EP0003725B1 - Longitudinally ventilated double-glazed window with interior curtain - Google Patents

Description

The invention relates to a longitudinally ventilated double-glazed window with internal blinds, which has on its outside of the weather a glazing designed as a single glass, which forms an exhaust air duct with an internal glazing arranged at a distance from it inside the room and also designed as a single glass, with the sun blinds being provided on the inside of the room.

Such a device has become known from DE-A-23 31 332. Here, either warm air from the room to be air-conditioned or air from an independent ventilation system should be introduced into the exhaust air duct via slot openings in such a way that a relatively thin film of air flows from the bottom upwards over the inner surface of the outer glazing, while the remaining air in the exhaust air duct flows through the Air film should be set in motion to flow past the outside of the inner glazing in a slightly turbulent flow. This is intended to achieve the highest possible heat-insulating effect. Glare protection is to be achieved by using reflection glasses for the outer and inner glazing or through the sun blinds.

In the embodiment explained above, the distance between the outer and inner glazing - as in the other known devices - is approximately 200 mm. Taking into account the usual boundary conditions, the amount of fresh air required for the windows generally results in approximately 50 to 100 m ^{3 of} air per hour and meter of window width. With these specified air volumes, no defined air flows are obtained in the relatively wide exhaust air duct. Rather, the air introduced into the exhaust air duct swirls in an uncontrolled manner. This is disadvantageous with regard to the condensation to be prevented under all circumstances on the inside of the outer glazing and with regard to the heat energy to be removed from the exhaust air duct in summer.

In the case of high solar radiation, in the known device explained above, a more or less large reflection of the solar radiation takes place on the surface of the sun blind facing the inner glazing, which in turn is absorbed to a greater or lesser extent by the inner glazing. As a result, the inner glazing heats up considerably and heats up the air between the inner glazing and sun blinds. As a result, the room to be air-conditioned maintains an excessively high room temperature despite the air flow in the exhaust air duct.

The US-A-2 874 61 1 and 2874612 already show sun blinds which have horizontally extending profiles on their outer surface facing the weather outside, which are approximately triangular in cross-section. The strip-shaped areas of each triangular profile lying at the top are provided with a reflective layer, while the respectively lower strip-shaped areas are transparent. This is intended to reflect directly incident sunlight towards the outside of the weather, while indirect light can enter the interior through the transparent strip areas.

The invention has for its object to improve the device described above so that condensation on the inside of the outer glazing is prevented with certainty and the air conditioning of the room can be improved.

This object is achieved according to the invention in that the distance between the outer and inner glazing is reduced so that a defined, largely laminar air flow is established in the exhaust air duct and that the sun blind has horizontally extending profiles on its outer surface facing the outside of the weather, the steeper incident sun rays largely reflect to the outside of the weather, and that the sun blind between the profiles is provided with a light-absorbing and strip-shaped selective coating, which is arranged so that it is only exposed to sun rays when the sun is low and causes extensive absorption of the sun rays and heating of the sun blind.

The optimal distance between the exterior and interior glazing is calculated taking into account the lowest exterior temperature to be expected in winter, the desired relative air humidity in the interior, the desired interior temperature, the air volume provided, the heat transfer from the interior to the exterior, and the desired surface temperature the sun blind in winter, the desired or required air volume in the interior and taking into account the location and the orientation of the room to be air-conditioned (climate of the country, orientation of the building facade, e.g. to the south or north, etc.).

As a guideline for the distance between the outer and inner glazing, there is a value of about 40 mm. As a result, a considerably smaller installation depth is achieved, which leads to corresponding cost savings.

Due to the greatly reduced width of the exhaust air duct according to the invention, taking into account the predetermined air quantities in the exhaust air duct, a defined, largely laminar air flow (the turbulent limit flow on the walls of the exhaust air duct can be disregarded here). This laminar air flow greatly reduces the energy loss in the air in winter. In addition, a defined temperature profile is obtained from the outside of the weather to the inside of the outer glazing and, in conjunction with the increased flow rate, can thereby reliably prevent condensation on the inside of the outer glazing.

• Der Sonnenstoren kann aber auch so ausgebildet sein, daß die von ihm reflektierten steil einfallenden Sonnenstrahlen zu einem möglichst großen Anteil in der Verglasung absorbiert werden, und daß dem Abluftkanal eine Kältemaschine nachgeschaltet ist, für die die Abluft als Arbeitsmedium dient. Bei dieser Anordnung führt also die vom Sonnenstoren reflektierte Sonnenstrahlung zu einer Aufheizung der Verglasung und damit zu einer starken Erwärmung der zwischen der Verglasung geführten Abluft. Diese warme Abluft kann als Arbeitsmedium für eine Kältemaschine dienen, die ihrerseits als Kühlaggregat eingesetzt wird.

In the context of the invention, the new air conditioning device can be advantageously adapted to the various needs:

• The sun blind can also be designed so that the steeply incident sun rays reflected by it are absorbed as much as possible in the glazing, and that the exhaust air duct is followed by a refrigerator, for which the exhaust air serves as the working medium. With this arrangement, the solar radiation reflected by the sun blinds leads to heating of the glazing and thus to a strong heating of the exhaust air guided between the glazing. This warm exhaust air can serve as a working medium for a chiller, which in turn is used as a cooling unit.

The sun blind can also be designed so that the flatly incident sun rays are largely absorbed in the sun blind and the portion of the sun radiation reflected by the sun blind largely in the glazing, and that the exhaust air duct is followed by a heat exchanger for heating a separate air stream. Here, the sun blind is heated up strongly and thus serves to heat the interior. At the same time, however, the glazing and, as a result, the exhaust air conducted between it are heated. The warm exhaust air can then be passed through a heat exchanger in order to heat another air flow, which is then supplied to rooms that are not, for example, in the area of solar radiation.

In night mode, the air in the room to be air-conditioned can be circulated in a closed circuit, for example bypassing the above-mentioned heat exchanger or a refrigeration machine, so that heat is given off to the outside of the weather in the exhaust air duct. In this case, it can be expedient to increase the distance between the inner glazing and the outer glazing in order to achieve a reduction in the air flow velocity and thereby an increased heat emission towards the outside of the weather. The distance between the inner glazing and the outer glazing could also be adjusted as a function of the heating of the interior to be air-conditioned as a result of the lighting being switched on.

According to the invention, transparent, ie no colored glasses are used for the glazing. This is intended to minimize the use of artificial light sources.

The sun blinds must be designed in such a way that a certain amount of visible radiation is always let through to illuminate the interior to be air-conditioned. It is essential, however, that this illumination does not occur through direct light, but only through diffuse light.

The surface profiles of the sun blind can in principle correspond to the curved lamellae which are shown and described in DE-A 25 22 154. The cross-sectional contour of these slats corresponds to a curve or an arc, which are designed so that all flat incident and reflected rays impinge on the adjacent slat. As a result, not only the directly incident solar energy is absorbed in the case of flat solar radiation, but also the solar energy reflected on the individual slats. This results in an increased heating of the sun blind, which can be desirable for example in winter or in principle in cold areas.

The arrangement of the lamellae explained above can be such that, in the case of steeper rays of the sun (position of the sun in summer), the sun's rays are largely reflected towards the outside of the weather, but if the rays of the sun fall more flat (position of the sun in winter), the above-described absorption takes place.

The desired effects can be further enhanced, for example, by mirroring the respective surfaces of the glazing.

The application of the invention is not limited to air-conditioned rooms, but can also be carried out analogously for ventilated rooms.

• Figur 1 einen senkrecht zur Verglasung geführten Vertikalschnitt und
• Figur 2 in verkleinertem Maßstab einen Schnitt gemäß Figur 1 durch eine abgewandelte Ausführungsform.

In the drawing, two exemplary embodiments of the invention are shown schematically. Show it:

• 1 shows a vertical section perpendicular to the glazing and
• Figure 2 shows a section on a smaller scale according to Figure 1 through a modified embodiment.

A room 1 to be ventilated or to be air-conditioned has, on its weather outside, an outer glazing 2 designed as single glazing, which forms an exhaust air duct 4 with an inner glazing 3 arranged at a distance from it inside the room and also designed as single glazing. The distance between the outer and inner glazing 2 or 3, which determines the width of this exhaust air duct 4, is designated by a.

• Bei hohem Sonnenstand treffen die entsprechend steil einfallenden Sonnenstrahlen 7 nach Durchtritt durch die Außen- und Innenverglasung 2 bzw 3 auf die Profilierungen 6 auf, werden hier zum größten Teil reflektiert und zwar auf die benachbarte Profilierung und von dort wiederum reflektiert in Richtung auf die Innenverglasung 3. Der überwiegende Anteil der steil einfallenden Sonnenstrahlen 7 wird somit wieder zur Wetteraußenseite reflektiert. Durch den lotrechten Abstand der Profilierungen 6 voneinander sowie durch die Höhe jeder einzelnen Profilierung 6 ist ausgeschlossen, daß steil einfallende Sonnenstrahlen 7 unmittelbar oder mittelbar auf den selektiv beschichteten streifenförmigen Bereich 9 des Sonnenstoren 5 auftreffen.

A sun blind 5 is arranged on the inside of the interior glazing 3, which has profilings 6 on its surface facing the outside of the weather, which are approximately triangular in cross-section and serve to reflect incident sun rays 7, 8. These profiles 6 run horizontally and are arranged at a vertical distance from one another. The strip-shaped region 9 of the sun blind 5 thus formed between two profiles 6 in each case is provided on its outside with a selective coating which gives this strip-shaped region 9 increased absorption and reduced reflection properties. This configuration of the sun blind 5 has the following effect:

• When the sun is high, the correspondingly steeply incident sun rays 7 strike the profiles 6 after passing through the outer and inner glazing 2 or 3, are largely reflected here, namely to the neighboring profiling, and from there reflected in the direction of the inner glazing 3 The majority of the steeply incident sun rays 7 are thus reflected back to the outside of the weather. The vertical spacing of the profiles 6 from one another and the height of each individual profile 6 preclude the possibility of steeply incident sun rays 7 striking the selectively coated strip-shaped region 9 of the sun blind 5 directly or indirectly.

On the other hand, the sun rays 8 which fall in a correspondingly flat manner at a low position of the sun can impinge directly on the strip-shaped area 9, or are largely reflected by the profiles 6 on this strip-shaped area 9. Because of the selective coating provided here, a correspondingly increased absorption and thus a heating of the sun blind 5 results in the strip-shaped areas 9, which can be used to heat the room 1.

The distance a between the outer glazing 2 and the inner glazing 3 is dimensioned such that a defined, largely laminar air flow 10 is established in the exhaust air duct 4.

The exemplary embodiment shown in FIG. 2 is rotated by 180 ° in relation to the illustration in FIG. 1, so that in FIG. 2 the weather outside is on the left. Here, the exhaust air duct 4 is followed by a heat exchanger 11, in which a separate air stream 12 is heated. This separate air flow 12 can be used, for example, to heat other rooms that are not in the area of solar radiation.

Claims (4)

1. Ventilated double glazed window with internal blind, which window has an exterior glazing (2) in the form of a single glass pane on its weather exposed outside forming a channel for outgoing air with interior glazing (3) arranged at a distance from the exterior glazing (2) to the room interior side and also in the form of a single glass pane while the sun blind is provided on the room interior side of the interior glazing (3), characterised in that the distance (a) between the exterior and interior glazing (2 respectively 3) is so reduced that a defined, largely laminar airflow (10) is created in the channel (4) for outgoing air, and that the sun blind (5) has horizontally extending profilations (6) on its surface facing the outside, which profilations (6) largely reflect steeply incident sun rays (7) to the outside, and that the sun blind (5) is provided with a light absorbing and strip-like selective layer between the profilations (6), which layer is so arranged that it is only impinged upon by sunrays (8) when the sun stands low and effects a considerable absorption of sun rays (8) and a heating of the sun blind (5).

2. Double glazed window according to claim 1 characterised by such a construction of the sun blind (5) that the steeply incident sun rays (7) reflected by the sun blind (5) are absorbed to a high proportion in the glazing (2, 3) as far as possible, and that a refrigerator is arranged downstream of the channel for outgoing air for which refrigerator the outgoing air serves as a working medium.

3. Double glazed window according to claim 1 characterised in such a construction of the sun blind (5) that the shallow incident sun rays (8) are largely absorbed in the sun blind (5) and that the reflected part of the sun rays are largely absorbed in the glazing (2, 3) and that a heat exchanger (11) is arranged downstream of the channel (4) for outgoing air to heat a separate airstream (12).

4. Double glazed window according to one of the preceding claims characterised in that the distance (a) between the interior glazing (3) and the exterior glazing (2) is adjustable.

Images