Sound insulation insert for decentralized residential ventilation systems or outdoor air inlet systems

Abstract

sound insulation insert (10), which is designed in particular for the interior noise reduction of a residential ventilation system that can be installed in a wall opening and has at least one axial fan having a central motor hub, wherein the sound-insulating insert (10) is made essentially of an acoustically absorbing material at least on its surfaces in contact with the airflow, and wherein the sound-insulating insert (10) has an annular outer element (12) for insertion into a wall penetration duct, wherein the sound-insulating insert (10) has an inner element (14) in an area which, in the mounted position, adjoins the motor hub of the at least one axial fan in the residential ventilation system, which is connected to the outer element (12) via at least one web (16a-c), so that an annular gap-shaped passage for the airflow is formed between the outer and inner elements, which passes through the at least one The bridge (16a-c) is divided into sections (18a-c), characterized by the fact that the outer element (12), which includes at least one web (16a-c) and the inner element (14) are made of an acoustically absorbing rigid or soft foam material, in particular a melamine resin foam.

Description

[0001] The present invention relates to a sound insulation insert for an air handling system, in particular for a decentralized residential ventilation system, according to the preamble of claim 1, as well as a decentralized residential ventilation system with such a sound insulation insert and an outdoor air passage system with such a sound insulation insert.

[0002] Controlled mechanical ventilation systems are a key component for the smooth operation of energy-efficient and largely airtight buildings. By using controlled mechanical ventilation systems, indoor air quality can be maintained while minimizing the heat losses that would otherwise occur with natural ventilation through windows. This also keeps humidity at a controlled level, thus preventing mold growth and other moisture-related structural damage.

[0003] In this context, the term "living space" is intended to clarify that the aim is to improve air quality for occupants. Such systems can also be used in office spaces, for example, so the term "residential ventilation system" should not be limited to use in residential buildings.

[0004] The market distinguishes between centralized and decentralized residential ventilation systems.

[0005] Decentralized ventilation systems have recently become increasingly common in residential construction compared to centralized residential ventilation systems. This is partly due to their generally lower installation costs, which makes them ideal for retrofitting in existing buildings. A further significant advantage of decentralized systems is that they eliminate the need for long, difficult-to-access, or even inaccessible air ducts leading to a central heat exchanger. This offers considerable benefits in terms of maintenance and hygiene.

[0006] To minimize heat loss, the aforementioned decentralized residential ventilation systems typically incorporate a heat storage unit. This unit is heated by the warm, exhausted indoor air during ventilation mode via a reversing fan operation. Then, during reverse operation, it preheats the incoming, generally cooler, outdoor air. This achieves heat recovery rates of over 80% in known systems.

[0007] One problem with decentralized residential ventilation systems is sound insulation, especially when the systems are used in bedrooms or rest areas.

[0008] Firstly, the system aims to prevent or at least reduce the audibility of fan and airflow noise during operation. Secondly, it also aims to reduce the transmission of external noise – such as road noise in particularly exposed locations – into the interior spaces.

[0009] Since the systems are installed in a cylindrical or rectangular wall opening towards an exterior wall, which provides only very limited axial installation space due to the existing wall thicknesses, common, particularly effective soundproofing measures, such as redirecting the airflow multiple times so that the sound "dissipates", are hardly feasible.

[0010] To achieve at least some improvement, optional ring-shaped sound insulation inserts made of an acoustically effective foam material are already known, which can be inserted into the structure of the ventilation system in the wall penetration in the direction of the interior between the fan and the air outlet - usually directly in spatial connection to the fan or its penetration protection grille.

[0011] Since the airflow should not be obstructed, known sound-insulating inserts are limited to rings made of a foam-like material in the form of an annular hollow cylinder, the outer diameter of which is adapted to the diameter or contour of the wall opening (usually round, possibly also rectangular) and whose inner diameter leaves the air passage unobstructed, so that the sound-absorbing effect is limited to the fact that the sound waves traveling on the inner walls of the pipe are acoustically absorbed by the foam material in the axial area of ​​the sound-insulating insert, whereby this effect can possibly be improved somewhat by a dimpled surface or the like.

[0012] However, it is understandable that the sound insulation effect of the known soundproofing inserts offers potential for improvement, although it must also be taken into account that the flow characteristics are not worsened and the pressure losses across the soundproofing insert are not increased, because otherwise acoustic improvements would be achieved at the cost of higher fan speeds, which could negate the acoustic improvements and would be energy-inefficient.

[0013] Furthermore, so-called ALD or external air inlet systems are offered, in which the forced air exchange takes place via a ventilation system (for example, in a bathroom) and so-called external air inlets are provided in the individual living spaces for air equalization, which then do not need to have their "own" fan and usually also no heat storage.

[0014] However, outdoor air inlets typically have a wind pressure relief device, i.e., a flap that closes automatically in the event of high pressure differences (usually due to wind pressure). In the area of ​​these wind pressure relief devices, the diameter of the wall penetration duct that can flow through, even when the flap is open, is usually significantly reduced.

[0015] Even with these types of outside air inlets, ambient noise, such as traffic noise, can enter the interior spaces. Therefore, special sound-absorbing inserts are useful and already available. Since only relatively low flow velocities prevail in these types of outside air inlets during normal operation, optimizing flow resistance is not the primary objective in this case.

[0016] From the generic DE 10 2011 115 530 A1, it is known to arrange guide lugs in a tubular fan, particularly for underground mining and tunneling, in the direction of the pipe before and after the fan and approximately centered with the fan hub. These lugs have a sound-absorbing coating at their free ends and are held in the pipe by means of supports. The supports are not specifically designed to be sound-absorbing.

[0017] From DE 10 2008 047 272 A1, an air duct element is known which has a cylindrical baffle silencer arranged centered in the air duct via supports.

[0018] From JP 2004 - 116 927 A, a ventilation outlet is known in which the transversely supplied outlet air is guided in an annular gap between two concentric cylinders, which are lined on the airflow side with a sound-absorbing material, wherein connecting webs for the two cylinders are provided at the outlet opening, wherein these connecting webs are not made of a sound-absorbing rigid or soft foam material.

[0019] Further ventilation arrangements using sound-absorbing materials are described in DE 27 16 957 A1 and DE 31 51 386 A1.

[0020] The invention is therefore based on the objective of proposing a sound insulation insert, which is particularly suitable for decentralized residential ventilation systems with axial fans, with improved acoustic performance, but which does not or does not significantly impair the flow characteristics.

[0021] Furthermore, according to another aspect of the present invention, such a sound insulation insert should also be advantageously usable as a sound-absorbing element for outside air passages.

[0022] The aforementioned problem is solved by means of a sound insulation insert with the features of claim 1 and by means of a decentralized residential ventilation system with the features of claim 10.

[0023] Furthermore, a sound insulation insert with a corresponding design according to the invention as per claim 2 can also be advantageously used in outdoor air inlets.

[0024] An outside air inlet with a corresponding sound insulation insert is the subject of patent claim 11.

[0025] Advantageous embodiments of the invention are explained in the respective dependent patent claims 3 to 9.

[0026] A sound insulation insert according to the invention is designed in particular for the interior sound reduction of a residential ventilation system that can be installed in a wall opening, wherein the residential ventilation system has at least one axial fan with a central motor hub.

[0027] The soundproofing insert consists – at least on its surfaces in contact with the airflow – essentially of an acoustically absorbing material.

[0028] Furthermore, the sound insulation insert – as with the known sound insulation inserts – has a ring-shaped outer element for insertion into a wall passage duct containing the residential ventilation system.

[0029] According to the invention, the sound insulation insert, particularly for decentralized residential ventilation systems, is characterized by the fact that an inner element is provided in an area which, in the mounted position, borders the motor hub of the axial fan, and which can be connected to the outer element via at least one web or otherwise attached.

[0030] The “adjacent” aspect of the axial fan’s motor hub means that the inner element should be located near the motor hub and essentially overlap its contour; however, elements may also be provided between the motor hub and the sound insulation insert – preferably those with relatively little influence on the flow pattern – such as handle guards or filters.

[0031] This results in an annular gap-shaped passage for the airflow between the outer and inner elements, which may be divided into sections by at least one web, according to the invention.

[0032] The additional inner element serves two purposes: firstly, it shields the interior from noise emissions directly emanating from the fan motor; secondly, it provides additional absorption surface for airflow noise and ambient noise from outside, thereby reducing the overall noise level penetrating the interior.

[0033] A particular advantage is that the additional inner element does not create any significant flow losses compared to a sound-dampening insert without it, since the axial fan does not allow any airflow in the area of ​​its motor hub anyway. Only the struts provided for mounting the inner element obstruct the main airflow, but with a sufficiently slim design, these hardly cause any disturbance.

[0034] Furthermore, according to another aspect of the invention, a sound insulation insert designed as described above is also advantageous for use with outside air inlets. In this case, the inner element is arranged – usually concentrically – so that it at least partially overlaps the opening of the wind pressure protection device of the outside air inlet.

[0035] Preferably, the inner element covers approximately the opening of the wind pressure barrier, creating two axially spaced barriers to sound. This prevents the sound from passing directly (or at least partially) through the outside air inlet in a straight line, forcing it to take a detour. The direct sound is then blocked either by the outer ring of the wind pressure barrier or by the inner element, thus preventing direct sound propagation within the outside air inlet with the corresponding sound-absorbing insert.

[0036] The sound insulation insert according to the invention is further characterized for both of the aforementioned applications - decentralized residential ventilation systems or wall air passage systems - in that the outer element, the at least one web and the inner element are made of an acoustically absorbing rigid or soft foam material, in particular a melamine resin foam.

[0037] For both of the aforementioned applications – decentralized residential ventilation systems or wall air passage systems – an identically designed sound insulation element can therefore be used in principle for a given wall passage pipe diameter, which reduces manufacturing and distribution costs.

[0038] Furthermore, other applications for the sound insulation insert described above are also conceivable.

[0039] For both of the above-described applications of a soundproofing insert, the following preferred designs exist: Preferably, the inner element is cylindrical in shape and its diameter is approximately adapted to the diameter of the motor hub of the at least one axial fan or to the diameter of the passage opening of the wind pressure protection device in the case of an outside air passage.

[0040] However, it is also possible that the diameter of the inner element is not perfectly matched to the diameter of the fan hub or the diameter of the opening in the outside air inlet, i.e., it may be larger or smaller. This is particularly advantageous because a single sound-insulating insert can be used for both decentralized residential ventilation systems and outside air inlet systems (with the same nominal diameter of the wall penetration duct).

[0041] Furthermore, the inner element is preferably arranged approximately coaxially centered within the wall passage duct, adapting to the rotor hub position of the axial fan or the position of the passage opening of the wind pressure protection in the case of an outside air passage.

[0042] Furthermore, the inner element is preferably connected to the outer element via several webs arranged at approximately equal angular intervals. The webs thus essentially form spokes for fastening the inner element.

[0043] Alternatively, the inner element could also be attached in another way; for example, by means of a single bridge, or to the motor hub of the axial fan itself, or to a protective grille of the fan, or by means of a bracket attached directly to the inner wall of the wall passage duct.

[0044] Preferably, the struts can be connected to the outer and inner elements in a top view of the sound insulation insert at an angle other than 90° and have a curved shape, resulting in a similar appearance to that of correspondingly curved fan blades.

[0045] In a preferred embodiment, in particular three webs can be provided at an angular distance of approximately 120°.

[0046] The sound insulation insert according to the invention can be manufactured as a stamped part from an acoustically absorbing rigid or soft foam material, in particular from a melamine resin foam, for example from the material with the brand name Basotect G (“Basoctect” is a registered trademark of BASF SE, Ludwigshafen).

[0047] Furthermore, the sound insulation insert can be die-cut from a foam board, the length of which is based on the axial installation space available for sound insulation, assuming a wall with a predetermined thickness and a correspondingly dimensioned ventilation system. The sound insulation insert is designed to be shortened for use with thinner walls or correspondingly shorter ventilation systems. Thus, the sound insulation insert is manufactured, for example, with a relatively long length of approximately 8 cm and can then be cut on-site to the actual available axial length, which is very easy to accomplish with rigid foam materials of the type described above.

[0048] If necessary, several soundproofing inserts can be arranged axially one behind the other.

[0049] Furthermore, in one embodiment of the invention it may be provided that the inner surface of the outer element and / or the surface of the inner element has a surface-enhancing texture, at least on the radial surfaces, which further increases the acoustic damping effect.

[0050] Furthermore, the invention proposes a decentralized residential ventilation system or an outdoor air inlet system, each of which has a sound insulation insert as described above.

[0051] The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawings. The drawings show: Fig. 1a,b a first embodiment of a sound insulation insert according to the invention in top view and in sectional view along line AA of Fig. 1a; as well as Fig. 2a,b a second embodiment of a sound insulation insert according to the invention in top view and in sectional view along line AA of Fig. 2a.

[0052] A first embodiment of a sound insulation insert according to the invention, designated overall as 10, in accordance with the Fig. 1a and Fig. 1b represents an elongated foam body made of a melamine resin foam with a typical axial length L ( Fig. 1b) of approximately 8 cm, which is a stamped part (extrusion or milling would also be conceivable) that is in Fig. The contour shown in 1a has smooth top and bottom surfaces. The required length can be adjusted by sawing.

[0053] The sound-absorbing insert 10 is designed for installation in a wall penetration duct (not shown) of a decentralized residential ventilation system. In this example, the wall penetration duct is cylindrical, and therefore the sound-absorbing insert also has a round outer contour. The sound-absorbing insert is preferably inserted into the wall penetration duct adjacent to an axial fan of the residential ventilation system and serves to dampen airflow and fan motor noise as well as external noise. The sound-absorbing insert 10 can also be retrofitted for this purpose.

[0054] Alternatively, the sound insulation insert 10 can also be used as described above in an outdoor air passage system to eliminate or reduce direct sound transmission.

[0055] The sound insulation insert 10 consists of an outer element 12 and a concentrically arranged inner element 14, both elements being die-cut from the same melamine resin foam board; of course, a design made of different materials and separate elements would also be possible.

[0056] The inner element 14 is dimensioned such that, in a decentralized residential ventilation system, it covers the (not shown) motor hub of a nearby axial fan when projected onto the duct cross-section. As a result, when the axial fan is operating, the inner element 14 tends to be located in a flow dead zone, so that the flow characteristics (pressure loss, etc.) are hardly affected by the additional inner element 14, while the acoustic damping is improved due to the direct shielding of motor noise and the additional damping surface provided.

[0057] In an outside air transmission system (ALD system), the inner element 14 preferably covers approximately the remaining passage opening through the wind pressure protection, so that direct sound propagation is eliminated or reduced.

[0058] The inner element 14 is connected to the outer element 12 via three spoke-like webs 16a-c, which have a non-rectangular and slightly curved shape. These webs divide the interior space through which the conveyed air flows into three sub-spaces, which are divided into Fig. 1a are designated with 18a-c. Due to the narrow shape of the webs 16a-c, this only slightly affects the flow characteristics.

[0059] Two cable passages 20 are also provided along the outer perimeter of the outer element 12.

[0060] In the embodiment according to the Fig. 2a and Fig. 2b - otherwise identical elements are provided with the same reference numerals - the inner surface of the outer element 12 is additionally provided with a jagged structure 22, so that the sound damping effect is gradually increased.

[0061] Similar structures could also be implemented on the radial surfaces (and in principle also on the end faces, although this would be more complex in terms of manufacturing) of the inner element 14 or the webs 16a-c.

[0062] A flow test of the soundproofing inserts according to the Fig. 1a,b and Fig. 2a,b compared to corresponding elements without inner element 14 and webs 16a-c results in flow or pressure losses in the single-digit percentage range.

Claims

[1] Sound insulation insert (10), which is designed in particular for the interior noise reduction of a residential ventilation system that can be installed in a wall opening and has at least one axial fan having a central motor hub, wherein the sound-insulating insert (10) is made essentially of an acoustically absorbing material at least on its surfaces in contact with the airflow, and wherein the sound-insulating insert (10) has an annular outer element (12) for insertion into a wall penetration duct, wherein the sound-insulating insert (10) has an inner element (14) in an area which, in the mounted position, adjoins the motor hub of the at least one axial fan in the residential ventilation system, which is connected to the outer element (12) via at least one web (16a-c), so that an annular gap-shaped passage for the airflow is formed between the outer and inner elements, which passes through the at least one The bridge (16a-c) is divided into sections (18a-c), characterized by , that the outer element (12), which includes at least one web (16a-c) and the inner element (14) are made of an acoustically absorbing rigid or soft foam material, in particular a melamine resin foam. [2] Sound insulation insert (10), which is particularly suitable for noise reduction in a, a is designed with an outside air inlet featuring a cross-section-narrowing wind pressure protection, wherein the sound-insulating insert (10) is made essentially of an acoustically absorbing material at least on its surfaces in contact with the airflow, and wherein the sound insulation insert (10) has an annular outer element (12) for insertion into a wall penetration duct, wherein the sound insulation insert (10) has an inner element (14) in an area which, in the mounted position, at least partially overlaps with the passage opening of the wind pressure protection of the outside air passage, which is connected to the outer element (12) via at least one web (16a-c), so that an annular gap-shaped passage for the airflow is formed between the outer and inner elements, which is divided into sections (18a-c) by the at least one web (16a-c), characterized by , that the outer element (12), which includes at least one web (16a-c) and the inner element (14) are made of an acoustically absorbing rigid or soft foam material, in particular a melamine resin foam. [3] Sound insulation insert (10) according to claim 1 or 2, characterized by, that the inner element (14) is cylindrical in shape and its diameter is approximately adapted to the diameter of the motor hub of the at least one axial fan and / or is arranged substantially centered within the wall passage duct. [4] Sound insulation insert (10) according to one of claims 1 to 3, characterized by , that the inner element (14) is connected to the outer element (12) via several webs (16a-c) which are arranged at approximately equal angular intervals. [5] Sound insulation insert (10) according to one of claims 1 to 4, characterized by that the struts are connected to the outer and inner elements in a top view of the sound insulation insert at an angle other than 90°. [6] Sound insulation insert (10) according to one of claims 1 to 5, characterized by , that three bridges (16a-c) are provided at an angular distance of approximately 120°. [7] Sound insulation insert (10) according to one of claims 1 to 6, characterized by that it is manufactured as a stamped part from an acoustically absorbing rigid or soft foam material, in particular a melamine resin foam. [8] Sound insulation insert (10) according to one of claims 1 to 7, characterized by , that the sound insulation insert (10) is punched out from a foam board, the thickness of which is based on the axial installation space available for sound insulation, taking into account a wall with a given wall thickness and a correspondingly dimensioned ventilation system, wherein the sound insulation insert (10) is designed to be shortenable for use in walls with a smaller wall thickness or correspondingly shorter ventilation systems. [9] Sound insulation insert according to any one of claims 1 to 8, characterized by , that the inner surface of the outer element (12) and / or the surface of the inner element (14) have a surface-enhancing texture (22) at least on the radial surfaces. [10] Decentralized residential ventilation system, characterized by that it has a sound insulation insert (10) according to one of claims 1 to 9. [11] Outdoor air inlet, characterized by that it has a sound insulation insert (10) according to one of claims 1 to 9.

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