EP3412843A1 - Ventilation system for the wall surface of a building and use of the ventilating system for the drying of façade surfaces or for the prevention of condensation water on façade surfaces - Google Patents

Abstract

The present invention relates to a ventilation system for the wall surface of a building with an upper, a lower and opposite lateral edges, in particular for the outer facade of an insulated building wall, comprising at least one ventilation unit with at least one ventilation opening with a Ventilationsöffnungsquerschnitt for the exit of an air flow, wherein the ventilation unit is arranged and adapted to direct the air flow over the at least one ventilation opening along at least a portion of the building wall surface, in particular the outer facade. Furthermore, the invention relates to a building wall with a building wall surface with an upper end and an opposite lower end, containing at least one ventilation system according to the invention. Moreover, the invention relates to a building containing at least one building wall according to the invention and the use of the ventilation system according to the invention for, in particular forced, drying a moist building wall surface, in particular the outer facade of a building wall, or for preventing the condensation of water on building walls, in particular on the outer facades of building walls. Finally, the invention relates to a humidity sensor and a humidity sensor measuring system for use with the ventilation system according to the invention.

Description

The present invention relates to a ventilation system for the wall surface of a building, in particular for the outer facade of an insulated building wall. Furthermore, the invention relates to a building wall, in particular building exterior wall, with a building wall surface, comprising at least one ventilation system according to the invention, and a building which is equipped with a building wall according to the invention. Moreover, the invention relates to the use of the ventilation system according to the invention for preventing the condensation of water or the formation of moisture on a building wall or for the drying of damp building walls.

It has long been known that moisture on exterior facades can cause problems. For example, this can lead to algae and / or mold growth. Façade surfaces are wet or damp mainly due to rain events and condensation of water from the air. Especially on thermally insulated facades occurs increased condensation of water from the ambient air. Due to the insulation, the energy used to heat the interiors will no longer escape to the outside. On thermally insulated facades, therefore, the condensation or dew point is much lower than on non-insulated facades. At the condensation point, the temperature and pressure conditions are such that the air is saturated with water vapor. The dew point temperature of humid air corresponds to the condensation point of pure water vapor, if the respective water vapor partial pressures coincide.

The problem of mold and / or algae formation is attempted, for example, by using biocidal substances in facade paints or by the aftertreatment of facades with aqueous systems containing biocidal substances.

In addition, attempts have been made to reduce the water content of external facade surfaces by rendering them hydrophobic. So will in the WO 2016/180453 A1 a composition containing a silicone-free wax, a binder, one or more first pigments and / or first fillers having an average particle size of 0.1 to 1.0 microns in a total amount of 8.0 to 55 wt.%, One or more second Pigments and / or fillers having an average particle size of greater than 1.0 to 10 microns in a total amount of 5.0 to 40 wt.%, One or more third pigments and / or third fillers having an average particle size of greater than 10 to 40 microns in a total amount of 3.0 to 30 wt.%, Each based on the solids content of the composition. Here, the three pigment or filler systems have to be different from each other, and the composition has to be free from silicone-containing oils and waxes. On surfaces coated with these compositions, dirt should adhere poorly and at the same time run off or run off water well.

The US 2016/0289487 A1 is concerned with compositions containing a hydrophobic wax, a silicone oil containing exclusively hydrocarbyl side chains, a hydrophilic binder, and pigments and / or fillers. Here, the composition has a pigment volume concentration of 25 to 60% according to EN ISO n4618-1, wherein the amount refers to the totality of the pigments and fillers. The facades coated with these compositions should also lead to improved re-drying of the surface in the case of dew.

Instead of providing the facade surface hydrophobic, there are also attempts to achieve via the use of hydrophilic surfaces to reduce the amount of water on facades. In hydrophilic façade surfaces, the water impinging on this surface is absorbed into the wall and is therefore no longer available for algae and mold growth on the surface. Here, however, there is the danger that the moisture absorbing porous wall is filled in particular after a long wet phase and then no longer available as a water reservoir. In these cases, a water film forms again on the façade surface. Also, it may come in the porous wall material due to the prevailing humidity conditions for mold and / or algae formation and thus structural damage.

In particular, in the case of thermally insulated exterior facades, the use of heating media integrated in the surface also attempts to overcome the problem of mold and algae formation. For example, in the DE 10 2009 035 656 A1 proposed a building envelope with an outside building layer in which the outside building layer at least partially has a heatable via a heater structure, which is used for heating and drying of the surface of the outside building layer intended to prevent the greening of the surface. As a heatable structure should then come, for example, an electrically conductive reinforcement fabric in question. Corresponding electrically heatable systems for mold avoidance have already been described for the drying of walls in the interior, so in the DE 20 2009 001 750 U1 , Such heating systems are regularly energy-intensive and often associated with high costs.

According to the DE 10 2010 008 520 A1 Attempts to solve the problem of moisture in a equipped with a thermal insulation system external facade by providing a capillary tube mat containing a heat transfer fluid in and / or below a resting on the thermal barrier coating of the thermal insulation composite cover layer. This capillary tube mat has to have at least one manifold and a manifold which connects the individual capillaries with a heat exchanger. In this case, the heat transfer fluid has to be circulated within the capillary tube mat.

Another approach is to use coating materials that absorb more light in the infrared and thus convert the IR radiation of daylight into heat. The EP 2,918,643 proposes for this purpose rapidly drying coatings containing at least one semiconductor selected from one or more of the groups a) A ^III B ^V semiconductors comprising compounds of the binary type, where A is gallium, indium, thallium, germanium, tin, lead and B for B) elementary semiconductors, in particular modifications of tin, indium, carbon, silicon and germanium and / or c) conductive organic polymers, in particular polypyrrole, polyaniline, polyparaphenylene, polythiophene, Poly (4,4-dioctylcyclopenta-dithiophene), poly (3,4-ethylenedioxythiophene) or poly (3,4-ethylene-dioxythiophene) / poly (styrenesulfonate).

The facades provided with said coatings do not allow a direct reaction to a rain or condensation event. Also, the temperature increase or the degree of dehydration depends on the orientation of the facade wall. Finally, even shaded areas caused by roof overhangs or trees can greatly reduce or even eliminate the desired effect. Controlled influence on the moisture conditions present on the surface of a facade is thus not possible.

In the DE 103 05 431 A1 describes a wall structure, by which the tendency to foul a thermally well-insulated building surface should be at least reduced, that this fouling tendency corresponds to the fouling tendency of a poorly or uninsulated building surface with a constant flow of heat to the outside, without having to use biocides. This is to succeed by using a heat-insulated exterior exterior wall, on which at least one heat storage layer and in turn an insulation layer with a lower thermal insulation effect is arranged. Even with this system, however, no controlled and needs-based heating succeeds. Sometimes these systems can at least temporarily lead to conditions that are conducive to microbial growth.

The DE 103 20 240 A1 discloses a method for drying damp walls of buildings by means of a multi-layer heating mat, which contains a thermal barrier coating, a heat-resistant on one side of the thermal barrier coating applied heating layer, an adherently applied thereto electrically insulating barrier layer and adhering to the barrier layer firmly bonded Wärmeleitschicht. Here, the heating layer is operated as electrical resistance heating with low voltage, and the heating mat is brought into surface contact with its Wärmeleitschicht with the wall. By applying electric current, the heating mat and, subsequently, the adjacent wall side are heated. As a result, the moisture is to be pressed from the heated wall side, starting through the wall and vented on the unheated side of the wall.

For drying concrete elements in facades beats the EP 2 693 128 A1 To introduce channels with holes in these concrete elements in order to allow the exchange of air within these channels and thus to accelerate the drying of the concrete.

The EP 501 840 A2 proposes an elongated ventilation plate made of rolled or pressed sheet metal construction for the reduction of moisture. This vent plate is designed to be such that lengths thereof can be cut off to form discrete plate modules. In this case, the ventilation plate has to be corrugated to form a series of grid and ventilation areas, which are arranged between the grids. The slats serve as an obstacle to the penetration of rain, for example through the ventilation region. In the in the EP 501 840 A2 The measures described are not active ventilation for drying the façade surface, but rain and moisture protection for the inner layers.

The use of biocidal agents in coating materials provides protection against microbial growth only for a limited period of time. Because with external facades, these substances are washed out over time. These biocidal materials can also be decomposed lose their activity. The same applies to by using hydrophobic substances water repellent equipped facade coatings.

The present invention was therefore based on the object to provide a system or a method available, with which the microbial growth can be permanently reduced or even eliminated. The invention was also based on the object to provide a system or method available with the building walls, in particular building exterior walls permanently energy-saving and controlled dried or can be kept dry.

Accordingly, a ventilation system has been found for the admission of at least one wall surface of a building with an upper, a lower and opposite lateral edges, in particular for the outer facade of an insulated building wall, with at least one air flow comprising at least one ventilation unit with at least one ventilation opening with a ventilation opening cross-section, in particular in the form of a ventilation slot, for the exit of an air flow, wherein the ventilation unit is set up and designed to direct the air flow over the at least one ventilation opening along at least a portion of the building wall surface, in particular the outer facade.

In one embodiment, the ventilation system according to the invention can already contain at least one building wall with the building wall surface.

The ventilation system according to the invention is particularly suitable for building walls which contain or represent an insulated building wall containing at least one insulating layer. Preference is given here equipped with a thermal insulation system exterior building walls.

The ventilation system according to the invention may in one embodiment be designed and arranged to be operated in permanent mode, i. the building wall surface is subjected to a continuous flow of air via the ventilation system. Of course, it is also possible to switch the ventilation system on and off manually or via a timer. Accordingly, a variant of the ventilation system according to the invention comprises at least one directly or indirectly coupled to the at least one ventilation unit timer.

Alternatively or additionally, the ventilation system according to the invention can also be provided with at least one interface for the connection to a, in particular local, weather data station be equipped. In this way, in particular via the application or integration of an evaluation and control unit adapted to current weather data admission of building wall surfaces with an air flow. The evaluation and control unit is usually a computer equipped with evaluation and control software.

In a further embodiment, the ventilation system according to the invention may alternatively or additionally also comprise at least one humidity sensor and / or at least one temperature sensor. With the help of the humidity sensor, for example, it can be determined very quickly whether or when a rain event has ended. Also, the progress of the drying process can be monitored via a humidity sensor or via a plurality of humidity sensors, for example in the form of an array of moisture sensors distributed over the wall surface of the building, and the drying can be terminated when a desired, preset drying or moisture level is reached.

Particularly expedient embodiments of the ventilation system according to the invention are therefore additionally equipped with at least one evaluation and control unit, set up and designed to detected data of the at least one humidity sensor and / or detected data of the at least one temperature sensor and / or data of at least one, in particular local To receive and optionally evaluate weather data station, and arranged and designed to control and / or regulate the at least one ventilation unit on the basis of the received and possibly evaluated data. By using an evaluation and control unit coupled with input data obtained from or from suitable sensors and / or weather stations building walls surfaces can be very targeted and energy-saving applied to an air flow. In this way, condensation can be prevented or the drying of a moist building wall surface can be forced. Conditions that usually lead to mold and / or fungal attack are eliminated or do not occur at all.

Suitable humidity sensors may for example be based on the measurement of the resistance or the voltage between two offending metal pins, which are present for example in a cover or plaster layer. In this case, the metal pins preferably protrude slightly, for example 1 to 3 mm, out of the cover or plaster layer.

The metal pins are preferably made of stainless steel, but can also be based, for example, on further corrosion-protected alloys, for example containing molybdenum. In a particularly expedient embodiment, the metal pins are in the form of metal sleeves. Two such metal pins or sleeves of a humidity sensor used according to the invention, for example, if introduced in a building wall surface, a distance of 5 to 40 mm, preferably a distance in the range of 10 to 30 mm. It has proven to be very useful for many applications to attach the metal pins on a non-conductive base plate, in particular a plastic plate. For better connection with a cover or plaster layer, it has proven to be advantageous to introduce one or preferably several holes into this base plate. Electrically conductive cable connections can be brought back with the respective metal pin in connection, for example, introduced into the cavity of the metal sleeve and soldered there. The electrically conductive cable connections can be introduced or embedded in a practical embodiment in the base plate. Such a unit can be easily mounted on an insulating layer. Subsequently, a cover layer, for example, a plaster layer can be applied, whereby the metal pins are embedded in this cover or plaster layer. Here, the lengths of the metal pins are preferably selected such that they protrude after solidification of the cover or plaster layer over the surface of this layer. The above-described humidity sensor can be excited with DC signals as well as with AC signals. AC rectangular signals, preferably having a frequency in the range from 300 to 600 Hz and in particular in the range from 450 to 550 Hz, for example 500 Hz, are preferably used here. The humidity sensor described above can be easily integrated into facades, is almost invisible and reacts very quickly to changes in humidity. Another advantage is its cost-effective production and attachment or introduction.

In one embodiment, the generated signals can be recorded by a signaling / signal reception and data processing unit (slave unit), digitized and forwarded to a data collection and data forwarding unit (master unit). The data collection and data forwarding unit can serve as a connection to the evaluation and control unit. In a particularly preferred embodiment, this connection is configured wirelessly.

Accordingly, in a development, the object underlying the invention is also achieved by a humidity sensor, comprising a non-conductive base plate having a front and a back and two metal pins having an upper and a lower end spaced from each other with their respective lower end or in the Area of these lower ends are connected to the front of the base plate, and a first conductor wire, which is connected to the lower end of the one metal pin, and a second conductor wire which is connected to the lower end of the further metal pin, a signaling / signal receiving and data processing unit connected via the first and the second lead wire to the two metal pins or is connectable and which is designed and arranged to send out DC or AC excitation signals and to receive and digitize detected signals and to a data collection and data forwarding unit or to an evaluation and control unit of a ventilation system, in particular of the ventilation system according to the invention, and optionally a data collection and data forwarding unit which is designed and arranged to collect the digitized signals obtained via the signaling / signal receiving and data processing unit and to an evaluation and control unit of a ventilation system, in particular of the invention ßen ventilation system, forward.

If several moisture sensors are used to determine the moisture content of a building wall in order to use their data for the control and / or regulation of the ventilation units of the ventilation systems according to the invention, it is also possible to speak of a humidity sensor system in the sense of the invention. Accordingly, in a development, the object underlying the invention is also achieved by a moisture sensor system comprising at least two, in particular a plurality of moisture sensors according to the invention, wherein a Signalgebungs- / Signalempfangs- and data processing unit each with a unit of non-conductive base plate with a front - And a back and two metal pins having an upper and a lower end, which are spaced from each other with their respective lower end or in the region of these lower ends connected to the front of the base plate, and a first conductor wire, which is connected to the lower end of the one metal pin and a second lead wire connected to the lower end of the further metal pin is connected or connectable via the first and second lead wires, and a data collection and data transfer unit having the at least two, especially the plurality of moistures is connected or connectable sensors and is designed and set up to collect the digitized signals received via the Signalgebungs- / Signalempfangs- and data processing units and forward to an evaluation and control unit of a ventilation system, in particular the ventilation system according to the invention.

In a further embodiment, it is possible to resort to a humidity sensor which is formed of two non-interconnected electrically conductive metal elements, for example copper plates or copper wires, which are at a distance from one another, for example on an adhesive strip. In the presence of moisture, there may be an electrically conductive connection between these two conductive metal elements. In this way it can be determined without great effort and therefore cost, whether it has come to a moisture or rainfall. The extent of the moisture input or a drying process can not or only partially track with these sensors. The metal elements are hereby regularly not embedded in a building wall layer, but on the surface of the building wall.

As a suitable humidity sensor is also considered one which is formed of electrically independently addressable electrodes and an electronic circuit for excitation and data processing. All of these components can be present on a single printed circuit board. The dielectric constant of the medium surrounding the sensor is measured. Hereby, one makes use of the fact that the dielectric constants of water and ice are significantly larger than those of air. These sensors can be used to determine if a surface, such as a building wall, is dry, damp or covered with ice or dew.

Suitable humidity sensors can accordingly u.a. based on the measurement of electrical conduction, resistance, voltage or capacitance. Alternatively or additionally, it may be provided to determine the occupancy of a wall surface with moisture or the extent of occupancy of this wall surface with moisture by means of an IR sensor.

Of course, humidity and temperature sensors can also be combined or integrated in a component / sensor.

For example, it has proved expedient to integrate the at least one temperature sensor in a plaster layer, in particular a cover layer, the building wall. In the case of an insulated building wall, this temperature sensor can also be present or fastened on the insulating layer.

Such temperature sensors are preferred, which have been coated with a conductive coating, in particular one, preferably 2-component, silver-conductive coating are. It has proven to be expedient in many cases, to attach the temperature sensors directly on that side of the insulating layer of a thermal insulation composite system, which faces the cover layer. In this case, the temperature sensors can be completely or partially covered by the cover layer, for example a reinforcing layer and / or a topcoat layer.

In many cases it has proven to be expedient to attach the moisture sensor (s) and optionally the temperature sensor or sensors in the region of the center of a surface to be dried by means of ventilation air.

Suitable ventilation units can be selected from the group consisting of centrifugal fans, axial fans, free-running paddle wheels and roller fans.

For example, a radial fan can be readily placed under or integrated into a roof overhang. In this way, high air masses can be transported. The advantage of axial fans is, as has been found, that they can be integrated into a roof overhang with relatively little effort, even subsequently. The freewheeling paddle wheels introduced into a building wall surface permit a circular application of the wall surface with an air flow and can likewise be retrofitted without further ado.

Suitable radial fans may e.g. with a power in the range of 10 to 1000 watts or in the range of 20 to 600 watts per meter of the ventilation opening, in particular the ventilation slot operated.

In an expedient embodiment, the at least one radial fan, the at least one free-running paddle wheel or the at least one roller fan are equipped with at least one front air inlet. Alternatively, the air inlet can also be on the back.

In the case of axial fans, however, it has proven to be advantageous for the at least one air inlet to be present on the upper side. According to a further expedient embodiment, the air inlet may also be present for example laterally, i. the required air for generating the air flow are sucked in laterally

Furthermore, it can be provided in a particularly advantageous embodiment that the at least one radial fan, the at least one free-running paddle wheel, the at least one roller fan or the at least one axial fan at least one lower-side Have air outlet. This underside air outlet preferably opens into a lower-side ventilation opening.

In principle, however, the at least one ventilation unit may have a front, rear, lower or upper side air inlet. The ventilation system according to the invention can thus be adapted very flexibly to the respective conditions of use. The air inlet may thus be concealed both for the viewer of a building wall, but may also be present in a recognizable manner. Of course, it is also possible that the air intake is objected to by the building wall surface to be ventilated.

The at least one ventilation opening, in particular the cross section of the ventilation opening, is expediently set up and designed to generate an airflow over at least a portion of the building wall surface via the ventilation unit. The ventilation opening can thus also be referred to as an air outlet. In principle, the ventilation opening, for example in the form of a ventilation slot, can be arranged in a variety of ways so as to always guide an airflow over at least a portion of the building wall surface, which either leads to drying of the building wall surface or to the prevention of condensation. For example, in one embodiment, the at least one ventilation opening can be set up and designed to guide an air flow in the direction from the upper edge to the lower edge of the building wall, in particular from the upper edge in the direction of the lower end, via the ventilation unit. It is also possible that such an air flow, in the direction from the lower edge to the upper edge, in particular from the lower edge in the direction of the lower edge, or in the direction from the first side edge to the opposite second side edge or in the direction of the second is directed to the first page margin. Further, the ventilation opening may also be configured and configured such that an airflow is directed at an angle to the orientation from the upper to the lower edge or at an angle to the orientation from the first to the opposite second side edge, for example diagonally across one square or rectangular building wall surface. Here, in one embodiment, the ventilation unit (s) and / or the ventilation opening (s) can essentially be present directly at the lower edge, upper edge, first side edge and / or second side edge or in the region thereof.

The ventilation opening cross-section of the ventilation opening, for example a ventilation slot, has an average width in the pragmatic embodiment Range of 15 to 120 mm, preferably in the range of 30 to 80 mm, on. The length of the ventilation opening can vary within wide ranges and, for example in an expedient embodiment, can have an average length in the range of 60 to 1200 mm. The length of a ventilation opening may extend, for example, over the entire length and / or the entire width of a building wall. In addition, ventilation openings can be provided with a length sufficient to span an entire building.

Suitable ventilation systems according to the invention can also have a ventilation unit in which at least one deflector plate is present in front of the ventilation opening. In this way, a particularly uniform air flow can be generated.

The ventilation unit is preferably set up and designed such that it can generate flow velocities of the air flow in the range of 1 to 12 m / s, preferably in the range of 2 to 8 m / s in the area of the ventilation opening. To achieve a constant air velocity over a greater distance, the air mass should be as high as possible. Under these conditions, no noise is regularly detected.

Accordingly, in one embodiment, a ventilation system for a building wall, in particular for a building exterior wall equipped with a thermal insulation composite system, comprising at least one insulating layer, comprising a) at least one ventilation unit with at least one ventilation opening, in particular in the form of a ventilation slot for the exit of a Air flow, b) at least one humidity sensor, c) optionally at least one temperature sensor, and d) at least one evaluation and control unit, set up and configured to receive and evaluate detected data of the at least one humidity sensor and possibly detected data of the at least one temperature sensor, and configured and configured to control and / or regulate the at least one ventilation unit based on the evaluated data.

A particularly effective drying of building walls, in particular building exterior facades, also succeeds with such ventilation systems according to the invention, which additionally with at least one sensor for determining the temperature of the ambient air and / or at least one sensor for determining the relative humidity of the ambient air and / or at least one sensor for determining the wind speed of the ambient air are equipped, wherein the evaluation and control unit is set up and designed to detect detected data of the at least one sensor for determination the temperature of the ambient air and / or to receive and evaluate detected data of the at least one sensor for determining the relative humidity of the ambient air and or to detected data of the at least one sensor for determining the wind speed of the ambient air, and is also set up and designed to the basis of the evaluated data to control and / or regulate the at least one ventilation unit.

The drying of building walls can also be carried out particularly effectively by such ventilation systems according to the invention, which furthermore have at least one heating unit for the heating of the air flow exiting via the at least one ventilation opening.

Particularly good and reproducible drying results are also obtained when using such ventilation units, which are set up and designed to generate an air flow in the range of 500 to 4000 m ³ , preferably 1000 to 1750 m ³ , air per hour per meter of building wall surface running.

The speed of the air flow is controllable in an expedient embodiment via the evaluation and control unit.

The ventilation unit or its ventilation opening according to the invention is expediently set up and designed in such a way that the optionally heated air stream emerging therefrom flows close to the surface of the building. Here, it is preferably ensured that the temperature of the air flow is greater than the temperature of the building exterior wall. This can be determined using the sensors of the ventilation system. If the temperature of the air flow is lower than the temperature of the external wall of the building, the ventilation is interrupted or the air used for the air flow is first heated via a heating module.

Thus, in an expedient embodiment, the ventilation opening, in particular the ventilation slot, can be spaced approximately 1 to 5 cm or even 2 to 4 cm away from the building wall. According to a further, particularly expedient embodiment, the ventilation opening, in particular the ventilation slots, can be directly connected to, i. unopposed from the building wall. In this way, a constant flow of air over the surface to be dried is regularly ensured.

In combination with the humidity sensors, which can be integrated in the cover layer of the building wall, it is possible to detect rain and condensation events.

In this way, the ventilation system according to the invention can be used selectively only to dry the surface when it is necessary.

By using temperature sensors in the building façade, it can be ascertained, for example, when a certain wall temperature is reached, below which the growth of microorganisms is regularly severely limited. It has been found that many of the relevant microorganisms hardly grow below 5 ° C. The temperature sensor can be used, for example, to turn off the ventilation unit at relatively low temperatures.

Additionally or alternatively, the switching off of the ventilation unit according to the invention at low temperatures avoids condensation due to the generated air flow. Here, in a preferred embodiment of help, that can be determined relatively accurately and promptly via the evaluation and control unit based on the data of humidity and / or temperature sensor and / or with the help of the data of a particular local weather station, when the dew point temperature is reached , so that condensation can be prevented from the outset by the time-correcting activation of the ventilation system according to the invention.

In particular, when the ventilation system according to the invention comprises sensors for detecting the wind speed of the ambient air of building walls, in particular building facades, it is possible to regularly ventilate the same even more according to need. For in the case of strong wind, an additional ventilation of the surface, for example, is not required. Furthermore, with the aid of sensors that determine the temperature of the ambient air and sensors that determine the temperature of the wall surface of a building wall, an adjustment can be made via the evaluation and control unit. In the event that the surface temperature of the facade is higher than that of the ambient air, can be dispensed with ventilation using the ventilation system according to the invention.

In many cases, it has proven to be advantageous, with the aid of the ventilation system according to the invention to operate the ventilation of building walls, in particular building exterior facades, when the outside air has a higher temperature than that of the wall surface. In this case, the surface is heated quickly, and even after switching off the ventilation, a lower tendency for condensation of water is observed.

Optionally, it can be provided to heat the ventilation air via upstream heat exchanger before it hits the building wall, in particular building exterior facades. For this purpose, for example, during the summer time, the air from indoor spaces can be used. Also can be resorted to regenerative sources such as geothermal.

The ventilation system according to the invention can be equipped in a further embodiment with a timer. For example, it can be ensured via such a timer that the ventilation process is performed in any case every day, in particular at the same time, for example within a period in which the condensation of water occurs more intensively, for example from 5:00 to 7:00 In the morning. In this way, a so-called condensation prevention is achieved.

For many applications, it has also proven to be advantageous to continue the ventilation process at least for a certain period of time after it has been indicated via the humidity sensor that the ventilated surface no longer has any moisture. In this way, a re-condensation of moisture can be prevented, in particular if the ventilation is continued until the temperature sensors indicate that the temperature of the building wall is again adjusted to the temperature of the ambient air.

The object underlying the invention is further achieved by a building wall, in particular building exterior wall, with an upper end and an opposite lower end, containing at least one ventilation system according to the invention.

In one embodiment it is provided that the at least one ventilation opening is set up and designed to guide an air flow in the direction from the lower to the upper end of the building wall, in particular from the lower end in the direction of the lower end, along the same. Alternatively it can be provided that the at least one ventilation opening is set up and designed to guide an air flow in the direction from the upper to the lower end of the building wall, in particular from the upper end in the direction of the lower end, along the same. Further, the at least one ventilation opening may be configured and configured to direct an airflow at an angle to the orientation from the upper to the lower edge or at an angle to the orientation from the first to the opposite second side edge therealong. Particularly satisfactory have also proven such building walls in which the moisture sensor two present in the plaster layer and preferably from this protruding metal pins, said moisture sensor is designed and adapted to measure the electrical resistance or the voltage between these metal pins.

The building wall according to the invention may further comprise at least one base and / or at least one profile and / or at least one decorative element and / or at least one roof overhang, wherein the at least one ventilation opening in the at least one base or the at least one profile or the at least one decorative element or in or under the roof overhang.

Furthermore, such building walls according to the invention are also included in an expedient embodiment in which these two or more ventilation units are provided with a ventilation opening or a ventilation unit having a first and a second and at least one optionally further ventilation opening, wherein the ventilation openings of the two or more ventilation units or the first and the second and possibly the further ventilation opening are rectified or arranged opposite one another or are arranged in such a way that the air streams escaping from these ventilation openings are at an acute or obtuse angle to each other, in particular arranged opposite one another. In this way, the drying or the suppression of the condensation can be even more forced. Two or more ventilation openings of one, two or more ventilation units are arranged in the same direction in the sense of the invention, if from these air flows each escape, they are mutually substantially parallel or collinear. Parallel flow air streams that escape from ventilation openings, which are arranged side by side or offset side by side, either at the same height or at different heights. These juxtaposed or offset juxtaposed ventilation openings may overlap each other to a minor extent and thus lead to an overlapping in this extent air flow. Two or more air streams are collinear in the context of the invention, when they escape from ventilation openings, which are arranged behind one another or successively and in which the next following air flow continues the preceding air flow in the same direction.

The object underlying the invention is further achieved by a building containing a building wall according to the invention. In this case, in a preferred embodiment, the at least one ventilation opening of the ventilation system may be present, for example, in or under a roof overhang. Thus, in one embodiment, the Ventilation unit are attached to the building wall, in particular on the building exterior facade.

Furthermore, when using free-running paddle wheels, these can be integrated in the building wall and expediently have a cover.

The ventilation systems according to the invention are particularly suitable for preventing the condensation of water on a building wall, in particular building exterior wall, and / or for the forced drying of wet building walls, in particular building exterior walls.

The invention has been explained below with reference to examples.

Examples

With the aid of a demonstrator, the ventilation system according to the invention was investigated under defined conditions. Humidity and temperature sensors are used.

The wind speeds were varied from 3 to 10 m / s, the ambient temperatures of 8-16 ° C and the humidity of 75-95%. Partly the ambient air was heated before it was used to ventilate the façade surface. It turns out that drying of the wall surface by means of air flow is possible even without the heating of the air even at high humidities.

The demonstrator was 3 meters wide and 2.5 meters high. The total area was subdivided to obtain a reference. Thus, the left side was equipped with the ventilation system according to the invention, the right not. Both sides were subdivided into a page that was artificially polluted with cultured algae and an untreated page. Rails were installed between the surfaces to prevent migration of the microorganisms and to prevent the air flow from reaching the other side.

The ventilation unit was a 1.5 meter wide curtain air curtain equipped with two centrifugal fans. This was anchored on the façade surface and roofed over for weather protection. The air was sucked in from behind and discharged downwards along the façade surface. There was a distance of 3 cm between the wall and the outlet of the ventilation unit. There was a constant flow of air over the area to reach. The test façade was each equipped with a humidity sensor and a temperature sensor equipped per area. The humidity sensor used the voltage measurement and was ultimately based on the determination of the electrical resistance of the plaster between two metal pins. The temperature sensor was a commercially available Pt1000 element, which was coated with a 2-component silver-conductive coating for use in the façade. These sensors were glued directly to the foamed insulation layer during the construction of the façade and completely or partially covered by the reinforcement layer and the finishing layer. The temperature sensor was accordingly completely covered and no longer visible, from the humidity sensor, the pins sticking out of the surface. The sensors were each mounted approximately in the middle of the respective surface. The sensitivity of the humidity sensor was determined with distilled water and tap water.

The air curtain system was designed for air volumes of 2200 m3 / h. The control was carried out via an evaluation and control unit, which also records the data of the sensors. The resulting wind speeds were measured by thermal anemometry. The remaining unventilated surfaces had an air flow of less than 0.5 m / s. Regardless of the initial speed was the loss of the initial speed, the loss of air velocity over the area of two meters is about 50%. To achieve a constant air velocity over a greater distance, the air mass should be as high as possible. The dependence of the air mass on the air velocity is shown in Table 1. Table 1 Air velocity [m / s] Air mass [m3 / h] 2 750 4 1500 6 2250 8th 3000 10 3750 12 4500

Drying tests were carried out under defined laboratory conditions. The air temperature was 19 ° C at 50% humidity. One area was wetted with a spray bottle, corresponding to about 130 ml of water per m2 area. After 4 minutes, the ventilation was stopped and operated until the temperature returned to its original level. This experiment was repeated for 5 different flow intensities. It could be seen that the ventilation significantly accelerated the drying compared to the reference without ventilation, at least by a factor of 4. It could also be seen that the cooling by the enthalpy of evaporation of the water was more pronounced on ventilated surfaces, but after drying by more Ventilation also returned to the original level faster. The ventilation should therefore preferably not stop as soon as the humidity sensor indicates that the wall is dry, but when the temperature is again adjusted to the ambient temperature. This allowed condensation of water on the cold surface to be avoided.

The present invention is based on the surprising finding that with the ventilation system according to the invention, the microbial growth can in particular also be suppressed or even completely suppressed on heat-insulated building walls. The reduced heating of the outer wall due to the insulation caused by the heated interiors no longer inevitably led to an increased condensation of moisture on the outer facades. With the present invention, it is possible to permanently, energy-saving and controlled to dry the surface of facades or to keep permanently dry. This significantly extends the cleaning and renovation cycles of wall surfaces.

Surprisingly, it has also been found that drying of the wall surface by means of air flow can be achieved even without the heating of the ventilation air even at high humidities. It has also been surprisingly found that for the required drying, which helps to prevent the microbial growth, already sufficient air flow, which does not lead to a sound pollution.

With the ventilation system according to the invention succeeds a sensor-controlled control of the ventilation of a building wall, in particular building exterior wall surface, in a particularly effective manner. With the aid of the ventilation system according to the invention, the wall surface is dried only when it is really necessary. In particular, compared to solutions based on the heating of the building wall, the ventilation is particularly energy efficient. Because plaster layers regularly have a high mass and thus also a high heat capacity and therefore require high amounts of energy to be warmed up.

A particular advantage of the ventilation system according to the invention is also that outside air can be used automatically for the air flow, in particular when the temperature is higher than that of the water surface. Also, it has proved to be advantageous that the ventilation system according to the invention can be subsequently placed on an existing thermal insulation system. This also succeeds in the renovation of heavily affected by microorganisms surface. It has often proven to be useful if the affected building has previously been subjected to cleaning. Furthermore, when using the ventilation system according to the invention on building walls, the washing out of substances from the facade can be prevented and thus premature aging of the building wall surfaces can be prevented. In this way it can be prevented that potentially environmentally hazardous substances are released by washing out. It has also been surprisingly found that building walls contaminate surfaces more slowly when using the ventilation system according to the invention. Without being bound by theory, it is currently believed that dirt particles, such as particulate matter, adhere better to wet or damp facades.

Further features and advantages of the invention will become apparent from the following description, are explained in the preferred embodiments of the invention by way of example with reference to schematic drawings.

Figur 1

eine schematische Draufsicht auf eine erste Ausführungsform einer erfindungsgemäßen Gebäudewand,

Figur 2

eine schematische Draufsicht auf eine zweite Ausführungsform einer erfindungsgemäßen Gebäudewand,

Figur 3

eine schematische Draufsicht auf eine dritte Ausführungsform einer erfindungsgemäßen Gebäudewand,

Figur 4

eine schematische Draufsicht auf eine vierte Ausführungsform einer erfindungsgemäßen Gebäudewand,

Figur 5

eine schematische Draufsicht auf eine fünfte Ausführungsform einer erfindungsgemäßen Gebäudewand und

Figur 6

eine schematische Draufsicht auf eine sechste Ausführungsform einer erfindungsgemäßen Gebäudewand.

Showing:

FIG. 1

a schematic plan view of a first embodiment of a building wall according to the invention,

FIG. 2

a schematic plan view of a second embodiment of a building wall according to the invention,

FIG. 3

a schematic plan view of a third embodiment of a building wall according to the invention,

FIG. 4

a schematic plan view of a fourth embodiment of a building wall according to the invention,

FIG. 5

a schematic plan view of a fifth embodiment of a building wall according to the invention and

FIG. 6

a schematic plan view of a sixth embodiment of a building wall according to the invention.

In the FIG. 1 shown schematic plan view of a building wall according to the invention shows the Gebäudewand- or facade surface 2 with an upper edge 4, with a lower edge 6 and opposite first and second side edges 8 and 10. Along the upper edge 4, a ventilation unit 12 of a ventilation system according to the invention is attached an opening 14 pointing downwards along this ventilation unit in the form of an opening slot from which directed airflow (arrows) escapes along the building wall surface 2. The opening 14 of the ventilation unit 12 is mounted so close to the building wall surface 2, that the air flow reaches as much of it as possible and sweeps over it. In this way, the formation of moisture, such as dew, on a building wall surface can be completely prevented. Also succeeds in this way, a particularly rapid drying of a damp building facade surface.

For particularly large areas that are to be dried or kept dry, it has proven to be expedient in some cases, two or more substantially horizontally extending ventilation units 12A and 12B, such as in FIG. 2 shown to be attached to each other, almost in series. While the first ventilation unit 12A with its downwardly directed ventilation opening 14A is present in the upper edge 4 of the building wall surface 2, the second ventilation unit 12B is spaced from, for example, in the middle of the building wall surface 2, with a likewise downwardly pointing ventilation opening 14B. With the first ventilation unit 12A, the upper portion of the building facade 2 and the second ventilation unit 12B, the lower portion of the building facade 2 each subjected to an air flow and thus dried or kept dry. The air flows of these ventilation units are rectified and are substantially collinear.

In addition, in another, in FIG. 3 1, a ventilation unit 12 according to the invention may be mounted substantially centrally and horizontally on a building wall surface 2. In this case, the ventilation opening 14 may, for example, either upwards or downwards, depending on which area is more threatened by moisture. Alternatively, it is of course also possible to provide this ventilation unit 12 with an upwardly and simultaneously downwardly facing ventilation opening 14C and 14D, so that the entire facade surface can be acted upon by an air flow. The example centrally mounted ventilation unit according to FIG. 3 For example, it can be integrated in a decor element or profile present on the facade wall and, in this way, does not appear visually more pronounced.

In addition, as in FIG. 4 1, a building wall 1 according to the invention may also be equipped with a ventilation unit 12 attached to a lateral edge 8 of the building wall, for example substantially vertically. The ventilation opening 14 then likewise projects laterally on the ventilation unit 12 and discharges an air flow (arrows) in the direction of the opposite second side edge 10.

According to a further embodiment, as in FIG. 5 reproduced, the ventilation units 12A, 12B of the ventilation systems according to the invention can also be selectively attached to such positions on a building surface 2, which are particularly threatened by moisture or exposed to moisture. The ventilation units 12A, 12B are arranged side by side in the illustrated embodiment and are not at the same height. The ventilation openings 14A, 14B are each located on the underside, so that the respective air flow (arrows) is directed in the direction of the lower edge 6. In the illustrated embodiment, the airflows of the two ventilation units 12A and 12B do not overlap, but are aligned in parallel.

Finally, in a further embodiment, see Fig. 6 , a first ventilation unit 12A of a ventilation system according to the invention at the upper edge 2 of a building surface 2 present with a downwardly facing ventilation opening 14A and at the same time a further ventilation unit 12B at the lower edge 6 with an upwardly facing ventilation opening 14B. The air streams (arrows) escaping from these ventilation openings 14A, 14B are thus aligned in opposite directions. In this way, very large building wall surfaces can also be dried or kept dry, especially with the simultaneous use of upper and lower ventilation unit.

The in the FIGS. 1 to 6 For example, ventilation systems according to the invention shown can of course also with a timer or with at least one humidity sensor, in particular a plurality of humidity sensors, and / or with at least one temperature sensor, in particular a plurality of temperature sensors, preferably a plurality of, in particular inventive, humidity sensors and an evaluation and Control unit, configured and designed to receive and evaluate detected data of the at least one humidity sensor and / or detected data of the at least one temperature sensor, and set up and configured on the basis of the received and possibly evaluated data, the at least one ventilation unit of the ventilation system according to the invention to control and / or to regulate.

The work leading to this invention has been funded under Grant Agreement GA No 609200 under the Seventh Framework Program of the European Union (\ IU) 7 / 2007-2013 \ [FP7 / 2007-2011]).

The features of the invention disclosed in the foregoing description, in the claims and in the drawings may be essential both individually and in any combination for the realization of the invention in its various embodiments.

Claims (19)

Ventilation system for the wall surface of a building with an upper, a lower and opposite lateral edges, in particular for the outer facade of an insulated building wall, comprising
at least one ventilation unit having at least one ventilation opening with a ventilation opening cross-section, in particular in the form of a ventilation slot, for the exit of an air flow, wherein the ventilation unit is set up and designed to move the airflow over the at least one ventilation opening along at least one section of the building wall surface, in particular the outer facade, to lead. Ventilation system according to claim 1, further comprising at least one building wall with the building wall surface. Ventilation system according to claim 1 or 2, characterized in that the at least one building wall comprises an insulated building wall, comprising at least one insulating layer, in particular a building exterior wall provided with a thermal insulation composite system. Ventilation system according to one of the preceding claims, further comprising at least one directly or indirectly coupled to the at least one ventilation unit timer,
at least one interface for connection to a, in particular local, weather data station and / or at least one humidity sensor and / or at least one temperature sensor. A ventilation system according to claim 4, further comprising
at least one evaluation and control unit, configured and designed to receive detected data of the at least one humidity sensor and / or detected data of the at least one temperature sensor and / or data of the at least one, in particular local, weather data station and optionally evaluate, and set up and designed to control and / or regulate the at least one ventilation unit on the basis of the received and possibly evaluated data. Ventilation system according to claim 4 or 5, characterized in that
the at least one temperature sensor in a plaster layer, in particular a cover layer, the building wall can be integrated or integrated and / or fastened or fixed on the insulating layer or is present at a distance from the building wall. Ventilation system according to one of the preceding claims, characterized in that
the at least one ventilation opening, in particular the cross section of the ventilation opening, is set up and designed to generate an airflow over at least a portion of the building wall surface via the ventilation unit. Ventilation system according to one of the preceding claims, characterized in that
the ventilation opening area of the ventilation opening has an average width in the range of 15 to 120 mm, preferably in the range of 30 to 80 mm. Ventilation system according to one of the preceding claims, characterized in that
this is set up and designed to generate flow velocities of the air flow in the range of 1 to 12 m / s, preferably in the range of 2 to 8 m / s, in the area of the ventilation opening, and / or
the speed of the air flow via the evaluation and control unit is controllable. Ventilation system according to one of the preceding claims, further comprising at least one sensor for determining the temperature of the ambient air and / or
at least one sensor for determining the relative humidity of the ambient air and / or
at least one sensor for determining the wind speed of the ambient air,
wherein the evaluation and control unit is set up and configured to detect detected data of the at least one sensor for determining the temperature of the ambient air and / or for detected data of the at least one sensor for determination the relative humidity of the ambient air and / or to receive and evaluate detected data of the at least one sensor for determining the wind speed of the ambient air, and is arranged and adapted to control and / or regulate the at least one ventilation unit on the basis of the evaluated data. Ventilation system according to one of the preceding claims, further comprising at least one heating unit for the heating of the over the at least one ventilation opening exiting air flow. Building wall with a building wall surface, in particular a building exterior wall, with an upper end and an opposite lower end, containing at least one ventilation system according to one of the preceding claims. The building wall of claim 12, further comprising
at least one base and / or at least one profile and / or at least one decorative element and / or at least one roof survived, wherein the at least one ventilation opening is present in the at least one base or the at least one profile or the at least one decorative element or in or under the roof overhang , Building wall according to claim 12 or 13, characterized in that
the moisture sensor comprises two metal studs present in the plaster layer and preferably protruding therefrom, and is designed and arranged to measure the electrical resistance between these metal studs. Building wall according to one of claims 12 to 14, characterized in that it comprises two ventilation units with a ventilation opening or a ventilation unit having a first and a second ventilation opening, wherein the ventilation openings of the two ventilation units or the first and the second ventilation opening are arranged rectified or opposite each other or arranged in such a way that the air streams escaping from these ventilation openings are at an acute or obtuse angle to each other, in particular are arranged opposite one another. Building comprising at least one building wall according to one of claims 12 to 15. Use of the ventilation system according to one of claims 1 to 11 for the, in particular forced, drying of a moist building wall surface, in particular the outer facade of a building wall, and / or for preventing the condensation of water on building walls, in particular on the outer facades of building walls. Humidity sensor, comprising
a non-conductive base plate having a front and a back and two metal pins having an upper and a lower end, which are spaced from each other with their respective lower end or in the region of these lower ends connected to the front of the base plate, and a first lead wire, the is connected to the lower end of the one metal pin, and a second conductor wire connected to the lower end of the further metal pin, a signaling / signal receiving and data processing unit connected via the first and the second lead wire to the two metal pins or connectable and which is designed and arranged to emit DC or AC excitation signals and to receive and digitize detected signals and to a data collection and data forwarding unit or to an evaluation and control unit of a ventilation system, in particular the ventilation system according to one of claims 1 to 11 , white terzuleiten,
and optionally, a data collection and forwarding unit configured and arranged to collect the digitized signals received via the signaling / signal receiving and processing unit and to an evaluation and control unit of a ventilation system, in particular the ventilation system of any of claims 1 to 11, forward. Humidity sensor system comprising
at least two, in particular a plurality of humidity sensors according to claim 18, wherein a signaling / signal receiving and data processing unit each having a unit of non-conductive base plate with a front and a back and two metal pins with an upper and a lower end spaced from each other are connected to their respective lower end or in the region of these lower ends with the front side of the base plate, and a first A lead wire connected to the lower end of the one metal pin and a second lead wire connected to the lower end of the another metal pin connected or connectable via the first and second lead wires, and
a data collection and data forwarding unit which is connected or connectable to the at least two, in particular the plurality of humidity sensors and which is designed and arranged to collect the digitized signals obtained via the signaling / signal receiving and data processing units and to an evaluation and control unit a ventilation system, in particular the ventilation system according to one of claims 1 to 11 forward.

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