WO2023016615A1

WO2023016615A1 - A shutter for mounting on an exterior side of a building and a method for making a shutter unit

Info

Publication number: WO2023016615A1
Application number: PCT/DK2022/050164
Authority: WO
Inventors: Patrick HOLT-HANSEN; Stefan Peter THIELEMANN; Ole BRENTING; Flemming KRAGERUP
Original assignee: Sorptionshade AS
Current assignee: Sorptionshade AS
Priority date: 2021-08-09
Filing date: 2022-08-09
Publication date: 2023-02-16
Anticipated expiration: 2024-02-09
Also published as: DK202170401A1; EP4384757A1; DK181577B1

Abstract

A shutter unit (1) for mounting on an exterior side of a building, which shutter unit (1) comprises a plurality of hollow slats (2) mounted to frame members (3, 4, 5, 6) in a shutter frame (8), an air outlet opening (72) for delivering ventilation air to a room on an interior side of the building, and an air inlet system for taking in fresh air from outside the building and conveying air to the air outlet opening, wherein the air inlet system comprises air inlet openings (10) in the hollow slats (2), and a first air flow passage (16) from the individual slat to a common air flow passage leading to the air outlet opening, characterized in that the shutter unit (1) is fully or partially covered by a transparent thermal insulating material (20), wherein the transparent thermal insulating material (2) is a coating (20, 30, 40).

Description

A SHUTTER FOR MOUNTING ON AN EXTERIOR SIDE OF A BUILDING AND A METHOD FOR MAKING A SHUTTER UNIT

TECHNICAL FIELD

The present invention relates to a shutter unit for mounting on an exterior side of a building, which shutter unit comprises a plurality of hollow slats mounted to frame members in a shutter frame, an air outlet opening for delivering ventilation air to a room on an interior side of the building, and an air inlet system for taking in fresh air from an exterior of the building and conveying air to the air outlet opening, wherein the air inlet system comprises air inlet openings in the hollow slats and a first air flow passage from the individual slat to a common air flow passage leading to the air outlet opening.

BACKGROUND ART

Such shutters have been known for some years, and they are used to provide shade and/or privacy and/or cooling/heating solutions. In EP patent No. 2683899 a window shutter unit for mounting on an exterior side of a building was presented, where fresh air from outside the building is drawn in through inlet openings in hollow slats and into the interior of the slats and flows in the length direction of the individual slat to a common air flow passage, from where it is brought to a room in the building via one or more air outlet openings. When passing through the slat, the air is heated by the sun energy originating from sunlight falling on the slat. During cold periods, heating of the air inside the air inlet system may also be provided by the sun warming the shutter frame, and in warm periods the shutter frame may provide shade and thus a cooling effect. In this way the temperature of the ventilation air supplied to the building via the air outlet openings can be regulated. It is noted that the air outlet openings of the shutter unit do not necessarily open directly into a room in the building but may open into a ventilation system of the building, from where it may be taken to a room in the building.

In general, such a shutter unit comprises a solar absorber system that comprises a solar absorber material. Typically, improvements of such solar absorber systems are not temperature or weather related, but mostly related to the optical characteristics of the unit itself, and can involve e.g. an antireflection coating for letting as much light as possible through the solar absorber material, or a highly reflective layer that reflects back as much light as possible to the solar absorber material. Temperature or weather depending improvements of a solar absorber system are mostly related to warm climate zones, where the building itself needs solutions for avoiding overheating in warm periods and have a comfortable indoor climate in the cold periods. In cold climate zones on the other hand buildings have higher heating needs and usually have larger windows than the ones in warm climates, which may require a system to regulate sun intake and/or adjust to the privacy needs of the building occupants.

The main factor that influences the efficiency of a shutter unit is the temperature that the slats can reach during operation. This factor is not a considerable problem in warm climates, but it is highly relevant in cold climates. Therefore, new solutions are needed to keep such shutter units operational and with a good efficiency in cold situations.

SUMMARY OF INVENTION

It is an object of the present invention to overcome the above- mentioned problems by providing a shutter for mounting on an exterior side of a building, which is better suited for use in cold climate zones by maintaining high the shutter unit efficiency also at low temperatures.

According to a first aspect of the invention, this and other objects are achieved by means of a shutter unit as defined above characterized in that the shutter unit is fully or partially covered by a transparent thermal insulating material, wherein the transparent thermal insulating material is a coating.

As explained above, the fresh air from an exterior of the building, i.e. from outside the building, is drawn in through the inlet openings in the hollow slats and into the interior of the slats where the ventilation air flows in the length direction of the individual slat to the first ventilation air flow passage and at the same time the ventilation air is heated by the sun energy. Within the shutter unit the ventilation air is close to the inner surfaces of the slats and the air flow passages, and heat can thus be transferred from the material of the shutter unit to the ventilation air to heat the same. By the shutter unit being fully or partially covered by a transparent thermal insulating material the efficiency of the shutter unit can be maintained high at low temperatures. The transparency of the thermal insulating material ensures the optimal heating of the shutter unit by the sun energy and the thermal insulation reduces heat loss to the surroundings, thus keeping the temperature of the shutter unit relatively high.

This effect is particularly pronounced in the slats, which are typically made of a material that comprises at least one of a metal and an alloy. Metals and alloys are a preferred choice of material since they have a high degree of robustness, even when made thin and lightweight, and a great heat transfer coefficient for transporting the heat from the sun exposed surface to the air inside the hollow slat. It is therefore presently preferred that the transparent thermal insulating material is provided on the slats. An example of a material, from which the hollow slats can be made, is sheet aluminium that can be coated with an absorbing layer and perforated.

The transparent thermal insulating material is a coating. A coating provides a good contact between the shutter unit and the transparent thermal insulating material, which is usually advantageous from an insulation point of view. A coating may also provide insulation by sealing assembly points or other potential sources of leakage in the air passage, thereby ensuring that the heated air travels through the shutter unit.

The coating may be provided on the outer surface of the shutter unit and/or the coating may be provided on the exterior side of the shutter unit.

The coating may be a multilayer coating. A multilayer coating could improve at least one of thermal, optical, impact resistant, weatherproof, and waterproof characteristics of the shutter unit compared to a single layer coating and may allow the combined use of two or more different transparent thermal insulating materials.

In the following, reference will primarily be made to the slats being coated with the transparent thermal insulating material. It is, however, to be understood that unless otherwise stated, other parts of the shutter unit may also or alternatively be coated with the transparent thermal insulating material, thereby achieving substantially the same effect. The energy efficiency of the shutter unit may, however, vary depending on the relative surface area and/or position of the parts coated with the transparent thermal insulating material. Additionally, reference will be made to an interior side and an exterior side, where the interior side is to be understood as the side facing the room of a building when the shutter unit is in a mounted state and the exterior side is to be understood as the side facing the exterior outside of a building when the shutter unit is in a mounted state. Additionally, an inner surface and an outer surface are defined, where the inner surface refers to the surface of the air passages and the outer surface refers to a surface of the shutter unit exposed to the surroundings.

In an embodiment, at least one of the plurality of hollow slats is covered by a solar radiation absorbing layer, and the solar radiation absorbing layer is located between said at least one hollow slat and a transparent thermal insulating material provided thereon.

As explained above, sunlight shining onto the hollow slat heats up the material of the slat, and the heat is transmitted through the material to the inner surface facing the interior of the slat and from there to the air inside the slat. The provision of the solar radiation absorbing layer, which may for example be a dark surface coating, like paint, may increase the absorption of energy from the sunlight.

A similar or supplemental effect may be achieved by at least one of the plurality of hollow slats having a textured surface, e.g. being blackbody microtextured or matted.

In an embodiment, the coating comprises at least one of surface irregularity, air entrapment, solvent popping, and bubbles. Such designed defects may result in improved thermal insulating properties of the coating, especially when trapping air inside the coating itself.

In an embodiment, at least one of the plurality of hollow slats is covered by a primer layer, and wherein the primer layer is located between the at least one hollow slat and a transparent thermal insulating material provided thereon. A primer layer placed in between the slat and the transparent thermal insulating material is beneficial for adhesion of the transparent thermal insulating material, and it can constitute a buffer layer for thickness and thermal management optimization.

As described above with reference to the transparent thermal insulating material, a solar radiation absorbing layer, a textured surface, a surface irregularity, air entrapment, solvent popping, bubbles, and/or a primer layer may also be provided on other parts of the shutter, particularly on the shutter frame.

In an embodiment, the thermal resistance of the transparent thermal insulating material is higher than the thermal resistance of the hollow slats.

As it is known, the higher the thermal resistance, the lower is the heat loss. Thereby, covering the hollow slats by the transparent thermal insulating material having a higher thermal resistance will contribute to ensuring that heat transport is towards the interior of the slats in addition to improving the heat insulation propriety of the hollow slats as such. The same applies to other parts of the shutter unit on which a transparent thermal insulating material is provided, particularly the shutter frame.

In an embodiment, the transparent thermal insulating material is at least one of a good UV resistant, an impact resistant, a weatherproof, and a waterproof material.

Transparent coverings and coatings exposed to direct sunshine often exhibit deterioration especially if made with plastic with excess of additives. This results in, e.g. exfoliation, yellowing and stress crack formation. Therefore, for outdoor applications, it is advantageous to use a weatherproof material that can withstand the negative impact of UV radiation and that can have the visual appearance and mechanical properties of transparent plastics. Typically, a qualitative assessment is made on the UV resistance of a polymer following international standard ISO 4582. Many materials were designed for the scope of being a good or an excellent UV resistant material, including fluorinated resins and Polyamide-lmide (PAI). By coating a surface of the shutter unit with this kind of material, a good impact resistance, an improved weatherproofing, and waterproofing of the shutter unit may be achieved. Materials, which are presently contemplated for use as a transparent thermal insulating material include polymers, such as polyurethane or clear polyester, resins, vinyl, Polyamide-lmide (PAI), polyimide, fiberglass, vinyl-coated fiberglass yams, polyethylene coated polypropylene yams, PAI with 30% fiberglass, as well as combinations and composites of such material. One commercially available material, which may be used for the transparent thermal insulating material, is the polyurethane based “Maritrans” coating marketed by Maris Polymers S.A..

Different transparent thermal insulating materials may be used on different parts of the shutter unit, for example using one on the hollow slats and another on the shutter frame, or the same material may be used in different concentrations and/or thicknesses on different parts of the shutter unit. A layer of insulating material covering the part of the hollow slats facing the interior side of the building in a mounted state of the shutter unit may be thicker and/or of a different kind of insulation than a layer of insulating material facing the exterior of the building in a mounted state of the shutter unit. This provides a better insulation on the part of the hollow slat facing the interior side of the building in a mounted state of the shutter unit. Thereby, heat loss through the interior side of the slats is reduced.

In an embodiment, the transparent thermal insulating material has a melting point above 100 °C and below the melting point of the hollow slat or other part of the shutter unit on which a transparent thermal insulating material is applied. This makes the shutter unit more sustainable for two main reasons: Firstly, it can be easily recycled by melting and separating the transparent thermal insulating material. A black body under the sun typically reaches a temperature of 70-80 °C, so to be on the safe side the thermal insulating transparent material should be able to endure a temperature of at least 100°C. Then in a recycling/reusing process the shutter unit can be heated to a higher temperature than 100°C for removing the coating, but below a damaging temperature for the slat/shutter unit. Secondly, the slat/shutter unit can be easily refurbished, and/or reused in different climate zones by removing and re-applying different transparent thermal insulating materials.

A second aspect of the invention relates to a method for making a shutter unit for mounting on an exterior side of a building, comprising the steps of: providing a shutter frame; providing a plurality of hollow slats comprising air inlet openings; and mounting the hollow slats to frame members in the shutter frame for the formation of a shutter unit comprising an air outlet opening for delivering ventilation air to a room on the interior side of the building, and an air inlet system for taking in air from an exterior of the building and conveying air to the air outlet opening, said air inlet system comprising a first air flow passage from the individual slat to a common air flow passage leading to the air outlet opening, characterized in that the method comprises the step of covering the shutter unit fully or partially with a transparent thermal insulating material, the method further comprising at least one of:

- painting a layer of the transparent thermal insulating material onto the shutter unit;

- depositing a thin film of the transparent thermal insulating material on the shutter unit;

- spreading a layer of the transparent thermal insulating material on the shutter unit; and wherein the layer or the thin film is a coating.

The advantages of covering the shutter unit fully or partially with a transparent thermal insulating material described with reference to the first aspect of the invention also applies to the second aspect of the invention and vice versa unless otherwise stated.

Different coating techniques can be used for different functional scope, e.g. brush painting and/or spray-painting a surface can be easy and affordable. For large scale precision deposition, techniques like evaporation or sputtering can be used for a precise thin film deposition. This kind of deposition could implement specific optical properties of a coating by tuning the thickness of the thin film and for example create an antireflection coating or an UV reflective thin film. Spreading a material, such as a paste or a gel, could create a thick protective layer that can be easily applied and removed. The choice of material for the transparent thermal insulating material may render some coating techniques more suitable than others, for example due to differences in their flow characteristic.

It is noted that the invention relates to all possible combinations of features recited in the claims.

Even though the invention has been described with reference to a shutter unit, the advantages of providing a transparent thermal insulating material will also apply to other similar structures including the so-called solar walls for mounting on an exterior side of a building, where an air inlet system is provided either in the solar wall itself or by allowing air to be conveyed between the solar wall and a wall of the building. An example of such a system is the product called "Solarwall” marketed by Conserval Engineering Inc..

BRIEF DESCRIPTION OF DRAWINGS

The present invention will now be described in more detail with reference to the appended drawings showing embodiment(s) of the invention.

Fig. 1 illustrates a perspective view of a shutter unit according to the present invention,

Fig. 2 illustrates an embodiment of a slat of the shutter unit in Fig. 1 , and

Fig. 3 and 4 are cross-sections of different embodiments of slats of the shutter unit in Fig. 2.

In the figures, the sizes of layers and regions are exaggerated for illustrative purposes and, thus, are intended to illustrate the general structures of embodiments of the present invention. Like reference numerals refer to like elements throughout, even though they may not be identical.

DESCRIPTION OF EMBODIMENTS

A shutter unit 1 mounted on exterior side of a partially cutaway facade 9 of a building is shown in Fig. 1 and comprises a plurality of hollow slats 2 arranged within a shutter frame 8. The shutter has an exterior side 100 facing the exterior of the building in a mounted state, i.e. the outside surrounding the building, and an interior side 200 facing a room of the building in a mounted state. Additionally, the shutter unit has an outer surface 150 and an inner surface 250 in the air passage of the shutter unit as shown in Fig. 3.

Returning to Fig. 1 , the shutter frame 8 comprises a first frame member 3 and a second frame member 4 extending in parallel and spaced apart by a third frame member 5 and a fourth frame member 6. In this embodiment the shutter unit 1 is mounted in front of a window (not visible) of the building and the frame members 3, 4, 5, 6 of the shutter frame 8 extend along window frame members of the window as will be readily understood by the skilled person. The shutter unit 1 may, however also be arranged in other positions.

In this embodiment a stationary part 7, which extends along the third frame member 5, is mounted on the facade 9 of the building. The stationary part 7 may be either a separate part or integrated with the third frame member 5. The stationary part 7 may serve only attachment purposes but may also serve as a housing for electrical or mechanical component, for example an operator for adjusting the position of the slats 2, and/or comprise an air flow passage.

In Fig. 1 the slats 2 extend horizontally between the first frame member 3 and the second frame member 4, but they can likewise extend vertically between the third frame member 5 and the fourth frame member 6, or obliquely between e.g. the first frame member 3 and the fourth frame member 6.

Each slat 2 is provided with air inlet openings 10. In Fig. 1 the air inlet openings are shown as local openings, such as circular or rectangular openings, and in Fig. 2, showing a single slat, three air inlet openings of a rectangular shape are shown. It is to be understood that the shape of the openings is not of consequence to the present invention.

In the embodiment in Fig. 2 the slat 2 has two major sides 11 (of which only the upper side is visible) and two minor sides 12, 13 extending between two opposed ends 14, 15 of the slat. As may be seen in Fig. 1 , the minor sides are facing away from the plane defined by the shutter frame 8 in the mounted state of the slat. The sides 11 , 12, 13 are spaced apart so that the slat is hollow with a free volume inside the slat. The sides 11 , 12, 13 are here illustrated as being flat, but they can also be curved, and the slat as such can have other cross-sectional shapes, such as a rounded, triangular, or drop-shaped.

At one end 15 of the slat 2 the free volume inside the slat is connected to a first ventilation air flow passage 16, which in turn is connected to a common air flow passage inside the first frame member 3 of the shutter frame 8. The common air flow passage thus receives air from all slats of the shutter unit configured with air inlet openings 10.

The first ventilation air flow passage 16 is here in the form a tubular element attached to the end of the slat and also serving for attachment of the slat by being inserted in an opening in the first frame member 3 but may also be in the form of a simple opening connected to the common air flow passage inside the first frame member 3 of the shutter frame 8.

In this embodiment the common air flow passage extends into the stationary part 7 and an air outlet opening 72 is provided at the end 71 of the stationary part 7, as depicted in Fig. 1 . The air outlet opening 72 may for example be connected to a ventilation system of the building by a pipe as shown by dotted lines in Fig. 1 or directly to an opening in the building for delivering ventilation air directly into a room in the building. It is, however, also possible to connect the air outlet opening 72 to another shutter unit so that several shutter units are connected in series. The openings 10, free volumes inside the slats 2, first ventilation air flow passages 16, and the common air flow passage inside the shutter frame 8 thus together form an air inlet system for taking in fresh air from outside the building and conveying this air to the air outlet opening 72.

Further details of the construction and function of a shutter unit is available to the skilled person in EP2683899A.

In the slat of Fig. 2 the air inlet openings 10 are elongate slits through the minor side 13, and the slits are located as distant as possible from the end 15 having the first ventilation air flow passage 16. This means that the ventilation air has to flow the longest possible distance inside the slat 2 and thus passing the largest possible area of the side of the slat being warmed by the sun during daytime, in this case the major side 11. In Fig. 2 three slit openings 10 are illustrated, but the slat 2 can have two slits or even only one slit or more than three as in Fig. 1 , where openings are distributed substantially evenly over the length of the slat. It is also possible to provide an air inlet opening 10 in end 14 opposite the end having the first ventilation air flow passage 16. Such an opening in end 14 can be provided in addition to openings in the sides of the slat 2, or it can be provided as the sole fresh air inlet opening in the slat. It is also possible to provide air inlet openings in the shutter frame 8.

The openings 10 can have a width of about 2 mm but preferably has a width of about 1.5 mm or less in order to prevent animals, particularly insects, from entering through them.

The possible shapes, sizes, and positions of the openings 10 apply to all embodiments of the invention regardless of how the slats and the shutter frame are embodied.

A side view of the slat detail “A” from Fig. 2 is illustrated in Fig. 3 and a cross-section of the detail “B” from Fig. 3 is illustrated in Fig. 4.

As seen in Fig. 4 at least the major side 11 of the slat 2 is covered by a solar radiation absorbing layer 40, a primer layer 30, and a transparent thermal insulating material 20 having a thickness T1. The thermal insulating material 20 is here illustrated as a single layer coating but may be a multilayer coating. The dimensions of the individual layers 20, 30, 40 are exaggerated for illustration purposes and it is to be understood that the relative thicknesses of the three layers may be different from what is shown in Fig. 4. Likewise, it is to be understood that the primer layer 30, and possibly even the solar radiation absorbing layer 40, may be left out.

Even though the coating 20, 30, 40 is only shown on the slat 2, it is to be understood that a similar coating may be found in the one or more frame members 3, 4, 5, 6 of the shutter frame 8 and/or on the stationary part 7. Details of the structure and function of the different layers 20, 30, 40 and of the materials used have been given above and will therefore not be repeated here.

The person skilled in the art realizes that the present invention is not limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. As an example of variation, it is possible to make a solar wall for mounting on an exterior side of a building in substantially the same way as described above with reference to the shutter unit. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.

Claims

P A T E N T C L A I M S

1. A shutter unit (1 ) for mounting on an exterior side of a building, which shutter unit (1) comprises a plurality of hollow slats (2) mounted to frame members (3, 4, 5, 6) in a shutter frame (8), an air outlet opening (72) for delivering ventilation air to a room on an interior side of the building, and an air inlet system for taking in air from an exterior of the building and conveying air to the air outlet opening, wherein the air inlet system comprises air inlet openings (10) in the hollow slats (2) and a first air flow passage (16) from the individual slat to a common air flow passage leading to the air outlet opening, characterized in that the shutter unit (1 ) is fully or partially covered by a transparent thermal insulating material (20), wherein the transparent thermal insulating material (2) is a coating (20, 30, 40).

2. A shutter unit according to claim 1 , wherein transparent thermal insulating material (20) is a multilayer coating.

3. A shutter unit according to any of the previous claims, wherein the coating on an interior side of the slats facing the interior of the building in a mounted state of the shutter unit is thicker and/or of a different material than the coating on an exterior side of the slats facing the exterior side of the building in a mounted state of the shutter unit.

4. A shutter unit according to any of the previous claims, wherein at least one of the plurality of hollow slats (2) is covered by a solar radiation absorbing layer (40), and wherein the solar radiation absorbing layer (40) is located between said at least one hollow slat (2) and a transparent thermal insulating material (20) provided thereon.

5. A shutter unit according to any of the previous claims, wherein at least one of the plurality of hollow slats (2) has a textured surface (40).

6. A shutter unit according to any of the previous claims, wherein the coating comprises at least one of surface irregularities, air entrapments, solvent popping, and bubbles.

7. A shutter unit according to any of the previous claims, wherein at least one of the plurality of hollow slats (2) is covered by a primer layer (30), and wherein the primer layer (30) is located between the at least one hollow slat (2) and a transparent thermal insulating material (20) provided thereon.

8. A shutter unit according to any of the previous claims, wherein the thermal resistance of the transparent thermal insulating material (20) is higher than the thermal resistance of the hollow slats (2).

9. A shutter unit according to any of the previous claims, wherein the transparent thermal insulating material (20) has a melting point above 100 °C and below the melting point of the hollow slat (2).

10. A method for making a shutter unit (1 ) for external mounting on a building, comprising the steps of:

- providing a shutter frame (8),

- providing a plurality of hollow slats (2) comprising air inlet openings (10)

- mounting the hollow slats (2) to frame members (3, 4, 5, 6) in the shutter frame (8) for the formation of a shutter unit (1 ) comprising an air outlet opening for delivering ventilation air to a room in the building, and an air inlet system for taking in air from outside the building and conveying air to the air outlet opening, said air inlet system comprising a first air flow passage from the individual slat to a common air flow passage leading to the air outlet opening, characterized in that the method comprises the step of covering the shutter unit (1 ) fully or partially with a transparent thermal insulating material (20), the method further comprising at least one of:

- painting a layer of the transparent thermal insulating material onto 15 the shutter unit (1 );

- depositing a thin film of the transparent thermal insulating material on the shutter unit (1 );

- spreading a layer of the transparent thermal insulating material on the shutter unit (1 ) and wherein the layer or the thin film is a coating (20, 30, 40).