DK181577B1

DK181577B1 - Shutter for exterior mounting on a building and method of manufacturing a shutter assembly

Info

Publication number: DK181577B1
Application number: DKPA202170401A
Authority: DK
Inventors: Holt-Hansen Patrick; Peter Thielemann Stefan; Brenting Ole; Kragerup Flemming
Original assignee: Sorptionshade As
Priority date: 2021-08-09
Filing date: 2021-08-09
Publication date: 2024-05-30
Also published as: EP4384757A1; WO2023016615A1; DK202170401A1

Abstract

A shutter unit (1) for external mounting on 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 for delivering ventilation air to a room in 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 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).

Description

DK 181577 B1 1

TECHNICAL FIELD

The present invention relates to a shutter unit for external mounting on 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 ven- tilation air to a room in 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 in the hollow slats and a first air flow passage from the individual slat to a common air flow pas- sage 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 external mounting on 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 open- ings. When passing though the slat, the air is heated by the sun energy origi- nating 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 shut- ter 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 does 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

DK 181577 B1 2 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 depend- ing improvements of a solar absorber system are mostly related to warm cli- mate 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 cli- mates. Therefore, new solutions are needed to keep such shutter units opera- tional 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 external mounting on a build- ing, 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 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

DK 181577 B1 3 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.

In the following, reference will primarily be made to the slats being covered or coated with the transparent thermal insulating material. It is, how- ever, to be understood that unless otherwise stated, other parts of the shutter unit may also or alternatively be covered or coated with the transparent ther- mal 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 covered or coated with the transparent thermal insulating material.

In an embodiment, the transparent thermal insulating material is a multilayer coating. A coating provides a good contact between the shutter unit and the transparent thermal insulating material, which is usually advanta- geous from an insulation point of view. 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.

DK 181577 B1 4

In an embodiment, at least one of the plurality of hollow slats is cov- ered by a solar radiation absorbing layer, and the solar radiation absorbing layer is located between said at least one hollow slat and a transparent ther- mal 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 ex- ample be a dark surface coating, like paint, may increase the absorption of energy from the sunlight.

In an embodiment, at least one of the plurality of hollow slats has a textured surface, e.g. being blackbody microtextured or matted.

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

In an embodiment, at least one of the plurality of hollow slats is cov- ered 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 ther- mal insulating material is beneficial for adhesion of the transparent thermal insulating material, and it can constitute a buffer layer for thickness and ther- mal management optimization.

As described above with reference to the transparent thermal insulat- ing 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

DK 181577 B1 heat loss. Thereby, covering the hollow slats by the transparent thermal insu- lating 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 5 other parts of the shutter unit on which a transparent thermal insulating mate- rial 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. There- fore, for outdoor applications, it is advantageous to use a weatherproof mate- rial that can withstand the negative impact of UV radiation and that can have the visual appearance and mechanical properties of transparent plastics. Typ- ically, 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-Imide (PAl). 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. Ma- terials, which are presently contemplated for use as a transparent thermal insulating material include polymers, such as polyurethane or clear polyester, resins, vinyl, Polyamide-Imide (PAI), polyimide, fiberglass, vinyl-coated fiber- (glass yarns, polyethylene coated polypropylene yarns, PAI with 30% fiber- glass, as well as combinations and composites of such material. One com- mercially 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 dif- ferent 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

DK 181577 B1 6 concentrations and/or thicknesses on different parts of the shutter unit.

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 materi- al is applied. This makes the shutter unit more sustainable for two main rea- sons: Firstly, it can be easily recycled by melting and separating the transpar- ent 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 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 covering or 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 remov- ing and re-applying different transparent thermal insulating materials.

A second aspect of the invention relates to a method for making a shutter unit for external mounting on 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 in the building, and an air inlet system for taking in air from outside the building and conveying air to the air outlet open- ing, 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, character- ized 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;

DK 181577 B1 7 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 the first as- pect of the invention also applies the second aspect of the invention and vice versa unless otherwise stated.

Different covering or 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 proprieties 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 or in general a stretchable sheet material, could create a tick protective layer that can be easily applied and removed. The choice of material for the transparent thermal insulating material may render some covering or 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 ma- terial will also apply to other similar structures including the so-called solar walls for external mounting on a building, where an air inlet system is provid- ed 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 refer- ence to the appended drawings showing embodiment(s) of the invention.

Fig. 1 illustrates a perspective view of a window shutter unit accord- ing to the present invention,

DK 181577 B1 8

Fig. 2 illustrates an embodiment of a slat of the window shutter unit in

Fig. 1, and

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

In the figures, the sizes of layers and regions are exaggerated for il- lustrative 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 externally on a 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 frame 8 comprises a first frame member 3 and a second frame member 4 held in parallel and spaced apart by a third frame member 5 and a fourth fame member 6. In this embodiment the shutter unit 1 is mount- ed 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 mem- ber 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 mem- ber 3 and the second frame member 4, but they can likewise extend vertically between the third fame member 5 and the fourth frame member 6, or obliquely between e.g. the first frame member 3 and the fourth frame member 6.

DK 181577 B1 9

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 open- ings, and in Fig. 2, showing a single slat, three air inlet openings of a rectan- gular 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 connect- ed to a first ventilation air flow passage (not visible), which in turn is connect- ed to a common air flow passage inside the first frame member 3 of the shut- ter 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 may for example be in the form a tubular element (not shown) 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.

In this embodiment the common air flow passage extends into the stationary part 7 and an air outlet opening (not visible) is provided at the end 71 of the stationary part 7. The air outlet opening may for example be con- nected to a ventilation system of the building 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 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, and the common air flow passage inside the shutter frame 8 thus together form an air

DK 181577 B1 10 inlet system for taking in fresh air from outside the building and conveying this air to the air outlet opening.

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. This means that the venti- lation 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 open- ings 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 pas- sage. 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 in- sects, 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 shut- ter 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 multi- layer coating. The dimensions of the individual layers 20, 30, 40 are exagger- ated for illustration purposes and it is to be understood that the relative thick-

DK 181577 B1 11 nesses 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 by no element is 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 so- lar wall for external mounting on a building in substantially the same way as described above with reference to the shutter unit.

Additionally, variations to the disclosed embodiments can be under- stood 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

DK 181577 B1 12 PATENT CLAIM

1. Shutter unit (1) for external mounting on a building, which shutter unit (1) comprises a plurality of hollow slats (2) mounted on frame elements (3, 4, 5, 6) in a shutter frame (8), an air outlet opening for supplying ventilation air to a room in the building, and an air intake system for taking in air from outside the building and guiding the air to the air intake opening, the air intake system comprising air intake openings (10) in the hollow slats (2) and a first air flow passage from the individual lamella to a common airflow passage leading to the air outlet opening, where the shutter unit (1) is completely or partially covered by a transparent thermal insulation material (20), characterized in that the transparent thermal insulation material (20) is a coating (20, 30, 40).

2. Shutter unit for external mounting on a building according to claim 1, wherein the transparent thermal insulation material (20) is a multi-layer coating.

3. Shutter unit for exterior mounting on a building according to any one of the preceding claims, wherein at least one of the plurality of hollow slats (2) is covered with a layer (40) that absorbs solar radiation, and wherein the layer (40), which absorbs solar radiation, is located between the at least one hollow lamella (2) and a transparent thermal insulation material (20) provided thereon.

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

5. A shutter unit according to any one of the preceding claims, wherein the covering or coating comprises at least one of surface irregularities, entrapped air, blistering of solvent and bubbles.

DK 181577 B1 13

6. Shutter unit for external mounting on a building according to any one of the preceding claims, wherein at least one of the plurality of hollow lamellae (2) is covered by a primer layer (30), and wherein the primer layer (30) is located between the at least one hollow lamella (2) and a transparent thermal insulation material (20) provided thereon.

7. Shutter unit for external mounting on a building according to any one of the preceding claims, where the thermal resistance of the transparent thermal insulation material (20) is greater than the thermal resistance of the hollow slats (2).

8. A shutter unit for external mounting on a building according to any one of the preceding claims, wherein the transparent thermal insulation material (20) has a melting point above 100 °C and below the melting point of the hollow lamella (2).

9. Method for manufacturing a shutter unit (1) for external mounting on a building, and which comprises the following steps: - provision of a shutter frame (8), - provision of a plurality of hollow slats (2) comprising air intake openings (10 ) - mounting the hollow slats (2) on frame elements (3, 4, 5, 6) in the shutter frame (8) to form a shutter unit (1) comprising an air outlet opening for supplying ventilation air to a room in the building , and an air intake system for taking in air from outside the building and guiding the air to the air outlet opening, which air intake system comprises a first air flow passage from the individual slat to a common air flow passage leading to the air outlet opening, characterized in that comprises the step of covering the shutter unit (1) in whole or in part with a transparent thermal insulation material (20), which method further comprises at least one of: - painting a layer of the transparent thermal insulation material on the shutter unit (1);

DK 181577 B1 14 - deposition of a thin film of the transparent, thermal insulation material on the shutter unit (1); - spreading a layer of the transparent thermal insulation material on the shutter unit (1) and where the layer or thin film is a coating (20, 30, 40).