The present invention relates to the formation of buildings and other habitable

constructions. More specifically it relates to apparatus and methods for forming dynamic insulation within the envelope of a building or habitable construction, and in particular the creation of void spaces between two or more panels to facilitate the uniform, bi-directional, active or passive flow of ventilation air through the void space.

Background to the invention

When forming a building or habitable construction it is normally a regulatory requirement to provide a minimum level of thermal insulation within the envelope or facade of the building or habitable construction. These minimum requirements are set in order to limit to some extent the amount of heat transferred between the interior of the building and the surrounding environment. The function of the insulation is to reduce the energy consumption for heating or refrigerating the building or habitable construction, particularly those used for residential, leisure, healthcare, educational, municipal and commercial purposes. Traditionally, insulation is employed to reduce heat flow through a building envelope or facade, for example the walls, floors and roofs. The wall construction in Figure 1 depicts a conventional static insulating system 1 which can be seen to comprise an outer brick rain screen 2, a layer of insulation material 3 located within the building envelope or facade and a pre-cast concrete block inner leaf 4. The insulating material 3 typically comprises a compliant foam such as expanded polystyrene (EPS), extruded polystyrene (XPS), phenolic foam (PF), polyurethane (PU) and polyisocyanurate (PIR); rigid foams such as autoclaved (and other) aerated concretes, aerated mineral insulation board such as Xella's Ytong Multipor™, natural and synthetic fibres such as sheep's wool, glass fibre, polyamide and polystyrene based fibres and mineral wool; bonded or processed fibre boards, timber and other celluloid based materials and, latterly, new generation nano materials such as Aerogels, fumed silica and Vacuum Insulation Panel (VIP) materials. Normally the insulating material 3 is supplied in the form of panels or rolls of defined dimensions, which are conveniently resized and/ or reshaped (i.e. cut) so as to locate within the building envelope or facade.

The determining properties for the efficiency of the insulation material 3 are the

characteristic thermal conductivity of the material from which it is formed and the thickness of the material deployed. Once the value of these parameters have been set then the thermal heat loss coefficient (U _s ) for the envelope or facade element is fixed. Many internationally leading building standards typically require a minimum thickness of 140mm of expanded polystyrene or bonded mineral wool insulation, or alternatively around 80mm of polyurethane foam insulation (or equivalent) to achieve U-value compliance.

Builders and developers therefore have to decide whether to spend their money on expensive insulation materials that they require less of, or inexpensive insulation that they require more of. This is not always an easy choice. Opting for a cheaper insulating material will require thicker insulating panels to achieve the required minimum insulation levels. Thick insulating panels result in thick walls, floors and roofs, which results in more expensive buildings. Exotic insulation materials, on the other hand, can either be very expensive or are simply not readily available.

Dynamic insulation (Dl) systems have been proposed in order to attempt to overcome the drawbacks of conventional static insulation systems 1 . With dynamic insulation, a proportion of the exterior skin, envelope or facade of the building is used as a ventilation source. The resulting air flow rate per unit area through the intervening Dl system employed to deliver a fresh air supply can be quite low. Under such conditions, efficient heat transfer between the building envelope or facade and incoming/outgoing air takes place as a function of air flow rate, thus significantly reducing thermal losses.

There are two main types of dynamic insulation known in the art. Permeodynamic insulation employs an air permeable media through which the air can flow. This enables an effect similar to contra flow thermal recovery of the fabric heat lost to the incoming air. Alternatively, parietodynamic insulation employs an impermeable media and an air flow conduit to enable a form of cross-flow thermal recovery. The basic effect of pre-warming or pre-cooling ventilation air is similar for both types of dynamic insulation, irrespective of the direction of air flow. The dynamic thermal recovery effect can also be conveniently expressed as a reduction in the rate of fabric thermal transmission.

It is important to note that in dynamic insulation the reduction in thermal transmission with air flow rate is independent of the direction of air flow to or from the building. This means that dynamic insulation will operate irrespective of whether it is employed as an air supply or as an air extraction device. This feature lends great flexibility to how dynamic insulation is used in a building, irrespective of the type of building or its geographic location.

Dynamic insulation systems reduce the material input required to reach the desired minimum insulation levels. The dynamic insulation systems known in the art are preformed components comprising an insulating panel through which a substantially internal airflow channel is formed. These components are then incorporated into the building envelope or facade so as to allow air to flow from the exterior of the building to the interior and vice versa. This flow of air allows for a heat exchange to take place between the building fabric and the flow of air in the sense that it reduces to a significant extent the heat transfer between the building interior and its surroundings. Dynamic insulation systems enable the production of thinner walls, roofs or floors since they reduces the thickness of insulating material needed to achieve the same insulation levels provided with a conventional static insulation system 1 .

Noteworthy examples of the prior art in dynamic insulation systems include patent publication numbers WO 03/057470 A1 , WO 2010/122353 A1 , US 2009236074 A1 ,

GB 2439191 A, JP 2008069574 (A), CA 1229714 A1 , FR 2522121 and FR 19860006083. These examples share the attribute that the dynamic insulation system is thereby produced by deploying several dynamic insulation panels that are attached to the structural elements (walls, floor and/or roofs) of a building. Furthermore, the dynamic insulation panels are produced in predetermined sizes and so are not amenable to being cut or shaped post production, thus imposing limitations on the area of the envelope or facade that can be dynamically insulated. Indeed, resizing or reshaping of the panels would render them unusable as dynamic insulation. In some cases they further constrain the direction of air flow. Therefore, their use is limited to certain building dimensions and they are not capable of being deployed under or above doors or windows, for example. This generally renders as impossible the complete dynamic insulation of a building. One further limitation of these systems is that they all require a fan to drive the ventilating air flow and so they are all incapable of operating in a passive manner.

In addition, the production and installation costs of such dynamic insulation panels are significantly higher compared to ordinary insulation. This is a potentially insurmountable barrier to the mass market adoption of dynamic insulation that is required to trigger the economies of scale that are essential for such a market to thrive and prosper.

It is therefore an object of an aspect of the present invention to provide a dynamic insulation system that obviates or at least mitigates the problems and or limitations encountered with the dynamic insulation systems known in the art.

Summary of the Invention

According to a first aspect of the present invention, there is provided a void space forming element suitable for connecting and defining a void space between two panels wherein the void space forming element comprises a panel attachment means for connecting the void space forming element to at least one panel and a spacer element that provides a means for defining a spatial separation between the two panels.

The void space forming elements provide a ubiquitous means for creating void spaces within a building envelope or facade with two very special attributes. Preferably the formed void space may be employed within an active, or passive, or combined active plus passive dynamic insulation system wherein the void space and void spacer elements serve to facilitate the uniform, bi-directional flow of air across the whole of the void space plane. The depth of the void space forming elements is such that it neither impedes the free flow of air through the void space (i.e., the pressure drop is low) nor does it exacerbate convective thermal bridging across the depth of the void space.

Alternatively the void space forming elements can provide a generic means for creating an aeration or drainage path within the envelope or facade of a construction, and or integrating other equipment, services and functions within the habitat envelope or facade and through partitions.

The spacer element may comprise two radially extending formations longitudinally separated along the length of the panel attachment means.

Alternatively the spacer element may comprise a plate. The plate may comprise an extruded panel engaging surfaces. The plate may further comprise a fixing hole. In this embodiment the panel attachment means may comprise one or more attachment pins located around the perimeter of the plate. The attachment pins are preferably located at regular intervals around the perimeter of the plate.

Preferably the spacer plate comprises one or more pin engagement means located around the perimeter of the plate. The pin engagement means are preferably located at regular intervals around the perimeter of the plate.

Most preferably the one or more attachment pins and the one or more pin engagement means provide a means for two void space forming elements to be inter-connected so as to provide a bidirectional void space forming element.

The spacer element may comprise a cylindrical component concentrically attached to one end of which is a radially extending formation. The radially extending formation is preferably in the form of a circular or disc shape having a radius that is greater than a radius of the cylindrical component.

In an alternative embodiment the spacer element may comprise an array of protrusions located on a backing sheet. The role of the protrusions is to simultaneously provide fixing, structural support, insulating features and also aid the air flow distribution within the formed void space. Preferably the array of protrusions comprises an irregular array. Alternatively, the array of protrusions comprises an regular array.

The array of protrusions may comprise a linear array. Alternatively the array of protrusions comprises two dimensional arrays of protrusions. Optionally the array of protrusions may comprise two or more interspersed two dimensional arrays of protrusions.

The protrusions may comprise conical, cylindrical, square or polygonal based prismatic shapes truncated in a plane parallel to the plane of the backing sheet.

The panel attachment means may comprise one or more attachment pins. The one or more attachment pins may comprise one or more barbed ends.

The panel attachment means may comprise one or more layers of adhesive located upon one or more panel engaging surfaces of the spacer elements.

The void space forming elements may be made from one or more materials selected from the non-exhaustive group of materials comprising plastic, coated plastics, sprayed-on plastic foams, plastic composites, metals, metallic and non-metallic foils, ceramics, fibre- reinforced resins, water-proof pressed, sprayed pulps, nano materials and nanomaterials composites..

According to a second aspect of the present invention there is provided a dynamic insulation system suitable for deployment within an envelope or facade of a building or habitable construction wherein the dynamic insulation system comprises one or more layers of insulation and one or more void space forming elements in accordance with the first aspect of the present invention wherein attachment of the void space forming elements to the one or more layers of insulation provides a means for defining at least one void space within the envelope or facade.

Preferably the dynamic insulation system further comprises two or more conduits arranged so as to provide fluid communication through the dynamic insulation system via the at least one void space. The dynamic insulation system may have a width such that it extends across the full width of the envelope or facade of the building or habitable construction. Alternatively, the dynamic insulation system may have a width such that it extends across only part of the width of the envelope or facade of the building or habitable construction.

The one or more layers of insulation may comprise a permeodynamic insulating material.

The one or more layers of insulation may comprise a parietodynamic insulating material. Optionally the parietodynamic insulating material comprises a spray on plastic foam.

The dynamic insulation system may comprise two layers of an insulating material and two or more void space forming elements arranged so as to form a multiple void dynamic insulation system. The multiple void dynamic insulation system provides a means for simultaneously supplying air to and extracting air from the internal area of a building without permitting the two air supplies to mix.

The multiple void dynamic insulation system may comprise two layers of a parietodynamic insulating material and two or more void space forming elements arranged so as to form a dual void dynamic insulation system.

Optionally the dual void dynamic insulation system further comprises a third layer of a parietodynamic insulating material located between the two or more void space forming elements.

Preferably the dual void dynamic insulation system comprises four or more conduits arranged to provide a first fluid communication path through the system via a first void space and a second fluid communication path through the system via a second void space.

The multiple void dynamic insulation system may comprise two layers of a permeodynamic insulating material and four or more void space forming elements arranged so as to form a quad void dynamic insulation system. Optionally the quad void dynamic insulation system further comprises a central layer of a parietodynamic insulating material located between two or more of the void space forming elements.

Preferably the quad void dynamic insulation system comprises four or more conduits arranged to provide a first fluid communication path through the system via a first layer of permeodynamic insulating material and a second fluid communication path through the system via a second layer of permeodynamic insulating material.

The dynamic insulation system may further comprise a membrane, foil or plate. The membrane, foil or plate may comprise a discrete vapour barrier or a reflective foil.

The dynamic insulation system may further comprise a dual function layer of insulation material. The dual function layer of insulation material may comprise a dual function layer of insulation material selected from a group comprising a phase change material layer that provides a means for thermal storage, an electrocatalytic material layer that provides a means for filtering airborne pollutants, a desiccant material that provides a means for regulating moisture content and an aerated material.

The dynamic insulation system may further comprise an additional function layer. The additional function layer may comprise a building integrated devices such as solar collector panels, a hydrogen fuel cell plate, a reformer or energy storage assembly, heating or cooling coils.

Embodiments of the second aspect of the invention may include one or more features of the first aspect of the invention or its embodiments, or vice versa.

According to a third aspect of the present invention there is provided a kit of parts that can be assembled to form a dynamic insulation system, the kit of parts comprising one or more layers of insulation and one or more void space forming elements in accordance with the first aspect of the present invention.

Embodiments of the third aspect of the invention may include one or more features of the first or second aspects of the invention or its embodiments, or vice versa. According to a fourth aspect of the present invention there is provided a method of producing a dynamic insulation system for use within an envelope of a building or facade or habitable construction the method comprising attaching one or more void space forming elements in accordance with the first aspect of the present invention to one or more layers of insulation.

The method of producing a dynamic insulation system may further comprise arranging two or more conduits so as to provide a fluid communication path through the dynamic insulation system.

The method of producing a dynamic insulation system may further comprise cutting the dynamic insulation system to a desired size for deployment within an envelope or facade of the building or habitable construction.

The method of producing a dynamic insulation system may further comprise attaching, a membrane, foil or plate to the one or more layers of insulation. The attachment may be a manual process or as part of a continuous automated process.

The method of producing a dynamic insulation system may further comprise attaching the one or more void space forming elements to a dual function layer of insulation material.

The method of producing a dynamic insulation system may further comprise attaching the one or more void space forming elements to a an additional function layer e.g. solar collector panels, a hydrogen fuel cell plate, a reformer or energy storage assembly, heating or cooling coils.

Embodiments of the fourth aspect of the invention may include one or more features of the first, second or third aspects of the invention or its embodiments, or vice versa.

According to a fifth aspect of the present invention there is provided a method of dynamically insulating an envelope or facade of a building or habitable construction the method comprising the deployment of a dynamic insulation system in accordance with the second aspect of the present invention within the envelope or facade. The method of dynamically insulating the envelope or facade of a building or habitable construction may further comprise deploying the dynamic insulation system across the full width of the envelope or facade. Alternatively, the method of dynamically insulating the envelope or facade of a building or habitable construction may further comprise deploying the dynamic insulation system across part of the width of the envelope or facade.

The method of dynamically insulating the envelope or facade of a building or habitable construction may further comprise deploying the dynamic insulation system across the full height of the envelope or facade. Alternatively, the method of dynamically insulating the envelope or facade of a building or habitable construction may further comprise deploying the dynamic insulation system across part of the height of the envelope or facade.

Embodiments of the fifth aspect of the invention may include one or more features of the first, second, third or fourth aspects of the invention or its embodiments, or vice versa.

According to a sixth aspect of the present invention there is provided a void space defining apparatus suitable for deployment within an envelope or facade of a building or habitable construction wherein the void space defining apparatus comprises one or more panels and one or more void space forming elements in accordance with the first aspect of the present invention wherein attachment of the void space forming elements to the one or more panels provides a means for defining at least one void space within the envelope or facade.

Embodiments of the sixth aspect of the invention may include one or more features of the first, second, third, fourth or fifth aspects of the invention or its embodiments, or vice versa.

According to a seventh aspect of the present invention there is provided a kit of parts that can be assembled to form a void space defining apparatus, the kit of parts comprising one or more panels and one or more void space forming elements in accordance with the first aspect of the present invention.

Embodiments of the seventh aspect of the invention may include one or more features of the first, second, third, fourth, fifth or sixth aspects of the invention or its embodiments, or vice versa. According to an eighth aspect of the present invention there is provided a method of producing a void space defining apparatus for use within an envelope or facade of a building or habitable construction the method comprising attaching one or more void space forming elements in accordance with the first aspect of the present invention to one or panels.

The method of producing a void space defining apparatus may further comprise cutting the void space defining apparatus to a desired size for deployment within an envelope or facade of the building or habitable construction.

The method of producing void space defining apparatus may further comprise attaching, , a membrane, foil, or plate to the one or more panels. The attachment may be a manual process or as part of a continuous automated process.

The method of producing a void space defining apparatus may further comprise attaching the one or more void space forming elements to a dual function layer of an insulation material.

The method of producing a void space defining apparatus may further comprise attaching the one or more void space forming elements to an additional function layer e.g. a solar collector panels, a hydrogen fuel cell plate, a reformer or energy storage assembly, heating or cooling coils.

Embodiments of the eighth aspect of the invention may include one or more features of the first, second, third, fourth, fifth, sixth or seventh aspects of the invention or its

embodiments, or vice versa.

According to a ninth aspect of the present invention there is provided a method of producing a void space within an envelope of a building or facade or habitable construction the method comprising the deployment of a void space defining apparatus in accordance with the sixth aspect of the present invention within the envelope or facade.

The method of providing a void space within the envelope or facade of a building or habitable construction may further comprise deploying the void space defining apparatus across the full width of the envelope or facade. Alternatively, the method of providing a void space within the envelope or facade of a building or habitable construction may further comprise deploying the void space defining apparatus across part of the width of the envelope or facade.

The method of providing a void space within the envelope or facade of a building or habitable construction may further comprise deploying the void space defining apparatus across the full height of the envelope or facade. Alternatively, the method of providing a void space within the envelope or facade of a building or habitable construction may further comprise deploying the void space defining apparatus across part of the height of the envelope or facade.

Embodiments of the ninth aspect of the invention may include one or more features of the first, second, third, fourth, fifth, sixth, seventh or eighth aspects of the invention or its embodiments, or vice versa.

Brief Description of the Drawings

There will now be described, by way of example only, various embodiments of the invention with reference to the following figures, of which:

Figure 1 presents (a) a schematic representation and (b) a side elevation of a conventional static insulation system;

Figure 2 presents schematic representations of void space forming elements comprising two attachment pins, as represented in Figure 2(a) and a single attachment pin, as shown in Figure 2(b);

Figure 3 presents schematic representations of alternative embodiments of the void space forming element comprising two barbed-ended attachment pins, as represented in Figure 3(a) and a single barbed-ended attachment pin, as shown in Figure 3(b);

Figure 4 presents a schematic representation of an alternative uni-directional, load bearing embodiment of the void space forming element; Figure 5 presents a schematic representation of hybrid bi-directional, load bearing void space forming element produced by connecting two of the void space forming elements shown in Figure 4;

Figure 6 presents schematic representations of three further alternative embodiments of the void space forming element;

Figure 7 presents a schematic representation of a plurality of void space forming elements of Figure 6 connected together to form of a mesh structure;

Figure 8 presents four linear array-type void space forming elements that are in the form of bars and / or strips;

Figure 9 presents four array-type void space forming elements;

Figure 10 presents schematic perspective and side views of the formation of a void space through the employment of:

(a) an array of hybrid void space forming elements;

(b) a mesh structure of void space forming elements;

(c) three linear array-type void space forming elements; and

(d) a two dimensional irregular array-type void space forming element.

Figure 1 1 presents (a) an exploded view of an array-type void space forming element deployed within a building envelope or facade so as to provide a dynamic insulation system and (b) a schematic representation of the airflow within the void space of the dynamic insulation system;

Figure 12 presents a schematic side view of:

(a) a void space permeodynamically insulated full-fill wall; and

(b) a void space permeodynamically insulated part-fill wall;

Figure 13 presents a schematic side view of:

(a) a void space parietodynamically insulated full-fill wall; and

(b) a void space parietodynamically insulated part-fill wall; Figure 14 presents:

(a) Table 1 which outlines the product specification employed to quantify the thermal performance of the void space parietodynamically insulated full-fill wall of Figure 13(a) using, for illustrative purposes, different thicknesses of XPS (W1 X to W6X) and PIR (W1 P to W6P) insulation materials;

(b) plots of the Dynamic U-value (U _d ) versus air flow rate for different thicknesses of XPS full-fill insulation material;

(c) plots of the Dynamic U-value (U _d ) versus air flow rate for different thicknesses of PIR full-fill insulation material;

Figure 15 presents a schematic side view of:

(a) a void space parietodynamically insulated dry wall cladding; and

(b) a void space parietodynamically insulated external cladding;

Figure 16 presents:

(a) Table 2 which outlines the product specification employed to quantify the

thermal performance of the void space parietodynamically insulated dry wall cladding of Figure 15(a) using, for illustrative purposes, different thicknesses of XPS (W1 pbX to W3pbX) and PIR (W1 pbP to W3pbP) insulation materials;

(b) plots of the Dynamic U-value (U _d ) versus air flow rate for different thicknesses of XPS insulated plasterboard wall construction;

(c) plots of the Dynamic U-value (U _d ) versus air flow rate for different thicknesses of PIR insulated plasterboard wall construction;

Figure 17 presents a schematic side view of:

(a) an alternative embodiment of a void space parietodynamically insulated dry wall cladding; and

(b) an alternative embodiment of a void space parietodynamically insulated

external cladding;

Figure 18 presents a schematic side view of:

(a) a concurrent supply plus extract void space parietodynamically insulated dual void wall; and

(b) a concurrent supply plus extract hybrid (permeo- and parieto-) void space dynamically insulated quad void wall; Figure 19 presents a schematic side view of:

(a) an alternative embodiment of a concurrent supply plus extract void space parietodynamically insulated dual void wall; and

(b) an alternative embodiment of a concurrent supply plus extract void space parietodynamically insulated quad void wall;

Figure 20 presents a schematic side view of:

(a) a hybrid (permeo- and parieto-) void space dynamically insulated wall; and

(b) an alternative hybrid (permeo- and parieto-) void space dynamically insulated wall configuration;

Figure 21 presents a schematic side view of:

(a) a hybrid (permeo- and parieto-) void space dynamically insulated wall

incorporating a thin membrane; and

(b) a void space parietodynamically insulated full-fill wall that incorporates a thin membrane;

Figure 22 presents a schematic side view of:

(a) a void space permeodynamically insulated hybrid wall incorporating an

additional material layer; and

(b) an alternative void space parietodynamically insulated hybrid wall

configuration that incorporates an additional material layer;

Figure 23 presents a schematic side view of:

(a) a void space permeodynamically insulated hybrid wall incorporating a

functional device layer; and

(b) an alternative void space parietodynamically insulated hybrid wall

configuration that incorporates a functional device layer;

Figure 24 presents:

(a) a wall constructions employed to theoretically model the effects of void space dynamic insulation used as an Internal Wall Insulation (IWI) layer;

(b) a plot of the Dynamic U-value (U _d ) versus void space depth for three Active (A), Passive (P) and Static (S) operating modes, plus the corresponding U- values (dotted lines) obtained using a standard calculation method such as BS EN ISO 6946 for 100 mm of unvoided full-fill insulation and a 1 -D analytical model of parietodynamic insulation that ignores the full effects of the void space on performance;

(c) a plot of the average void space air temperature versus void space depth for the three Active (A), Passive (P) and Static (S) operating modes;

(d) a plot of the bulk void space air flow velocity versus void space depth for the three Active (A), Passive (P) and Static (S) operating modes;

(e) a plot of the parietodynamic wall total air supply through-flow volume versus void space depth for the Active (A) and Passive (P) operating modes;

(f) a plot of the area averaged absolute void space pressure versus void space depth for the Active (A) and Passive (P) operating modes;

Figure 25 presents theoretical plots of the Dynamic U-value versus air flow rate at temperature differences of ΔΤ = 20°C (0°C outdoor and 20°C indoor temperatures) for two different wall types;

Figure 25 presents:

(a) a first wall constructions employed to theoretically model the effects of full- fill in-cavity void space dynamic insulation;

(b) a second wall constructions employed to theoretically model the effects of an internally applied void space dynamic insulation lining;

(c) a plot of the Dynamic U-value (U _d ) for a range of spacer types, climates and for three Active (A), Passive (P) and Static (S) operating modes. Also included are corresponding U-values obtained using a standard calculation method such as BS EN ISO 6946 for 100 and 1 15 mm of un-voided full-fill insulation (dashed line) and a 1 -D analytical model of parietodynamic insulation that ignores the full effects of the void space on performance (solid line).

Detailed Description of Preferred Embodiments

With reference to Figures 2 to 9, there will now be described a number of void space forming elements in accordance with an aspect of the present invention. The void space forming elements can be employed to connect and or space two or more panels so as to form one or more predetermined void spaces which can then be deployed within the envelope of a building or habitable construction. Several examples of how these void spaces may be deployed so as to provide a dynamic insulation system for a building or a habitable construction are then described.

It will be appreciated by the skilled reader that reference to a building or a habitable constructions should be considered as referring to any such platform irrespective of its particular location e.g. on land, at sea or in the air.

Figure 2 presents a first and second embodiment of a void space forming elements, depicted generally by reference numerals 5 and 5b. The void space forming elements 5 and 5b are single point connectors and can be seen to comprise a panel attachment means 6 upon which is mounted a spacer element 7. The panel attachment means 6 may comprise two attachment pins 8, as shown in Figure 2(a), or a single attachment pin 8, as shown in Figure 2(b). It will be appreciated that the two attachment pin embodiment of Figure 2(a) may in fact comprise a single pin both ends of which are made pointed so as to facilitate deployment of the void space forming element 5. In both embodiments presented in Figure 2 the spacer element 7 further comprises two radially extending formations 9 longitudinally separated along the length of the panel attachment means 6. The two radially extending formations 9 are typically separated by 2 - 100 mm. Preferably, the separation lies between 10 - 50 mm. The two radially extending formations 9 may have a circular or disc shape. The radially extending formations 9 may also comprise a layer of adhesive on their panel engaging surfaces so as provide a further means for assisting in the attachment of the two panels.

Figure 3 presents alternative embodiments of the single point void space forming elements, depicted generally by reference numerals 10 and 10b. These embodiments are similar to those described above with reference to Figure 2 however in these embodiments the panel attachment means 6 comprise two barbed-ended attachment pins 1 1 , as shown in Figure 3(a), or a single barbed-ended attachment pin 1 1 , as shown in Figure 3(b).

Employing barbed-ended pins 1 1 provides a more secure, pull-resistant attachment between the void space forming elements 10 and 10b and a panel when compared with the void space forming elements 5 and 5b presented in Figure 2. Figures 4 and 5 present further alternative embodiments of the void space forming elements, depicted generally by reference numerals 12 and 12b. From Figure 4 it can be seen that the void space forming elements 12 comprises a plate 13 with integrated fixing hole 13b as the spacer element 7 and that the attachment means 6 comprises four barbed-ended attachment pins 1 1 located at equally spaced intervals around the perimeter of the plate 13. The thickness of the spacer plate 13 typically lies between 1 - 50 mm. Preferably, the thickness lies between 5 - 15 mm.

Radially arrayed, extruded panel engaging surfaces 14 may be formed within the spacer plate 13 so as to assist with the flow of air within the formed void space when the void space forming elements 12 are deployed within a dynamic insulation system, as described in further detail below. The panel engaging surfaces 14 also provide a means for conserving raw materials, reducing thermal mass, reducing thermal bridging and facilitating component alignment and interlock of hybrid bi-directional void spacer assembly 12b as presented below in Figure 5.

The integrated fixing hole 13b provides the void space forming element 12 with a means to directly attach the element onto an exposed surface, e.g. a drywall or rainscreen re- cladding application featuring internal and external wall void space dynamic insulation.

The spacer plate 13 may also comprise a layer of adhesive on its panel engaging surfaces 14 so as provide a further means for assisting in the attachment of the two panels.

It is preferable for the void space forming elements 12 to further comprise pin engagement means 15 located around the perimeter of the plate 13. In the presently described embodiment, four pin engagement means 15 are provided at equally spaced intervals around the perimeter of the plate 13 such that they are interspersed between the four barbed-ended attachment pins 1 1 . The function of the pin engagement means 15 is to allow two void space forming elements 12 to be connected together so as to form a single hybrid, bi-directional fixing device 12b as presented in Figure 5. In this embodiment the resulting void space depth produced typically lies between 2 - 100 mm. Preferably, the void space depth will lie between 10 - 30 mm.

In this embodiment the integrated fixing holes 13b provide the void space forming element 12b with a means to directly attach the resulting multi-layer assembly onto an exposed surface, e.g. a drywall or rainscreen re-cladding application featuring internal and external wall void space dynamic insulation.

To produce the panel connector 12b one of the panel connectors 12 is simply inverted and positioned such the spacer plates 13 locate together. By introducing a relative rotation between the panel connectors 12 the barbed-ended attachment pins 1 1 of one of the panel connectors 12 locate with the pin engagement means 15 of the other so as to secure the hybrid device 12b. The coupling between the component void space forming elements 12 is further augmented by the panel engaging surfaces 14, which are designed to interlock securely when the two void space forming elements 12 are rotated by the appropriate angle (45° for the presently described embodiment relative to each other to form the hybrid-bi-directional fixing device 12b.

Increasing the plate diameter in this void space fixing device type will increase its load bearing / support capacity, such as may be required, for example, in the production of large, dynamically insulated pre-cast concrete building envelope or facade elements.

It will be appreciated by the skilled reader that in further alternative embodiments the number of attachment pins 1 1 , pin engagement means 15 and their spacing around the perimeter of the plate 13 may be varied.

Figure 6 presents yet further alternative embodiments of the single point void space forming elements, depicted generally by reference numerals 16, 16b and 16c. In each of these embodiments the spacer element 7 comprises a cylindrical component 17 concentrically attached to one end of which is radially extending formation 18. The radially extending formation 18 is in the form of a circular or disc shape having a radius that is greater than the radius of the cylindrical component 17. The height of the cylindrical component 17 typically lies between 5 to 100 mm. Preferably, the height is between 10 to 50 mm.

In the presently described embodiments, four attachment tabs 19 are provided at equally spaced intervals around the perimeter of the radially extending formation 18. The attachment tabs 19 allow the void space forming elements 16, 16b and 16c to be connected together in the form of an array or mesh structure 20, as presented in Figure 7. The mesh structure 20 may itself provide the means for connecting two panels together. It is preferable however for the void space forming elements to further comprise either a layer of adhesive 21 (see element 16) and or attachment pins (see element 16c) on one or more of its panel engaging surfaces.

Figures 8 and 9 present a number of alternative array-type void space forming elements. In particular, Figure 8 presents four different linear array-type void space forming elements 22, 22b, 22c and 22d. In Figure 8(a) the linear array-type void space forming element 22 is formed by the introduction of a plurality of equally spaced notches 23 along the length of a strip of material 24 e.g. a plastic strip. The linear array-type void space forming element 22b of Figure 8(b) is formed by attaching a series of blocks 25 at equally spaced intervals along the length of the strip 24.

In the alternative embodiment 22d shown in Figure 8(d) the series of blocks 25b are trapezoidal shaped, although it will be appreciated that any other geometrical shape may similarly be employed. The resulting trapezoidal linear array-type void spacer 22d thus produced combines void separation, structural strength, fixing durability, ease of use, versatility and flexibility, low production cost and very low total pressure drop (i.e., flow resistance) in both the longitudinal and lateral flow directions in the void space.

The linear array-type void space forming element 22c of Figure 8(c) is similar to that of Figure 8(b) however in this embodiment each element of the array in fact comprises a 3x3 array of protrusions 26. The protrusions 26 can be thought of as square based pyramids that have been truncated in a plane parallel to the plane of the square base. Other protrusions 26 may include conical, cylindrical and/or polygonal based pyramids truncated in a plane parallel to the plane of the backing sheet. Void space forming element 22c may be formed by injection moulding of an appropriate plastic material, metal shaping, etc.

Figure 9 presents four different alternative array-type void space forming elements 27, 27b, 27c and 27d. Each of the void space forming elements 27, 27b, 27c and 27d comprise a backing sheet 28 upon which an array of protrusions 26 have been formed, the pattern formed by the protrusions 26 being the differing factor between each of these elements.

In Figure 9(a) the void space forming elements 27 comprises a regular 2x2 array of protrusions arranged at a 45° angle to the edges of the backing sheet 28. In Figure 9(b) the protrusions comprise two superimposed regular 2x2 arrays of protrusions 26. Each element of the first array of protrusions comprises a single protrusion 26 while each element of the second array comprises a 3x3 array of protrusions 26. The embodiment presented in Figure 9(c) comprises a regular 2x2 array of protrusions wherein each element of the array comprises a 3x3 array of protrusions 26. The embodiment presented in Figure 9(d) comprises an irregular array or random pattern of protrusions 26 wherein the arrangement is organised to contribute to achieving even, uniform air flow within the void space plane.

It will be appreciated that the array pattern of the protrusions 26 of the above described embodiments may be varied. For example, the arrays of protrusions may not be regular in form or the number of protrusions contained within a particular array element may also vary. The role of the protrusions 26 is to simultaneously provide fixing / structural support and also aid the air flow distribution within the formed void space and so variations in the array pattern simple leads to corresponding variation in the air flow distribution.

The above described void space forming elements may be made from any durable, inert, fire resistant material or combination of materials. For example they can be made of plastic by injection moulding, extrusion or thermoforming. Other materials may

alternatively be employed such as multi-layered plastics, coated plastics, sprayed-on plastic foams, plastic composites, metals, metal foils, ceramics, fibre-reinforced resins or water-proof pressed and/or sprayed pulps. In addition the void space forming elements may be made from conventional insulating material or newly developed materials including aerogels and Vacuum Insulation Panel (VIP) materials.

It should be noted that the use of any thermally conductive material e.g. metals in the production of sheet-type void space forming elements 27, 27b, 27c and 27d, for example aluminium, will enhance lateral heat transfer within the void space. This acts to improve the performance in zones of localised stagnation or where the air flow rate is significantly lower than the mean air flow rate. Furthermore, the use of metals may also provide the void spacing elements, and hence systems and apparatus incorporating these devices with RF and or elecromagnetic insulation properties. Method of Forming a Void Space

There now follows a description of how the above described void space forming elements may be deployed so as to provide a void space 29 within the envelope or facade of a building or habitable construction. In particular, Figure 10 presents schematic perspective and side views of the formation of a void space 29 through the employment of (a) an array of hybrid void space forming elements 12b; (b) a mesh structure 20 of void space forming elements 16; (c) three linear array-type void space forming elements 22b; and (d) a two dimensional irregular array-type void space forming element 27d. Each of the void spaces 29 in these illustrative example applications are produced by locating the void space forming element 12b, 20, 22b or 27d between two sheets of standard insulation material 3. The appropriate attachment means 6 act to attach the void space forming elements 12b, 20, 22b or 27d to the two sheets of insulation material 3 while the corresponding spacing elements 7 simultaneously act to provide and maintain the desired void space 29. If required, the composite structure can then be cut to the desired size so as to fit within the building envelope or facade e.g. that formed between the outer brick rain screen 2 and the concrete block inner leaf 4.

It is envisaged that similar arrangements to those thus far described with reference to Figure 10 can be used to form a void space between a single sheet of insulation and any material, for example the rainscreen or drywall cladding surfaces in External Wall

Insulation (EWI) and Internal Wall Insulation (IWI) applications, or device surfaces, to produce a single void space dynamic insulation system. Equally, similar stacked arrangements may be used to create more than one discrete void space simply by adding insulation layers and / or surfaces to create double, triple and greater tandem void spaces for use in double, triple and greater tandem void space dynamic insulation systems (see Figure 18 below for examples of double and quad tandem void space dynamic insulation systems).

It will be further appreciated by the skilled reader that the above methodology may be adapted such that the void space forming elements 12b, 20, 22b, 22d or 27 are provided preformed on a layer of standard insulation material 3. The production process is thereafter completed by simply attaching the second layer of standard insulation material 3 to the void space forming elements 12b, 20, 22b, 22d or 27. Preforming the void space forming elements 12b, 20, 22b, 22d or 27 on a layer of standard insulation material 3 acts to reduce the time required to form the void space, particularly when employing singly point type void space forming elements 12b and 20.

The above methodology can easily be adapted so as to cost effectively produce a simple to make, easy to apply range of dynamic insulation panels for use in a building or habitable construction. This is explained in further detail with reference to Figure 1 1 (a) which presents an exploded view of the array-type void space forming element 27 deployed within a building envelope or facade so as to provide a dynamic insulation system 30.

With reference to the arrangement in Figure 1 1 (a), the first step is to again locate the void space forming element 27 between the two sheets of standard insulation material 3.

Apertures for receiving an entrance / inlet conduit 31 and an exit / outlet conduit 32 are then formed within the two sheets of insulation material 3 and the void space forming element 27. With the entrance and exit conduits 31 and 32 in place the panel attachment means 6, in this embodiment adhesive layers 21 located on the panel engagement surfaces, again act to attach the void space forming element 27 to the two sheets of insulation material 3. The spacer elements 7 simultaneously act to provide and maintain the desired void space 29 between the sheets of insulation material 3. If required, the composite structure can then be cut to the desired size so as to fit within the building envelope or facade formed between the outer brick rain screen 2 and the concrete block inner leaf 4.

The void space forming element 27 serves a secondary but equally important function. The parameters that govern air flow are the separation distance, shape, size and spacing of the device, the location of the entrance 31 and exit conduits 32 to the void space 29, the number and type of systems 30 employed and the systems 30 orientation and location (vertical for walls, horizontal for ceilings and floors, pitched for roofs, etc.). The void space forming element 27 permits the free flow of air vertically and laterally within the wall, as presented schematically in Figure 1 1 (b). In practice, this results in an almost complete envelope or facade area coverage for the air flow. Since a uniform air flow is important in achieving the best performance from a dynamic insulation system 30 the presence of multiple protrusions 26 in the void space forming element 27 that effectively disperse the air flow acts to maximise the overall reduction in building fabric thermal transmission. It will be appreciated that the void space forming elements need to have sufficient strength and stiffness to function as a support and to deliver the required separation between the layers of insulation material or cladding surface so as to enable them to function as part of a dynamic insulation panel, without adversely impacting or impeding the air flow rate or the routing of services where applicable. In order to achieve these objectives the void space forming elements may be produced in specific shapes and sizes.

With regard to their wider use in building construction, the void space forming elements enable users to vary the spacing of cladding material layers in the range of 5 to 100 mm, and more commonly in the range of 10 to 50 mm for the majority of applications.

The footprint of the void space forming elements can similarly vary, depending on the available area, the rigidity of the material layers to either side thereof and the load bearing capacity that the void space forming elements are required to support within the acceptable deformation limits of both the device or the insulation (or other) material layers to which they are attached.

It will be appreciated that the inlet 31 and or outlet 32 that connect the indoor and outdoor spaces through the one or more void spaces 29 can be of any shape or size, including part or full wall width rectangular apertures. For example, in the case of an external wall insulation void space dynamic insulation applications, an external inlet 31 could be formed by simply offsetting the external insulation sheet / layer from the wall and using the full width opening that is created below the overhang to draw air into the void space 29, and thereafter into the building.

Dynamic Insulation Systems

Employing the above described void space forming elements and methods of construction provides for a significantly greater degree of flexibility in the configurations of the dynamic insulation systems that can be achieved. A number of example configurations of void space dynamic insulation systems will now be described with reference to Figures 12 to 25.

Figure 12(a) presents a schematic side view of a void space permeodynamically insulated full-fill wall 33 while Figure 12(b) presents a similar arrangement but in a part-fill configuration 34. In both embodiments there is located a void space permeodynamically insulated material 35 which is fixed in place within the building envelope or facade by a plurality of void space forming elements 12b. The spacer elements 7 of the void space forming elements 12b act to define a void space 29 and 29b on either side of the void space permeodynamically insulated material 35 which are in fluid communication with an entrance conduit 31 and an exit conduit 32, respectively.

For the avoidance of doubt, any one of the void space forming elements described above may used in place of the hybrid bi-directional void space forming element 12b described with reference to Figure 12 and all other void space dynamic insulation systems described hereinafter. The void space forming elements may be in discrete form for use with flat sheet insulation layers and / or cladding surfaces, or integral to specially pre-formed insulation layers and / or cladding surfaces.

In a similar manner the described apparatus and methods can be readily employed so as to provide a void space parietodynamically insulated wall system. In particular Figure 13(a) presents a schematic side view of a void space parietodynamically insulated full-fill wall 36 while Figure 13(b) presents a similar arrangement but in a part-fill configuration 37. In both embodiments there are located a plurality of void space forming elements 12b between two panels of standard insulation material 3. The spacer elements 7 of the void space forming elements 12b act to define a central void space 29 which is in fluid communication with both an entrance conduit 31 and an exit conduit 32.

The parameters governing steady-state heat transfer through a void space dynamically insulated wall are the thermal conductivity of the constituent materials, the physical properties of the air, the air flow rate, the internal and external temperatures and the wall geometry e.g. layer thicknesses, void space depth, wall height, etc. This allows theoretical modelling to be carried out so as to quantify the active and / or passive thermal performance of the void space dynamically insulated wall.

Figure 14(a) presents Table 1 which outlines the product specification employed to theoretically quantify the thermal performance of the void space parietodynamically insulated full-fill wall 36 of Figure 13(a). Figure 14(b) plots the Dynamic U-value (U _d ) versus air flow rate for different thicknesses of an XPS full-fill insulation material while Figure 14(c) plots the Dynamic U-value (U _d ) versus air flow rate for different thicknesses of a PIR full-fill insulation material. PIR offers lower thermal conductivity and, compared to XPS, is the better insulator. In both cases the trend is reduction in the dynamic U-value as a function of air flow rate and insulation thickness. At air flow rates in the range 0 - 1 .5 l/m ² -s the type of insulation and its thickness can have a significant impact. However, at flow rates > 2.0 l/m ² -s the effect of air flow rate becomes the dominant factor, with the type of material and thickness being only marginally significant.

Figure 15 presents a system whereby the described apparatus and methodologies can be employed to dynamically insulate a wall cladding 38. In particular, Figure 15(a) presents a schematic side view of a void space parietodynamically insulated dry wall cladding 39, otherwise referred to as void space parietodynamic Internal Wall Insulation (IWI), wherein void space forming elements 12b are deployed so as to define an air flow void space 29 between the internal side of cladding wall 38 and a panel of standard insulation material 3. An internal drywall lining layer 41 may be applied to the inward-facing surface of the panel 3. As before, entrance conduit 31 and an exit conduit 32 again provide for fluid

communication from the outside to the inside of the building via the air flow void space 29.

Figure 15(b) presents a void space parietodynamically insulated external cladding 40, otherwise referred to as void space parietodynamic External Wall Insulation (EWI), that is of a similar configuration to the arrangement of Figure 15(a). However in this embodiment the air flow void space 29 is located between the external side of cladding wall 38 and the panel of standard insulation material 3. An external render 41 may be applied to the external surface of the panel 3.

The void space parietodynamic IWI 39 and EWI 40 systems presented in Figure 16 can be used beneficially in both new build and retrofit applications. With regard to the former, void space parietodynamic IWI 39 offers an efficient and affordable building retrofit solution that is appropriate for use in existing solid wall construction where the original external appearance is to be preserved and the loss of internal floor space is relatively small or within limits that are acceptable to the occupants of the building. On the other hand, void space parietodynamic EWI 40 offers an efficient, low cost retrofit solution that is appropriate for use in existing solid wall construction where the original external appearance of the construction can be changed and there is a requirement to eliminate or minimise access, indoor spaces and disruption to occupants. Figure 16(a) presents Table 2 which outlines the product specification employed to theoretically quantify the thermal performance of the dynamically insulated dry wall cladding 39 of Figure 15(a). The thermal performance of the dynamically insulated rainscreen cladding 40 of Figure 15(b) is broadly similar. Figure 16(b) plots the Dynamic U-value (U _d ) versus air flow rate for different thicknesses of an XPS plasterboard insulation material while Figure 16(c) plots the Dynamic U-value (U _d ) versus air flow rate for different thicknesses of a PIR plasterboard insulation material. The highlighted trend is the same as previously discussed with reference to Figure 14. PIR offers lower thermal conductivity and, compared to XPS, is the better insulator. In both cases the trend is reduction in the dynamic U-value as a function of air flow rate and insulation thickness. At air flow rates in the range 0 - 1 .5 l/m ² -s the type of insulation and its thickness can have significant impact. However, at flow rates > 2.0 l/m ² -s the effect of air flow rate becomes the dominant factor, with the type of material and thickness being only less significant.

As a result of the increased flexibility provided by the employment of the void space forming elements, novel void space dynamic insulation system configurations can be produced. Furthermore, these systems may also employ novel combinations of materials. By way of example, Figure 17(a) and Figure 17(b) present alternative embodiments of the void space dynamically insulated dry wall cladding and the void space dynamically insulated external cladding described above with reference to Figure 15(a) and Figure 15(b), respectively and generally depicted by reference numerals 39b and 40b. The difference between the presently described embodiments and those presented in Figure 15 is that the use of the void space forming elements allows for the panels of insulation material 3 to be replaced by layers of spray-on foam or pulp insulation 42. The air flow void space 29 is formed using either void space forming elements 27, 27b, 27c and 27d or with void space forming elements 10, 10b, 12, 12b, 16, 16b, 16c, 22, 22b and 22c employed in conjunction with a rigid backing substrate 43 (that could also exhibit insulating properties), over which the foam insulation may be sprayed on and subsequently dressed.

The increased flexibility provided by the employment of the void space forming elements allows for new and unique high performance dynamic insulation system configurations that can simultaneously supply air to and extract air from the internal area of a building without permitting the two air supplies to mix. For example, Figures 18(a) and Figures 18(b) present schematic side views of a dynamically insulated dual void space wall 44 and a dynamically insulated quad void space wall 45. The parietodynamically insulated dual void space wall 44 is produced by having three panels of insulation material 3 attached to each other by two layers of void space forming elements so as to form two air flow void spaces 29 and 29b. Each of the air flow void spaces 29 and 29b has an associated entrance conduit 31 and 31 b and an exit conduit 32 and 32b again employed to provide means for fluid communication between the outside to the inside of the building.

The hybrid permeo-parietodynamically insulated quad void space wall 45 can be seen to comprise a central impermeable panel of insulation material 3 on either side of which is located a layer of air permeable insulation insulated material 35 and 35b. Four layers of void space forming elements 5, 5b, 5c and 5d are employed to attach the layers of insulation material 3, 35 and 35b so as to define four air flow void spaces 29, 29b, 29c and 29d. An entrance conduit 31 and an exit conduit 32 provide a means for fluid

communication from the outside to the inside of the building via the layer of void space permeodynamically insulating material 35b. Similarly, an entrance conduit 31 b and an exit conduit 32b provide a means for fluid communication from the inside to the outside of the building via the layer of void space permeodynamically insulating material 35.

The void space parietodynamically insulated dual void space wall 44 and hybrid void space dynamically insulated quad void space wall 45 provide means for reducing both the fabric and ventilation conductance losses i.e. the incoming air is pre-heated or pre-cooled by both the fabric and exhaust air. Such multiple void space dynamic insulation systems can in this way reduce both the fabric and ventilation conductance of the building, i.e., they can recover to fresh ventilation air both fabric heat (or coolth) loss and the heat (or coolth) normally dumped when spent air is exhausted from the building, thus significantly boosting the energy-saving performance of these advanced void space dynamic insulation system

Figure 19(a) and Figure 19(b) present alternative embodiments of the void space dynamically insulated dual void space wall and the void space dynamically insulated quad void space wall described above with reference to Figure 18(a) and Figure 18(b), respectively and generally depicted by reference numerals 44b and 45b. The difference between the presently described embodiments and those presented in Figure 18 is that the central panel of insulation material 3 can be omitted if the void spaces 29 and 29b of the void space dynamically insulated dual void space wall 44b, or the air void spaces 29b using void space forming elements 27, 27b, 22c and 27d. Alternatively, if with void space forming elements 10, 10b, 12, 12b, 16, 16b, 16c, 22, 22b and 22c are employed to produce the aforementioned void spaces then the central panel of insulation material 3 is replaced by a thin, air impermeable, conducting membrane 46.

Figure 20 presents a schematic side view of two alternative void space dynamically insulated hybrid walls 47 and 48. Each embodiment comprises a layer of

permeodynamically insulating material 35 and a panel of air impermeable insulation material 3. Two layers of void space forming elements are employed so as to define air flow void spaces 29 and 29b on either side of the layer of void space permeodynamically insulating material 35. An entrance conduit 31 and an exit conduit 32 are employed to provide means for fluid communication between the outside to the inside of the building via the layer of permeodynamically insulating material 35. The described dynamically insulated hybrid walls 47 and 48 deliver the superior thermal performance and functionality of permeodynamic insulation while exploiting the utility and functionality of parietodynamic insulation.

The flexibility provided by the above described void space forming elements and their method of deployment can be further exploited so as to allow for additional layers of material to be incorporated within the dynamic insulations systems. For example Figure 21 (a) presents the void space dynamically insulated hybrid walls 47 of Figure 20(a) which now incorporates a membrane, foil or plate 49 on the internal surface of the panel of insulation material 3. Similarly, Figure 21 (b) presents the void space parietodynamically insulated full-fill wall 33 of Figure 13(a) which now incorporates the membrane, foil or plate 49 on an internal surface of one of the panels of insulation material 3. The membrane, foil or plate 49 may comprise a discrete vapour barrier or a reflective foil to block radiant heat transfer through certain types of insulation, such as EPS or XPS that are transparent to long wave radiation, or a functional device such as a heating or cooling element, humidity buffer or other device, etc.

This facility may be further exploited as shown by the embodiments presented in Figure 22 which are similar to those discussed previously with reference to Figure 21 . However, in these embodiments instead of adding a membrane, foil or plate 49 to an internal surface of one of the panels of insulation material 3 these panels have simply been replaced by a layer of material 50 that may be used to deliver not only insulation performance but also further expand functionality e.g. a phase change material layer for thermal storage, an electrocatalytic material layer to filter airborne pollutants, a desiccant layer to regulate moisture content; or alternatively sheets of autoclave aerated concrete or aerated mineral insulation board such as Xella's Multipor™ building product to provide structural strength.

Yet further embodiments of the void space dynamically insulated hybrid walls 47d and 33d are presented in Figure 23. These embodiments are similar to those discussed previously with reference to Figures 21 , as depicted generally by reference numerals 47b and 33b. In these embodiments, the panels of insulation material 3 with the membrane, foil or plate 49 on an internal surface thereof has been replaced with a layer that exhibits an additional functionality 51 . This layer may comprise a different type of embedded component or a fully autonomous functional device that would benefit from being adjacent or in close proximity to a void space so as to provide air flow access to waste heat generated by the device in the course of normal operation. Examples of such devices include building integrated devices such as solar collector panels, a hydrogen fuel cell plate, a reformer or energy storage assembly, heating or cooling coils. The waste heat from these devices can either be used to reduce the heating load or be dumped to the outside so as to prevent it from increasing the cooling load. These arrangements have the added advantage that they will act to dynamically reduce the thermal transmittance of the fabric or facade of the building or habitable construction, and / or to improving the efficiency of operation of the embedded device.

In some of the above described examples of embedded component or device 51 require to be exposed to the sun e.g. solar panels. In the embodiment of Figure 23(b) the cladding wall with external render 38 would be omitted and ruggedized variants of the component or device 51 would serve, in addition to their primary function (e.g. energy conversion in the case of solar collectors), as the rainscreen.

Factors Governing the Performance Void Space Dynamic Insulation

A comprehensive understanding of how the above described void space dynamic insulation operates has been achieved from comparative evaluation of its in-use energy performance as a building component, at full-scale and under realistic conditions. A wall incorporating void space dynamic insulation can function in three distinct operating modes: as an Active (A) fan driven dynamic insulation component; as a Passive (P) dynamic insulation component that relies on the indoor to outdoor temperature difference to generate the resulting buoyancy driven air flow through the wall; and as a Static (S) insulation component when there is no ventilation air flow through the wall and therefore no dynamic recovery of heat (or coolth) loss to the incoming supply (or extract) air stream. It is likely that mode permutations and combinations may form part of the of the building's operating schedule, for example during different times of the day or different seasons of the year.

The performance of passive void space dynamic insulation is dependent on the size of the buoyancy driven air flow rate, and thus on the indoor to outdoor temperature difference - i.e. the greater the temperature difference the higher the flow rate, and therefore the less heat lost through the dynamically insulated envelope or facade. This is a prime example of auto-adaptive building response. Performance is also dependent on the size of the in- plane pressure drop across the full width and height of the void space, which has to be low for passive operation to work. At the same time, this has to be balanced against the void spacer geometry effectively promoting the uniform, bi-directional distribution of air flow across the entire height and width of the void plane. Passive performance is an important feature of void space dynamic insulation that differentiates it from all other dynamic insulation products and technologies in existence. Void spacer design can further enhance passive performance.

To facilitate further understanding, a 3.6 m wide x 3.0 m high, commonly encountered wall constructions 52, as presented schematically in Figure 24(a) will now be used to illustrate and compare the predicted real-world performance of void space parietodynamic insulation in Active (A), Passive (P) and Static (S) operating modes. The wall construction 52 comprises a 225 mm thick solid brick rainscreen 2 rendered with 9mm thick plaster render 53. A parietodynamically insulated drywall liner comprising a 50 mm sheet of PIR insulation 54 on 12mm thick plasterboard 55 is also present. A variable (10 - 50 mm depth) plain void space 29 is located between the solid brick rainscreen 2 and the surface of the insulation sheet 54.

Fresh ventilation air is supplied from outside (cold outdoor ambient) to inside (warm heated space) via the dynamically insulated wall 52, but it should be understood that comparable performance would be achieved if the wall 52 was employed to exhaust spent ventilation air, for example from an air conditioned building during summer, or for buildings located in hot or hot-humid climatic regions. In supply mode the outdoor supply inlet 31 to the wall should ideally be positioned lower than the indoor outlet 32 to the room or HVAC system, and vice versa, i.e., in extract mode the indoor extract inlet to the wall should ideally be positioned lower than the outdoor extract outlet to outdoor ambient. This allows greater advantage to be taken of the buoyancy contribution to air flow in Active (A) and Passive (P) operating modes, to maximise the performance of the void space dynamically insulated wall 52.

In the theoretical model the fresh air flow rate was fixed at 0.5 L/m ² s in the active case, a variable to be determined in the passive case and fixed at 0 L/m ² s in the static case. The rainscreen 2 has a ¼ height air supply inlet 31 and ceiling height wall outlet 32 through which fresh ventilation air is drawn into the building or habitable construction. A temperature difference ΔΤ = 20°C (0°C outdoor and 20°C indoor temperatures) was assumed in all cases.

Figure 24(b) presents a plot of the Dynamic U-value (U _d ) versus void space depth for the three Active (A), Passive (P) and Static (S) operating modes, plus the corresponding U- values (dashed lines) obtained using a standard calculation method such as BS EN ISO 6946 for 100 mm of unvoided full-fill insulation and a 1 -D analytical model of

parietodynamic insulation that ignores the full effects of the void space on performance.

With reference to Figure 24(b) the effects of void depth on Dynamic U-value for the different Active (A), Passive (P) and Static (S) operating modes are plotted and compared. For completeness, the Static U-value for 50 mm of unvoided PIR insulated drywall liner in the same wall construction is included (the upper dashed line), as well as the Dynamic U- value estimated a 1 -D analytical model of parietodynamic insulation that ignores the full effects of the void space on performance (the lower dashed line).

The significant characteristics of void space dynamic insulation that emerge from these results for the case in question are:

(i) the presence of the void space significantly reduces the U-value

irrespective of what operating mode Active (A), Passive (P) and Static (S) is employed; a steep reduction in Dynamic U-value is seen as the void depth is increased between 10 - 20 mm, followed by a slightly less steep reduction between 20 - 50 mm, in both Active (A) and Passive (P) operating modes; and Dynamic U-value in the Active (A) operating mode is lower than in the Passive (P) operating mode but the gap closes at void space depths of 25 mm and higher.

It can be seen that increasing the void depth from 20 to 50 mm can provide meaningful reductions in Dynamic U-value at little extra cost, especially in a Passive operating mode (P)-

Figures 24(c) to 24(f) are present plots of void average air temperature, bulk air velocity, air flow volume and average absolute void space pressure, respectively, as functions of void depth. A common feature in all of these plots is steep change at void depths below 25 mm followed by less steep change in the values of all of these parameters in Passive operating mode (P). It is noteworthy that the increase in air flow volume in this mode is why the drop in Dynamic U-value is so profound at void space depths approaching 25 mm. Figure 24(f) shows the effect of void space depth on the average absolute void space pressure for both Active (A) and Passive (P) operating modes. This translates to a relative pressure drop across the void space of around 6 Pa for the range of depths that were considered in Passive operating mode (P). The increase in the Active dynamic operating mode (A) is less pronounced, with the pressure drop rising moderately below void depths of 20 mm.

The above results illustrate the effect of void depth on a range of operating parameters such as the Dynamic U-value, void air temperature, velocity, flow volume and pressure. They confirm that an optimum void spacer depth can be found (20 mm for the presently described embodiment). They also suggest that Active dynamic mode (A) generally delivers better performance compared to Passive mode (P), but that the latter very nearly succeeds in closing the gap at larger void depths. Furthermore, increasing the void space depth is not detrimental to performance, and in the present example it can be seen to be beneficial. Finally, the constant, very low void space pressure drop in passive operation is part of the reason why the Passive operating mode (P) of void space dynamic insulation provides such great results. In addition to establishing the effects of void depth on performance in the preceding paragraphs, all of which offer ways in which both the void spacer and void space dynamic insulation can be optimised, the effects of indoor and outdoor temperature on performance are summarised in Figure 25.

The main plot is of the Dynamic U-value as a function of air flow rate at a temperature difference ΔΤ = 20°C (0°C outdoor and 20°C indoor temperatures) for a full-fill

parietodynamically insulated cavity wall construction, see for example Figure 13(a), incorporating a 20mm depth steel trapezoidal profile void space fixing elements 7 positioned at 600mm centres horizontally and vertically within the void space 29 (the solid line).

Superimposed over this is a plot of the Dynamic U-value for the same construction predicted using a 1 -D analytical model of parietodynamic insulation that ignores the full effects of the void space on performance (the dashed line), the passive Dynamic U-value under the same boundary conditions (the solid marker), plus a further 4 passive Dynamic U-values (the plain markers) corresponding to ΔΤ ₁₅ =15 (0°C outdoor and 15°C indoor temperatures), ΔΤ ₂₀ =15 (5°C outdoor and 20°C indoor temperatures), ΔΤ ₂₀ =10 (10°C outdoor and 20°C indoor temperatures) and ΔΤ ₂₀ =5 (15°C outdoor and 20°C indoor temperatures).

These results address questions about how the passive void space dynamic insulation system performs when ΔΤ < 20°C, at 15, 10 and 5°C. For example, we see two occurrences of ΔΤ = 15°C, the first when the room temperature is permitted to fall to 15°C (ΔΤ ₁₅ =15), for example when the building is not occupied in winter, and the second when the outdoor temperature is 5, 10 and 15°C (ΔΤ ₂₀ =15, ΔΤ ₂₀ =10 and ΔΤ ₂₀ =5 respectively), for example in spring or autumn as the weather begins to progressively improve. The result is remarkable in that all of the points appear to lie on the original Dynamic U-value plot.

This is further surprising because, in addition to this and contrary to what one might reasonably expect, the convection driven air flow rate within the void space increases (and the passive parietodynamic U-value decreases) as the outdoor temperature increases (and the temperature difference decreases). The reason why this happens is that, although buoyancy force reduces as the temperature difference across the wall reduces, the increase in the average void space air temperature as the weather improves causes the air to expand, it's density to fall and the through volume flow rate to increase, i.e., the lighter air is easier to move even when the motive force (buoyancy) is less.

The above results are testament to the versatility of void space dynamic insulation as an effective, potent technology for the reduction of building envelope and facade heat (and coolth) loss that works in all operating modes, as an Active dynamic insulation component (A), a Passive dynamic insulation component (P) and as a Static insulation component (S), and in all climates. The performance of void space dynamic insulation is not likely to be adversely affected by ambient outdoor temperature or the indoor set point temperature of the building. Although most of the above results relate to parietodynamic void space dynamic insulation, it is found that the performance of permeodynamic and hybrid void space dynamic insulation, as well as multiple void space dynamic insulation, will exhibit broadly similar trends.

Two example embodiments of void space dynamic insulation are depicted in Figure 26(a) and Figure 26(b) in order to theoretically demonstrate the effects of various void forming elements 5.

The wall constructions 56 of Figure 26(a) is set to be 3.6 m wide x 3.0 m high and is an example of a parietodynamically insulated full-fill wall cavity wall. It can be seen to comprise an internal drywall 57 made of concrete, first and second 50 mm thick sheets of phenolic foam insulation layers 3 between which is located a irregular array-type void space forming element 27 and an outer rainscreen 58, also made of concrete.

The wall constructions 59 of Figure 26(b) is also set to be 3.6 m wide x 3.0 m high and is an example of a parietodynamically insulated internal drywall lining wall. It can be seen to comprise an internal drywall 57 made of plasterboard, 50 mm thick sheet of phenolic foam insulation 3 and an outer rainscreen 58. In this embodiment a number of linear array-type void space forming elements 22d are located between the insulation layers 3 and the outer rainscreen 58.

In order to evaluate the performance of these walls operating in active dynamic (A), passive dynamic (P) and static (S) modes, the fresh air flow rate was fixed at 0.5 L/m ² s in the active case, self-setting in the passive case and fixed at 0 L/m ² s in the static case. The void space depth was fixed at 15 mm for all of the cases considered, but greater void depths could alternatively also be employed. In all cases the rainscreen 58 and drywall 57 openings were located at ¼ and ¾ height respectively, although it has been subsequently shown that hot climate extract would perform better if the drywall 57 and rainscreen 58 openings are located at ¼ and ¾ height respectively. A temperature difference ΔΤ = 20°C (0°C for cold climates and 40°C for hot climates outdoor and fixed 20°C indoor

temperatures) was assumed in all cases;

According to BS EN ISO 6946: 2007, 100 mm of phenolic foam, in the absence of an internal void space, would result in a static U-value of just below 0.20 W/m ² K for this wall construction. If a 15 mm mid-depth void is included in the simulation, the static U-value drops to around 0.175 W/m ² K, which is comparable to 1 15 mm of contiguous phenolic foam. However, according to the analytical model, a dynamic U-value of 0.09 W/m ² K results when the air flow rate is 0.5 L/m2s. This corresponds to a 48.6% reduction in thermal transmittance in the static case and a 55% reduction compared to 100 mm of contiguous phenolic foam (i.e. using the same volume of insulation material) in the same wall construction.

With reference to Figure 26(c), reasonable agreement can be seen when the analytical model and standard calculation method results are compared to full 3-D conjugated Computational Fluid Dynamics (CFD) simulations for different wall arrangements and void spacer types. The results that are shown are all for the same geometry (2 ^χ 50 mm sheets of phenolic foam separated by a 15 mm void space) and ventilation air flow rate of 0.5 L/m ² s through a 3.6 m (w) x 3.0 m (h) reference wall. Cold climate supply appears to perform slightly better than the hot climate case, and this is attributed to the effect of convection. In both cases the rainscreen 58 and drywall 57 openings were located at ¼ and ¾ height respectively. Hot climate extract would have performed better if the drywall and rainscreen openings had been located at ¼ and ¾ height respectively. Using optimized void spacers yields dynamic U-values in supply and extract mode of around 0.06 W/m ² K, a 67.6% reduction compared to the static case.

Results displaying similar trends were found for the parietodynamically insulated drywall lining cases, and the numerous other types of wall construction that have been explored.

Although these above described configurations, example constructions and factors governing performance have been presented in relation to a wall envelope or facade it will be appreciated by the skilled reader that similar configurations,, example constructions, etc. for roofs and floors, using other materials, are also possible. It should also be noted that different permutations and combinations of these configurations, example

constructions, etc. are also possible.

Furthermore, it will be appreciated by the skilled reader that the above production methods may be adapted so as to enable the formation of curved void spaces and hence curved dynamic insulation panels. This may be achieved by employing a former, over which the sheets of insulation material 3, or other material layers 50, could be flexed before being coupled together using appropriately designed void space forming elements to preserve and maintain the desired curvature and geometry.

It will also be appreciated that the void space forming elements can be made from any durable, inert, fire resistant material or combination of materials including but not limited to injection moulded, extruded and thermoformed plastics, multi-layered or coated plastics and plastic composites, 'sprayed-on' plastic foams, metals, ceramics, fibre-reinforced resins, waterproof pressed and sprayed pulps and insulation materials that use nano technology in their formation.

The method of attaching and anchoring the void space forming elements to the adjacent material layers within the construction can, where required, be via mechanical penetration, a combination of penetration and interlock and / or the use of adhesive coatings or layers, reactive bonding etc. The attachment methods will clearly be different for rigid, foam- based or fibre-based insulation materials, but the objective of fixing, separating and supporting the materials to create a void space is the same.

The various above described embodiments of the void space forming elements can be applied either manually or automatically, as part of a production line process. They can be supplied in discrete form or as pre-fabricated inter-linked or meshed arrays, strips or sheets in both rigid, or flexible, flat pack form, or in rolls to facilitate rapid, cost-effective application in the production of void space dynamic insulation systems. They can be fitted either off-site (in the factory) or on-site, during construction, or retrofitted into existing habitats. Variants of the device can be used in combination, for instance to facilitate certain types of edge fixing or to help correct, regulate and control specific air flow distribution scenarios within the void plane. The void space forming elements can also be made or pre-fabricated as an integral part of one or more of the sheet materials or combination of materials that are employed in for the production of dynamic insulation systems described above. The elements may be contiguously formed, stamped onto, carved out of or bonded to the base insulation layer.

Alternatively, the void space forming elements may be provided as an integral feature, during the process of construction, of the one or more other building envelope or facade layers that may be employed within an active, or passive, or combined active plus passive dynamic insulation system. It is conceivable, for example, for a pre-cast concrete wall panel to be formed with integral void spacer features during casting. This approach further extends the range of void spacer materials to include specially formed bricks, concrete blocks, other cast concrete and cementitious parts, all metallic and non-metallic (e.g., timber, plastic, etc.) cladding layers and all ceramic and glass based materials.

As discussed in the introduction, prior art dynamic insulation systems employ bespoke, relatively complex moulded products that are fragile, inefficient (unidirectional flow only) and expensive to manufacture. Furthermore these systems are not easy to install. The presently described void space dynamic insulation overcomes all of these shortcomings as it employs commercially available mass-market flat sheet insulation, held in place using one of several void spacer variants to create a void plane through which ventilation air readily flows across the height and width of the wall.

The dynamic insulation products and applications that have been described highlight a number of the advantages provided by employing the void space forming elements. In the first instance the void space forming elements allow for the fixing and support of different layers of insulation material within the exterior envelope or facade elements or cladding and internal partitions of habitable constructions (i.e., dwellings, other building types and other stationary and mobile platforms)

Secondly the resulting void space dynamic insulation systems can made directly, without modification, from any commonly available, inexpensive, mass produced flat insulation sheet material (and by extension henceforth, any other sheet material), or combination of materials. This acts to reduce the costs of the system without sacrificing performance or versatility. A further advantage is that the described systems facilitate the uniform, bi-directional flow of ventilation (or exhaust) air across the entire plane of the insulation sheets.

Finally, the insulation sheets can be cut to any size and shape, and joined together without loss of functionality to maximise dynamic insulation coverage of the building envelope or facade for superior fabric efficiency and energy-saving performance, and with it provide an overall energy-saving performance for the building.

In addition to the above described dynamic insulation systems it will be appreciated by the skilled reader that the void space forming elements can provide a generic means for creating an aeration or drainage path within the envelope or facade of the construction, and or integrating other equipment, services and functions within the habitat envelope and through partitions. For example, they can be employed to prevent deposition or accumulation of moisture, or provide a drainage conduit, within the envelope.

Alternatively, they can be used to facilitate hidden cabling, pipes, etc, within the

construction. The void space forming elements thus provide a ubiquitous means for creating voids within the building envelope.

Another example to illustrate the benefits of aeration is when building-integrated functional devices or panels, such as solar collectors are coupled to a void space dynamically insulated building envelope, where ventilation air flow in the shared void space can capture or reject heat from the devices or panels (depending on whether in supply or extract mode) to improve both the thermal performance of the envelope and efficiency of the device or panel.

The invention provides void space forming elements that can be used to make void spaces within the envelope or facade of a building by means of a simple (manual or automated) production method. In particular, high performance, low cost void space dynamic insulation panels can be made from any type of mass-produced flat sheet insulation material. The void space dynamic insulation systems produced eliminate the constraint of directional flow associated with the known prior art systems since air is allowed to flow freely in any direction within the void space plane created by the void space forming elements. As a result more of the external envelope or facade of a building can be dynamically insulated. Previously, inaccessible spaces such as above and below windows, above doors, etc., can thus be void space dynamically insulated where previously they could only be insulated statically. A number of new void space dynamic insulation configurations are also presented that are achievable as a direct result of the use of the void space forming elements.

A dynamic insulation system suitable for deployment within an envelope or facade of a building or habitable construction is described. The system comprises one or more layers of insulation and one or more void space forming elements. The void space forming element comprises a panel attachment means for connecting this element to a layer of insulation and a spacer element that provides a means for defining at least one void space within the envelope or facade to facilitate the uniform, bi-directional, actively or passively driven flow of ventilation air through the void space. The resultant dynamic insulation systems can be made directly from any commonly available insulation sheet material, or combination of materials. This reduces the costs of the system without sacrificing performance or versatility. The system can be cut to any dimension, and joined together without loss of functionality to maximise insulation coverage of the building envelope or facade.

The foregoing description of the invention has been presented for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilise the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of the invention as defined by the appended claims.