to transfer heat from e.g. the inside of a building to the outside of a building.

Optionally the building component comprises a wetting means. Advantageously, the wetting means is able to alter the thermal conducting properties of the building component.

Optionally the wetting means is configured to wet an internal or external surface of the building component with working fluid.

Optionally the wetting means comprises a capillary wicking arrangement, an evaporative falling film and/or a spray nozzle arrangement.

Optionally the building component comprises a vapour control valve.

Optionally the vapour control valve is configured to control transfer of gas between the first chamber and the second chamber.

Optionally the vapour control valve can be in an open configuration in which transfer of gas between the chambers is permitted.

Optionally the vapour control valve can be in a closed configuration in which transfer of gas between the chambers is prevented.

Optionally the building component comprises a cover member.

Optionally the building component comprises a transparent cover member. Optionally the cover member covers the outside surface of the building component. Optionally the cover member is attached to the first chamber via a cover member support.

Optionally a gap is formed between the cover member and the first chamber.

Optionally a gap is formed between the cover member and the outer surface of the first chamber. Advantageously, the transparent cover and gap improve the solar heat collection performance during windy and cold weather conditions when the device is operating to supply heat into a building (e.g. in winter).

Optionally the gap is sealed.

Optionally the building component comprises one or more shading elements. Optionally the or each shading element is formed of an opaque material.

Optionally at least one shading element extends in a direction which is perpendicular or parallel to the first chamber. Optionally at least one shading element extends in a direction which is perpendicular or parallel to the outer surface of the first chamber.

Optionally at least one shading element extends in a direction which is perpendicular or parallel to the plane of the outer surface of the first chamber.

Optionally the angle between each shading element and the outer surface of the first chamber is 90 degrees or less.

Optionally the or each shading element may include a photovoltaic panel. Optionally the building component comprises an airflow separator. Advantageously, the airflow separator prevents unwanted recirculation of exhausted hot air in cases where the building component is deployed in an array with other similar devices. Optionally the airflow separator is configured to deflect a heated airflow. Optionally the building component comprises a misting device.

Optionally the misting device is attached to the first chamber.

Optionally the misting device is configured to create a water mist or water film in the vicinity of the first chamber. Advantageously, the water mist or water film produced by the misting device through phase change acts to absorb heat and reduce the ambient air temperature in the vicinity of the outside surface of the first chamber, so that heat transfer is increased when the building component is operating to reject heat out of a building (e.g. in summer).

Optionally the misting device is configured to create a water mist or water film in the vicinity of the outside surface of the first chamber.

According to a further aspect of the invention there is provided a method of controlling the transfer of heat between the interior and exterior of a building or building element, the method comprising: providing a building component according to any preceding claim; operating the building component in the insulating configuration or in the at least one thermally conductive configuration to control the transfer of heat between the interior and exterior of the building or building element. Advantageously, the method allows the transfer of heat by or through a building or building element to be controlled.

Optionally operating the building component comprises: operating the building component in the insulating configuration such that the transfer of heat through the building component is prevented or substantially prevented. Advantageously, in the insulating configuration the building component can reduce the transfer of heat into or out of the building envelope.

Optionally operating the building component comprises: operating the building component in the at least one thermally conductive configuration such that the transfer of heat through the building component is permitted or substantially permitted. Advantageously, in the at least one thermally conductive configuration the building component can increase the transfer of heat into or out of the building envelope.

According to a further aspect of the invention there is provided a building comprising a building component. Advantageously, the building component allows the transfer of heat by or through the building to be controlled.

Optionally the building component is coupled to a building element of the building. Optionally the building element is a thermal storage element such as a masonry wall or water storage tank.

Optionally the building component is arranged such that the first chamber is located on or adjacent to an outer surface of the building and the second chamber is located on or adjacent to an inner surface of the building. Advantageously, the building component being located on or adjacent to an outer surface or an inner surface of the building envelope allows the thermal conductance of the building envelope to be adjusted in accordance with user preferences.

Optionally the building component is arranged to control the transfer of heat between the interior and exterior of the building.

Optionally the building comprises a plurality of building components.

Optionally the plurality of building components are arranged in an array.

Optionally the building comprises a plurality of building components mounted on the building.

Optionally the plurality of building components are arranged in an edge-to-edge configuration.

Optionally the plurality of building components are independently operatable. Optionally the building comprises a plurality of modular building components. Optionally the plurality of building components are mounted such that they are arranged in parallel. By “arranged in parallel” it is meant that the plurality of building components are physically arranged or mounted such that the outer planar faces of each of the building components are parallel or substantially parallel and the outer planar faces of the building components collectively define a plane.

Any feature or features described in relation to any aspect, embodiment or example may be combined with any one or more features of any other aspect, embodiment or example.

Brief Description of the Drawings

The invention will be described by way of example only referring to the figures, in which:

Figure 1 shows a perspective view of a building component according to an embodiment of the invention.

Figure 2 shows a cross sectional view of the building component of figure 1 in an insulating configuration.

Figure 3 shows a cross sectional view of the building component of figure 1 in a thermally conductive configuration.

Figure 4 shows a cross sectional view of the building component of figure 1 in a further thermally conductive configuration.

Figure 5 shows a schematic view of a method according to an embodiment of the invention.

Figure 6 shows a cross sectional view of a building according to an embodiment of the invention.

Figure 7 shows a cross sectional view of a building component according to an embodiment of the invention.

Figure 8 shows a cross sectional view of a building component according to an embodiment of the invention.

Figure 9 shows cross sectional views of a part of the building component of figure 8. Figure 10 shows a cross sectional view of a building component according to an embodiment of the invention.

Figure 11 shows a cross sectional view of the building component of figure 10. Figure 12 shows a cross sectional view of a building component according to an embodiment of the invention.

Figure 13 shows a cross sectional view of a building component according to an embodiment of the invention.

Figure 14 shows a cross sectional view of a building component according to an embodiment of the invention.

Figure 15 shows a cross sectional view of a building component according to an embodiment of the invention.

Figure 16 shows a cross sectional view of a building component according to an embodiment of the invention.

Detailed Description

In figure 1 there is shown a building component 1 according to an embodiment of the invention. The building component 1 comprises a first chamber 2 locatable on or adjacent to an outer surface of a building or building element and a second chamber 4 locatable on or adjacent to an inner surface of the building or building element. A two-phase working fluid 6 comprising a gas-phase 6a and a liquid-phase 6b (see figure 2) is contained within the first chamber 2 and/or the second chamber 4. Conduits in the form of pipes 8 provide a path for the gas-phase 6a of the working fluid 6 to move between the first chamber 2 and the second chamber 4. At least one fluid transfer arrangement 10 is configured to control transfer of the liquid-phase 6b and/or gas phase 6a of the working fluid 6 between the first chamber 2 and the second chamber 4.

In use, the building component 1 can be employed in a building or building element as a switchable thermal insulation element. The building component 1 has a plurality of configurations with contrasting heat conducting properties to allow selective transfer of heat, for example between the interior and exterior of a building or building envelope.

The building component 1 comprises an insulating configuration in which latent heat transfer between the first and second chambers 2, 4 is prevented or substantially prevented. The insulating configuration may be the default configuration. By ‘substantially prevented’ it is meant that in the insulating configuration the building component 1 will have at least some minimum thermal conductance and therefore at least some minimal amount of heat will still be able to pass through the building component 1 in this configuration. The building component 1 comprises at least one thermally conductive configuration in which latent heat transfer between the first and second chambers 2, 4 is permitted or substantially permitted. By ‘substantially permitted’ it is meant that more heat will be transferred through the building component 1 in the (or each) thermally conductive configuration compared to when the building component 1 is in the insulating configuration. For example, more than twice as much heat may be transferred through the building component 1 in the (or each) thermally conductive configuration compared to the insulating configuration. The conductance of the building component 1 in the (or each) thermally conductive configuration may be at least twice as much, or at least 10 times as much, or at least 100 times as much as the conductance of the building component 1 in the insulating configuration.

The at least one fluid transfer arrangement 10 has an inactive state in which transfer of the working fluid between the first and second chambers 2, 4 is prevented or substantially prevented and an active state in which transfer of the working fluid between the first and second chambers 2 ,4 is permitted or substantially permitted. Switching the at least one fluid transfer arrangement 10 from the inactive state to the active state causes the building component 1 to switch from the insulating configuration to the at least one thermally conductive configuration. The switching process may be initiated by a simple local controller such as a bi-metallic thermostat or thermofluid-filled piston which actuates e.g. a valve or pump of the at least one fluid transfer arrangement 10 (for example via a relay or thermostatic switch). An electronic controller such as a multi-channel programmable Building Management System may trigger such electric valve actuator(s) and/or pump relay(s) of the at least one fluid transfer arrangement 10.

As shown in figure 1 , the first chamber 2 comprises an outer planar surface 22. The second chamber 4 also comprises an outer planar surface 42 on the opposite side of the building component 1 . The first chamber 2 further comprises an inner planar surface 24 on the opposite side of the first chamber 2 to the outer planar surface 22. The second chamber 4 further comprises an inner planar surface 44 on the opposite side of the second chamber 4 to the outer planar surface 42. The outer planar surfaces 22, 42 are each located on an outer surfaces of the building component 1 i.e. in an accessible position. The inner planar surfaces 24, 44 are located on inner surfaces of the building component 1 and face each other.

Each planar surface 22, 24, 42, 44 can support further components to increase the effectiveness or utility of the building component 1 such as photovoltaic cells, a heatabsorber material, or insulation such as an evaporative capillary surface. The outer surfaces 22, 42 may comprise PV, absorptive coatings or wetting mechanisms. The inner surfaces 24, 44 may comprise insulation or thermal storage. The inner surfaces 24, 44 may comprise or abut insulation or thermal storage, either with or without a cavity therein. In examples, heat-absorber material provided on the outer planar surfaces 22, 42 can be used to absorb heat and/or solar radiation incident on the building component 1 . Alternatively or additionally, photovoltaic cells can be used to generate electricity from solar radiation incident on the outer planar surfaces 22, 42 of the building component 1. Alternatively or additionally, insulation can be used to reduce the radiation of heat from the planar surfaces 24, 44 where necessary.

The first chamber 2 and second chamber 4 each have a similar construction. Each chamber 2, 4 is formed of a first member and a second member. In an example, each first member and each second member comprises a thermally conductive material, such as a metal tray or plate. The use of a thermally conductive material ensures good thermal conductance of the first and second chambers. In the present example, each of the first chamber 2 and the second chamber 4 comprises two pressed-metal trays sealably joined around the perimeters thereof. Pressed-metal trays allow simple manufacture of the building component 1 . In optional embodiments, the second member of the first chamber 2 is formed of a sheet of tempered glass or a glass-glass encapsulated photovoltaic panel, to facilitate the generation of electricity from solar radiation incident on the planar surfaces 22.

As shown in the cross-sectional view of figure 2, each of the first chamber 2 and the second chamber 4 comprise internal support arrangements 28, 48 located on the inside of the respective chambers 2, 4. The internal support arrangements 28, 48 extend between the opposing interior surfaces of the chambers 2, 4 and are configured to prevent collapse of the first and/or second chambers 2, 4, in use, while allowing the working fluid to move through each chamber. In some embodiments the internal support arrangements 28, 48 comprise pillar arrays. In other embodiments porous infill, interlocking lattice plates or mesh frameworks can be used to provide internal support to the chambers 2, 4. The internal support arrangements 28, 48 may take a variety of different forms, can be constructed from a variety of different materials (metal, glass, ceramics, plastics) and arranged in a way which generally minimises conductive, convective, and radiative heat transfer through the panel whilst also resisting implosion forces acting upon the outer shell due to vacuum-to- atmosphere pressure differences (~100kPa).

A cavity 12 is located between the first chamber 2 and the second chamber 4, and between the inner planar surfaces 24, 44. The cavity 12 reduces the thermal coupling between the first chamber 2 and the second chamber 4 so that heat is less easily transferred between the inner planar surfaces 24, 44. In some examples the building component 1 comprises insulation 14, such as expanded foam insulation, located in the cavity 12. The insulation 14 minimises the transfer of heat between the adjacent inner surfaces 24, 44 of first chamber 2 and the second chamber 4. In embodiments the cavity 12 can be partially or entirely filled with insulation. The insulation may be any suitable insulation having a suitable fire rating.

In the present embodiment, conduits in the form of three pipes 8 provide paths for the gas-phase 6a of the working fluid 6 to move between the first chamber 2 and the second chamber 4, in use. In optional embodiments more or fewer pipes or conduits may be used, for example a single pipe or plenum may provide the path for the gasphase vapour 6a to pass between the chambers 2, 4. Use of a single pipe or plenum simplifies the construction and installation of the device. The or each pipe or plenum may include a valve to control transfer of gas therethrough.

In the present embodiment, the fluid transfer arrangement 10 comprises a valving and/or pumping arrangement which is configured to selectively transfer liquid-phase 6b of the working fluid 6 between the first chamber 2 and the second chamber 4. In other embodiments, the fluid transfer arrangement 10 may additionally or alternatively comprise a valving and/or pumping arrangement which is configured to selectively transfer gas-phase 6a of the working fluid 6 between the first chamber 2 and the second chamber 4. In such other embodiments, the fluid transfer arrangement 10 may include a valving and/or pumping arrangement which is configured to control e.g. the transfer of gas-phase 6a of the working fluid 6 through the conduits/pipes 8.

In use, the amount of condensed working fluid 6b in each chamber 2, 4 can be controlled by the fluid transfer arrangement 10. The fluid transfer arrangement 10 comprises a bi-directional valving or pumping arrangement. The bi-directional nature of the valving and/or pumping arrangement allows condensed working fluid to be transferred from the first chamber 2 to the second chamber 4, and vice versa, in use. The building component 1 may comprise a power supply 16, such as batteries or a photovoltaic cell, to provide electrical power to the fluid transfer arrangement 10.

The fluid transfer arrangement 10 may be controlled by a central control unit, for example an electronic controller such as a multi-channel programmable Building Management System. The building component 1 may be in communication with the central control unit via a wired or wireless connection. The building component 1 may comprise a sensor arrangement 18, such as a plurality of temperature or light sensors, on which the operation of the fluid transfer arrangement 10 may be based. The sensor arrangement 18 may be build into the panel, or may be provided remotely from the building component 1 .

The central control unit may be used to remotely control one or more building components 1 according to a control strategy. A variety of different control strategies can be implemented by the control unit including rule-based approaches. For example, switching between states may be triggered by indoor/outdoor temperature differences, temperature setpoints, and/or user-interactive controls. Intelligent predictive approaches may be used such as Model Predictive Control and Receding Horizon Control based upon a variety of different sensory inputs (for example temperature, solar irradiance, and building occupancy sensors). The central control unit may control the operation of the building component 1 based on a stimulus, for example internal or external temperatures as measured by one or more sensors. In an example, one or more remote temperature sensors may be used to control a plurality of building components 1 . Such sensors may be remote from the building components 1 and located e.g. on the exterior and/or interior of a building. Alternatively, one or more temperature or light sensors may be built into each building component 1 , and the central control unit may control each individual building component 1 based on the output of these local sensors. Messages and/or control signals may be sent from the central control unit to the or each building component 1 via a wired or wireless connection.

In use, working fluid 6 is contained within the building component and is able to pass between the chambers 2, 4 around a circuit via the fluid transfer arrangement 10 and the conduits/pipes 8. The working fluid is a non-toxic saturatable working fluid comprising water and water vapour. The use of a non-toxic working fluid such as water/water vapour reduces the risk of contamination in the area immediately surrounding the building component 1 , in use.

The building component 1 is sealed or substantially sealed to prevent egress of the working fluid 6. Sealing the building component 1 provides an enclosed system which can support an evaporation-condensation cycle of the working fluid 6 within the building component 1. The pressure inside the building component, i.e. inside the chambers 2, 4, is less than atmospheric pressure, for example by as much as 100 kPa. The building component 1 is an enclosed system, which ensures that the amount of working fluid in the building component 1 does not need to be adjusted, in use.

As shown in figures 2 to 4, the first and second chambers 2, 4 are able to retain and store the liquid phase 6b of the working fluid 6. In use, the lower parts of each respective chamber 2, 4 act as a reservoir for the liquid-phase 6b of the working fluid 6. By ‘lower part’ it is meant the lowermost in use part of the respective chambers 2, 4. The lower part of each respective chamber 2, 4 features a sloped section 26, 46 configured to collect condensed working fluid 6b and drain said condensed working fluid 6b towards the fluid transfer arrangement 10. The lower part of each respective chamber 2, 4 may alternatively extend in a longitudinal direction.

The building component 1 comprises an insulating configuration (figure 2) in which latent heat transfer between the first and second chambers 2, 4 is prevented or substantially prevented and at least one thermally conductive configuration in which latent heat transfer between the first and second chambers 2, 4 is permitted or substantially permitted. In the present embodiment the building component 1 comprises a plurality of thermally conductive configurations. The building component 1 comprises a first thermally conductive configuration (figure 3) in which heat can be transferred from the first chamber 2 to the second chamber 4, in use. The building component 1 comprises a second thermally conductive configuration (figure 4) in which heat can be transferred from the second chamber 4 to the first chamber 2, in use.

In the insulating configuration, shown in figure 2, the building component 1 is configured to reduce the transfer of heat through the building component 1 and between the first chamber 2 and the second chamber 4. In particular, in this configuration the fluid transfer arrangement 10 does not permit movement of the liquid phase 6b of the working fluid 6 between the chambers 2, 4. Since the fluid transfer arrangement 10 does not permit movement of the liquid phase 6b of the working fluid 6 between the chambers 2, 4, an evaporation-condensation cycle of the two-phase working fluid cannot take place. Therefore heat in the first chamber 4 is less easily transferred to the second chamber 4. Therefore the building component, in this state, is generally more insulating.

In the example of figure 2 the first and second chambers 2, 4 contain equal amounts of liquid phase 6b of the working fluid 6. However, as will be appreciated more or less liquid phase 6b of the working fluid 6 may be contained in the first or second chamber 2, 4, depending on the conditions of the building component 1. For example, the building component 1 , whilst in the insulating configuration, may be in an initial state in which the chambers 2, 4 contain equal amounts of liquid phase 6b. If the first chamber 2 is exposed to heat, then some of the liquid phase 6b in the first chamber 2 may evaporate, exit the first chamber 2 via the conduits/pipes 8 and enter the second chamber 4 where it will condense. In this case, the amount of liquid phase 6b in the second chamber 4 will increase. The amount of liquid phase 6b in the first chamber 4 will decrease because the fluid transfer arrangement 10 does not permit return of the liquid phase 6b from the second chamber 4 into the first chamber 2. The process may continue until substantially all of the liquid phase 6b in the first chamber 2 evaporates, at which point the ability of the building component 1 to transfer heat from the first chamber 2 to the second chamber 4 will be minimal.

Figure 3 shows the building component 1 in the first thermally conductive configuration. In the first thermally conductive configuration the building component 1 is configured to enable the transfer of heat between the first chamber 2 and the second chamber 4. In particular, the building component 1 is configured to enable the transfer of heat from the (relatively warmer) first chamber 2 to the (relatively cooler) second chamber 4. In the first thermally conductive configuration, the fluid transfer arrangement 10 is configured to cause/permit movement of the liquid phase 6b of the working fluid 6 from the second chamber 4 to the first chamber 2, while the conduit 8 allows movement of the gas phase 6a of the working fluid 6 from the first chamber 2 to the second chamber 4. In the example shown in figure 3, the second chamber 4 contains more liquid phase 6b of the working fluid 6 than the first chamber 2 due to the action of the fluid transfer arrangement 10.

In use, when the building component 1 is in the first thermally conductive configuration, heating the first chamber 2 (e.g. by exposing the outer planar surface 22 to solar radiation) causes the first chamber 2 to heat up and the liquid phase 6b of the working fluid 6 in the first chamber 2 to enter a gas phase 6a (i.e. evaporate). The gas phase 6a travels towards the top of the first chamber 2 and moves into the second chamber 4 via the conduits/pipes 8. The gas phase 6a which enters the second chamber 4 returns to liquid phase 6b (i.e. condenses) on contact with the inner surfaces of the relatively cooler second chamber 4. The condensed liquid phase 6b in the second chamber 4 moves towards the fluid transfer arrangement 10 by draining along the inner walls and the sloped section 46 of second chamber 4. The fluid transfer arrangement 10 returns the condensed liquid phase 6a to the first chamber 2 in order to restart the cycle. In the first thermally conductive configuration, the building component 1 can be used to transfer heat from e.g. the outside of a building (adjacent to the first chamber 2) to the inside of a building (adjacent to the second chamber 4).

Figure 4 shows the building component 1 in the second thermally conductive configuration. In the second thermally conductive configuration the fluid transfer arrangement 10 is configured to cause/permit movement of the liquid phase 6b of the working fluid 6 from the first chamber 2 to the second chamber 4. In the example shown in figure 4, the first chamber 2 contains more liquid phase 6b of the working fluid 6 than the second chamber 4 due to the action of the fluid transfer arrangement 10.

In use, when the building component 1 is in the second thermally conductive configuration, heating the second chamber 4 (e.g. by exposing the outer planar surface 42 to a warm room) causes the second chamber 4 to heat up and the liquid phase 6b of the working fluid 6 in the second chamber 4 to enter a gas phase 6a (i.e. evaporate). The gas phase 6a travels towards the top of the second chamber 4 and moves into the first chamber 2 via the conduits/pipes 8. The gas phase 6a which enters the first chamber 2 returns to the liquid phase 6b (i.e. condenses) on contact with the inner surfaces of the relatively cooler first chamber 2. The condensed liquid phase 6a in the first chamber 2 moves towards the fluid transfer arrangement 10 by draining along the inner walls and the sloped section 26 of first chamber 2. The fluid transfer arrangement 10 returns the condensed liquid phase 6a to the second chamber 4 in order to restart the cycle. In the second thermally conductive configuration, the building component 1 can be used to transfer heat from e.g. the inside of a building (adjacent to the second chamber 4) to the outside of a building (adjacent to the first chamber 2).

Figure 5 discloses a method 500 of controlling the transfer of heat between the interior and exterior of a building or building element according to an embodiment of the invention. The method 500 allows the transfer of heat by or through a building or building element to be controlled.

The method 500 comprises: providing a building component 1 (step 502); and operating the building component 1 in the insulating configuration (step 504), in the first thermally conductive configuration (step 506) or in the second thermally conductive configuration (step 508) to control the transfer of heat between the interior and exterior of the building or building component 1. In the insulating configuration the building component 1 can reduce the transfer of heat into or out of the building envelope, while in the thermally conductive configurations the building component 1 can be used to increase the transfer of heat into or out of the building envelope.

The method 500 may also include switching the building component 1 to another configuration (step 510) and operating the building component 1 in another configuration (step 512), wherein said another configuration may the insulating configuration, the first thermally conductive configuration or the second thermally conductive configuration (different to the previous configuration). Switching may be carried out in response to changing conditions inside or outside the building measured using e.g. temperature sensors located on or adjacent to both chambers 2, 4, one sensor being located on each side of the building component 1 . Measuring the conditions inside and/or outside the building may form part of step 510.

Figure 6 discloses a building 600 according to an embodiment of the invention. The building 600 comprises four building components 602, 604, 606, 608. Each of the four building components 602, 604, 606, 608 are similar to the previous embodiment 1 shown in figures 1 to 4 and are independently operatable. The building components 602, 604, 606 and 608 allow the transfer of heat by or through the building 600 to be controlled and adjusted.

The building 600 comprises a sun-facing side 620 and a shade-facing side 622. The building components 602, 604 on the sun-facing side 620 of the building 600 are mounted on the building 600 such that they are arranged in an edge-to-edge configuration in an array. The building components 602, 604 arranged in parallel. By “arranged in parallel” it is meant that the plurality of building components 602, 604 are physically arranged or mounted such that the outer planar faces of each of the building components are parallel or substantially parallel and the outer planar faces of the building components collectively define a plane. The building components 606, 608 on the shade-facing side 622 of the building 600 are also arranged in an array and in parallel. The building 600 includes heating system 630, a cooling system 632 and a room 634 in which heat-generating activities are carried out (e.g. a gym, kitchen, or densely occupied room).

Each building component 602, 604, 606, 608 is coupled to a masonry wall at the edge of the building 600. For example, each building component 602, 604, 606 and 608 may be a cladding panel. Each building component 602, 604, 606, 608 is arranged such that the respective first chamber thereof is located on or adjacent to an outer surface of the building 600 and the second chamber thereof is located on or adjacent to an inner surface of the building 600. Each building component 602, 604, 606, 608 being located on or adjacent to an outer surface or an inner surfaceof the building envelope allows the thermal conductance of the building envelope to be adjusted in accordance with user preferences.

On cold, sunny days solar radiation may be incident on the sun-facing side 620 of the building 600. To facilitate heating of the interior of the building 600 by this solar radiation, the building components 602, 604 on the sun-facing side of the building 600 may be operated in the first thermally conductive configuration to allow transfer of heat from the outside to the inside of the building 600 on this side of the building 600. This beneficial free heating will reduce the need to operate heating system 630, thereby saving fuel (carbon reduction). To reduce loss of heat through the walls on the shade-facing side of the building the building components 606,608 on the shadefacing side of the building 600 may be operated in the insulating configuration. These actions can reduce the burden on the heating system 630 used to heat the interior of the building 600.

If the building 600 begins to overheat in summer (e.g. due to solar radiation passing through windows and/ or due to heat generated by internal activities), the building components 602, 604, 606, 608 can be used to bypass the insulation on shaded exterior walls and/or roofs to enable unwanted heat to be passively rejected to the outdoor environment. This functionality could be particularly useful at night in summer when outdoor temperatures are commonly lower than indoor temperatures, especially if the sky is clear. This beneficial free cooling will reduce the need to operate cooling systems (thereby reducing operating costs and carbon emissions) and could potentially avoid the need to install cooling systems in some cases (significant capital cost saving).

For example, during times when heat-generating activities are being carried out in room 634 and the building 600 interior reaches excessive temperatures, the building components 602, 604, 606, 608 on both sides of the building 600 may be operated in the second thermally conductive configuration, to increase heat loss through the building envelope.

On warm, sunny days solar radiation may be incident on the sun-facing side 620 of the building 600. To reduce the heating of the interior of the building 600 from this solar radiation, the building components 602, 604 on the sun-facing side of the building 600 may be operated in the insulating configuration to reduce transfer of heat from the outside to the inside of the building 600. Doing so reduces the burden on the cooling system 632 used to cool the interior of the building 600.

During times when the heating system 630 is being used to heat the interior of the building, the building components 602, 604, 606, 608 on both sides of the building 600 may be operated in the insulating configuration, to reduce heat loss through the building envelope.

Figure 7 discloses a further building component 700 according to an embodiment of the invention. The further building component 700 is generally similar to the previous embodiments, having pairs of interconnected modular planar vacuum chambers A, a cavity C, an insulating material D and a valve E. The further building component 700 further comprises an external wetting device B. The wetting device is configured to wet an external surface of the building component 700 with working fluid. The external wetting device B is configured to produce a thin film of water 701 on the external vacuum vessel’s outer surface during heat transfer extraction from the inner space (cooling mode). The external wetter is activated when the valve E is in the open position and evaporation/condensation vapour transfer is occurring from the inner vacuum vessel (second chamber) to the outer vacuum vessel (first chamber). The evaporation (and latent heat extraction) from the external vacuum outer surface will increase the internal condensation process, thereby increasing heat transfer from the building (inside to outside). This external indirect evaporation is affected by external ambient air temperature and relative humidity and is aided by increasing air movement across the wetted surface. It is beneficial to have the unit fitted on a shaded fagade with exposure to external air movement. Reduced heat transfer through the building component 700 device is achieved by simultaneously switching off both the external wetting mechanism B and the internal evaporation-condensation cycle by closing normally-open valves E. The operating mode can be switched from a fully insulated mode (with no latent heat transfer) to a thermally conductive mode (where latent heat transfer is enabled) depending upon cooling demand.

Each vacuum chamber A is a hermetically sealed planar vessel which can be constructed of metal, glass, or other suitably robust material capable of transferring heat, which may in some cases be covered by an applied or bonded surface finish (such as exterior stone or timber cladding, or interior drylining, wallpaper, or paint). In one variant of the invention, each vacuum chamber is formed of two pressed-metal trays joined around the perimeter by a seam weld or other hermetic seal. The lower part of the vacuum chamber will function as a reservoir for the liquid working fluid 6 and may feature a sloped section to enable the condensate liquid to drain towards the lower pipe 706 under gravity. The upper part of the vacuum chamber allows for the transport of vapour to another vacuum chamber, either via a connecting pipe 705. The upper and lower parts of the vacuum chambers may feature recesses 706 which provide access to the pipes 705 and valves/pumps E during installation and for maintenance purposes. The vacuum chambers will typically feature fixing points around the perimeter for attaching to a substrate or structure, and in one variant of the invention, these fixing points will be arranged in a tessellating pattern which enables the chambers to be fixed abutting one another with minimal intervening gaps. In another variant of the invention the chambers may be held in place by double-ended clamps.

Figure 8 discloses a further building component 800 according to an embodiment of the invention. The further building component 800 is generally similar to the previous embodiments, having pairs of interconnected modular planar vacuum chambers A, a cavity C, an insulating material D, a valve E and support structures H. The coupled pairs of modular planar vacuum chambers A are interconnected by two or more pipes S. Each chamber contains a small amount of two-phase saturated working fluid which enables latent heat transfer between the panels. Vapour and condensate flows can be activated or deactivated by means of a ported valving E or pumping arrangement which can be configured to facilitate either unidirectional or bidirectional latent heat transfer or to prevent latent heat transfer. The working fluid will ideally be non-toxic and non-flammable to minimise safety and environmental risks. Each pair of vacuum chambers is separated by a cavity C which may or may not contain an insulating material D to minimise conductive, convective, and radiative heat transfer between the chambers. The vacuum chambers are typically arranged parallel to one another so that one is in close proximity to an exterior surface of the building envelope G and the other is in close proximity to an interior surface within the building, or one or more of the vacuum chambers may be coupled to a thermal storage element such as a masonry wall F or water storage tank. During operation, the vacuum chambers act interchangeably (depending upon the operating mode) as evaporator, condenser, solar absorber, heat rejector, or thermally insulating elements depending upon the desired operating mode. The operating mode can be switched from a fully insulated mode (with no latent heat transfer) to a thermally conductive mode (where latent heat transfer is enabled) depending upon demand. For example, a thermally conductive mode might be chosen to enable passive solar heat gains to be admitted into a building on a sunny winter day to offset space heating demands in the building, or to enable passive heat rejection to cool an overheating building when the outdoor ambient temperatures are lower than indoor temperatures. A thermally insulating mode would typically be the default operating scenario in cases where the building envelope needs to prevent unwanted heat loss (such as on a cold winter night) or to prevent unwanted heat gain (such as on a hot summer day).

As shown in figure 9, each vacuum chamber consists of an outer shell 901 , an internal support structure 908, and may or may not feature a capillary wicking and/or spray nozzle arrangement 902 to wet one or more internal surfaces of the chamber with working fluid. The internal support structure 908 may take a variety of different forms such as pillar arrays, porous infill, interlocking lattice plates, mesh frameworks, etc, which can be constructed from a variety of different materials (metal, glass, ceramics, plastics) arranged in a way which generally minimises conductive, convective, and radiative heat transfer through the panel whilst also resisting implosion forces acting upon the outer shell due to vacuum-to-atmosphere pressure differences (~100kPa). Each vacuum chamber is a hermetically sealed planar vessel which can be constructed of metal, glass, or other suitably robust material capable of transferring heat, which may in some cases be covered by an applied or bonded surface finish (such as exterior stone or timber cladding G, or interior drylining, wallpaper, or paint). Each vacuum chamber is formed of two pressed-metal trays joined around the perimeter by a seam weld or other hermetic seal 904. In another variant, one part of one of the vacuum chambers is formed of a metal tray and the other part is formed of a sheet of tempered glass or a glass-glass encapsulated photovoltaic panel enabling generation of electricity, in addition to the passive solar heating, passive heat rejection, and insulation functions of the device. The lower part of the vacuum chamber functions as a reservoir for the liquid working fluid 903 and may feature a sloped section to enable the condensate liquid to drain towards the lower pipe 905 under gravity. The upper part of the vacuum chamber allows for the transport of vapour to another vacuum chamber, either via a connecting pipe 905 or, in another variant of the invention, by a plenum which combines the two chambers to form a single U-shaped vessel (see figures 10 and 11 ). The upper and lower parts of the vacuum chambers may feature recesses 906 which provide access to the pipes 905 and valves/pumps E during installation and for maintenance purposes. The vacuum chambers will typically feature fixing points 907 around the perimeter for attaching to a substrate or structure, and in one variant of the invention, these fixing points will be arranged in a tessellating pattern which enables the chambers to be fixed abutting one another with minimal intervening gaps. In another variant of the invention the chambers may be held in place by double-ended clamps B.

Heat transfer through the building component 800 is switched on by activating the evaporation-condensation cycle to facilitate latent heat transfer. Conversely, minimisation of heat transfer through the building component 800 is achieved by switching off the evaporation-condensation cycle. Negative switching of the wetting mechanism 902 can be achieved by closing normally-open valves E to interrupt the flow of vapour or condensate. Positive switching of the wetting mechanism 902 can be achieved by opening normally-closed condensate return valve(s) E or by activating liquid flow pump(s) E. The switching process can be initiated by a simple local controller 909 such as a bi-metallic thermostat or thermofluid-filled piston which mechanically or electrically operates (for example via a relay or thermostatic switch) the valve or pump E, or by an electronic controller 909 such as a multi-channel programmable Building Management System which triggers electric valve actuator(s) and/or pump relay(s). A variety of different control strategies can be implemented including rule-based approaches such as switching being triggered by indoor and outdoor temperature differences, temperature setpoints, and user-interactive controls, or intelligent predictive approaches such as Model Predictive Control and Receding Horizon Control based upon a variety of different sensory inputs (for example temperature, solar irradiance, and building occupancy sensors).

Figures 10 and 11 disclose a further building component 1000 according to an embodiment of the invention. The further building component 1000 is generally similar to the previous embodiments, having pairs of interconnected modular planar vacuum chambers A, a cavity C, an insulating material D and a valve E. The upper part of the vacuum chamber A allows for the transport of vapour to another vacuum chamber, via a plenum which combines the two chambers A to form a single U- shaped vessel 1005a.

Figure 12 discloses a further embodiment of a building component 1200 according to the invention. The further building component 1200 is generally similar to the building component 1 shown in figure 1 , with similar numerals (e.g. 2/1202, 4/1204) denoting similar features. The further building component 1200 is distinguished from the building component 1 by a vapour control valve 1209, a cover member 1250, a cover member support 1252 and a gap 1254. The vapour control valve 1209 and conduit/pipe 1208 can be connected at any height to the first and second chambers 1202, 1204.

The conduit 1208 of the building component 1200 allows movement of the gas phase 6a of the working fluid 6 to pass from the first chamber 1202 to the second chamber 1204, and vice versa. The vapour control valve 1209 can be used to control this transfer of gas between the chambers 1202, 1204. The vapour control valve 1209 can be in an open configuration in which transfer of gas between the chambers 1202, 1204 is permitted. The vapour control valve 1209 can be in a closed configuration in which transfer of gas between the chambers 1202, 1204 is prevented. In this way, the vapour control valve 1209 can be used to switch the building component 1200 between an insulating configuration and a thermally conductive configuration, either in tandem with or instead of the fluid transfer arrangement 1210.

In examples, the cover member 1250 of the of the building component 1200 is transparent (e.g. glass or transparent plastic) and covers the outer surface 1222 of the building component 1200. The cover member 1250 is attached to the first chamber 1202 via the cover member support 1252. A gap 1254 is formed between the cover member 1250 and the outer surface 1222 of the first chamber 1202. The gap 1254 is sealed and may be filled with dry air or another non-condensing thermally insulating inert gas, such as Argon. The transparent cover 1250 and gap 1254 improve the solar heat collection performance during windy and cold weather conditions when the device is operating to supply heat into a building (e.g. in winter).

Figure 13 discloses a further embodiment of a building component 1300 according to the invention. The further building component 1300 is generally similar to the building component 1 shown in figure 1 , with similar numerals (e.g. 2/1302, 4/1304) denoting similar features. The further building component 1300 is distinguished from the building component 1 by shading elements 1360, 1362, 1364, 1366.

In examples, each shading element 1360, 1362, 1364, 1366 is formed of an opaque material (e.g. a metal such as steel or aluminium) and extends in a direction which is perpendicular to the plane of the outer surface 1322 of the first chamber 1302. In this way, each shading element 1360, 1362, 1364, 1366 is an orthogonal shading element. The angle between each shading element 1360, 1362, 1364, 1366 and the outer surface 1322 of the first chamber 1302 may be 90 degrees, or could be less than 90 degrees (e.g. 80, 60 or 45 degrees). The building component 1300 may include more or fewer orthogonal shading elements, for example 1 , 2 or 10 shading elements. Each shading element may include a photovoltaic panel.

In use, the shading elements 1360, 1362, 1364, 1366 shade the outer surface 1322 of the first chamber 1302 from high-angle direct solar radiation, for example near midday during summer months when the device is typically operating to reject heat out of a building. When the outer surface 1322 of the first chamber 1302 is sunfacing, the shading elements 1360, 1362, 1364, 1366 prevent the first chamber 1302 from absorbing too much solar radiation, and facilitate the rejection of heat from a building when the sun is shining. The size and position of each shading element 1360, 1362, 1364, 1366 may be configured to permit exposure of the first chamber 1302 to low-angle direct solar radiation, for example during winter months when the device is typically operating to supply heat into the building.

Figure 14 discloses a further embodiment of a building component 1400 according to the invention. The further building component 1400 is generally similar to the building component 1 shown in figure 1 , with similar numerals (e.g. 2/1402, 4/1404) denoting similar features. The further building component 1400 is distinguished from the building component 1 by shading element 1470, shading element supports 1472 and airflow separator 1490.

In examples, the shading element 1470 is formed of an opaque material (e.g. a metal such as steel or aluminium) and extends in a direction which is parallel to the plane of the outer surface 1422 of the first chamber 1402. In this way, the shading element is a parallel shading element. The shading element 1470 may include a photovoltaic panel. The shading element 1470 is attached to the outer surface 1422 of the first chamber 1402 via one or more shading element supports 1472.

In use, the shading element 1470 shades the outer surface 1422 of the first chamber 1402 from direct solar radiation. Furthermore, the gap between the shading element 1470 and the outer surface 1422 of the first chamber 1402 acts as a solar chimney. Free-flowing air passing through the gap between the outer surface 1422 and the shading element 1470 (see dashed upward arrow in figure 14) increases heat transfer when the device is operating to reject heat out of the building (e.g. in summer). As will be appreciated, the shading element supports 1472 do not prevent movement of air into the space between the shading element 1470 and the outer surface 1422 of the first chamber 1402. When the outer surface 1422 of the first chamber 1402 is sun-facing, the shading element 1470 prevents the first chamber 1402 from absorbing too much solar radiation and facilitates the rejection of heat from a building when the sun is shining.

As noted above, the gap between the shading element 1470 and the outer surface 1422 of the first chamber 1402 acts as a solar chimney. Free-flowing air passes through the gap between the outer surface 1422 and the shading element 1470 and moves upwardly through the gap. As air passes upwardly through the gap between the outer surface 1422 and the shading element 1470, heat is transferred from the outer surface 1422 of the first chamber 1402 to the flowing air, creating a heated airflow. The airflow separator 1490 is located at or towards the top of the gap and is configured to deflect the heated airflow out of the gap and in a direction away from any building component(s) above the building component 1400. Particularly, in use, the airflow separator 1490 prevents the heated airflow from passing into a similar gap of a similar building component (not shown) above building component 1400. Advantageously, the airflow separator 1490 ensures that the solar chimney draws in cool fresh air and prevents unwanted recirculation of exhausted hot air in cases where the building component 1400 is deployed in an array with other similar devices.

Figure 15 discloses a further embodiment of a building component 1500 according to the invention. The further building component 1500 is generally similar to the building component 1 shown in figure 1 , with similar numerals (e.g. 2/1502, 4/1504) denoting similar features. The further building component 1500 is distinguished from the building component 1 by misting device 1580.

The misting device 1580 is attached to the first chamber 1502. In use, the misting device 1580 is configured to create a water mist or water film in the vicinity of the outer surface 1522 of the first chamber 1502. The water mist or water film produced by the misting device 1580 through phase change acts to absorb heat and reduce the ambient air temperature in the vicinity of the outer surface 1522 of the first chamber 1502. Heat transfer is thereby increased when the building component 1500 is operating to reject heat out of a building (e.g. in summer). Figure 16 discloses a further embodiment of a building component 1600 according to the invention. The further building component 1600 is generally similar to the building component 1 shown in figure 1 , with similar numerals (e.g. 2/1602, 4/1604) denoting similar features. The further building component 1600 is distinguished from the building component 1 by shading element 1670, shading element supports 1672 and the misting device 1680.

In optional embodiments, the building component 1600 may additionally include an airflow separator, similar to the airflow separator described above with respect to building component 1400 shown in figure 14. The shading element 1670 and shading element supports 1672 are similar to the shading element 1470 and shading element supports 1472 described above with respect to building component 1400 shown in figure 14. The misting device 1680 is similar to the misting device 1580 described above with respect to building component 1500 shown in figure 15.

In use, the shading element 1670 shades the outer surface 1622 of the first chamber 1602 from direct solar radiation. Furthermore, the gap between the shading element 1670 and the outer surface 1622 of the first chamber 1602 acts as a solar chimney. Free-flowing air passing through the gap between the outer surface 1622 and the shading element 1670 (see upward arrow in figure 16) increases heat transfer when the device is operating to reject heat out of the building (e.g. in summer). As will be appreciated, the shading element supports 1672 do not prevent movement of air into the space between the shading element 1670 and the outer surface 1622 of the first chamber 1602. When the outer surface 1622 of the first chamber 1602 is sun-facing, the shading element 1670 prevents the first chamber 1602 from absorbing too much solar radiation and facilitates the rejection of heat from a building when the sun is shining.

The misting device 1680 is attached to the first chamber 1602. In use, the misting device 1680 is configured to create a water mist or water film in the vicinity of the outer surface 1622 of the first chamber 1602 and within the gap between the outer surface 1622 and the shading element 1670. The water mist or water film produced by the misting device 1680 through phase change acts to absorb heat and reduce the ambient air temperature in the vicinity of the outer surface 1622 of the first chamber 1602 and within the gap between the outer surface 1622 and the shading element 1670. Heat transfer is thereby increased when the building component 1600 is operating to reject heat out of a building (e.g. in summer).

As will be understood by the skilled person, the example embodiments presented above can be modified in a number of ways without departing from the scope of the invention. For example, the building component may comprise, or be in communication with, one or more sensors such as one or more temperature sensors. The operation of the building component can be based on the output of such sensors. For example, temperature sensors can be used to measure temperatures near the building component and/or the performance of the building component. Optical sensors can be used to measure the amount of light incident on the building component. The building component may be a structural panel. For example the building component could be a Structural Insulated Panel (SIP). The building component may be covered in cladding or brick slips, etc. While the above disclosure is primarily focused on buildings, but the building component 1 could potentially have other uses in industrial heating/cooling processes (e.g. food and chemicals industries); electronics cooling; and aerospace (e.g. thermal shielding on rockets).

The features disclosed in the foregoing description or the following drawings, expressed in their specific forms or in terms of a means for performing a disclosed function, or a method or a process of attaining the disclosed result, as appropriate, may separately, or in any combination of such features be utilised for realising the invention in diverse forms thereof.

Claims

1 . A building component comprising: a first chamber locatable on or adjacent to an outer surface of a building or building element; a second chamber locatable on or adjacent to an inner surface of the building or building element; a two-phase working fluid comprising a gas-phase and a liquidphase contained within the first chamber and/or the second chamber; at least one conduit configured to provide a path for the gas-phase of the working fluid to move between the first chamber and the second chamber; and at least one fluid transfer means configured to control transfer of the liquid-phase and/or the gas phase of the working fluid between the first chamber and the second chamber, wherein the building component comprises an insulating configuration in which latent heat transfer between the first and second chambers is prevented or substantially prevented by the at least one fluid transfer means, and wherein the building component comprises at least one thermally conductive configuration in which latent heat transfer between the first and second chambers is permitted or substantially permitted by the at least one fluid transfer means.

2. The building component of claim 1 , wherein the at least one fluid transfer means has an inactive state in which transfer of the working fluid between the first and second chambers is prevented or substantially prevented and an active state in which transfer of the working fluid between the first and second chambers is permitted or substantially permitted.

3. The building component of claim 2, wherein switching the at least one fluid transfer means from the inactive state to the active state causes the building component to switch from the insulating configuration to the at least one thermally conductive configuration

4. The building component of any preceding claim, wherein the first chamber and/or the second chamber comprises at least one planar surface, and wherein the or each planar surface is located on an outer surface of the building component, and wherein at least one planar surface comprises a heat-absorber material, an evaporative capillary surface or one or more photovoltaic cells.

5. The building component of any preceding claim, wherein the first chamber and/or second chamber is formed of a first member and a second member, wherein at least one of the first member and the second member is a metal tray.

6. The building component of claim 5, wherein the first chamber and/or the second chamber comprises two pressed-metal trays sealably joined around the perimeters thereof.

7. The building component of claim 5, wherein the second member is formed of a sheet of tempered glass or a glass-glass encapsulated photovoltaic panel.

8. The building component of any preceding claim, wherein the first chamber and/or the second chamber comprise internal support means, and wherein the internal support means comprise pillar arrays, porous infill, interlocking lattice plates or mesh frameworks.

9. The building component of any preceding claim, wherein a cavity is located between the first chamber and the second chamber.

10. The building component of claim 9, comprising insulation means located in the cavity, and wherein the cavity is partially or entirely filled with insulation means.

11 . The building component of any preceding claim, wherein the building component is an enclosed system, and wherein the building component is sealed or substantially sealed to prevent egress of the working fluid.

12. The building component of any preceding claim, wherein the at least one conduit comprises at least one pipe or plenum.

13. The building component of any preceding claim, wherein the lower part of each chamber functions as a reservoir for the liquid working fluid.

14. The building component of any preceding claim, wherein the fluid transfer means comprises a bi-directional valving and/or pumping means.

15. The building component of any preceding claim, wherein the building component comprises a plurality of thermally conductive configurations.

16. The building component of claim 15, wherein the building component comprises a first thermally conductive configuration in which heat is transferred from the first chamber to the second chamber, and wherein the building component comprises a second thermally conductive configuration in which heat is transferred from the second chamber to the first chamber.

17. The building component of any preceding claim, wherein the building component comprises a wetting means configured to wet an internal or external surface of the building component with working fluid.

18. The building component of claim 17, wherein the wetting means comprises a capillary wicking arrangement, an evaporative falling film and/or a spray nozzle arrangement.

19. A method of controlling the transfer of heat between the interior and exterior of a building or building element, the method comprising: providing a building component according to any preceding claim; operating the building component in the insulating configuration or in the at least one thermally conductive configuration to control the transfer of heat between the interior and exterior of the building or building element.

20. The method of claim 19, wherein operating the building component comprises: operating the building component in the insulating configuration such that the transfer of heat through the building component is prevented or substantially prevented.

21. The method of claim 19, wherein operating the building component comprises: operating the building component in the at least one thermally conductive configuration such that the transfer of heat through the building component is permitted or substantially permitted.

22. A building comprising a building component according to any one of claims 1 to 18.

23. The building of claim 22, wherein the building component is coupled to a building element of the building, and wherein the building element of the building is a thermal storage element such as a masonry wall or water storage tank.

24. The building of claim 22, wherein the building component is arranged such that the first chamber is located on or adjacent to an outer surface of the building and the second chamber is located on or adjacent to an inner surface of the building, and wherein the building component is arranged to control the transfer of heat between the interior and exterior of the building.

25. The building of claim 22, wherein the building comprises a plurality of building components, and wherein the plurality of building components are arranged in an array.