DE202017104406U1 - Building facade system with hygroscopic and autoreactive dehumidification mechanism - Google Patents

Abstract

A building facade system (100) comprising: a frame structure (150); an outer pane (140) supported by the frame structure (150) and defining an interface with outside air (B); an inner pane (130) formed from the frame structure (150 ), spaced from the outer pane (140) by a distance (A), and disposed facing the building (C), the frame structure (150) having the outer pane (140) and the inner pane (130) being a space between the panes (160) defined; wherein the frame structure (150) comprises: a first port (110) that allows gas flow between the outside air and the disc space, a first shutter mechanism (112) that can substantially airtightly close the first port (110), and a first moisture-responsive control element (114) communicating with air in the disc space (160) and opening or closing the first shutter mechanism (112) via a moisture-responsive dimensional change of the control member (114) that depends on the relative humidity in the disc space (160).

Description

Technical area

The present invention relates to a building facade system with a hygroscopic and autoreactive dehumidifying mechanism. In particular, the invention relates to a double façade, such as a closed-cavity façade, with a hygroscopic and autoreactive dehumidification mechanism that requires no additional control or expensive maintenance.

Technical background

In conventional double façades, the space between the shells, in particular mechanical sun protection components, is dimensioned such that it can be used primarily for cleaning but also for maintenance purposes. Because this gap is exposed by the constant exchange with the outside air dirt, which occur, for example, by sand, insects or other particles in the air In recent years, facades were with a closed and maintenance-free gap between facades marketable. This so-called closed-cavity façade is a special kind of double-skin façade, which usually has a very high proportion of glazing and in which the space between the two glazings or shells (also referred to below as "cavity") forms a closed space from inside or outside air.

Here, the tightness and the seclusion of the façade gap is a central product idea, because this is to prevent contamination of the wind-protected components, such as sun protection, in the shell space. Thus, according to the manufacturers, this space no longer has to be made accessible for cleaning purposes, which has a decisive advantage over facade constructions with open shells: the smaller depth of the interspace allows a corresponding increase in the effective area of the interior with the same external dimensions of a building. While the double facades built worldwide in recent decades have a gap of up to one meter in depth, this application shows a reduction in depth down to 10-15 cm. This area gain multiplies as the floor of the building increases.

In addition, the facade gap needs no additional cleaning measure, since it is completely sealed from the outside and from the inside and ventilated with clean air. This is made possible by a continuous supply of dry and clean air and a slight overpressure in the closed shell space. With this measure, the aim is to prevent the resulting condensation of water vapor due to temperature fluctuations and thus fluctuating relative humidity. The amounts of air introduced into the cavity are preconditioned, especially dried. In some applications, the air can be optionally adapted by home automation systems at different temperatures. The dehumidified air, which is introduced into the space with a constant overpressure, prevents condensation, which arise in conventional double-shelled facades, especially in the lower area of the inside of the (outer) glazing, especially with temperature variations within a day. Especially in the transitional periods arise in conventional, not supplied with preconditioned air double facades temperature fluctuations by solar heating during the day and radiation exchange of the facade surfaces with the universe and thus strong cooling of the outer pane. The dehumidified and clean air in the cavity of the conventional closed-cavity façade attempts to prevent condensation. The disadvantage, however, is the technical effort for the dehumidification of the cavity, so for example for the provision of preconditioned and dehumidified air as described above or other dehumidifying measures.

EP 2441910 A1 discloses a double skin member for structures comprising an inner pane assembly having at least one glass sheet and an outer pane assembly having at least one glass sheet each supported by a frame assembly, the frame assembly having at least one pressure equalization port connecting the gap to the atmosphere. The activation of the valve is triggered by a control device, which is equipped with data from sensor elements for detecting air temperature, humidity or air pressure. The actuation of the valve and thus the ventilation of the space between the panes can thus be automated.

Although this solution effectively prevents condensation in the space between the panes of the facade. However, the mechanical elements have to be maintained. In addition, the sensors and the control of the valve require power, which reduces the effort and cost of the EP 2441910 A1 proposed solution increases.

Brief description of the invention

The present invention provides a building facade system that effectively overcomes the disadvantages of the prior art. The following disclosure is for the improved understanding of Invention as defined by the appended claims.

In a preferred embodiment of the disclosure, there is provided a building facade system comprising a frame construction; an outer disk held by the frame structure and forming an interface with outside air; an inner disk held by the frame structure, spaced from the outer disk by a distance, and disposed facing the building. The frame construction defines with the outer pane and the inner pane a space between the panes. The frame structure further includes a first opening that allows gas flow between the outside air and the space between the panes, a first shutter mechanism that substantially airtightly closes the first opening, and a first humidity-responsive control element that communicates with air in the panes of space first closure mechanism opens or closes via a moisture-sensitive dimensional change of the control element, which depends on the relative humidity in the space between the panes.

The use of a closure mechanism which opens or closes via a moisture-sensitive dimensional change of the control element eliminates the need for expensive sensors and appropriately controlled electronics and mechanical components. The moisture-responsive controller is autoreactive, i. responds autonomously to changing environmental conditions, and by suitably adjusting the transmission of the dimensional change to the shutter mechanism, the dehumidification is achieved by automatic ventilation of the cavity or the space between the panes.

The moisture-reactive control element reacts particularly preferably to the change in the relative humidity. At a high relative humidity in the cavity, e.g. as a result of the evening cooling of the ambient air and the absence of solar radiation, the control element responds e.g. with a length extension. This is transferred to the shutter mechanism, which opens the opening and starts the ventilation of the cavity. Cool, relatively drier air gradually replaces the relatively humid air of the cavity, causing the control element to contract again and close the shutter mechanism. Condensation does not occur because the air in the cavity is quickly heated to a higher temperature than the outside air due to its proximity to the building.

In a preferred embodiment of the present disclosure, the distance between the outer and inner disks is from 70 mm to 250 mm, preferably from 100 mm to 150 mm. These distances are merely preferred dimensions of so-called "closed cavity" facades and should not be construed as limiting. Façades with smaller or larger inter-slice distances, such as other types of double facades, may also benefit from the present invention.

In a preferred embodiment of the present disclosure, the shutter mechanism is a shutter which is opened or closed by a lever by a change in length of the control member. However, the invention can be implemented with different closure mechanisms, as are familiar to the expert. Thus, e.g. Actuators, punches, bottle or cable systems, gears, hydraulic transmissions and sliding windows and doors each alone or in combination with each other as a locking mechanism conceivable.

In a preferred embodiment of the present disclosure, the moisture-responsive control member is in strip form and is fabricated from an extruded, cast and / or rolled, moisture-reactive material. This embodiment uses a length change of the strip to control the closure. Typically, high surface area elements are preferred, such as multiple parallel, very fine fibers, as this increases the effects of dimensional change, such as length change. In another embodiment of the disclosure, the moisture-responsive control member is made of a woven and / or braided moisture-responsive material. Again, the finer the fibers used are, the larger the area that can react with the ambient air, more specifically the water vapor contained therein, which also increases the dimensional change of the control element.

In a preferred embodiment of the present disclosure, the moisture-responsive control element comprises a hygroscopic plastic from the group of polyamides. In a more specific embodiment of the present disclosure, the moisture-responsive control element is the hygroscopic plastic of the group of polyamides.

The hygroscopic plastic may preferably be selected from PA6, PA66, PA11, PA12 or mixtures or copolyamides of two or more (co) polyamides from this group. It should be understood, however, that the invention is not limited to specific moisture-reactive materials is and other substances we natural fibers or other plastic classes may also find use. It is important only the property of the substance when water absorption to change the length or the volume.

In a preferred embodiment of the present disclosure, the frame structure further includes a second opening that allows gas flow between the outside air and the space between the panes, and the second opening may also be opened or closed via the first closure mechanism and the first moisture-responsive control element. By the first shutter mechanism, the first and the second opening are opened at the same time and it immediately occurs a ventilation or draft effect. This can be amplified by a chimney effect, when about the first opening in a lower frame portion and the second opening is disposed in an upper frame portion. This is particularly preferred since the direction of the air flow through the cavity is thus determined and corresponding optional filters or dehumidification measures, as described below, need only be provided at one of the openings, since the other only serves to discharge the air flow. This can be further ensured by interposed valves (e.g., butterfly valves).

In a preferred embodiment of the present disclosure, the frame structure also includes a second opening that allows gas flow between the outside air and the disc space. However, for this opening, a second shutter mechanism substantially airtightly seals the second opening and a second humidity-responsive control member communicating with air in the disc space and opening or closing the second shutter mechanism via a humidity-responsive dimensional change of the control member are provided Relative humidity in the space between the panes provided. It should be noted at this point that the first and the second closure mechanisms can also open or shave openings in two adjacent facade systems. This is possible because the moisture conditions in two adjacent facade modules are usually very similar and can be ventilated simultaneously.

By using two independent opening mechanisms for the first and the second opening respectively, a gradation of the degree of ventilation of the cavity can be achieved. For example, opens at a slightly humid air, which does not necessarily lead to condensation of water vapor, only one of the two shutter mechanisms and a slower ventilation of the cavity occurs. In addition, it is desirable that in the case of the use of the chimney effect, the air inlet opening of the cavity is opened in front of the outlet opening. Otherwise, debris or non-dehumidified air could enter through the second opening. It should be noted at this point, however, that both openings can be equipped with particle filters or dehumidifying measures.

In a preferred embodiment of the present disclosure, the first opening comprises a particulate filter and / or a dehumidifier. These serve for cleaning and dehumidifying the penetrating air and may equally be provided at the second opening. In preferred embodiments, the particulate filter comprises a cotton filter, a Gorex membrane filter, a dry filter, an electrostatic filter, a mesh filter, or an inertial filter. Furthermore, in preferred embodiments, the dehumidifying agent comprises aluminum silicate, zeolite, a pNIPAAm polymer, a combination of pNIPAAm polymer and cotton or a superabsorbent (SAP). It should be understood that the above-mentioned filters and dehumidifiers may be provided both individually and in combination, e.g. by serially switching a plurality of filters and / or dehumidifiers in the airflow entering the cavity.

It should also be noted that between the outer pane and the inner pane further elements, e.g. Shading devices, or discs can be arranged. In the case of additional slices, additional interspaces may either be in sufficient gas exchange with one another, or alternatively additional intermittent interventions may be provided as described above.

In accordance with the above disclosure, it is an object of the present invention to provide a solution that dehumidifies the interstice space of a closed-cavity façade without the use of external energy when there is a condensation problem.

list of figures

• 1 shows a building facade system according to a preferred embodiment of the present disclosure.
• 2A to 2D each show a schematic building facade system according to a preferred embodiment of the present disclosure in different situations.

Description of the disclosed embodiments

In the following, the present invention will be described with reference to figures, which show schematically different exemplary embodiments of a building facade system according to the invention. The embodiments shown in the figures are not drawn to scale, some dimensions have been selected, which bring the principle of the present invention to advantage.

Both in the description and in the figures, the same or similar reference numbers are used to refer to the same or similar elements or components. In order to keep the description short, elements which have already been mentioned in other figures are not necessarily explicitly mentioned again in the description of each further figure.

1 shows a building facade system 100 in accordance with a preferred embodiment of the present disclosure. The building facade system according to 1 includes a frame construction 150 , The frame construction does not need to be additionally modified to implement the present invention over the known prior art. Only the openings and the control over the locking mechanisms 112 and 122 or the control elements 114 and 124 As described below, space must be found in the frame structure.

The building facade system 100 further comprises an outer pane 140 that of the frame construction 150 is held and forms an interface with the outside air B. The direct contact between outside air B and outer pane 140 causes water vapor to preferentially condense on it when the outside temperature drops sharply (eg at night). This phenomenon is to be prevented by the present invention.

The building facade system 100 further comprises an inner pane 130 that of the frame construction 150 is held by the outer pane 140 is spaced at a distance A, and which faces the building C is arranged. The frame construction 150 defined with the outer pane 140 and the inner pane 130 a disc space 160 in the present specification also referred to as Cavity. The frame construction 150 also includes in the lower area of this a first opening 110 , which allows a gas flow between the outside air and the space between the panes. The opening is not limited in the present disclosure. However, a sufficient size is desirable to allow adequate gas exchange. Alternatively to the in 1 indicated individual first opening, a plurality of first openings may be provided.

The first opening 110 can by a first shutter mechanism 112 essentially be hermetically sealed. Suitable sealing elements (not shown) are preferably provided in the contact area between the opening and closure. The locking mechanism 112 is controlled by a first moisture-reactive control element 114 operated, ie open or closed. The control element 114 stands with air in the space between the panes 160 and open or close the lock 112 depending on the relative humidity in the space between the panes 160 , In particular, the control element opens 114 the lock 112 when the relative humidity in the cavity 160 exceeds a preset value. An appropriate vote of locking mechanism 112 and control element 114 can be implemented by a person skilled in the art with only a few tests and will not be described in more detail here.

A second opening 120 , which allows a gas flow between the outside air and the space between the panes, is in the upper area of the frame construction 150 , ie in the region of the upper edges of the discs 130 and 140 arranged. As in 1 is shown, a second locking mechanism 122 be provided, which closes the second opening substantially airtight. In 1 is also a first shutter mechanism 210 a system arranged above the illustrated facade system or façade module indicated.

A second moisture-reactive control element 124 that with air in the disk space 160 communicates and that the second locking mechanism 122 via a moisture-reactive dimensional change of the control element 124 opens or closes, depending on the relative humidity in the space between the panes 160 is also in the upper part of the frame construction 150 intended. The second control element 124 may also be the adjacent first shutter mechanism 210 to open or close an adjacent first opening (not shown).

The system according to the above description can also be provided with only a single opening and the associated closure and moisture-reactive elements. The ventilation in this embodiment is correspondingly slower. The invention preferably finds application in the space between the panes of a double-shell, large-area glazed façade. Depending on the relative humidity conditions, autoreactive moisture-reactive Materials that are dehumidified cavity. The autoreactive material responds to the rising level of humidity by inducing water uptake and, consequently, an increase in volume, as a geometric change. The change in length or volume is preferably introduced by means of calibrated fiber ribbons (with integrated actuator-sensor functions) made of polyamide or the like (PA6, PA66, PA11, PA12 or mixtures or copolyamides thereof) in a folding mechanism, the air exchange of the cavity with the environment, ie the natural ventilation of the façade space; allows.

When the humidity of the ambient air increases, the facade closes again without additional energy. By exploiting effects of the Quellkinetik as well as simple constructive measures certain opening parameters are adjustable.

The incoming air is additionally dehumidified in a preferred embodiment of a desiccant (aluminum silicate, zeolite or the like). Alternatively, pNIPAAm polymers can be used for temporary drying of the cavity. The combination of pNIPAAm polymers and cotton can store and release 3.4 times its own weight in water. Up to 34 ° C, the material can absorb large amounts of water. At higher temperatures, however, there is water. Furthermore, superabsorbents (superabsorbent polymers, SAP) are also possible.

The desiccant can control the humidity on dry days. The process described works auxiliary energy-free and automatically reversible and thus always possible.

The invention provides in a preferred embodiment, the use of multiple polymer actuators: one is located in the lower part of the facade element (box member); the other in the upper part. For better protection against contamination entering the cavity through entrained particles, a membrane (Gore-tex or similar) is used as filter. Other filtering devices may alternatively be used, e.g. Dry filter, electrostatic filter, sieve filter or inertial filter.

The only temporary opening to the surrounding external air reduces the contamination of the cavity in that it reduces by the time of the exchange with the environment and thus the entry of unclean and particulate air into the cavity.

2A to 2D each show a schematic building facade system according to a preferred embodiment of the present disclosure in different situations. 2A and 2 B are schematic representations of the conditions on a summer day, especially the transition from great heat ( 2A ) on the conditions in the late afternoon or evening ( 2 B ). In 2A is shown, the relative humidity in each case outside (50-75%), in the space between the panes 160 (55-75%) and inside (30-55%) are not critical per se. The high temperature difference between cavity 160 and interior, ie 50-60 ° C compared to <26 ° C (eg by an air conditioner), however, ensures a local humidity in the inner pane of more than 100% and condensation occurs. It is therefore necessary for indoor ventilation 160 in order to lower the temperature in it and thus to keep the relative humidity of the inner pane below 100%.

This situation changes in the evening, as shown schematically in 2 B is shown. The outside temperature drops rapidly (15 ° C, 65-95% RH) during the space between the panes 160 and the interior is still relatively warm. Too much cooling of the cavity is not desired. Therefore, when cool outside air enters the cavity 160, it is heated quickly, decreasing the relative humidity in the cavity 160 quickly and the dehumidification system according to the above description prevents the ventilation. Therefore, energy can be saved at night for heating the building.

2C and 2D are schematic representations of the conditions on a winter day, in particular the transition from early morning or night ( 2C ) on the conditions in the morning or generally during the day ( 2D ).

In the situation in 2C are similar to that of 2 B , Energy saving aspects important. Should the moisture in the cavity 160 rise to almost 100%, the ventilation should be triggered by the above-described facade system. Cool outside air flows in and is heated by the relatively warm building quickly to approx. 5-10 ° C. Therefore, the relative humidity decreases rapidly and the ventilation is again inhibited or the control (not shown) fails the opening (not shown) via the shutter mechanism (not shown). This procedure corresponds to the generally recommended in winter ventilation.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2441910 A1 [0005, 0006]

Claims (14)

A building facade system (100) comprising: a frame construction (150); an outer disk (140) held by the frame structure (150) and forming an interface with outside air (B); an inner disk (130) held by the frame structure (150) is spaced from the outer disk (140) by a distance (A) and facing the building (C); wherein the frame construction (150) with the outer pane (140) and the inner pane (130) defines a pane clearance (160); wherein the frame construction (150) comprises: a first port (110) permitting gas flow between the outside air and the disc space; a first shutter mechanism (112) capable of sealing the first opening (110) substantially airtight, and a first moisture-responsive control element (114) in communication with air in the panes of space (160) and which opens or closes the first closure mechanism (112) via a moisture-responsive dimensional change of the control element (114) dependent on the relative humidity in the panes ( 160). Facade building system (100) according to Claim 1 , wherein the distance (A) from 70 mm to 250 mm, preferably from 100 mm to 150 mm. Facade building system (100) according to Claim 1 or 2 wherein the shutter mechanism (112) is a shutter which is opened or closed by a lever by a change in length of the control member (114). A building facade system (100) according to any of the preceding claims, wherein the moisture-responsive control member (114) has a strip shape and is made of an extruded, cast and / or rolled moisture-reactive material. A building facade system (100) according to any one of the preceding claims, wherein the moisture-responsive control member (114) is made of a woven and / or braided moisture-reactive material. Building facade system (100) according to one of the preceding claims, wherein the moisture-reactive control element (114) comprises a hygroscopic plastic from the group of polyamides, in particular the homo- or copolyamides. Facade building system (100) according to Claim 6 , wherein the moisture-reactive control element (114) consists of the hygroscopic plastic from the group of polyamides, in particular the homo- or copolyamides. Facade building system (100) according to Claim 6 or 7 , wherein the hygroscopic plastic is selected from the group consisting of PA6, PA66, PA11, PA12, or mixtures or copolyamides of two or more (co) polyamides from this group. A building facade system (100) according to any of the preceding claims, wherein the frame structure (150) further comprises: a second port (120) allowing gas flow between the outside air and the disc space, the second port (120) also being opened or closed via the first shutter mechanism (112) and the first moisture-responsive control element (114). Building facade system (100) according to one of Claims 1 to 8th wherein the frame structure (150) further comprises: a second port (120) that allows gas flow between the outside air and the disc space, a second shutter mechanism (122) that substantially hermetically seals the second port, and a second moisture-responsive control element (150); 124) communicating with air in the disc space (160) and which opens or closes the second closure mechanism (122) via a moisture-responsive dimensional change of the control member (124) that depends on the relative humidity in the disc space (160). Facade building system (100) according to Claim 9 or 10 wherein the first opening (110) is provided in a frame portion below the second opening (120) so that an air flow is generated when the first and second shutter mechanisms (112, 122) are simultaneously opened by the chimney effect. A building facade system (100) according to any one of the preceding claims, wherein a particulate filter and / or dehumidifying means is provided at the first opening to clean and / or dehumidify air entering the disc space (160) through the first opening (112) , Facade building system (100) according to Claim 12 wherein the particulate filter comprises: a cotton filter, a Gorex membrane filter, a dry filter, an electrostatic filter, a mesh filter, or an inertial filter. Facade building system (100) according to Claim 12 or 13 wherein the dehumidifying agent comprises: aluminum silicate, zeolite, a pNIPAAm polymer, a combination of pNIPAAm polymer and cotton or a superabsorbent (SAP).

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