GB2044328A - Sun Blind - Google Patents

Abstract

A blind comprises a plurality of pivotally mounted slat members. A first side of said slat members which is to receive solar radiation thereon has a surface 103 with reflective characteristics. The second or opposite side of said slat members have a coloured and/or absorbing surface 104. <IMAGE>

Description

SPECIFICATION Sun Blind This invention relates to a venetian solar blind.

A blind collector has been suggested in the art and which comprises a plurality of slats having a first and second opposite surface. The first surface facing the sun radiation has an absorbing surface and the opposite or second surface has a reflecting surface. Several distinct disadvantages are associated with such a known construction.

One such disadvantage is that the heat reflection of the absorbing surfaces occurs towards the window side.

Accordingly, a primary object of this invention is to propose a venetian solar blind capable of reflecting and/or absorbing solar energy.

Another object of this invention is to propose a venetian solar blind capable of insulating a zone from solar energy.

A further object of this invention is to propose a venetian solar blind having effective draping properties.

Yet a further object of this invention is to propose a venetian solar blind which is comparatively simple in construction.

A still further object of this invention is to propose a blind such that the heat reflection of the absorbing surfaces are conveyed to the interior of the room and that in spite of varying functions of the blind a uniform width of light penetration is given for diffuse radiation.

According to this invention there is provided a blind comprising a plurality of pivotally mounted slat members, a first side of said slat members which is to receive solar radiation thereon having reflective characteristics, the second or opposite side of said slat members having a coloured or absorbing surface.

The venetian blind of the present invention is adapted to be disposed at the window or any opening of a constructional building and which is exposed to sunrays. The venetian blind consists of a plurality of slats and which are disposed in a spaced relationship to each other. The slats are capable of being rotated about their longitudinal axis.

In accordance with this invention a first side of said slats, have a reflective surface or a surface having reflective characteristics. Such a first side is that side which is capable of directly receiving the solar radiation. The opposite side of each of the slats have an absorbing or coloured surface.

Thus, and when an absorption of reflection of solar energy is required by the venetian blind, and dependent on the angle of incidence, the sun rays strike the first surface of each of the slats. The sun rays from the first surface are reflected onto the second surface of the adjacent slat or directly into the room. Such a condition prevails during cold periods. It will be apparent that in cold periods, and when the angle of incidence is small, all of the sun radiation is reflected into the interior of the room or onto said second surface. However, in partly cold periods, and when the angle of incidence is greater than in completely cold periods, and due to the spacing of adjacent slats, a part of the solar radiation striking the first side of each slat may be reflected back into the atmosphere, and which is a desired feature.

However, in a hot period, and as the angle of incidence increases to a greater value, all of the sun rays are reflected back into the atmosphere.

In such an instance, the venetian blind functions as an insulation means.

As described hereinabove, the slats have a rotatable movement along their longitudinal axis and such that the reflective side of the slats can also face the inside of a room. In such an instance, the venetian blind serves as an infra red reflector and retains the warmth within the room. Further, it can also serve as a reflector for indirect light.

One of the advantages derived by the device of the present invention is that all emission or nonabsorbed energy is reflected into the room and such that all energy losses of a known collector is avoided.

Further, in accordance with this invention, and by making use of the different angle of incidence, the angle of slat is the same for all climatic conditions. The diffused light radiating through the blind into room is the same as in winter and summer and, whereby the room is never darkened.

Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein: Figure 1 shows the blind as a solar radiation reflecting means; Figure 2 shows the blind as a solar radiation insulating means; and Figure 3 shows the blinds as insulating device.

Referring to the drawings, Figure 1 shows the vertical section through a horizontal blind 100 as a solar collector. The solar radiation 101 travels through the window 102 and strikes the reflecting surface 103 of a slat 107. From the latter, the solar radiation is reflected on to the absorbing surface 104 of slat 107. The absorbed component of radiation is radiated into the room interior as heat. The not-absorbed component of radiation is radiated into the room interior as light radiation and absorbed on the objects and converted into heat. A particular advantage of absorbing the energy on the side of room interior lies among others also in the fact, that the convective flows 105 remain with the room and do not flow out of the window. Thus, a loss of energy on the cold window pane is avoided.

Further the blind can be fixed directly on the window.

Figure 2 shows the blind as a solar insulating means for energy reflection. The interior of the room is shaded, and the incident radiation 101 is reflected back to the outside space by the reflecting surface 103, so that not only a sun protection, but also a heat protection is provided.

This is effected merely by means of a minor rotation of the slats about their horizontal axis, so that the width of light penetration between adjacent slats remains approximately the same.

Since, however, the sun incidence in summer is under a larger angle of radiation, a rotation of the slats can largely be done without.

Figure 3 shows the blind in insulating position.

The reflective sides 103 are reoriented towards the room interior. Above the blind, an indirect illumination 106 is arranged. The blind is used as a reflection system.

In order to control the reflection for heating or coating purpose, the reflective surface 103 should have a mirror chatacteristic. Such a mirror can be produced through a metallic vaporasition and subsequent lacquer coating. In the instance where decorative properties are also required, the surfaces could be of a silver or golden-mirror-like design, and which can be obtained, for instance, by means of an aluminium or copper vaporasition or through mixing of various metals. Further techniques to obtain a mirror surface are anodizing of aluminum, electrolytical coating with copper, or other non-ferrous metals or plating with such metals. Furthermore, such surfaces can be coated with transmittive and pigmented lacquers.

The reverse sides of the slats, namely surfaces 104, may be of any colour shade. The absorption capacity of the lacquer is irrelevant, since the notabsorbed component of radiation is radiated into the room interior and absorbed on the objects. A dark lacquer co, however, is to be preferred in order to damp the brightness of the light.

However, surface 104 should possess a capacity to reflect the radiation in a diffuse manner, in order to avoid a dazzling effect and ensure a good protection against the sun, whereas on the radiation side the radiation is to be reflected as regularly as possible (mirror effect). Only through the mirror effect a good energy reflection into outside space is achieved in summer and a good energy radiation into the interior of the room in winter. However, the term absorbing does not necessarily refer to a dark lacquer coating and is not to be understood in a quantitative manner.

The blind collector in accordance with its objective is to be understood as a device, that makes possible in spite of shading of the interior of the room a collection of the radiated solar energy for the room interior as heat energy. This is effected even with a largely reflecting surface 104 of the slat.

Claims (9)

Claims

1. A blind comprising a plurality of pivotally mounted slat members, a first side of said slat members which is to receive solar radiation thereon having a surface with reflective characteristics, the second or opposite side of said slat members having a coloured and/or absorbing surface.

2. A blind as claimed in claim 1, wherein for the purpose of collecting heat energy the slats can be rotated about their longitudinal axis and such that the solar radiation impinging upon the reflecting or first side is reflected on to the second side of the adjacent slat.

3. A blind as claimed in claim 1, wherein the slats can be rotated about their longitudinal axis such that the radiation impinging upon the reflecting or first side of the slats can be reflected back into outside space.

4. A blind as claimed in any one of claims 1 to 4, wherein the reflecting side has a mirror surface for visible light, said mirror surface being formed by metallic vaporization anodizing, plated with non-ferrous metals, electrolytically coated galvanized and/or lacquered.

5. A blind as claimed in claim 4, wherein the mirror surface has a gold or silver like surface.

6. A blind as claimed in claim 4 or 5, wherein the surface is formed by means of a metallically vaporized plastic foil or aluminium foil.

7. A blind as claimed in claim 1, wherein the second side of the slats is provided with a dark coating.

8. A blind as claimed in claim 1, wherein said second side has also reflective characteristics.

9. A blind substantially as described herein with reference to the accompanying drawings.