RU2604584C2 - Ventilation plant - Google Patents

Abstract

FIELD: ventilation.

SUBSTANCE: invention relates to ventilation equipment, in particular, to reverse suction-and-exhaust ventilation plants with heat recovery, and can be used for installation in domestic and special purpose rooms. Ventilation plant comprises outer hood, internal module, ventilation duct, which connects inner environment with ambient environment, where external hood outputs to ambient environment, and internal module is to internal environment, whereby there are reverse fan with motor, recuperator, at least one filter and noise silencer, electric control module, which is located in inner module, wherein ventilation duct additionally contains inner housing, whereby there are reverse fan with motor, recuperator, at least another one, filter and which is made with possibility of disconnection from ventilation duct, wherein fan is located on ambient environment side, and recuperator is on inner environment side, and filters are located on inner housing both end sides.

EFFECT: invention aims at developing ventilation plant, in which enables convenient access to plant during repair or preventive maintenance works, as well as providing low level of noise during ventilation plant operation.

17 cl, 8 dwg

Description

The invention relates to ventilation equipment, in particular to reverse supply and exhaust units with heat recovery, and can be used for installation in premises for domestic and special purposes. The ventilation unit is compact and does not require ducting, suitable for various climatic zones and operating conditions.

The prior art knows many different technical solutions, various shapes and designs, designed for natural ventilation of residential and non-residential premises.

The motivation for finding the best solutions for ventilation systems is an attempt to build the premises in such a way as to ensure maximum energy saving in the building. However, an increase in the energy saving coefficient of a building leads to a proportional decrease in indoor climate self-regulation.

In other words, as a result of the use of central heating during operation of a significant number of household appliances and other modern technological factors, there is a significant dehumidification of indoor air, thereby creating favorable conditions for the development of allergic diseases and respiratory complications or diseases.

In the spring and in the summer, energy-saving buildings poorly absorb high air humidity, making natural air circulation difficult inside the room, thereby creating favorable conditions for the development of fungi and harmful microorganisms.

The above statements have long been known to mankind, therefore, in many developed countries, medical facilities often recommend airing the premises.

In most countries, regulations governing standards for permanent ventilation systems are in place.

Basically, airing occurs due to the opening of windows, thereby ensuring the natural circulation of air inside the room. However, airing by opening only windows creates a lot of inconvenience. In particular, in winter, an open window significantly cools the room due to a large area, and heats it in summer, which, as a result, leads to significant energy costs, to ensure acceptable and comfortable working and living conditions. Therefore, work on the creation of ventilation systems is underway for a considerable time.

Known ventilation installation [Patent RU No. 91412, F24F 7/07, F24F 7/06 from 09/04/2009], which is intended for placement in the wall of the room. The ventilation unit contains a noise-insulating ventilation channel of a cylindrical shape, a fan with an electric motor and at least one filter are placed in the channel. On both end sides of the ventilation duct there are ventilation grilles. Additionally, the ventilation unit can be equipped with a recuperator. To provide the ability to control the parameters of the installation, it can be equipped with a mechanical, or remote, or electronic automatic control system.

The well-known inVENTer iV12-Smart ventilation unit of the company inVENTer GmbH, which is available on the website (http://www.inventer.eu/products/inventer-ventilation-systems/inventer-iv12-smart/), which contains an external ventilation duct grill and indoor unit. The ventilation unit is compact and designed for installation in the wall of a room. A ventilation duct connects the room with the external environment, where the grill is located on the outside and the indoor unit is on the inside of the room. An axial reversible fan with an electric motor, at least one filter, a recuperator and a muffler are installed in the ventilation duct. The indoor unit is made in a three-dimensional housing, in which there is an electrical installation control module.

Known ventilation unit [Patent CN No. 202338980, F24F 7/007, F24F 11/02 F24F 12/00, F24F 13/30 dated July 18, 2012], adopted as the closest analogue that contains a ventilation duct that connects the external grille and the indoor unit . The ventilation unit is installed in the hole in the wall of the room to be ventilated. The ventilation duct connects the rooms with the external environment, and the external grill goes to the external environment, and the internal module goes to the internal environment. An axial reversible fan with an electric motor, a recuperator and a filter are sequentially located in the ventilation duct. A silencer is located on top of the fan and recuperator. Additionally, a filter can also be installed in front of the fan. To provide the ability to control the parameters of the installation, it can be equipped with a mechanical, remote or electronic automatic control system.

The disadvantage of the closest analogue is the location directly in the ventilation duct of the individual elements of the axial reversible fan, recuperator and filters, which leads to their difficult maintenance during repair or maintenance work.

The main elements of an air handling unit are a fan with an electric motor, because they work almost continuously. In the event of an emergency or a malfunction with the electric motor, it is necessary to have convenient and free access to it. Also, the filters become dirty during long-term operation, they need to be changed or cleaned and, accordingly, have convenient and easy access to them.

Another disadvantage is the location of the axial reversible fan with an electric motor from the side of the room. A fan with an electric motor generates noise; a silencer located on top of the fan does not completely suppress noise. This means that the consumer will always hear when the ventilation unit is working, which is a rather annoying moment.

The objective of the invention is the creation of a ventilation installation in which:

- due to a reversible fan with an electric motor located in the inner casing, a recuperator and at least one filter and housing placement with the possibility of disconnecting from the ventilation duct, convenient access to the installation is provided during repair or maintenance work;

- due to the location of the reversible fan with an electric motor in the inner case from the side of the external environment, a low noise level is ensured during operation of the ventilation unit.

The problem is solved so that the ventilation unit, which contains an external hood, an internal module, a ventilation duct that connects the room with the external environment, where the external hood goes to the external environment, and the internal module to the internal environment, in which there is a reversible fan with an electric motor , a recuperator, at least one filter and a silencer, an electrical control module, which is located in the internal module, according to the invention, the ventilation duct further comprises an internal a housing in which a reversible fan with an electric motor is located, a recuperator, at least one filter, and which is configured to be disconnected from the ventilation duct, the fan being located on the side of the external medium, and the recuperator on the side of the internal medium, and on both end sides Inner housing are filters.

In the ventilation installation, seals from the end faces in the grooves can be installed over the inner case.

In a ventilation installation, the inner case may consist of separate parts of the case that are interconnected.

In a ventilation installation, the inner case may comprise a device for ease of disconnection from the ventilation duct.

In a ventilation installation, the inner case may contain positioners for installation in the ventilation duct.

In a ventilation installation, the inner case may contain a temperature sensor, which is connected to an electrical control module, for sequential monitoring of the temperature of the exhaust and supply air.

In the ventilation installation, an ozonation device may also be located in the inner case.

In a ventilation unit, the fan can be mounted on an elastic ring to damp natural vibrations.

In a ventilation unit, a heat insulating material may be located on top of the recuperator.

In a ventilation installation, the indoor module may comprise a housing that includes an electrical control module, a front cover mounted on the housing, which includes louvers and a decorative cover mounted on the front cover.

In the ventilation installation, latching elements can be formed on the sides of the housing of the indoor module, and holes are made on the sides of the front cover that engage with the latching elements of the housing.

In a ventilation installation, the decorative cover may be located at some distance from the front cover, or it may fit snugly against the front cover and may be detached from the front cover.

In a ventilation installation, a touch panel can be made on the housing of the indoor unit to manually control the operation modes of the installation.

The ventilation unit may include a remote control for controlling the operation modes of the installation.

The ventilation unit may include an air humidity sensor, which is connected to an electric control module to control the air flow rate to provide the specified humidity parameters in the room, a light sensor is connected to an electric control module to regulate the air flow rate, depending on the lighting in the room.

In a ventilation installation, the electrical control module may comprise an input terminal for connecting to an electrical network and an output terminal for connecting an identical ventilation installation.

In the ventilation installation, the outer hood can be made in a special form, which ensures the prevention of rainwater from entering the installation.

The proposed ventilation installation differs from the closest analogue in the presence of an internal case located in the ventilation channel, in which there is a reversible fan with an electric motor, a recuperator and at least one filter and a housing design with the possibility of disconnecting from the ventilation channel; the location of the reversible fan with an electric motor in the inner casing from the side of the external environment.

As a result of using the present invention, a ventilation installation is created in which a low noise level during operation and ease of maintenance during repair or maintenance work are provided.

The invention is illustrated by figures, where:

In FIG. 1 - 3D model of an air handling unit;

In FIG. 2 - 3D model of the ventilation unit in cross section;

In FIG. 3 - image of the internal module in the closed and open positions;

In FIG. 4 is a cross-sectional view of the inner case;

In FIG. 5 is an image of a ventilation unit with constituent elements;

In FIG. 6 - image of the front cover of the inner case;

In FIG. 7 - images of various cellular structures of the recuperator;

In FIG. 8 - image of sealed chambers, with the closed position of the decorative lining.

The ventilation unit (1) is made as follows.

The ventilation unit contains (1) a ventilation duct (2), an outer hood (3), an internal module (4) and an inner case (5).

The ventilation channel (2) connects the room with the external environment, and the cap (3) goes to the external environment - fresh air, and the module (4) to the indoor environment, the room.

The internal module (4) consists of a housing (11) and a front cover (12), which is mounted on the housing (11). An opening (17) is made in the housing (11), which coincides with the opening of the ventilation duct. The housing (11) contains the entire electrical control module (13), with which the unit (1) is controlled.

The electrical module (13) to prevent moisture, condensation from entering the control board is closed with an additional cover with a special seal around the perimeter. On the sides of the housing (11), grooves are made in which protruding locking elements (14) are made.

The front cover (12) contains louvers (15) and a decorative trim (16). The blinds (15) ensure the tightness of the ventilation duct (2) and prevent the free flow of outside air into the room when the unit (1) is turned off. In the event of an emergency or shutdown of the installation, the blinds (15) are automatically closed.

On the inside, the decorative trim (16) contains a seal. When the cover (16) is in the closed position, the sealant provides additional sealing of the ventilation duct (2) from the ingress of external air into the room, with the unit (1) turned off.

When the decorative cover plate (16) is closed, an airtight chamber (K1) is formed with air between the closed shutters (15) and the seal. Thanks to the sealant, which is installed in the housing (11), and the sealant installed in the front cover (12), a sealed chamber (K2) is created with air, which acts as a heat insulator (Fig. 8).

Holes (19) are made on the sides of the cover (12), which engage with protruding locking elements (14) of the housing (11), thus, the front cover (12) is attached to the housing (11). If you simultaneously press on the protruding locking elements (14), the front cover (12) can easily be disconnected from the housing (11). For reliable and tight installation of the front panel (12) on the housing (11), the latter contains a seal located around the perimeter (not shown).

Before turning on the installation (1), the decorative trim (16) is manually or automatically, using manual controls, such as a touch panel (18), or a remote control, set at a distance from the front of the front cover (12), as shown in FIG. 3 - open position of the lining. The distance between the cover (16) and the cover (12) can be adjusted. For ease of installation and manual adjustment of the lining (16), decorative recesses (not shown) are made on the lid (12).

In order to manually close the decorative trim (16), just click on it in the middle, and the installation (1) is automatically turned off: the fan (7) is turned off and the blinds (15) are closed, as shown in FIG. 3 - closed position of the lining.

The electrical modules (13) contain optosensors that respond to the supply and termination of the signal to them. A pin (not shown) is made in the patch (16), which passes through the front cover (12) and controls the signal to the optical sensor. When closing the cover (16), the pin lowers and closes the optical sensor, the electronics module (13) reacts by turning off the installation (1). The pin additionally controls the signal to the 2nd optical sensor. When the front cover (12) must be removed from the housing (11), the pin opens the optical sensor, the electronics module (13) reacts by turning off the installation (1). After the front cover (12) is installed on the installation (1), it automatically switches to the operating mode that was before its removal.

After turning on the installation (1), the blinds (15) automatically open. And, conversely, when the unit (1) is turned off, the blinds (15) are closed.

A touch panel (18) is made on the housing (11) for manual control of the operation modes of the installation (1). A recess is made on the front cover (12) under the touch panel (18).

As an option of manual control of the installation, buttons can be made on the cover (11). The installation can optionally be equipped with a remote control (not shown).

Installation (1) can be additionally equipped with a liquid crystal screen or a touch liquid crystal screen, which displays the current operating parameters, microclimate parameters in the room, additional information, etc. The LCD screen can be either integrated into the installation (1) on the front surface or have retractable structure (not shown).

The controls of the touch panel (18) of the installation (1) are made in the form of buttons with which it is possible to adjust the fan speed, select the operation mode of the installation (1) and emergency warnings (for example, the need to replace the filter or a malfunction of the installation (1)) .

The inner case (5) is installed in the ventilation duct (2) from the side of the indoor module (4).

The inner case (5) consists of three components of the case (5.1, 5.2, 5.3), which are interconnected. In parts of the housing (5.1, 5.2), which are interconnected, contains a recuperator (6) with a heat insulating material located on it. The housing part (5.3) contains an axial reversible fan with an electric motor (7). On both ends of the inner case (5) there are filters (8) that serve to protect the recuperator (6) and fan (7) from contaminated air entering them and the room.

A temperature sensor can be installed inside the inner case (5), which monitors the supply and exhaust air parameters. If the supply air temperature drops below the user-specified temperature, the electronics module (13) of the installation (1) gives a signal to reduce the fan speed (7) so that the supply air has time to “warm up” for the temperature set by the user, and vice versa.

The design of the inner casing (5) allows the use of various types and configurations of recuperators, various types of filters with the required filtration class.

Additionally, an ozonizing device or a UV device for additional processing, filtration, and humidification of the air supplied to the room (not shown) can be located in the housing (5).

The inner case (5) is made with the possibility of disconnection from the ventilation duct (2), which simplifies the maintenance of the installation (1) during repair or maintenance work.

Thanks to the positioners located on one of the end sides of the inner case (5), the unit is fixed on the case (11) of the inner module (4) and is tightly installed in the ventilation duct (2). Thanks to the positioners, the inner case (5) can be installed in only one way - correctly, if it was not installed correctly, the front cover (12) will not be installed on the case (11). The grooves made in the cover (12) additionally rigidly fix the block (5).

The inner case (5) on the premises side contains a device (20), made as a handle located from one side to another. The dismantling of the block (5) from the housing (11) is carried out by the device (20), which must be pulled, and the housing (5) is removed from the ventilation duct (2).

Seals (10) are installed in the grooves on the top of the housing (5) from the end sides to ensure a tight installation of the housing (5) in the channel (2). The fan with an electric motor (7), which is located in the housing (5.3), is also mounted on a special elastic ring (not shown), which provides effective damping of the natural vibrations of the fan with the electric motor (7), which in turn provides a low noise level during work.

From the side of the outer cap (3), the ventilation duct (2) contains a silencer (9), which is located around the perimeter of the channel (2) (not shown). The silencer may have a different structure and shape.

As an electric drive of the blinds (15), a thermal actuator is used, which ensures smooth opening and closing of the blinds (15). The blinds (15) can be set in motion either by means of an electric drive, or by means of a manual lever or a solenoid.

The ventilation unit (1) can be mounted on the external surface of the wall, indoors.

Advantageously, the ventilation unit (1) is installed in the wall opening of the room to be ventilated. Thanks to the ventilation duct (2), for example, made as a telescopic pipe, it is possible to mount the installation (1) in the wall of a building of various thicknesses.

Channel (2) can have both square and cylindrical shapes, and can be made of metal or PVC plastic. The ability to control the length of the telescopic channel (2), depending on the thickness of the wall, accelerates and facilitates the installation of the installation (1).

A high-tech heat exchanger is used to transfer heat contained in the exhaust air to heat the supply air (6). Due to its cellular structure, the recuperator (6) has a large contact area with air and has high heat-conducting and storage properties. The honeycomb structure may be square, cylindrical, honeycomb openings, as shown in FIG. 7. The recuperator (6) can be made of absorbent cellulose. Due to this, moisture returns to the room in the recuperator (6) with the supply air; there is no effect of dryness in the winter and there is no problem of condensation. The surface of the recuperator (6) is treated with a special antibacterial substance that prevents the development of bacteria inside. On top of the recuperator (6), a heat-insulating material is used, which is used to better retain heat and additionally as a sealant.

The supply and exhaust air is cleaned using at least two filters (8), which ensure the cleaning of fresh air from dust and insects and serve to protect the elements of the installation (1) from clogging. Filters (8) can be treated with an antibacterial composition.

A reversible axial fan with an EC engine (7) is used to pump and extract air. Thanks to the use of the EC motor, the fan is energy efficient.

In case of negative external influence, for example, gusts of wind, the unit (1) is equipped with a cap (3) from the outside.

The outer hood (3) is made according to a specially developed design, it exhausts exhaust air and condensate formed inside the hood (3) from the wall of the house. The cap (3) prevents water and foreign objects from entering the unit (1). Inside the cap (3) is covered with a layer of soundproofing material (not shown). The cap design (3) can also be “labyrinth”, where the air flow changes its direction of movement several times, which prevents direct wind from entering the channel. The cap (3) can be made of both aluminum with a polymer coating and stainless steel with a polymer coating or polymer.

The ventilation unit (1) is equipped with a power cable.

The ventilation unit (1) operates as follows.

The ventilation unit (1) is connected to the general power supply network of the room. The installation (1) can be switched on using both the manual controls - the touch panel (18) and the remote control. Before turning on the unit (1), the cover (16) of the front cover (12) must be in the open position. When the unit (1) is turned on, the manual controls (18) or the remote control signal to fully open the blinds (15) and start the operation of the fan with the electric motor (7).

The operating modes of the installation (1) are set by the consumer. Unit (1) can operate in heat recovery mode (reverse mode), in exhaust mode or in inflow mode. The design of installation (1) also allows you to implement passive inflow modes, night mode, humidity control mode, timer mode, etc.

Reverse mode - when the mode is turned on, the fan with the electric motor (7) is turned on:

1. Contaminated warm air is drawn from the room and, passing through the recuperator (6), gradually heats and moisturizes it, losing up to 90% of its heat. After a while, when the heat exchanger has “warmed up”, the unit (1) automatically switches to the air supply mode.

2. Fresh, but cold air from the street, passing through the recuperator (6), is moistened and heated to a temperature due to the heat accumulated in it. When the recuperator (6) cools down, the fan with the electric motor (7) again switches to the air exhaust mode and the cycle repeats.

The durations of the processes of "inflow" and "exhaust" of air are equal to each other, after a specified time, a signal is generated in the electronics module (13) to change the direction of rotation of the fan (7), to the inflow or exhaust. Additionally, the duration of the processes of "inflow" and "extraction" of air can be adjusted depending on the needs of the consumer, that is, the time of air inflow can be more or less than the time of air extraction, and vice versa. The establishment of various modes is set both from the remote control panel and from manual controls (18).

When air passes through the recuperator (6), heat exhaust, then fresh external, heat exchange occurs. Outside air enters the room partially heated (in summer, on the contrary, partially cooled) due to heat (in summer - cold), taken from the removed air from the room. The heat exchange process occurs through the heat transfer surface of the recuperator (6) and the air flows do not mix with each other.

When the passive supply mode is turned on, airing is carried out through natural air exchange through open louvers (9) and a decorative cover (16), and the reversible fan with an electric motor (7) does not turn on (open window effect).

When the inflow mode is turned on, the reversible fan (7) is turned on, the direction of rotation of the fan (7) is set so that it provides external air through the unit (1) to the room.

When the exhaust mode is turned on, the reversible fan (7) is turned on, the direction of rotation of the fan (7) is set so that it removes room air through the installation (1) to the outside.

The implementation in the installation (1) of the humidity control mode is carried out thanks to the humidity sensor, where the humidity parameters are set by the consumer.

In the recovery mode, for example, when extracting room air, the humidity sensor monitors the humidity parameters in the room, and when the air flows in the room, the humidity sensor monitors the external humidity parameters. The humidity sensor continuously compares the humidity parameters in the room with those set by the consumer. If the humidity parameters in the room are lower than the set value, then a signal is sent from the humidity sensor to the control unit located in the electronics module (13), which transmits a signal to reduce the fan speed (7) to equalize the humidity parameters to the set value, and vice versa, if humidity in the room above a predetermined one, there is a signal to increase the fan speed (7), to align the parameters. When the humidity parameters in the room are equalized to the humidity set from the humidity sensor, a signal is sent to the control unit, which is located in the electronics module (13), and the fan (7) starts to work at the speed that was set before. As a humidity sensor, a resistive type sensor is used.

The night operation mode of the installation (1) is set by the consumer. The light sensor continuously reacts to illumination in the room where the installation (1) is installed. The light sensor is forced to work at night in the room and transmits a signal to the electronics module (13), which transmits a signal to reduce the fan speed (3) to the minimum speed, or turn off the installation, depending on the mode selected by the consumer. Additionally, due to the reaction of the light sensor to illumination in the room, the controls (18), which are illuminated during the day, reduce their backlight brightness in the dark. In daylight, installation (1) works depending on the mode selected by the consumer. A phototransistor is used as a light sensor.

The consumer can set various rotation speeds for the fan (7).

When the timer mode is turned on, the setting (1) starts working at the maximum fan speed (7) for the set time. The set time can be different, for example 3 or 8 hours.

The invention can be used to provide air exchange both in one room and in several separate rooms at the same time. For example, if it is necessary to use several units, the units are connected in series with each other by a power circuit. Connecting installations to the network can be done using any wired or wireless connection. The network may have a chain, branched, parallel or any other structure.

Installation (1) can also be controlled using a personal computer, tablet, smartphone or other device that has a radio connection connected to the Internet. Installation (1) or a network of installations can have feedback with a client device (computer, tablet, smartphone) and inform it through an intermediate server that is connected to the Internet of the microclimate (humidity, temperature, level of air pollution) in the room where device.

Serial connection of the settings to each other allows you to implement any of these operating modes and provides for the simultaneous inclusion of settings. Installations can work in antiphase, for example, one of the installations works on the inflow, at the moment when the other on the hood. Moreover, the management of all settings connected to each other is carried out from one installation, the so-called "Master", all other "Slave" installations are subordinate to another installation. The consumer has the opportunity to establish himself which of the installations can be “Master” and during operation to change the “Master” installation to another, for example, which is located in a different room, depending on the needs of the consumer.

In case of emergency in one of the installations, it stops, and the “Master” installation stops the operation of all other installations.

Claims (17)

1. A ventilation unit comprising an external hood, an internal module, a ventilation duct that connects the internal environment to the external environment, where the external hood goes to the external environment, and the internal module to the internal environment, in which there is a reverse fan with an electric motor, a recuperator, at least at least one filter and a silencer, an electrical control module, which is located in the internal module, characterized in that the ventilation duct further comprises an internal housing in which A fan fan with an electric motor, a recuperator, at least one more filter, which is adapted to be disconnected from the ventilation duct, the fan being located on the side of the external medium, and the recuperator on the side of the internal medium, and the filters are located on both ends of the inner case. 2. The ventilation installation according to claim 1, characterized in that seals are installed on the inside of the housing from the end sides of the grooves. 3. The ventilation installation according to claim 1, characterized in that the inner casing consists of separate parts of the casing, which are interconnected. 4. The ventilation installation according to claim 1, characterized in that the inner case comprises a device for disconnecting from the ventilation channel. 5. The ventilation installation according to claim 1, characterized in that the inner case contains positioners for installation in the ventilation duct. 6. The ventilation installation according to claim 1, characterized in that the inner case comprises a temperature sensor that is connected to an electrical control module for sequentially monitoring the temperature of the exhaust and supply air. 7. The ventilation installation according to claim 1, characterized in that an ozonizing device is located in the inner case. 8. The ventilation unit according to claim 1, characterized in that the fan installed in the inner casing is mounted on an elastic ring for damping its own vibrations. 9. The ventilation installation according to claim 1, characterized in that a heat insulating material is located on top of the recuperator. 10. The ventilation installation according to claim 1, characterized in that the internal module comprises a housing that comprises an electrical control module, a front cover installed on the housing, which comprises louvers and a decorative cover mounted on the front cover. 11. The ventilation installation according to claim 10, characterized in that the fixing elements are made on the sides of the housing of the indoor module, and the holes are made on the sides of the front cover that engage with the housing fixing elements. 12. The ventilation installation according to p. 10, characterized in that the decorative plate is located at some distance from the front cover or fits snugly on the front cover and is configured to disconnect from the front cover 13. The ventilation installation according to claim 10, characterized in that the touch panel for manually controlling the operation modes of the installation is made on the housing of the indoor unit. 14. The ventilation installation according to claim 1, characterized in that it comprises a remote control for controlling the operation modes of the installation. 15. The ventilation installation according to claim 1, characterized in that it contains an air humidity sensor connected to an electric control module for controlling the air flow rate to provide the specified humidity parameters in the room, a light sensor connected to an electric control module for controlling the air flow rate in depending on the lighting in the room. 16. The ventilation installation according to claim 1, characterized in that the electrical control module includes an input terminal for connecting to an electric network and an output terminal for connecting an identical ventilation installation. 17. The ventilation installation according to claim 1, characterized in that the outer hood is shaped so as to prevent rainwater from entering the installation.

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