ES2559618T3 - Aerial lighting device for protection of an area against solar radiation - Google Patents

Abstract

Sun protection procedure of a zone, called illuminated zone (2), in an installation site capable of being exposed to direct radiation from the Sun, in which: - a screen (3) is arranged above the zone (2 ) illuminated in such a way that it hides at least a part of the rays coming directly from the Sun in the solar noon on the summer solstice; - the screen (3) is mounted fixed with respect to the installation site; characterized in that: - the screen (3) is arranged in such a way that it forms, with the illuminated area, a first opening, called the equatorial opening, on the side of the Earth's equator, and a second opening, called the polar opening, on the side of the terrestrial pole closest to the installation site, the polar opening being higher than the equatorial opening with respect to the illuminated area (2); - the screen (3) is continuous between the equatorial opening and the polar opening; - the shape, orientation and position of the screen (3) are selected so that: - less than a quarter of the illuminated area (2) is illuminated by the direct rays of the Sun at solar noon on the summer solstice ; - at least one quarter of the illuminated area (2) is illuminated by the direct rays of the Sun in the solar noon on the winter solstice.

Description

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Aerial lighting device for protection of an area against solar radiation DESCRIPTION

The invention relates to a method of protection of an area susceptible to being exposed to direct radiation from the sun, in particular from a roof area or from a window, against direct solar radiation in summer, as well! as to a protection device obtained by implementing said procedure. This extends to a zenith lighting device consisting of said protection device.

The protection of said area, especially of a roof area, in particular of an area delimited by a frame equipped for example with a glass (for example a skylight), against direct radiation from the Sun allows to limit the heating of the air in the room located under the roof. In fact, hiding the direct radiation of the Sun allows to avoid the greenhouse effect due to the presence of a glass mounted on the roof frame.

However, although it is often desired to avoid such direct illumination on a glass on the roof in summer, in winter this direct radiation can be highly sought both by the light it provides and by the natural warming it provides, in particular by the greenhouse effect. The same problem arises with other areas likely to be exposed to solar radiation (roof opening, skylights, building openings ...).

Numerous known devices are mobile and orientable depending on the time and seasons in such a way that they protect an area from the sun's rays in summer but allowing the sun to strike in this area in winter. However, these known devices are energy consumers and are complex and fragile because of their moving parts. They also have the disadvantage of being expensive to manufacture and maintain.

Other fixed known devices allow hiding a roof window from the sun's rays, but either hide the direct rays of the sun in both summer and winter, or do not allow sufficient natural illumination of the room under the roof when they hide Sun rays in summer. These known devices prevent the penetration of light through the roof window frame at all stations.

The devices described in documents FR 2 705 985 A1, XP-001473404, CH 390 510 A and DE 295 20 570 U1 can also be consulted.

The invention aims to offer, therefore, a method of protection of an area, such as a roof area, susceptible to being exposed to direct radiation from the Sun, allowing said area to be protected from direct radiation from the Sun in summer and allowing said area receives a direct radiation from the sun in winter.

The invention also aims to offer a method of protection of said roof area allowing said area to receive a significant amount of indirect light in summer, although it is hidden from the direct radiation of the Sun at this station.

The invention aims to offer said simple and easy to implement protection procedure.

The invention relates in particular to a process of economic protection.

The invention also aims to offer a protection device for said area that has the same advantages.

This refers in particular to a protection device that only requires minimal maintenance that corresponds to routine cleaning.

The invention also relates to an overhead lighting device comprising said protection device whose placement is simple and does not require adjustments.

To this end, the invention relates in accordance with the revindication to a sun protection process of an area, called an illuminated area, in an installation site capable of being exposed to direct radiation from the Sun, in which:

- a screen is arranged above the illuminated area in such a way as to hide at least a part of the rays directly coming from the Sun in the solar midday on the summer solstice;

- the screen is mounted fixed with respect to the installation site;

characterized by:

- the screen is arranged in such a way that it forms, with the illuminated area, a first opening, called the equatorial opening, on the side of the Earth's equator, and a second opening, called the polar opening, on the side of the land pole closest to the location of installation, the polar opening being higher than the equatorial opening with respect to the illuminated area;

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- the screen is continuous between the equatorial opening and the polar opening;

- the shape, orientation and position of the screen are selected so that:

or less than a quarter of the illuminated area is illuminated by the direct rays of the Sun in the solar midday at the summer solstice;

or at least a quarter of the illuminated area is illuminated by the direct rays of the Sun in the solar noon on the winter solstice.

Throughout the text, any element located on the side of the Earth's equator with respect to the other elements is designated as “equatorial”. For example, for an installation site located in the northern hemisphere, the equatorial edge of the screen is the edge located on the south side of the screen.

Likewise, any element located on the side of the Earth's pole closest to the installation site is designated as "polar." For example, in the northern hemisphere, the polar edge of a screen is the edge located on the north side of the screen.

In addition, throughout the text, the noon time is designated as "solar noon" according to the solar time, sometimes also called "real noon." It is the culmination point of the Sun in the terrestrial sky on a given day, seen from a given terrestrial installation site. It is also the point at which the hour angle of the Sun is null at the installation site considered.

An installation site according to the invention is fixed in the terrestrial reference system, that is to say that its latitude, its longitude and its azimuthal orientation are fixed. Thus, an installation site according to the invention can be in particular a building roof or a floor.

An illuminated area is, in particular, a building surface capable of being exposed to direct radiation from the Sun and of being heated by it. Said illuminated area is in particular located substantially under a protective screen arranged in accordance with a method according to the invention. It is desired to protect this illuminated area (and / or a volume of air below) from any warming caused by the radiation of the Sun in summer, and it is desired instead to favor its heating by the radiation of the Sun in winter.

An illuminated area according to the invention extends to all types of surfaces, and in particular comprises surfaces that are heated under the effect of solar radiation and glazed surfaces that allow at least some components of sunlight to pass through. For example, an illuminated area according to the invention located on a roof is in particular capable of allowing a greenhouse volume heating of a volume of air located under the roof.

In a procedure according to the invention, the screen is mounted fixed with respect to the installation site and, therefore, is fixed with respect to the illuminated area. It is a procedure to obtain a simple and economical device, without any mobile mechanical part once it is installed and while guaranteeing its functions.

In a procedure according to the invention, the variation of the position of the Sun in the terrestrial sky is used to the maximum, depending on the time, but also and especially depending on the seasons so that the direct illumination of the illuminated area varies. function of time and seasons.

In said procedure, the screen is arranged above the illuminated area, that is to say that it is located substantially above the illuminated area in an orthogonal direction to a plane tangent to said illuminated area. In particular, for a horizontal illuminated area, the screen is globally vertical above the illuminated area. On the contrary, the orthogonal projection of the screen does not generally have the same shape as the illuminated area.

In addition, the screen is arranged away from the illuminated area, that is, it is usually separated from the latter. Each screen arranged in accordance with the invention is above an illuminated area.

In addition, the edges of the screen, that is to say the outer contours that delimit the surface of the screen, are not necessarily located in the vertical of the edges of the illuminated area. In particular, the screen may be moved north or south with respect to the screen. For example, in the areas between a pole and the tropics closest to this pole you can choose to move the equatorial edge of the screen in the direction of the equator with respect to the vertical of the equatorial edge of the illuminated area. That is, between the north pole and the tropic of Cancer for example, the southern edge of the screen is advantageously displaced in a southern direction with respect to the southern edge of the illuminated area.

Indeed, in this part of the globe, the rays coming from the Sun, in the solar noon in the summer solstice in particular, have a non-zero angle with respect to the vertical (with the condition of not being fair

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in the tropics).

Thus, if it is desired to protect the entire illuminated area from the direct rays of the Sun, the screen must be arranged slightly offset with respect to the equatorial edge of the illuminated area. The screen is further displaced in this direction the farther the installation location of the tropics is in the direction of the nearest pole. In the same way, the screen is more displaced in this sense the higher it is arranged with respect to the illuminated area.

The screen is arranged in such a way that it forms, with the illuminated area in particular and with the installation site in general, an equatorial opening formed by the equatorial edge of the screen and a curve of the illuminated surface, or of the installation site. This curve is formed by the closest points of each point of the equatorial edge of the screen. Similarly, the polar edge of the screen forms a polar opening with the illuminated area and / or the installation site.

The polar opening is of a higher average with respect to the illuminated area and / or the installation site than the equatorial opening. Thus, the polar aperture is larger than the equatorial opening (particularly if the east-west size of the equatorial edge of the screen is similar to the east-west size of the polar edge of the screen).

Thus, for example, for a lighted area and a substantially flat installation site, and for a substantially flat screen, the screen is advantageously installed inclined in a north-south direction with respect to the plane of the installation site.

The equatorial edge of the screen is usually installed lower than its polar edge. Thus, for example, in the northern hemisphere, a screen is arranged with the upper edge to the north, and with the lower edge to the south. The bottom edge of the screen is, therefore, arranged on the south side in the northern hemisphere and on the north side in the southern hemisphere.

This arrangement of the screen allows, in summer, to protect the illuminated area from the direct rays of the Sun while allowing a diffused or reflected light (therefore not direct) to illuminate the illuminated area. This diffused or reflected light penetrates through the polar aperture. In particular, if the installation site is a roof, and the illuminated area a window, this arrangement of the screen allows to guarantee an important natural illumination of a room located under the illuminated area, while avoiding a greenhouse heating in summer .

The shape, the azimuthal direction and the position of the screen are selected in particular so that at least three quarters of the illuminated area is hidden from the direct rays of the Sun in the solar midday at the summer solstice and that at least A quarter of the illuminated area is illuminated by the direct rays of the Sun that pass through the equatorial opening in the solar noon on the winter solstice.

In addition, a screen according to the invention is advantageously selected continuously between its equatorial edge and its polar edge. Therefore, there is only one screen, in one piece, between the equatorial edge and the polar edge.

In this way, the shape of the screen is selected, in combination with its orientation and final arrangement above the illuminated area, on the one hand so that its equatorial edge is at least partly away from the surface of the area illuminated and of the installation site. By the equatorial opening as! formed, the direct rays of the Sun can pass and the air can circulate.

More particularly, the shape, azimuth direction and screen position can, for example, be selected such that:

- no direct ray of the Sun passes through the equatorial opening in the solar noon on the summer solstice;

- the illuminated area is fully illuminated by the direct rays of the Sun that pass through the equatorial opening in the solar noon on the winter solstice.

In this way, the invention allows minimizing the greenhouse effect through an illuminated area formed by a translucent or transparent glazed surface in summer, and maximizing the greenhouse effect by means of said area illuminated in winter.

For example, with an absolutely opaque and non-perforated screen, you can select the shape, azimuth direction and position of the screen so that no direct ray of the Sun impacts the illuminated area in the solar midday on the summer solstice.

For example, the shape and arrangement of a screen can be selected in such a way that the projection of its shadow on the solar midday on the summer solstice covers at least the illuminated area, in particular such that the shadow contour of the screen corresponds perfectly with the contour of the illuminated area in the

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solar midday at the summer solstice.

In a procedure according to the invention, the shape, the azimuthal direction and the position of the screen can be selected such that in the summer solstice no direct ray of the Sun impacts the illuminated area at any time between the exit and the sunset.

By means of a procedure according to the invention, the illuminated area impacted by the direct rays of the Sun in the solar midday is growing between the summer solstice and the winter solstice, and decreases between the winter solstice and the solstice of summer.

Advantageously and according to the invention, in some particularly simple embodiments, the shape, orientation and position of the screen are selected so that the edge of the screen that delimits the equatorial opening, called the equatorial edge, is found at any point at a minimum height with respect to the illuminated area, such that:

to> p.an.tan (a)

being:

• at the angle between the lighted area and the sun's rays in the solar midday on the winter solstice;

• still the dimension of the illuminated area according to the north-south direction at the point considered; Y

• 1/4 <p <1 the proportion of the illuminated area that the direct rays of the Sun should illuminate in the solar midday on the winter solstice.

Likewise, in an advantageous way of carrying out a method according to the invention, the screen is arranged in such a way that it conceals the illuminated area of any direct ray of the Sun in the solar midday on the summer solstice.

In another particularly advantageous embodiment of a method according to the invention, the amount of light that passes through the screen at any station is adjusted by selecting a screen that has holes that allow direct sunlight to pass through.

Thus, although the greenhouse effect is very limited in summer by a shadow made over almost the entire illuminated area, some holes in the screen allow to obtain a more important natural lighting. The choice of said screen is especially advantageous when the illuminated area is a surface of light penetration into a room located under the roof, such as a window for example.

The number of holes, its dimensions, its forms, its embodiment and its arrangement on the screen are parameters that can be selected according to different criteria such as: the amount of light that must pass through the screen , the aesthetics of the screen, etc.

Alternatively, a screen that is not perforated but partially translucent can be selected in a particular form of embodiment of the invention.

In addition, advantageously and in accordance with the invention, the shape, direction and position of the screen are selected for the greater part - in particular the totality - of the illuminated area is illuminated by the direct rays of the Sun passing through the equatorial opening in the solar noon in the winter solstice.

In the particular case in which the entire illuminated area is illuminated at this time, p = 1. This configuration allows to maximize thermal recoveries in winter.

An illuminated area according to the invention can be of any type, and can be found in any type of installation site. In particular, this may be an area of a roof or a floor.

Advantageously and according to the invention, the installation site is a roof and the illuminated area is an opening made in the roof, said opening being closed by a covering element of a watertight and at least translucent material.

A material at least translucent according to the invention is translucent or transparent in at least part of the solar radiation. For example, said material can be selected from glass, polycarbonates and equivalents.

Said covering element is advantageously a covering window, such as a skylight, a point skylight, a running skylight (for example vault type), a fixed frame, a skylight glazed frame, a ventilation or outlet frame smoke, a Velux® window, etc.

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Likewise, advantageously and according to the invention, the covering element is mounted on a frame in turn mounted on the contour of the opening made on the roof, allowing the direct rays of the Sun on the covering element to heat a volume of air located under the roof, in particular located under the illuminated surface and under the covering element.

Advantageously, the respective assemblies of the covering element on the frame and the frame on the contour of the opening can be carried out in a watertight, at least water-tight manner.

In this way, the water tightness of the roof is made while allowing light to penetrate an underlying room. In addition, a greenhouse effect is possible when the direct rays of the Sun hit the glazed illuminated area.

Likewise, in order to guarantee complete water tightness of the roof, advantageously and in accordance with the invention, the covering element can be mounted tightly in the contour of the illuminated area, allowing direct rays of the Sun in the illuminated area heating a volume of air located under the roof, in particular located under the illuminated area and under the covering element.

Thus, at least in the closed state, the illuminated area is not a source of air exchange between a volume of air (a room) located under the roof and the outside in such a way that thermal losses are minimized.

However, nothing prevents the provision of an illuminated area, in particular an opening in the roof that allows, by its very nature and its assembly, a water tightness and an air-related permeability, with a ventilation purpose for example.

In an advantageous way of realizing the invention, the screen is selected in a material opaque to solar radiation.

In addition, advantageously and according to the invention, being the screen outside and separated from the installation site (at least by its equatorial and polar edges) allows the creation of a convection air flow under the screen.

Particularly in summer, when the screen is heated by solar radiation, the air under and near the screen is heated and rises towards the polar edge of the screen that is higher than the equatorial edge of the latter. Therefore, an aspiration is created at the bottom of the screen, near its equatorial edge. A convection movement is then established between the screen and the illuminated area, usually substantially in a north-south direction, in particular from the equatorial edge to the polar edge. This air flow allows you to cool the lighted area.

Moreover, since the screen is mounted in accordance with the method of the invention, separated from the illuminated area and located outside, its heating does not cause heating, for example, of a room located under a roof.

Finally, a procedure according to the invention can be implemented in existing installation sites, for example on existing roof windows. This procedure allows to add a solar protection after and outside.

The protection procedure according to the invention allows obtaining a protection device of an area illuminated against direct radiation from the Sun in summer.

The invention extends in particular to a protection device according to claim 9.

In particular, said device comprises at least one screen and fixing means of this screen above said illuminated area according to a method according to the invention.

According to claim 9, said device is a protection device for a zone, called a lighted area, in an installation location capable of being exposed to direct radiation from the Sun, said protection device consisting of a screen:

- arranged above the illuminated area in such a way that it hides it from at least a part of the rays coming directly from the Sun in the solar midday on the summer solstice;

- fixed mounting with respect to the installation site,

characterized by the screen:

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- forms, with the illuminated area, a first opening, called the equatorial opening, on the side of the Earth's equator, and a second opening, called the polar opening, on the side of the land pole closest to the installation site, the polar opening being more high than the equatorial opening with respect to the illuminated area;

- is continuous between the equatorial opening and the polar opening;

- presents a form, orientation and position such that:

• less than a quarter of the illuminated area is illuminated by the direct rays of the Sun in the solar midday at the summer solstice;

• At least a quarter of the illuminated area is illuminated by the direct rays of the Sun in the solar noon on the winter solstice.

A device according to the invention is simple and cheap since it does not consist of any mobile part in operation and, in particular, of any motorization.

The invention also extends to a zenithal lighting device according to claim 10 intended to be disposed within an opening made on a roof capable of being exposed to direct radiation from the Sun, the opening delimiting an area, called the illuminated area, and said zenith lighting device comprising:

- a frame adapted to be mounted on the contour of the opening;

- a covering element of a watertight or at least translucent material, the edges of which are adapted to be mounted on the frame;

- at least one protection device consisting of a screen:

• arranged above the illuminated area in such a way that it hides it from at least a part of the rays coming directly from the Sun in the solar midday on the summer solstice;

• fixed mounted with respect to the installation site,

characterized by the screen:

- forms, with the illuminated area, a first opening, called the equatorial opening, on the side of the Earth's equator, and a second opening, called the polar opening, on the side of the land pole closest to the installation site, the polar opening being more high than the equatorial opening with respect to the illuminated area;

- is continuous between the equatorial opening and the polar opening;

- presents a form, orientation and position such that:

• less than a quarter of the illuminated area is illuminated by the direct rays of the Sun in the solar midday at the summer solstice;

• At least a quarter of the illuminated area is illuminated by the direct rays of the Sun in the solar noon on the winter solstice.

Said zenith lighting device can be prefabricated at the factory according to prefabrication instructions according to a manufacturing process relative to the final installation site of said zenith lighting device. In particular, said zenithal lighting device can be manufactured at a latitude different from that of the installation site, as long as the latitude of the installation site is known. Therefore, the assembly of a device according to the invention is simplified, since the whole of the window and the protection screen (s) can be delivered and installed in block or kit.

A protection device or a zenith lighting device according to claim 9 or 10 makes it possible in particular to obtain an effective protection against the greenhouse effect of a glass on the roof in summer, while at the same time obtaining an important greenhouse heating in winter .

These devices also allow to conserve an important natural illumination throughout the whole year by means of its great opening oriented towards the north in the northern hemisphere, or towards the south in the southern hemisphere. This lighting can be advantageously improved, without substantially increasing the greenhouse effect in summer, by means of a perforated screen (s) with holes or slightly translucent (s).

Other objectives, characteristics and advantages of the invention will be shown in reading the following description given by way of non-limitation and referring to the attached figures in which:

- Figure 1 is a schematic perspective view of a zenithal lighting device according to the invention, considered mounted in the northern hemisphere;

- Figure 2 is a schematic view cut by a vertical plane containing the north-south axis of the device

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zenithal illumination according to figure 1;

- Figure 3 is a schematic perspective view of devices according to the invention mounted on a flat roof, and installed in the southern hemisphere;

- Figure 4 is a schematic side view from the south of the device according to Figure 3;

- figure 5 is a schematic view cut transversely by a vertical plane comprising the north-south axis, designated as A in figure 4 of the device, according to figures 3 and 4;

- Figure 6 is a schematic perspective view of two devices according to the invention, considered mounted in the northern hemisphere;

- Figure 7 is a schematic side view from the west of the devices of Figure 6.

The vertical plane according to the north-south axis at the installation site according to one of Figures 1 to 7 is also called the meridian of sidereal time in astronomy, or also the "local meridian", is the plane ( or disk) containing the celestial north pole, the celestial south pole and the zenith of the installation site. It carries the reference A in Figure 4. The solar midday is reached when the Sun crosses this plane.

In the set of figures 1 to 7, the protection and overhead lighting devices according to the invention are shown installed in the northern terrestrial hemisphere. In addition, the letters N and S respectively designate the north and south directions, E designates the east direction and W the west direction.

In general, an installation site according to the invention, and in particular a roof, advantageously has an inclination of less than 90 degrees with respect to the horizontal one, that is to say that the installation location is not vertical. The installation site is in particular advantageously inclined less than 45 degrees with respect to the horizontal, and is in particular substantially horizontal, that is to say that it forms an angle less than 20 degrees with the horizontal. However, nothing prevents the implementation of a method according to the invention for an inclined installation site, in particular an inclined roof, for example of 20 degrees.

In the set of the figures, the installation site is considered to be a horizontal roof 1, that is to say that this forms an orthogonal plane to the local zenith-nadir axis, is the plane of the roof. However, the invention also applies to other areas to be protected and to other configurations.

The zenithal lighting device shown in Figure 1, presents a screen 3 of a truncated cone shape, fixedly mounted above an illuminated area 2 covered by a glass 4. The glass is framed by a frame 6 in turn mounted on a roof 1 in which an opening has been made to be able to arrange said frame 6.

Nothing prevents, in an overhead lighting device according to the invention, that the frame 6 is in two parts: a part fixed to the roof 1 and a second mobile part with respect to the first part, in order to open the glass 4, of so that it forms a swing.

The screen is fixed to the frame, to a curb or to the roof by means of fixing means 5. In this way, arcs 5 can be used on which the screen 3 is bolted with bolts. The arches are in turn bolted to the frame 6 in the embodiment shown.

Screen 3 is arranged inclined in the north-south direction. In this way it has a higher upper edge 31 with respect to the plane of the roof 1 than its opposite edge: the lower edge 32.

Since the represented zenithal illumination device is installed in the northern hemisphere, the upper edge 31 of the screen is oriented to the north: it is the polar edge 31. The lower edge 32 is oriented to the south: it is the equatorial edge 32. The equatorial edge 32 defines with its orthogonal projection to the roof plane, an opening, called the equatorial opening.

It is through this equatorial opening, between the equatorial edge 32 and the roof 1, where the rays of the Sun can pass in the solar midday on the winter solstice to impact on the illuminated surface 2, and in particular on the crystal 4.

Similarly, the upper edge 31 defines with its orthogonal projection to the roof plane, an opening, called a polar opening, larger than the equatorial opening. The polar opening is, in particular, on average and in each north-south section higher than the equatorial opening.

The screen 3 is made of an opaque material in the sunlight. It is for this reason that, in summer, most of the lighting of a room located under the illuminated zone 2 comes from diffused or reflected sunlight that penetrates through the polar opening. Likewise, in order to allow more intense natural lighting to be obtained through the glass 4 without significantly increasing the greenhouse effect, small holes have been drilled in the screen 3.

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Other means allow to improve the natural illumination through the glass, for example the lower surface of the screen can be covered with a reflective material such that it transmits a maximum of diffused or reflected light received by the polar aperture in the direction of the surface 2 illuminated

The height of the equatorial edge 32 can be defined as described below.

Considering a point x of a curved abscissa of the equatorial edge of the illuminated area, the illuminated area has a width an (x) in the north-south direction, in this abscissa.

In the case of an illuminated area, such as a portion of a globally flat roof, that defines a plane, so that, for all x, in the solar noon in the winter solstice, a proportion p of an (x) will be impacted by direct sunlight from the Sun, the lower (equatorial) edge of the screen should be arranged at a minimum height (x) defined by the relation (R1):

al (x)> p.an (x) .tan (a) (R1)

In this relationship, a represents the angle of the sun's rays with respect to said plane of zone 1, in the solar noon on the winter solstice at the latitude of the installation site. Therefore, a is determined, in degrees, by the relation (R2):

a = 90 ° - l - 5 + 0 (R2)

in which:

- l is the latitude of the land location considered, expressed in degrees;

- 5 is the inclination of the axis of rotation of the Earth on itself with respect to a line orthogonal to the plane of the ecliptic, this is approximately + 23 °;

- 0 is the inclination of the roof in the north-south direction with respect to the local horizontal, expressed in positive degrees when the north edge of the area is higher than the south edge of the area, and negative in the opposite case.

In particular, in the forms of realization represented in Figures 1 to 7, being the flat and horizontal illuminated area, 0 is null. It should be noted that 0 is not necessarily always determined in the case of complex roofs or illuminated areas located on the crest of a roof. It is therefore more correct to use the angle that forms the illuminated area with the local horizontal for 0.

The coefficient p can be selected based on the proportion of illuminated zone 2 that is desired to be illuminated by the direct rays of the Sun in the solar midday on the winter solstice.

The relation (R1) allows to express in a simple way the height at which the lower edge of a screen is installed with respect to the illuminated area. However, nothing prevents foreseeing to illuminate, for example a quarter (p = 1/4) of the illuminated area in the solar midday on the winter solstice, without illuminating a quarter of an (x) for all x. In this way, it can be expected that some portions of the illuminated area are illuminated in more than a quarter by direct solar radiation from the Sun, and others in less than a quarter. This is particularly the case when the equatorial edge of the screen does not have the same shape as the equatorial edge of the illuminated area.

Similarly, the relationship (R1) is a simplified relationship that does not take into account the installation of the screen to hide the illuminated area of the direct rays of the Sun in summer. Indeed, in order to protect the entire illuminated area in the solar midday at the summer solstice, the equatorial edge of the screen must be more displaced towards the equator with respect to the vertical of the southern edge of the illuminated area, the closer to a Earth pole is the installation site of the protection device or the zenithal lighting device resulting from a process according to the invention.

Indeed, in the solar midday at the summer solstice, the sun's rays reach the roof with an angle p determined by the relation (R3):

P = 90 ° - l + 5 + 0 (R3)

from which the relation is obtained (R4):

P = a + 25 (R4)

Thus, in order to obtain a full overhead cover of the illuminated area to its equatorial edge in summer, and a direct illumination of a proportion p of the illuminated area in winter, one embodiment according to the invention is to arrange the lower edge from the screen at a height at (x) for any point x of the curvilinear abscissa of the equatorial edge of the illuminated area according to the relationship (R5):

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image 1

In the sectional view of said zenithal lighting device represented in Figure 2, the sun's rays have been represented at noon in the summer solstice and in the solar noon at the winter solstice.

The rays of the Sun in the solar noon in the summer solstice arrive at an angle p with respect to the plane of the roof. The sun's rays in the solar noon on the winter solstice arrive at an angle to the plane of the roof. The angle p is related to the angle a through the relationship (R4).

The height of the equatorial edge 32 with respect to the plane of the roof 1 can be determined by means of the ratio (R5) based on the proportion p of illuminated zone 2 that it is desired that it receives the direct rays of the Sun in the solar noon in the Winter Solstice.

Thus, for example, for a zenith lighting device according to the invention presented by an illuminated zone 2 with a constant width of 1 meter in the north-south direction, said zenith lighting device intended to be installed on a roof in Toulouse (31,000, France), with a latitude of approximately l = 44 °, the angle a is worth approximately = 23 °, and the angle p is approximately p = 69 °. To be able to illuminate exactly 50% (p = 0.5 and in case of equality in the ratio (R5)) of the zone 2 illuminated in the solar noon on the winter solstice, the equatorial edge 32 of the screen 3 must, therefore, have an average at a height of approximately 50 = 25 cm.

In addition, the equatorial edge 32 of the screen must be arranged offset towards the equator, with respect to the equatorial edge of the illuminated surface 2, with a distance d determined by the relation (R6):

d = al / tan (P) (R6)

In the previous example, the equatorial edge 32 of the screen should therefore be displaced south approximately d = 10 cm from the vertical of the equatorial edge of the illuminated surface 2.

Various protection devices according to the invention in the assembled state are shown in Figures 3 and 4. Each device comprises a profiled screen 3 whose profile has a monotonous curvature in a section along the plane of the local meridian, and means 5 for fixing this screen above an illuminated surface 2. Each screen is fixed to the frame 6, to a curb or to the roof 1 by means of fixing means 5. In this way, arcs 5 can be used on which each screen 3 is screwed with bolts. The arches are in turn bolted to the frame 6 in the embodiment shown.

Each screen is arranged above a corresponding illuminated area.

The illuminated areas of the roof are covered by a transparent cover 4 mounted on a frame 6. The transparent cover 4 is framed by the frame 6 in turn mounted on the roof 1 in which an opening has been made to be able to arrange said frame 6 .

In this embodiment, the screens 3 are made of a material opaque to the sun's rays and are perforated. In this way, the cover 4 is completely hidden from the direct radiation of the Sun in the solar noon in the summer solstice with the exception of the rays of the Sun that can pass through each screen through the holes.

Indeed, Figure 5 shows a device according to Figures 3 and 4, seen cut by plane A (from the west). The rays of the Sun in the solar noon on the summer solstice arrive at an angle p with respect to the roof. The polar edge 31 and the equatorial edge 32 are, therefore, shifted southward with respect to the respective polar and equatorial edges of the deck 4, to protect the latter from the sun's rays that strike an angle p.

The polar edge 31 of each screen is arranged higher with respect to the plane of the roof than its equatorial edge 32. In this way each screen is globally tilted in the north-south direction.

It should be noted that any form of screen can be used as long as its lowest point conceals the zone 2 illuminated by the rays that strike with an angle p, without hiding the rays that affect with an angle to which they pass through the equatorial opening between the equatorial edge 32 of a screen and the roof 1.

Thus, the straight lines tangent to the polar edge 31 or the equatorial edge 32, with an angle p, must be secant with the roof 1, but not with the illuminated zone 2. Similarly, the line tangent to the equatorial edge 32, with an angle a, must be secant with the illuminated zone 2 and, therefore, with the cover 4.

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The height and the southward displacement of the equatorial edge 32 of each screen can be selected for example according to the relationships (R5) and (R6).

In Figures 6 and 7 a long opening is shown in a horizontal flat roof covered by a dome-like covering element 4 with a north-south main direction. The covering element 4 is a glass, mounted on a frame 6, in turn mounted on the contour of the opening made in the roof 1.

Figures 6 and 7 present an embodiment in which a series of two screens 3 - each one above an illuminated area - is arranged in the north-south direction. The north-south distance between the screens can be adapted according to the desired lighting in winter and summer.

In particular, the distance between two successive screens can be selected such that no direct ray of the Sun can reach one or the other of the illuminated areas that pass between the two screens in the summer solstice.

In particular, in Figures 6 and 7, only the equatorial screen (south side) is selected and installed according to a procedure according to the invention. In particular, it allows the penetration of direct rays of the Sun in winter, in particular in the solar noon in the winter solstice (with an angle a), while protecting the illuminated area in summer, particularly in the solar midday in the summer solstice (with an angle p).

The two screens of figures 6 and 7 cannot be considered as parts of the same screen according to the invention. Indeed, a screen according to the invention is continuous between its equatorial edge and its polar edge, and allows a direct illumination of at least a quarter of the illuminated area above which it is mounted, so that only the Equatorial screen is in accordance with the invention.

The invention may be the subject of numerous other embodiments not shown.

In particular, the dimensions, shape, orientation and arrangement of a screen 3 according to the invention can be modified to obtain a direct illumination by the sun's rays more or less important in summer and / or winter. In the same way, these parameters are adjusted for each latitude of the terrestrial globe in which the device according to the invention, obtained by a procedure according to the invention, or the zenithal lighting device according to the invention, is intended to install.

In addition, the equatorial edge 32 of each screen is not necessarily at the same distance from the roof plane along its entire length (in the east-west direction), as shown in Figure 4. This height can, as represented in Figure 1, vary along the length of the screen.

If the screen is selected perforated with holes, the holes can be of any type, of any shape and distributed according to various reasons. These holes do not prevent the screen from being continuous between its equatorial edge and its polar edge.

On the other hand, a curb sometimes allows a covering element 4 to be raised relative to the roof. The screen of a device according to the invention can advantageously be fixed to this curb, to the frame of the covering element or directly to the roof itself.

Claims (10)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 65 Claims 1. Procedure for sun protection of an area, called illuminated area (2), in an installation site that may be exposed to direct radiation from the Sun, in which: - a screen (3) is arranged above the area (2) illuminated in such a way that it hides at least a part of the rays coming directly from the Sun in the solar midday in the summer solstice; - the screen (3) is mounted fixed with respect to the installation site; characterized by: - the screen (3) is arranged in such a way that it forms, with the illuminated area, a first opening, called the equatorial opening, on the side of the Earth's equator, and a second opening, called the polar opening, on the side of the Earth's pole plus next to the installation site, the polar opening being higher than the equatorial opening with respect to the illuminated area (2); - the screen (3) is continuous between the equatorial opening and the polar opening; - the shape, orientation and position of the screen (3) are selected so that: or less than a quarter of the illuminated area (2) is illuminated by the direct rays of the Sun in the solar noon on the summer solstice; or at least a quarter of the area (2) illuminated is illuminated by the direct rays of the Sun in the solar noon on the winter solstice. 2. Method according to claim 1, characterized in that the shape, orientation and position of the screen (3) are selected so that the edge of the screen delimiting the equatorial opening, called the equatorial edge (32), is find at any point at a minimum height with respect to the illuminated area (2), such that: to> p.an.tan (a) being: • at the angle between the illuminated area (2) and the rays of the Sun in the solar noon on the winter solstice; • an the dimension of the area (2) illuminated according to the north-south direction at the point considered; Y • 1/4 <p <1 the proportion of the illuminated area (2) that the direct rays of the Sun have to illuminate in the solar noon on the winter solstice. 3. Method according to one of claims 1 or 2, characterized in that the screen (3) is arranged such that it conceals the illuminated area (2) of any direct ray of the Sun in the solar noon on the summer solstice . Method according to one of claims 1 or 2, characterized in that the amount of light passing through the screen in any station is adjusted by selecting a screen (3) that has holes that allow direct rays to pass through. of the sun. 5. Method according to one of claims 1 to 4, characterized in that the shape, orientation and position of the screen (3) are selected so that most of the illuminated area (2) is illuminated by the rays direct from the Sun passing through the equatorial opening in the solar noon on the winter solstice. Method according to one of claims 1 to 5, characterized in that the installation site is a roof (1) and that the illuminated area (2) is an opening made in the roof (1), said opening being closed by a covering element (4) of a watertight and at least translucent material. 7. Method according to claim 6, characterized in that the covering element (4) is mounted on a frame (6) in turn mounted on the contour of the opening made on the roof, allowing direct rays of the Sun on the covering element (4) heating a volume of air located under the roof (1), in particular located under the illuminated surface and under the covering element. Method according to one of claims 1 to 7, characterized in that the screen (3) is selected in a material opaque to solar radiation. 9. Protection device for a zone, called illuminated zone (2), in an installation site capable of being exposed to direct radiation from the Sun, said protection device consisting of a screen (3): - arranged above the area (2) illuminated in such a way that it hides it from at least a part of the rays coming directly from the Sun in the solar midday on the summer solstice; 5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 65 - fixed mounting with respect to the installation site, characterized in that the screen (3): - shape, with the area (2) illuminated, a first opening, called the equatorial opening, on the side of the Earth's equator, and a second opening, called the polar opening, on the side of the land pole closest to the installation site, the polar opening higher than the equatorial opening with respect to the illuminated area (2); - is continuous between the equatorial opening and the polar opening; - presents a form, orientation and position such that: • less than a quarter of the illuminated area (2) is illuminated by the direct rays of the Sun in the solar midday at the summer solstice; • at least a quarter of the illuminated area (2) is illuminated by the direct rays of the Sun in the solar midday on the winter solstice. 10. Aerial lighting device intended to be disposed within an opening made on a roof (1) capable of being exposed to direct radiation from the Sun, the opening delimiting an area, called illuminated area (2), and comprising said lighting device zenith: - a frame (6) adapted to be mounted on the contour of the opening; - a covering element (4) of a watertight and at least translucent material, the edges of which are adapted to be mounted on the frame; - at least one protection device consisting of a screen (3): • arranged above the area (2) illuminated in such a way that it hides it from at least a part of the rays coming directly from the Sun in the solar midday on the summer solstice; • fixed mounted with respect to the installation site, characterized in that the screen (3): - shape, with the area (2) illuminated, a first opening, called the equatorial opening, on the side of the Earth's equator, and a second opening, called the polar opening, on the side of the land pole closest to the installation site, the polar opening higher than the equatorial opening with respect to the illuminated area (2); - is continuous between the equatorial opening and the polar opening; - presents a form, orientation and position such that: • less than a quarter of the illuminated area (2) is illuminated by the direct rays of the Sun in the solar midday at the summer solstice; • at least a quarter of the illuminated area (2) is illuminated by the direct rays of the Sun in the solar midday on the winter solstice.