WO2019050484A1

WO2019050484A1 - Ventilation device

Info

Publication number: WO2019050484A1
Application number: PCT/SI2018/050021
Authority: WO
Inventors: Peter Novak; Tadej KRESNIK
Original assignee: Mikrovent 5 d o o
Current assignee: Mikrovent 5 d o o
Priority date: 2017-09-11
Filing date: 2018-07-11
Publication date: 2019-03-14
Anticipated expiration: 2020-03-11

Abstract

The subject-matter of the invention is a ventilation device (1) of an oblong prismatic shape, which includes a pre-fabricated housing (11), wherein individual ventilation device components are arranged in the pre-fabricated housing (11) in a line. The pre-fabricated housing (11) is connected with a wall pipe (12) inserted into an opening provided in the wall, while a box-like external grid (17) is arranged on the external side of the external wall, in which grid a pivotal airflow distributer (19) is arranged. Fans (3a, 3b) are arranged in the pre-fabricated housing (11) in a way that the air intake openings face the interior of the pre-fabricated housing (11) and are separated from each other by a partition wall (5), while the air discharge openings each faces its own channel (2a, 2b). The housings of the fans (3a, 3b) and consequently the air intake openings and the air discharge openings are arranged in the pre-fabricated housing (11) either in parallel with the longer sides of the pre¬ fabricated housing (11) or rotated one relative the other at an angle with respect to the longer sides of the pre-fabricated housing (11), such that the axes of the air intake openings lie either on the same imaginary line which connects both axes or their axes are arranged on imaginary parallel lines offset in the longitudinal direction of the ventilation device (1), i. e. in the longitudinal direction of the longer sides of the housing (11).

Description

Ventilation device Description of invention Field of invention

Ventilation; heat recuperation; heat exchanger; counter-flow heat exchanger.

Technical problem

In old buildings, problems concerning the lack of fresh air are not experienced as the buildings were breathing due to the way of construction and the materials used. Moreover, the price of energy was lower and consequently the cost of heating was lower. New buildings are more airtight due to current regulations, while higher building efficiency often has negative impacts such as presence of poor quality air and humidity in a room (dew formation on glass and mould formation on walls).

New buildings have become much more airtight because of growing needs for energy savings. As natural ventilation of rooms has practically become inexistent, forced ventilation must be used. One of possible solutions is a local ventilation system with heat exchange from the internal air to the fresh external air (heat recuperation).

The currently known local heat exchange ventilation systems do not provide for the arrangement of components in a way to fabricate a device in the form of a narrow long prism. More and more windows are arranged on external walls and they have become larger, so there are reduced possibilities for the arrangement of flat local ventilation systems.

Recommended living conditions in a room are a temperature in a range from 18 to 22° and relative humidity between 35 and 70%. Too high relative humidity is uncomfortable and may cause water vapour condensation on cold surfaces of walls and glass thus promoting fungus formation on cold parts of the walls (particularly in the corners of external walls). In a building adequately glazed and insulated, an average of 50% of energy is used for heating and cooling to a temperature suitable for comfortable and quality living, while the remaining 50% of energy is used for the ventilation of living rooms. This is why a building needs not only adequate glazing and insulation but also adequate room ventilation. The use of local heat recuperation systems yet additionally reduces the consumption of energy and costs.

Prior art

Rooms can be ventilated in several ways: by short-term and sporadic opening of windows, which results in cold air entering the room, draught and a huge loss of heat from a room in winter, and huge amounts of hot air entering a room in summer (natural ventilation)

by local or central forced ventilation devices, where the air is purified, pre-heated or cooled and delivered to a room without draught and considerable heat losses (force ventilation).

Modern devices for local or central mechanical ventilation of rooms may have an integrated exhaust air heat recovery device because they allow an energy efficient ventilation of rooms.

Local ventilation systems provide for more adaptability since the quality of air can be regulated in each room separately. Needs for fresh air cannot be precisely determined for a flat or business premises neither in terms of time nor location. For instance, bathrooms are more heavily occupied in the morning, kitchens at noon, common living rooms and bedrooms in the evening. This is why local ventilation is technically much more adaptable and therefore suitable and cost efficient in all rooms.

There is currently no commercially available device that would use a counter-flow heat exchanger and would at the same time have an oblong shape. The market is full of local heat exchange ventilation systems, yet they are mostly of a flat shape and provided with a cross-flow heat exchanger.

The subject-matter of the invention solves a problem of construction of an oblong-shaped ventilation device provided with a counter-flow heat exchanger that at the same time allows:

simple assembly simple wall mounting

use of a single opening in a wall for air inlet and outlet

any position on the wall (from 0° to 360° around the opening for air inlet and outlet).

New possibilities for mounting such a device in living rooms are herewith provided.

Description of the new solution

The subject-matter of the present invention is a local oblong-shaped ventilation device that includes a counter-flow heat exchanger and a two-part pre-fabricated housing formed in a way to allow for a rapid and simple arrangement of individual ventilation device components in a pre-determined configuration into a housing that is subsequently, possibly by way of a mounting panel, fastened to a wall, wherein only one opening needs to be made in a wall for the operation of the device. In this way, a ventilation device is rapidly and simply mounted on a wall and simply serviced. The oblong shape means that the sides of the device are significantly longer in one direction of the coordinate system than in the other two directions, such as an oblong-shaped cuboid. Airflows move along the longer sides of the ventilation device, which reduces pressure losses of the airflow through the ventilation device.

In order to provide for an optimal operation of an oblong-shaped ventilation device, the arrangement of individual components of the ventilation device within a housing needs to be optimized, namely individual components within the housing need to be arranged in a line, i. e. in a certain order or sequence along the longer sides of the housing. The ventilation device of the invention comprises a two-part pre-fabricated oblong-shaped housing that is provided at one side with an inlet opening for external air supply into the device and an adjacent outlet opening for internal air discharge from the device into the environment, whilst it is provided at the other side with two inlet openings for the supply of external air from the device into the room and an inlet opening for the supply of the internal air from the room into the device, the pre-fabricated housing including a counter-flow heat exchanger, an external air ventilator, i. e. for the intake of external air from the environment and for the delivery of same through the heat exchanger and then along an external air channel into the room, an internal air ventilator, i. e. for the intake of internal air from the room into an internal air channel and for pushing same through the heat exchanger into the environment, a sound absorber that simultaneously functions as a distributer of air to both sides of the housing, and a partition wall extending from the counter-flow heat exchanger between both fans at the sound absorber, which simultaneously functions as a distributer of air, to the wall of the housing and defines an external air channel and an internal air channel, thus preventing mixing of the external air and the internal air.

A preferable arrangement of fans for the heat exchanger is on the so-called hot side, because the fans are here positioned centrally, i. e. predominantly in the central part of the ventilation device, which reduces the noise of the device. In one of the embodiments of the ventilation device, the fans may be arranged upstream of the heat exchanger on the cold side; it is herewith prevented that the air from the room would mix with the external air in the event of the lack of tightness. A drawback of this arrangement is that the external air fan operates in various temperature conditions.

The pre-fabricated housing is formed of two symmetrical parts, wherein each part of the housing is provided with partition walls and grooves at predetermined positions on its internal side, such that areas are defined within the housing, which are adapted in their dimensions to the ventilation device components and into which individual ventilation device components are inserted in a predetermined configuration. Each part of the housing is thus provided on its internal side with partition walls for the arrangement of fans, a partition wall for separating the external air and the internal air, i. e. for defining the external air and the internal air channels in the section of fastening the housing to a wall pipe, grooves for the arrangement and sealing of the heat exchanger, and grooves for the insertion of a partition wall. The edges of each individual part of the housing are formed in a way to fit each other in a form-locking manner when both parts of the housing are assembled. The configuration and the position of the edges, the partition walls and the grooves ensure that, when all components of the ventilation device are inserted into the predefined places and both parts of the housing are coupled (assembled), individual components of the ventilation device are sufficiently fixed in the predefined places, that they cannot inadvertently move and that sufficient tightness is provided to prevent the external air and the internal air from mixing while passing through the ventilation device.

The housing is connected with a wall pipe inserted into an opening provided in the wall. As only one wall opening is needed for the operation of the ventilation device, the wall pipe must ensure that the external air is separated from the internal air when passing through the wall pipe. This may be achieved by having two channels arranged in the wall pipe, one for the external air and the other for the internal air, wherein one channel is attached to the inlet opening for the external air supply into the device, while the other channel is attached to the outlet opening for the internal air discharge from the device into the environment. The wall pipe may be provided in its interior by a barrier extending over its entire length, preferably along the centre, thus forming two channels, namely one external air channel and one internal air channel. The barrier rests against a groove provided on the partition wall provided within the housing. In a preferred embodiment, each of the channels has a semi-circular cross-section. An adequate gradient of the wall pipe for the condensate discharge from the ventilation device may be achieved by the mounting of the wall pipe, the wall pipe is namely mounted at a gradient, such that the condensed liquid flows from the ventilation device into the environment. In a preferred embodiment, the wall pipe is mounted horizontally and an adequate gradient is achieved by modifying the wall thickness of the wall pipe, namely that the internal wall is provided with a gradient, which is solved in terms of construction by modifying the wall thickness of the wall pipe. To ensure an undisturbed discharge of the condensed liquid from the ventilation device towards the environment the gradient must be at least 1%.

The housing may alternatively be connected with the wall pipe through an attachment element. On the housing, above the inlet opening for the supply of the external air into the device and above the outlet opening for the discharge of the internal air from the device into the environment an attachment element is mounted that is provided with a central opening of preferably a circular shape, said attachment element leaning with its internal surface against the partition wall formed in the housing and against the edges of said openings, wherewith additional sealing is provided and wherewith the external air and the internal are prevented from mixing in the area where the housing is fastened to the wall pipe. The attachment element is provided on its external surface around the opening with a groove, into which the wall pipe is inserted.

Both the housing and the attachment element are made from materials which can be adequately shaped in moulds, preferably from insulation materials, particularly from expanded polystyrene.

The fans are electric fans and include a fan housing and a rotor with blades, wherein the air intake opening is provided on the lateral side of the fan housing, while the air outlet opening is provided on the front side of the housing. The fans are arranged in the pre-fabricated housing in a way that the air intake openings substantially face each other and are separated from each other by a partition wall, while the air discharge openings each faces its own channel. The housings of the fans and consequently the air intake openings and the air discharge openings for discharging the air are arranged in the pre-fabricated housing either in parallel with the longer sides of the pre-fabricated housing or rotated one relative the other at an angle with respect to the longer sides of the prefabricated housing by a maximum of 30 angular degrees, such that the axes of the air intake openings lie either on the same imaginary line which connects both axes or their axes are arranged on imaginary parallel lines offset in the longitudinal direction of the ventilation device, i. e. in the longitudinal direction of the longer sides of the housing, by an offset that is no more than identical to the diameter of the air intake opening. In a preferred embodiment, the housings of the fans and consequently the air intake openings and the air discharge openings are arranged in the prefabricated housing in parallel with the longer sides of the pre-fabricated housing and such that the axes of the air intake openings lie on the same imaginary line which connects both axes.

The function of the partition wall is to prevent mixing of the external air and the internal air when passing through the ventilation device, i. e. definition of channels for the external air and the internal air and provision of an optimal intake airflow into the fans. The shape of the partition wall in the section between the fans is formed at an angle in order to provide for an adequate inflow of the intake air into the fans. Between the housing and the heat exchanger there is provided double sealing with gaskets in the form of a hollow tube from a material resistant to aging, said gaskets fitting into the groove in the housing. Special sealing with gaskets is also provided between each fan and the partition wall; this provides for adequate sealing and prevents mixing of the airflows on the intake and pressure sides of the fan. The sound absorber which simultaneously also functions as an air distributer is arranged downstream of the external air fan and has two functions, it functions as a sound absorber reducing the noise of the ventilation device, and as an air distributer to distribute the air to the left and right sides of the ventilation device, where it is discharged into the room through discharge rotary nozzles provided on the protective housing. The discharge rotary nozzles enable unlimited adjustment of air supply into the room.

The ventilation device may alternatively include an external air filter and an internal air filter, wherein the internal air filter is arranged in the housing downstream of the inlet opening for the external air supply into the ventilation device and upstream of the heat exchanger, while the internal air filter is arranged above the inlet opening for the internal air supply into the ventilation device. A slot is provided in the housing to allow for a simple replacement of the external air filter.

The ventilation device may alternatively include an external air heater that is arranged in the housing preferably upstream of the external air filter. The ventilation device may alternatively include an intake flap for the control of the external air flow rate into the device and a discharge flap for the control of the internal air flow rate from the device. The flaps are arranged in the attachment element, one at the mouth into the inlet opening for the fresh air supply into the device, and the other one at the mouth into the outlet opening for the air discharge from the device into the environment. The flaps are motor driven and serve to exhaust the room, to supply air into the room or both. They are operated by remote control. They are particularly important in summer when only external cold air is supplied into the room at night, thus cooling the room without a cooling device.

On the external side of the external wall there is arranged a box-like external grid that is fixed to a holder by means of fastening elements, said holder being fixed to the external wall in known ways. The box-like grid is provided with slots at two opposite surfaces. The holder is provided with a centrally formed opening of preferably a circular shape that corresponds to the dimension of the inner cross-section of the wall pipe. Within the external grid, a pivotal airflow distributer is arranged that is fixed in each case to respective fastening elements. The airflow distributer is dimensioned and shaped in a way to divide the space within the box-like external grid, when fastened to the fastening elements, into two parts; it is herewith prevented that the external air which enters the box-like external grid through the slots provided on one lateral surface of the grid and travels further into the wall pipe, i. e. into the external air channel, would mix with the internal air which travels from the wall pipe, i. e. from the internal air channel, and exits the box-like external grid through the slots provided on the opposite lateral surface of the grid. The box-like external grid must be arranged on the external side of the external wall in a way that the slots face downwards in order to prevent the water from entering the wall pipe in the event of rain. The distributer of airflows which is pivotable by 90 degrees around its axis prevents mixing of the external air and the internal air within the box-like external grid and subsequently when passing through the wall pipe irrespective of whether the ventilation device is arranged on the wall vertically or horizontally, i. e. that the longer sides of the device are in horizontal or vertical position.

A standard equipment of the device includes temperature sensors of the external and the internal air and an internal humidity sensor, which all ensure undisturbed operation. The ventilation device may alternatively be provided with a carbon dioxide sensor, a sensor for air-borne volatile organic compounds, an outside humidity sensor, an air pressure sensor, and a radon sensor. All sensors are integrated in the two-part housing which is provided with special grooves for guiding electrical conductors to the control unit.

The sensors automatically activate the device or increase its operation each time when at least one of the values in the air detected by the sensors deviates from the required value. The device thus provides for a possibility of automatic regulation of air quality in the room, of course, ventilation switch on/off can also be set manually; operation of the device only by external air supply (important for night cooling in summer) and operation only by air discharge from the room. Moreover, the humidity sensor and the indoor temperature sensor also serve for the dew-point calculation and switch on the air heater, if needed, in order to prevent the condensate in the system from freezing.

The ventilation device is preferably installed onto the wall such that the longest sides are in a vertical position; it may, however, also be installed in a way that the longest sides are in a horizontal position or any other position around the opening in the wall. It is desired that the ventilation device is mounted on the wall such that the internal air intake opening is arranged as high as possible, just below the ceiling if possible. As the air under the ceiling is normally hottest and most heavily polluted, the most heavily polluted air is discharged from the room and the heat of the exhausted air is thus exploited.

The ventilation device is preferably fastened to the wall by means of a mounting panel, such that the two-part housing with all belonging elements is attached to the mounting panel. Once the ventilation device has been fastened to the mounting panel, a protective housing is fastened over the entire housing, said protective housing being provided on the surface above the inlet opening for the internal air supply from the room into the device with an exhaust grid and provided on the surface above the inlet openings for the external air supply from the device into the room with discharge rotary nozzles to allow the intake or discharge of the air into and from the ventilation device, i. e. into and out of the housing of the ventilation device.

The invention will be explained in more detail hereinbelow by way of an embodiment and the enclosed drawings representing in: Figure 1 illustrates an inventive ventilation device with inserted components, wherein out of the total of two parts of a pre-fabricated housing only one is illustrated for the simplicity and clarity reasons

Figure 2 illustrates one part of the pre-fabricated housing with connection to a wall pipe

Figure 3 illustrates the inventive device with a fastened protective housing, the wall pipe and a boxlike external grid

Figure 4 illustrates the box-like external grid with one embodiment of placement of a pivotal air flow distributer

Figure 5 illustrates the box-like external grid with another embodiment of placement of a pivotal air flow distributer

A ventilation device 1 shown in Figures 1 to 3 comprises an oblong pre-fabricated housing 11 formed of two symmetrical parts, wherein out of the total of two parts only one is illustrated for the simplicity and clarity reasons, and the housing 11 is provided on one side with an inlet opening 7 for external air supply into the device and an adjacent outlet opening 6 for internal air discharge from the device into the environment, and is provided on the other side with two outlet openings 15 for the discharge of external air from the device into the space and an inlet opening 14 for the supply of the internal air from the room into the device, and within the housing 11 there are arranged, viewed in consecutive order from the inlet opening 7 for the fresh air supply into the device and the outlet opening 6 for the air discharge from the device into the environment: a counter-flow heat exchanger 2, an external air fan 3a, an internal air fan 3b, wherein the housings of the fans 3a, 3b and consequently the air intake openings and the air discharge openings are arranged in the prefabricated housing 11 in parallel with the longer sides of the pre-fabricated housing 11, and such that the axes of the air intake openings lie on the same imaginary line which connects both axes, a sound absorber 4 that simultaneously functions also as an air distributer, and a partition wall 5 extending from the counter-flow heat exchanger 2 between both fans 3a, 3b and along the sound absorber 4 that simultaneously functions as an air distributer to the wall of the housing 11 and defines an external air channel 2a and an internal air channel 2b. The ventilation device 1 further includes an external air filter 9 and an internal air filter 10, wherein the internal air filter 9 is arranged in the housing 11 downstream of the inlet opening 7 for the external air supply into the ventilation device and upstream of the heat exchanger 2, while the internal air filter 10 is arranged above the inlet opening 14 for the internal air supply into the ventilation device. A slot 11a is provided in the housing 11 to allow for a simple replacement of the external air filter 9. At the mouth into the opening 7 on an attachment element 20, there is arranged an inlet flap 21, while at the mouth into the opening 6 a discharge flap 22 is arranged for the control of the internal air and external air flows. The ventilation device 1 further includes an external air heater 8 that is arranged in the housing 11 upstream of the external air filter 9. An integrated sensor for temperature, humidity and external air pressure is arranged on the upper part of the bend upstream of the air heater 8, while an integrated sensor for temperature, humidity and internal air pressure and a special radon sensor are arranged in an internal air channel 2b downstream of the internal air filter 10 and upstream of the internal air fan 3b.

Each of the two parts of the housing 11 is pre-fabricated from expanded polystyrene and provided on its internal side with partition walls lib for the arrangement of fans 3a, 3b, a partition wall 11c for separating the external air and the internal air in the section of fastening the housing 11 to a wall pipe 12, grooves lid for the arrangement and sealing of the heat exchanger 2, and grooves lie for the insertion of a partition wall 5. Edges llf of each individual part of the housing are formed in a way that the edges llf fit each other in a form-locking manner when both parts of the housing are assembled. The configuration and the position of the edges llf, the partition walls lib, 11c and the grooves lid, lie of an individual part of the housing 11 ensure that, when both parts of the housing 11 are assembled, the individual components of the ventilation device 1 are fixed into the predefined places, such that they cannot inadvertently move and that sufficient tightness is provided to prevent the external air and the internal air from mixing while passing through the ventilation device 1.

The housing 11 is provided above the inlet opening 7 for external air supply into the device and the outlet opening 6 for internal air discharge from the device into the environment, with an attachment element 20 provided with a centrally formed opening 20a of a circular shape. The attachment element 20 leans with its internal surface against the partition wall 11c formed in the housing 11 and against the edges of the openings 6, 7, wherewith additional sealing is provided and wherewith the external air and the internal air are prevented from mixing in the area where the housing 11 is fastened to the wall pipe 12. The attachment element 20 is provided on its external surface around an opening 20a with a groove 20b, into which the wall pipe 12 is inserted, which is inserted in the wall opening.

The wall pipe 12 is connected to the outlet opening 6 for the internal air discharge from the room and the inlet opening 7 for the external air supply. The wall pipe 12 is provided in its interior by a barrier 12a extending centrally over its entire length, thus forming an internal air channel 12b and an external air channel 12c, both having a semi-circular cross-section. When the wall pipe 12 is fastened to the attachment element 20, the barrier 12a leans against the groove provided on the partition wall 11c provided in the housing 11, which separates the internal air and the external air, wherewith a separation of both airflows in the wall pipe 12 is provided for. The external wall of the wall pipe 12 is arranged horizontally, while the internal wall is arranged with a gradient.

On the external side of the external wall there is arranged a box-like external grid 17 shown in Figures 3 to 5. The box-like external grid 17 is fastened to a holder 18 through fastening elements 18a. The box-like external grid 17 is provided with slots 16 at two opposite surfaces 17a, 17b. The holder 18 is provided with a centrally formed opening 18b of a circular shape, into which the wall pipe 12 is inserted upon installation. Within the box-like external grid 17, there is arranged a pivotal airflow distributer 19, the arrangement of which depends on the arrangement of the outlet opening 6 for the discharge of air from the room and the inlet opening 7 for the fresh air supply.

Once the ventilation device 1 has been fastened to the wall, a protective housing 13 is fastened over the entire housing 11, said protective housing 13 being provided on the surface above the opening 14 with an exhaust grid and provided on the surface above the openings 15 with rotary nozzles to allow the intake or discharge of the air into and from the ventilation device 1, i. e. into and out of the housing 11.

The fan 3a gets the external air through the slots 16 provided in the surface 17a of the external grid 17. The external air travels through the wall pipe 12 along the channel 12c and enters the housing 11 through the opening 7 provided with a flap 21 for the airflow rate control. As soon as the air enters the device 1, it rotates by 90° and passes through the external air heater 8, the external air filter 9, the heat exchanger 2 and along the channel 2a past the sound absorber 4 which simultaneously functions as the air distributer, and exits through the openings 15 via the rotary nozzles formed in the protective housing 13 into the room. The inlet opening 14 for the supply of the internal air from the room into the device 1 is arranged below the ceiling. The fan 3b obtains the internal air through the intake grid formed in the protective housing 13 above the opening 14. The internal air travels through the internal air filter 10 along the channel 2b and the heat exchanger 2. Closely before exiting the ventilation device 1, the air rotates by 90° and leaves the ventilation device 1 through the opening 6 provided with a discharge flap 22 and travels through the wall pipe 12 along the channel 12b and exits through the slots 16 formed on the surface 17b of the external grid 17.

It is to be understood that the described solution can be executed in a different variant that does not change the essence of the invention.

Claims

1. A ventilation device comprising a housing provided with openings for external air supply from the environment into the device and for internal air discharge from the device into the environment, a heat exchanger and two fans for separate intakes of the external air and the internal air, characterized in that the ventilation device (1) is of an oblong shape and includes a pre-fabricated oblong-shaped housing (11), wherein individual components of the ventilation device are arranged in the housing (11) in a linear manner and the pre-fabricated housing (11) is provided on one side with an inlet opening (7) for external air supply into the device (1) and an adjacent outlet opening (6) for internal air discharge from the device (1) into the environment, and is provided on the other side with inlet openings (15) for the supply of external air from the device (1) into the room and an inlet opening (14) for the supply of the internal air from the room into the device (1), the pre-fabricated housing (11) including a counter-flow heat exchanger (2), an external air ventilator (3a), i. e. for the intake of external air from the environment and for the delivery of same through the heat exchanger (2) along an external air channel (2a) into the room, an internal air ventilator (3b), i. e. for the intake of internal air from the room into an internal air channel (2b) and for pushing same through the heat exchanger (2) into the environment, a sound absorber (4) that simultaneously functions as a distributer of air to both sides of the housing (11), and a partition wall (5) extending from the counter-flow heat exchanger (2) between both fans (3a, 3b) to the wall of the housing (11) and defining the external air channel (2a) air and the internal air channel (2b), thus preventing mixing of the external air and the internal air, and the housing (11) is connected with the wall pipe (12) inserted in the opening formed in the wall, wherein the fans (3a, 3b) are arranged in the pre-fabricated housing (11) in a way that the air intake openings substantially face each other and are separated from each other by a partition wall (5), while the air discharge openings each faces its own channel (2a, 2b), and wherein the housings of the fans (3a, 3b) and consequently the air intake openings and the air discharge openings for discharging the air into the channels (2a, 2b) are arranged in the pre-fabricated housing (11) either in parallel with the longer sides of the pre-fabricated housing (11) or rotated one relative the other at an angle with respect to the longer sides of the pre-fabricated housing (11), such that the axes of the air intake openings lie either on the same imaginary line which connects both axes or their axes are arranged on imaginary parallel lines offset in the longitudinal direction of the ventilation device (1), i. e. in the longitudinal direction of the longer sides of the housing (11).

2. Ventilation device according to claim 1, characterized in that the prefabricated housing (11) is formed of two symmetrical parts and each of the two parts of the housing (11) is provided on its internal side with partition walls (lib) for the arrangement of fans (3a, 3b), a partition wall (11c) for separating the external air and the internal air in the section of fastening the housing (11) to a wall pipe (12), grooves (lid) for the arrangement and sealing of the heat exchanger (2), and grooves (lie) for the insertion of the partition wall (5), and that edges (llf) of each individual part of the housing (11) are formed in a way that the edges (llf) fit each other in a form-locking manner when both parts of the housing (11) are assembled, wherein the configuration and the position of the edges (llf), the partition walls (lib, 11c) and the grooves (lid, lie) of an individual part of the housing (11) ensure that, when both parts of the housing (11) are assembled, the individual components of the ventilation device (1) are fixed into the predefined places, such that they cannot inadvertently move and that sufficient tightness is provided to prevent the external air and the internal air from mixing while passing through the ventilation device (1).

3. Ventilation device according to claims 1 and 2, characterized in that the angle, at which the housings of the fans (3a, 3b) are rotated one relative to the other is no more than 30 angular degrees with respect to the longer sides of the pre-fabricated housing (11), and that the offset of the axes of the air intake openings in the longitudinal direction of the longer sides of the housing (11) is not more than identical to the diameter of the air intake opening.

4. Ventilation device according to any of preceding claims, characterized in that the housings of the fans (3a, 3b) and consequently the air intake openings and the air discharge openings for discharging the air into the channels (2a, 2b) are arranged in the pre-fabricated housing (11) in parallel with the longer sides of the pre-fabricated housing (11) and such that the axes of the air intake openings lie on the same imaginary line which connects both axes of the fans (3a, 3b) and that the fans (3a, 3b) are arranged in the pre-fabricated housing (11) downstream of the heat exchanger (2).

5. Ventilation device according to any of preceding claims, characterized in that the housing (11) is provided above the inlet opening (7) for external air supply into the device (1) and the outlet opening (6) for internal air discharge from the device (1) into the environment with an attachment element (20) provided with a centrally formed opening (20a) preferably of a circular shape, and that the attachment element (20) leans with its internal surface against the partition wall (11c) formed in the housing (11) and against the edges of the openings (6, 7), and that the attachment element (20) is provided on the external surface around the opening (20a) with a groove (20b), into which the wall pipe (12) inserted in the opening made in the wall is inserted, and at the mouth into the opening (7) on the attachment element (20) there is arranged an inlet flap (21), while at the mouth into the opening (6) a discharge flap (22) is arranged for the control of the internal air and external air flows.

6. Ventilation device according to any of preceding claims, characterized in that the partition wall (5) in the section between the fans (3a, 3b) is formed at an angle in order to provide for an adequate inflow of the intake air into the fans (3a, 3b) and that between the housing (11) and the heat exchanger (2) double sealing is provided with gaskets that fit into the groove in the housing (11), and that sealing with gaskets is also provided between each fan (3, 3b) and the partition wall (5), thus providing for adequate sealing and preventing mixing of the airflows on the intake and pressure sides of the fans (3a, 3b).

7. Ventilation device according to any of preceding claims, characterized in that the wall pipe (12) is provided in its interior along its entire length, preferably centrally, by a barrier (12a), wherewith an internal air channel (12c) and an external air channel (12b) are formed and the barrier (12a) leans against the groove formed on the partition wall (11c) provided in the housing (11), and both channels (12b, 12c) preferably have a semi-circular cross-section.

8. Ventilation device according to claim 7, characterized in that the external wall of the wall pipe (12) is arranged horizontally, while the internal wall is arranged with a gradient, wherein the gradient from the ventilation device towards the environment is at least 1%.

9. Ventilation device according to any of preceding claims, characterized by further including an external air filter (9) and an internal air filter (10), wherein the external air filter (9) is arranged in the housing (11) downstream of the inlet opening (7) for the external air supply into the ventilation device (1) and upstream of the heat exchanger (2), while the internal air filter (10) is arranged above the inlet opening (14) for the internal air supply into the ventilation device (1) and an external air heater (8), which is arranged in the housing (11) upstream of the external air filter (9).

10. Ventilation device according to any of preceding claims, characterized by additionally including an integrated sensor for temperature, humidity and external air pressure arranged on the upper part of the bend upstream of the air heater (8), and an integrated sensor for temperature, humidity and internal air pressure, and a special radon sensor are arranged in an internal air channel (2b) downstream of the internal air filter (10) and upstream of the internal air fan (3b).

11. Ventilation device according to any of preceding claims, characterized in that a box-line external grid (17) is arranged on the external side of the external wall and is fastened to a holder (18) by means of fastening elements (18a) and is provided with slots (16) at two opposite surfaces (17a, 17b), wherein the holder (18) is provided with a centrally formed opening (18b) preferably of a circular shape, into which the wall pipe (12) is inserted upon installation, and that a pivotal airflow distributer (19) is arranged within the box-like external grid (17).

12. Ventilation device according to claim 10, characterized in that the pivotal airflow distributer (19) is pivotable by 90 degrees around its axis to prevent mixing of the inlet air and outlet air within the box-like external grid (17) and subsequently when passing through the wall pipe (12) irrespective of whether the ventilation device (1) is arranged vertically or horizontally.

13. Ventilation device according to any of preceding claims, characterized in that a protective housing (13) is fastened over the entire pre-fabricated housing (11), said protective housing (13) being provided on the surface above the opening (14) with an exhaust grid and provided on the surface above the openings (15) with rotary nozzles to allow the intake or discharge of the air into and from the ventilation device (1), i. e. into and out of the housing (11).

14. Ventilation device according to any of preceding claims, characterized in that it is fastened to a wall by means of a mounting panel, wherein the ventilation device (1) is arranged vertically or horizontally.