Bracket and reinforcement method for wall-fan system

Abstract

The present invention relates to vibration management brackets 40 and a reinforcement method for a wall-fan system 20, specifically addressing the prevention of metal exhaustion in the metal sheet wall resulting from vibrations caused by an electric wall mounted fan 30. The method involves the use of metal sheet bars in the form of brackets 40, especially having a hat-profile 40'' affixed to a fan wall metal plate 22, a metal sheet wall, to enhance its structural integrity and durability. As a result, vibrations are reduced, metal exhaustion problems are eliminated, and the vibration peak frequency is shifted.

Description

[0001] BRACKET AND REINFORCEMENT METHOD FOR WALL-FAN SYSTEM

[0002] Technical field

[0003] The present invention generally relates to wall-fan systems and, more particularly, to vibration cancelling and reinforcement methods for air handling units and wall-fan systems.

[0004] Background

[0005] Wall-fan systems have gained widespread use in various industrial, commercial, and residential applications for efficient air circulation and ventilation, including applications for air handling units. These wall-fan systems involve mounting electric duct fans onto metal sheet walls.

[0006] Continuous vibrations generated by the electric duct fan during operation can lead to metal exhaustion in the metal sheet wall over time, compromising its structural integrity. Vibrations also lead to reduced life span for the fan and motor bearings, due to vibration impact. With further metal exhaustion, vibrations will increase, hence worsening the wear on bearings, and noise.

[0007] Extensive investigations have been made to evaluate a best technique to reduce, and or to eliminate the vibrations problems, using vibration analysis and digital synthesis of technical solutions, but all attempts have results in suboptimal solutions concerning performance to effort and cost ratio. For example, by adding material to strengthen the fan-motor, or the wall, more unwanted weight is added, and new weak spots for metal exhaustion may occur. Also, added weight makes maintenance more difficult.

[0008] Hence, a new configuration or technical solution is needed to overcome the mentioned vibration and metal fatigue problems.

[0009] Summary of invention

[0010] The invention relates to wall-fan systems and, more particularly, to a vibration cancelling bracket and reinforcement method using at least two brackets that are sheet metal hat-profile bars, to prevent metal exhaustion in a metal sheet wall fan system. Metal exhaustion is caused by vibrations originating mainly from the fan wall's electric duct fan, or fans, and the electrical fan motor. The method ensures long-term stability and reliability of the wall-fan system, thus minimizing damage and the need for frequent repairs or replacements. The invention is enabled by a new versatile bracket, a sheet metal profile shaped as a hatprofile, provided with preferably hexagonal fixation points according to a preferable hole pattern. The hexagonal holes have been positioned at feasible fixation points. Hexagonal holes have been provided to fit fixation using pop-nuts or blind rivet nuts, as well-suited fixation means, to attach the hat-profile onto a wall-fan metal sheet surface. Alternative fixation methods such as pop-rivets are usually of smaller sizes and of less sturdy material than the pop-nuts, also known as blind rivet nuts. The hexagonal holes provided as fixation points along the reinforcement hat-profiles are well suited to receive blind rivet nuts that can easily and quickly be engaged using a riveting tool or a wrench tool, to properly fixate the reinforcement hat-profile vertically onto corresponding fixation point holes in the fan-wall metal sheet. As a result, the hat-profiles when vertically fixated onto the wall-fan metal sheet surface, are reinforcing the fan-wall along two vertical sides while surrounding the wall fan's at least one air outlet or air inlet.

[0011] According to one aspect, the present invention is a fan -wall upgrading method using hatshaped metal profile brackets, that reduces and handles vibration problems, while reinforcing the metal sheet fan wall, while enabling a quick system upgrade without adding unnecessary weight to the wall fan. By installing the at least, a pair of the hat-profile brackets, these adapted brackets increase the strength of the fan wall, and distributes and counter measures vibration forces, such that vibration damages can be avoided or handled within system requirements for fan walls for usage in air handling units.

[0012] It has been found that the hat-profile shape is preferred over other common profiles such as L-profiles, tubes and folded profiles.

[0013] The hat-profile brackets have a clever design and hole pattern for fixation, that can be adjusted to support common sizes of fan-wall designs for air handling units and ducts, while providing a symmetry for each hat-profile bracket, allow the same profile to be used for left and right side vertical reinforcements around fan wall air inlet or air outlets.

[0014] In another embodiment, the invention is a complete wall-fan design incorporating mounted or installed hat-profile brackets, at a single fan-wall or a system of wall-hung fans in an air handling unit with reduced vibrations and noise reduction.

[0015] The Hat solution has shown promising results in mitigating vibrations and improving the overall performance of units equipped with less stiff spider legs. The Hat solution has proven to be particularly effective in cases where units exhibit high levels of vibration or have specific vibration peaks at about 75% of the working speed range. By implementing the Hat solution, these vibration issues have been successfully addressed, resulting in reduced vibration levels and improved stability.

[0016] Furthermore, the spider legs have been identified as a crucial factor in the vibration behavior of the units. The stiffness provided by the spider legs plays a significant role in influencing vibration patterns and their mitigation. Units equipped with less stiff spider legs have shown better performance coupled with Hat Solution in terms of vibration control compared to units with fans with reinforced spider legs.

[0017] Overall, the combination of the Hat solution with low stiffness-spider legs has proven to be a successful approach in reducing vibrations and enhancing the operational efficiency of the units.

[0018] This highlights the importance of considering both the wall design and the specific design and characteristics of spider legs when seeking effective vibration reduction solutions.

[0019] The underlying concept is that when spider legs possess a high level of stiffness, it is beneficial for the wall or structure to have a higher degree of flexibility. Conversely, if the spider legs have lower stiffness, it is advantageous for the wall to exhibit greater stiffness.

[0020] This principle is based on the idea of achieving a balanced system that can effectively absorb and dissipate vibrations. When the spider legs are already stiff, they can handle a significant portion of the vibration, but a more flexible wall allows for better absorption and dispersion of the remaining vibrations. On the other hand, if the spider legs have lower stiffness, a stiffer wall helps in providing additional support and stability to counteract the vibrations.

[0021] By matching the stiffness characteristics of the spider legs and the wall or structure, it is possible to optimize the vibration reduction capabilities of the system. This approach ensures that the components work synergistically to minimize vibrations and maintain the overall stability and performance of the unit. Technical problem

[0022] Vibration is a problem in air handling units equipped with wall-hung fans. As vibration increases, the risk increases for fan motor bearing damages, which then increases vibration even further.

[0023] The wall-hung fan is fixated to a bracket, typically a spider bracket, which is fixated to a fan wall metal sheet. Vibrations are generated by electrical motors, air flow turbulence, imperfections in bearings and structural fixation of fans with motor, and by the air duct material and air handling unit.

[0024] Fan brackets and fan wall metal sheets are at risk of receiving metal exhaustions due to vibration. Metal exhaustion further increases the risks for vibration damages to fan wheel bearings and fixations. Vibration to structural damages, shorter life span, increased energy usage, noise, and reduced efficiency of the fans, and Air Handling Unit (AHU). Vibration and noise in the AHU can be reproduced along air ducts and via air flows to rooms and sensitive areas occupied by humans, animals, to low-noise or silent locations.

[0025] Fixation of wall-hung fans in air handling units is a challenge, as a too soft fan wall and fixation leads to increased risks for vibrations. By making the structure more rigid and stronger, more material is needed, which increase weight, difficulties to manage the fan wall during maintenance and drives material cost. Increased vibrating mass may further increase the vibration energy, thus increasing vibration damages on the fans, the wall structure, fan motors bearings, and sheet metal.

[0026] Wall fan systems comprises a fan wall usually made of metal sheet with one or several openings for the fans. Each fan is propelled by an at least one motor, typically an electrical motor. The motor is connected in the center of a spider frame with legs attached to the fan wall, using preferably a threaded nuts and bolt attachment method. In between the spider legs attached to the fan wall, an extra reinforcement sheet may be provided, and preferably a duct outlet shaping an aerodynamic outlet thru the fan-wall opening.

[0027] The problem identified is that the due to vibration problems, the fan-wall and other parts are damaged because of long-term metal exhaustion and increased vibration over time of use.

[0028] For example, out of a sample, approximately 20 fan-wall unit fans have failed because of vibration problems. Even more have failed in refurbished units, with vibration levels significantly higher than the ISO 14694 limit values, when measured and assessed in the field and in the lab.

[0029] It is a technical challenge to update, or upgrade, a wall fan system 20 in the field. To ease replacement and upgrading, the wall mounted fan 30 can be removed and the fan wall metal sheet plate 22 can be removed and replaced with an upgraded version, provided with reinforcing and vibration reducing brackets; or this type of upgrade may be conducted at the location for installation. The maintenance and upgrading procedure are expected to be similar or near identical.

[0030] For wall mounted fans 30, it is desired to reduce or to avoid vibrations induced from the fan, ducts, and the motor. As the motor's and fan's bearing wears and dirt builds up at the fan wings, the vibration will gradually increase. Any improvements introduced needs to fit for integration with the actual air handling unit, without degrading any other system parameter, and it must not worsen the problem, or to add significant weight, or require extensive redesigns of any existing structure fan wall system 20 in part or completely.

[0031] Solution to problem

[0032] The technical and practical superior solution to the vibration, metal fatigue, and bearing related problems, is to make use of brackets in the form of hat-profiles, which are in pairs vertically fixated at the sides of the fan wall air inlet or outlet in the wall fan system's fan wall metal sheet. The fixation is made using blind rivet nuts fixating a hat-profile thru hexagonal holes onto the fan wall metal sheet, in combination with pop rivets; a solution that has been found to withstand vibration exhaustion for the application in mind. The hat-profiles reduces the vibration transients while evening out the vibrations entering the wall fan metal sheet, from the fan motors attached to the wall fan metal sheet using bolted spider leg frames.

[0033] It has also been identified thru experiments and vibration analyses, that the hat-profile is superior at cancelling the vibrations at the metal sheet, in comparison to other metal profile shapes such as J-, L-, and U-shaped profiles, which could be used as fewer good alternatives.

[0034] To further reduce vibration and to strengthening the fan wall sheet metal, a folded at the top of the fan wall sheet metal plate, can be introduced, which reinforces the plate, and offering a direct rivet nut fixation point for the hat-profile's upper hexagonal hole provided for rivet nut fixation, acting as a pop rivet. Usage of pop rivets and blind rivet nuts, also known as popnuts, makes the assembly and installation quick and easy, while also offering upgrading activities on site of an installation, such as when upgrading an installation at an ever-moving cruiser ship. At certain installation, an installation upgrade at an air handling unit can be made by replacing the wall fan system with an upgraded version having the hat-profiles preinstalled, while other installations may require an installation upgrade on site, where the fan wall system metal plate is upgraded with fixated hat-profiles.

[0035] Vibration levels relate to the combination of fan's architecture / speed and fan wall design, imperfections, and bearings. Several engineering projects have been focused on enhancing fan-wall design to improve the vibration performance of the entire system, especially relating to vibration and metal exhaustion of the wall fan metal sheet plate that connects each fan wall thru a spider frame connecting with the wall fan metal sheet plate. Metal exhaustion may develop at multiple locations at the metal sheet plate.

[0036] It is a natural result and inert problem that spider legs with fan installation leads to high carrying loads and forces upon the fan wall system metal sheet plate. As the wall fan with motor, impeller, and spider legs are carried on one side of the metal sheet plate, a large momentum force from the fan wall unit with spider legs, pushes onto the lower part of the wall system metal sheet plate, while the upper fixation point for the spider legs exercises a pulling force. The high forces in combination with vibrations makes the installation sensitive to vibrations from the fan, imbalances in the impeller, turbulence, and vibrations carried by the air duct, as well as vibrations for imperfections of the motor and bearings resulting in extra vibrations. As metal exhaustion tend to build ups, damages to bearings and fan installation will follow adding to the vibration problem.

[0037] Vibrations from the wall fan and its impeller are transferred via the bolted spider legs, also referred to as a spider frame, connecting the fan motor with impeller, further to the fan wall system's metal sheet plate,

[0038] At a first glance at the vibration problem, one may think that any type of reinforcement would solve the vibration and metal exhaustion problem. Thorough studies shows that analytical, vibration analysis and straight forward solutions are inferior to the design and method later found to be more feasible for the upgraded design.

[0039] It has been recognized that several air-handling-units (AHU) with wall-hung fans have received failures not limited to metal fatigue and escalating vibration problems at various installations in multiple countries. The symptoms are similar; severe vibrations have resulted in metal fatigue failures such as, broken welds, loosen screws, collapsed fan-walls, detached fan-motors, and broken fan-frames, or broken bearings.

[0040] Solutions to overcome the metal fatigue problem have been tested using multiple vertical reinforcement iron bars, adjoined the fan-wall's to metal sheet wall, resulting in insufficient or no reduction effects on bearing of fan motor and metal fatigue on sheet metal, due to increased vibrations. Increasing the number of vertical beams where even found to have less effect than using just two vertical beams surrounding each fan inlet or outlet.

[0041] The invention introduces a novel bracket solution, termed the "hat- solution" due to the bracket sheet metal profile shape; for enhancing the performance and lifetime of fan-wall structures.

[0042] The hat-shaped brackets can be made as a folded or roll shaped sheet metal profile in the form of a top hat profile, hence the name hat-profile, a type of profile being referred to as a hatprofile in the mechanical engineering, that is a field that includes the HVAC and AHU design field. The hat-profile, along with L-profiles, J-profiles and U-profiles are all examples of commonly known metal profiles.

[0043] By folding or bending a sheet metal strip into a hat-profile, usually using a roll -profile shaping process, different profiles can be shaped, even near the place of assembly or production. These profiles are well-known in the technical field in mind. Similar shaped profiles can of course be formed by injection or molding, or profile molding in iron, zinc, or light-metal materials.

[0044] Roll-formed hat-profiles are recognized as the economical preferable and technical most efficient means to achieve a control over vibration and cancelling of vibration in combination with some reinforcement of the fan wall metal sheet plate.

[0045] To accomplish an efficient vibration cancelling effect, the stiffness of the fan wall metal sheet plate, and resonance patterns must be considered when selecting the best position and fixation positions for the hat-profiles. In general, a stiff plate can be matched with softer hat-profiles and vice versa. To ensure a vibration cancelling effect, it should be avoided to combine elements with similar resonance frequency, such as combining a fan wall metal sheet plate with the same resonance frequency as the hat-profiles.

[0046] The top of the fan wall sheet metal plate may be double folded 27 towards the fan wall metal plate's first surface area 23 meeting the wall mounted fan 30, along its top horizontal edge for extra strength and stability. Then, each hat-profile is preferably screwed fixated through, or at least as close to the fold as possible, to the top horizontal fold, preferably first entering an optional top guide L-profile, before fixating the fan wall metal plate 22 onto the brackets 40. Alternatively, rivet-nuts or pop-rivets may be used for the fixation, but it found that the use of a screw fixating thru the sheet metal is sufficient, possibly secured with a nut is the preferred method for fixation.

[0047] To accommodate for variations for different fan wall system dimensions and configurations, each hat-profile is provided with a hole pattern that fits several fan wall system configurations, even including fan wall systems with multiple fans installed. Hence, the hole patterns are duplicated in pair and symmetrical along the base of the out-stretched hat profile, as well as symmetrical from end to end, thus allowing the same hat-profile to be used on the left and on the right hand side of a wall fan air outlet or air inlet.

[0048] Each hat-profile is preferably designed with in at least three pairs of preferably hexagonal holes for blind rivet nuts 42, but often using total of 16 hexagonal holes for the blind rivet nuts, that are four pair of holes at the top part of the bracket, and four pair of holes at the lower part of the bracket 40.

[0049] Also, each hat-profile is preferably designed with in total 18 holes for the pop-rivets, also known as blind rivet nuts, where in the topmost pair of the 18 holes are configured to be fixated using a screw fixation onto a folded top edge of the fan wall metal sheet plate.

[0050] Advantageous effects of the invention

[0051] The new hat-profile bracket reinforcement and vibration cancellation solution and method, using the vertical hat-profiles, has achieved excellent results for new products and as a technical solution for upgrading existing fan wall systems 20 with fan wall metal plate 22.

[0052] The new hat-profile bracket (40) solution has been tested with both new fans and new fan wall system configurations. Changing fans completely changes the vibration and metal fatigue problems, the problem parameters are also impacted by selection of different rotor diameters, different spider legs and proportions, and different mass.

[0053] It has been verified that the hat-solution comprising two vertical hat-profile beams, configured to finish before reaching the lower edge of the fan wall metal plate 22, only affixed to the fan-wall metal plate 22; brings excellent performance improvements in most wall fan system 20 configurations. A further improvement is to fixate the top of the bracket at the top edge of the fan-wall metal plate 22 preferably provided with a double folded to edge

[0054] 27, and furthermore preferably connected with a top guide L-profile 28, for increased stability for the brackets 40.

[0055] Hence, the hat-profile solution can be seen as a new method for improving fan-wall solutions, and to eliminate or reduce vibrations and risks for metal fatigue, which eventually leads to damages to the wall mounted fan 30 motor 32, with bearings and other delicate components. New wall-fan configurations can integrate the hat-solution during manufacturing, while existing installations may be upgraded on site using the hat-solution and the hat-vertical beam with improvement method as described.

[0056] Traditional vertical bars are surpassed by the utilization of long horizontal beams along the fan-wall length. The surprising effectiveness arises from the dampening effect, reducing vibration amplitudes and shifting the natural frequency of the wall, making the system less stiff. To further enhance the vibration dampening effects, it has been identified that a soft and flexible fan wall metal plate 22, needs to be matched with a pair of stiff brackets 40; and vice versa, for maximal vibration dampening effect. This is likely an effect of matching materials with different ego frequencies, that are the material's resonance frequencies.

[0057] Efforts to directly connect the fan to horizontal beams proved ineffective, leading to a preference for fixing long horizontal beams to the fan -wall. Testing involved adding a hem to the fan-wall's top edge, with positive effects on performance but increased manufacturing complexity. The hat-solution integrates vertical beams, efficiently reducing vibrations without the undesired metal fatigue identified in comer connections.

[0058] The hat-solution offers multiple positive effects: enhancing vibration cancelling, lifetime of the wall-hung fans, performance parameters such as reduction in noise and vibration, simplifying production, while allowing retrofitting upgrades to existing fan-wall installations. Horizontal beams, formed as U, L, J, or hat-shaped profiles, preferably hat-shaped, provide structural reinforcement through attachment methods like riveting, welding, or gluing.

[0059] Configurations with coaxial horizontal and vertical beams proved effective in reducing vibrations, outperforming alternatives. Three-dimensional box-shaped structures and reinforced spider legs were tested but showed poorer results or increased material costs. The hat- solution's hat-shaped beams, without rigid connection to an external frame, demonstrated efficiency in vibration reduction. Optimization involved determining beam length and fixing points, with vertical reinforcement proving superior to horizontal beams. The “hat-solution” reduces the impact on vibration intensity, normally estimated to 1 mm / s, makes it suitable for existing installations. Further testing with different fan configurations and spider leg designs confirmed the hat-solution's versatility and effectiveness in mitigating vibrations.

[0060] In conclusion, the hat-solution, combining vertical beams and hat-shaped profiles, proves to be a highly effective and versatile approach to enhancing fan-wall performance, offering benefits in vibration reduction and simplified production processes.

[0061] In conclusion, the Hat solution has shown promising results in mitigating vibrations and improving the overall performance of units equipped with less stiff spider legs. The Hat solution has proven to be particularly effective in cases where units exhibit higher levels of vibration or have specific vibration peaks after the 75% of the working speed range. By implementing the Hat solution, these vibration issues have been successfully addressed, resulting in reduced vibration levels and improved stability.

[0062] Furthermore, the spider legs have been identified as a crucial factor in the vibration behaviour of the units. The stiffness provided by the spider legs plays a significant role in influencing vibration patterns and their mitigation. Units equipped with less stiff spider legs have shown better performance coupled with hat Solution in terms of vibration control compared to units with fans with reinforced spider legs.

[0063] Overall, the combination of the hat solution with low stiffness-spider legs has proven to be a successful approach in reducing vibrations and enhancing the operational efficiency of the units.

[0064] Though the hat-solution is preferable used in combination with a folded hem at the top of the fan-wall sheet; it has been found during tests with a plain wall, that the results are not as excellent as when suing a hem, but well within acceptable limits. Also, it has been verified that the technical improvements are also seen in hat-solutions for double fan configurations. In such configurations, each fan-wall around each fan unit is reinforced by two surrounding vertical hat-beams each, again with positive results.

[0065] Also, the hat-solution has been evaluated in combinations with spider legs with stiff and spider legs that does not give enough stiffness to the system. Again, the hat-solution mitigated higher levels of vibration, and contributed to a more stable and improved operation. This highlights the importance of considering both the wall design and the specific design and characteristics of spider legs when seeking effective vibration reduction solutions.

[0066] The underlying concept is that when spider legs possess a higher stiffness, it is beneficial for the wall or structure to have a increased degree of flexibility. Conversely, if the spider legs have lower stiffness, it is advantageous for the wall to exhibit greater stiffness.

[0067] This principle is based on the idea of achieving a balanced system that can effectively absorb and dissipate vibrations. When the spider legs are already stiff, they can manage a massive portion of the vibration, but a more flexible wall allows for better absorption and dispersion of the remaining vibrations. On the other hand, if the spider legs have lower stiffness, a stiffer wall helps in providing additional support and stability to counteract the vibrations.

[0068] By matching the stiffness characteristics of the spider legs and the wall or structure, it is possible to optimize the vibration reduction capabilities of the system. This approach ensures that the components work synergistically to minimize vibrations and maintain the overall stability and performance of the unit.

[0069] Brief description of drawings

[0070] The invention is described, by way of example, with reference to the accompanying drawings, which follows.

[0071] Fig. 1 is an exploded view of the complete fan wall system 20 with the new vibration attenuating brackets 40, fan wall metal plate 22, and wall mounted fan 30, prior to assembly.

[0072] Fig. 2a is an Air Handling Unit (AHU) with fan wall system 20 partially installed.

[0073] Fig. 2b is an Air Handling Unit (AHU) with fan wall system 20 installed.

[0074] Fig. 3 is a complete fan wall system 20 with the new vibration attenuating brackets 40, fan wall metal plate 22, and wall mounted fan 30, with complete installation, as seen in a perspective view.

[0075] Fig. 4 is a complete fan wall system 20 with the new vibration attenuating brackets 40, fan wall metal plate 22, and wall mounted fan 30, with complete installation, as seen from a front view. Fig. 5 is a read view of the fan wall system 20, where the top edge is a double folded 27 towards the first surface 23 of the fan wall metal plate 22, also showing the top guide L-shaped profile 27.

[0076] Fig. 6a. shows the bracket 40 as a sheet metal piece 40’ before it has been folded, folding lines are presented. Note that brackets 40 can be produced by other production methods such as profile form extrusion in light weight metal, and even in other materials such as plastics, ceramics, and composite material.

[0077] Fig. 6b. show a cross section of the hat-profile after the sheet metal piece 40’ has been folded into the characteristic hat-profile.

[0078] Fig. 7. Shows the bracket 40, in perspective as a hat-profile 40” as formed with hole patterns and folded into a hat-profile.

[0079] Fig. 8. Show a cross section of how the bracket 40, as a hat-profile 40, fixated with the fan wall metal plate 22, and inlet nozzle plate 33, using threaded bolt 44, and blind rivet nut 42; as well as pop rivet 41.

[0080] Fig. 9. Shows a side view of how the top guide L-profile 28 can be screwed using screw 29, onto the double folded top of the fan wall metal plate 22 and fixated into the bracket 40.

[0081] Fig. 10 shows a perspective view of a prior art fan wall system 21, a fan wall system prone to vibration and metal exhaustion or metal fatigue related problems and increase in vibrations leading to wall mounted fan 30 bearing break-down. Note that there are no brackets 40 in the prior art fan wall system 21.

[0082] Fig. 11 shows a front view of a prior art fan wall system 21, with no brackets 40 installed.

[0083] Fig. 12 shows a side view of the wall mounted fan 30, with no brackets 40 installed, and no top guide L-profile present.

[0084] Fig. 13 visualizes examples of methods as flow charts, according to the teachings herein. Circles represent possible starting points for the methods, while the black circle represents an end state. The first flow is represented by step S200 to S500. SI 00 and S600 are optional steps. The flow for identification and optimization of the selection of best usage and proportions of the brackets 40, is described as step S700 to S740, where in step S730 makes use of the earlier steps SI 00 to S600. Description of embodiments

[0085] The embodiments of the invention are as follows:

[0086] The bracket 40 that enables vibration reduction at a fan wall system, where in the bracket 40 configured with a hole pattern for blind rivet nuts 52, pop rivets 51, and a screw 29 for top edge fixation of the bracket 40 to the topmost edge of a fan wall metal plate 22.

[0087] The fan wall system 20 with a pair of brackets 40 installed on either side of an opening for an airflow form a wall mounted fan 30.

[0088] The fan wall noise reduction system 20 that makes use of the brackets 40.

[0089] A method for modification of a fan wall and how to install the brackets 40 onto the fan wall metal plate 22.

[0090] A method for measurements and identification of feasible dimensions, for the hole pattern 51, 52, 54, and hole pattern distances 53, and placement of the brackets 40 in relation to a fan wall metal plate 22.

[0091] Usage of vertical brackets has been identified as the most favorable technical solution among alternatives.

[0092] Usage of long vertical brackets that stretch along the fan-wall length, has been found to give better effect than using horizontal brackets stretching from side to side of the fan wall metal plate.

[0093] This surprising effect is likely to the dampening effect, so amplitudes of vibration is reduced, alternatively that the natural frequency of the fan wall metal plate 22 is shifted, and that the system is less stiff than when using horizontal brackets. Attempts to directly connect the fan with the horizontal brackets did not improve the performance, hence a fixation of the vertical brackets 40 have been found to be preferred.

[0094] Tests have been made by adding a double hem 27 to the top edge of the fan -wall metal plate 22, using a hem folded 27 towards the wall mounted fan 30 with motor 32, that is on the first planar surface of the fan wall metal plate 22; with positive effects on performance and vibration reduction. While the folding 27 requires a more complicated manufacturing method tests show that the added strength to the top edge of the fan wall metal plate, contributes to further reduction in amplitude of vibrations. Tests do not show any difference in performance between orientations of the folded hem 27, such as towards the first planar surface 23, or the second planar surface 25 of the fan wall metal plate 22.

[0095] Finally, it was conceived that a combination of vertical and horizontal beam, efficiently reduces vibrations, but undesired metal fatigue at rivets was identified in corners if between vertical and horizontal beams that was riveted together forming a frame. Added mass due to usage of a combination of vertical and horizontal beams, influenced the natural frequency and reduced the damping ratio. Hence, an inventive design was identified, comprising only vertical beams, thus omitting the weight of any horizontal brackets. Also, the vertical brackets 40 could be made smaller, and shorter. Finally, this leads to the hat-profile 40’, 40”, or hat-solution, described as follows.

[0096] With the invention, the hat-solution, it has had been identified that the invention makes it possible to couple the positive effects: improvement in vibration performance and simplification on the production line, while also making it possible to add the hat-bracket (40) comprising the vertical beam, to an existing fan-wall installation, for reinforcement and vibration dampening effect. Tests using the vertical brackets 40 surrounding each the opening in the fan wall metal plate 22; shows that the fan wall metal plate's 22 earlier peak vibration spectrum completely disappeared, while moving the peak vibration to another frequency and at a much lower amplitude.

[0097] The horizontal brackets 40 can be made of a U-shaped, L-shaped, J-shaped, and / or preferably using a hat-shaped profile, typically made from a bent metal sheet forming a beam, feasible for fixation onto a fan-wall. Extrusion of similar profiles, in e.g. light weight metal is an alternative to the hat profiles bracket 40 made of folded sheet metal.

[0098] The hat- profile, known under the word “Hat profile” is recognized by its intersection profile, resembling a top hat; with four lengthwise folds, the first a valley fold, the second and third hill fold, followed by a fourth valley fold.

[0099] Other similar hat-profiles may be provided with different angles and rounded hat-profiles 40, if these profiles are configured for being attached to a sheet, preferably a fan-wall sheet metal. Feasible attachment methods for fixation of the preferably hat-profile to the fan-wall sheet, are methods such as: riveting, using ordinary rivets or pop rivets, pop nuts and bolts, welding, spot-welding, gluing, fixation using double sided tape, or nuts and bolts. For the application described in the invention, three different methods have been selected: pop riveting the brackets 40 on to the fan wall metal plate 22; blind rivet nut and bolt to detachable connect the wall mounted fan 30 onto the fan wall metal plate's first surface 23, while fixating a threaded bolt 44 onto a blind rivet 42 nut pre-installed in the bracket 40.

[0100] A configuration with at least a pair of coaxial horizontal brackets enclosing a pair of vertical brackets, attached to the fan-wall metal plate, has been evaluated, and found to be effective in reducing vibrations, but less efficient compared the proposed usage of two vertical oriented brackets 40 adjacent to the opening 24 in the fan wall metal plate 22. Increasing the number of beams had no beneficial effects on the system's stiffness; instead, it merely de-creased the damping.

[0101] Also, a box-shaped 3-dimensional structures to reinforce and prevent fatigue due to vibration, have been tested with and without rubber dampers, with results that were poorer than those obtained with long horizontal beams and with vertical beams. Rubber dampers bring added complexity to the product, have been found to have a slightly positive effect on horizontal and vertical beam configurations.

[0102] Adding comer reinforcement as patches at the fan bracket connection points with the fan wall, have been found to add complexity but gave a better performance in combination with at least the vertical beam configuration with a likeliness that similar results would be achieved in combination with horizontal beams,

[0103] Also, increased thickness of the fan wall metal sheet plate 22 up to 3 mm thickness have been evaluated showing that the best results were found in combination with horizontal or vertical brackets.

[0104] Also, reinforced spider legs have been evaluated with positive results but with considerably increased material cost, hence a less attractive solution for the technical problems described. Usage of alternative support structures to a spider frame, such as using added legs to the spider frame to support the weight of the motor unit towards a floor has been tested with limited results, mostly relating to added stiffness and increased damping mass, while brining cost issues.

[0105] The most preferred technique and highly effective technical solution, that is the invention, is here denote the “hat solution”, due to the usage its hat-shaped reinforcement brackets 40, or beams. It has been found that the “hat solution” proposed is more efficient when not rigidly connected to any external frame, mounted around an air inlet opening 24 in the fan wall metal plate 22. The inventor has found that the Hat-shaped beams do not need to be connected to any frame around the fan wall metal plate 22, as the performance is very similar without any such connection.

[0106] Weight ratio of the Hat-shaped beams have been found to have an impact on the performance of the design.

[0107] The final step of the optimization process involved determining the correct length of the beams and identifying the optimal fixing points. It was found that the length of the beams and the subsequent connection through the wall and the ceiling support had a significant and positive impact.

[0108] Horizontal reinforcement beams or brackets of the same type, hat-profile, were tested, but they yielded inferior results compared to the vertical reinforcements 40. Thus, it can be concluded that the optimal balance between mass, stiffness, and damping is achieved through vertical reinforcement.

[0109] A specific configuration has proven successful with both wall layouts; therefore, it opens the prospect of having not just excellent performance but also an easily fabricable wall thanks to the hem 27 . Vibration intensity tests in orthogonal X (horizontal), Y (vertical) directions and to some degree Z direction (along the fan motor axis) have been studied. The influence of the hat-solution with vertical brackets 40 having a hat-profile, on the X and Y directions is estimated to be around 1 mm / s, compared to peaks of 3 to 4 mm / s without the hat-solution.

[0110] The Hat-solution, has further been tested for new fans and new units and fans, which influences the problem, due to the different diameter of the rotor, different spider legs and different mass. As a result, it has been identified that for certain types of spider leg configurations, a hat-solution with longer horizontal brackets may yield better results, but for most scenarios usage of vertical brackets 40 are sufficient and a generic mean to achieve wanted improvements and to eliminate metal exhaustion problems.

[0111] The hat-solution has also been tested with a double fan configuration with positive results, where the hat-solution outperforms the standard solution, indicating that it is well suited and effectively coupled with this specific shape of spider legs. These findings suggest that the Hat-solution can be considered a suitable and beneficial solution for mitigating vibration in units with similar spider leg designs. The peaks of vibration observed in units with this specific spider leg design, including some wall fan units where peaks were occurring near the maximum speed. By implementing the hat-solution as a reinforcement method, these vibration peaks are effectively shifted away from the working speed range, an interesting result.

[0112] The final step of the optimization process involved determining the correct length of the beams and identifying the optimal fixing points. It has been found that the proper length of the bracket 40 beams and location of the subsequent connection through the wall and the ceiling support have a significant and positive impact. Horizontal beams yielded inferior results compared to vertical reinforcement brackets 40. Hence, it was concluded that the optimal balance between mass, stiffness, and damping is achieved through vertical reinforcement brackets 40. Furthermore, as the vertical brackets can be configured to not reach the upper nor lower edge of the fan wall metal plate, preferably a sheet metal of about 2 mm thickness; the fan wall metal plate 22 can be configured with its upper part of the fan wall metal plate 22 folded into hem 27, in arbitrary direction, for further reinforcement without any interference with the vertical brackets 40, preferably made of a folded metal sheet 40’ as a hat-profile 40” . As the hat-profile can easily be riveted, or pop-riveted to the fan-wall, the production can be simplified, automated and the reinforcement method can be used on existing installations. The folded hem 27 is preferably made on the first surface 23 of fan wall metal plate 22, directed away from the second surface 25 where the vertical brackets 40 are to be fixated. Such a hem provides for a flat surface between the bracket 40 and the fan wall metal plate 22 for good alignment.

[0113] As a result, the successful hat-solution, comprising vertical beams 40, preferably configured to not reach the upper, nor lower edge of the fan-wall metal sheet, with or without any hems, preferably atop hem 27; yields excellent performance results. The influence of the Hat-solution on the X and Y directions is estimated to be around 1 mm / s. This minimal impact makes it almost impossible to achieve significant improvements since the reference value for some tested wall mounted fans 30, already exhibits a peak of approximately 3 mm / s, and the test was conducted solely on the fan 30 without any additional reinforcement. It is important to mention that the measured peak in the three units with the hat-solution is approximately 4 mm / s.

[0114] Hence, among other alternatives, it has been identified that vertical bracket 40 and the mounting methods provided for, results in excellent vibration reduction, thus extending the lifespan of the fan mounted wall motor 32, bearings, turbine 36, and mechanical fixation with the fan wall metal plate 22 and components in the fan wall system 20 supported. First embodiment is a vibration cancellation and vibration reduction bracket 40 pair for fan walls 20

[0115] In an embodiment, the invention is a bracket configured for installation at a fan wall 20, for operation inside an air handling unit 60.

[0116] The bracket 40 is provided for vibration management, especially reduction of peak vibration amplitudes at operational frequencies for a fan wall system 20, provided for an air handling unit 60.

[0117] The bracket 40 comprises at least a bracket 40 made of preferably sheet metal (40’), alternatively made of an extruded metal such as a lightweight metal. The bracket is provided with at least four holes for blind rivet nuts 52 and at least six holes for pop rivets 5, for attaching the bracket onto a fan wall metal plate22, of a fan wall installation 20, usually in an air handling unit, using pop rivets. As such the wall mounted fan 30 can be attached using threaded bolts that lock the wall mounted fan onto the fan wall metal plate 22 and installed blind rivet nuts installed at each bracket 40.

[0118] The bracket 40 is especially configured to be fixed vertically onto a fan wall 20 for a vibration reduction effect, or vibration spectrum distribution, where a wall mounted fan 30 can be detachable fixable to at least two blind rivet nuts 42 per bracket 40.

[0119] Through tests and investigations, it has been identified that a preferably shape of the bracket 40 profile, is to make use of a hat-shaped hat-profile. Such a bracket 40 can be folded, stamped, and roll-shaped into a hat-shaped profile 40”.

[0120] The bracket 40 is made of a bracket metal sheet profile 40’ having two base members 48 forming a brim of the hat-profile, connected at 90-degree angle with each of the two hat sides 46 wherein each side 46 is connected at an opposite 90-degree angle with the crown 47, thus forming a hat-shaped form, the hat-profile.

[0121] Furthermore the bracket 40 has been found to have certain preferred dimensions: a thickness 59 of a bracket metal sheet profile 40’ is 1.5 mm to 3 mm, preferably 2 mm; two base members 48 each has a width 58 of 15 mm to 25 mm, preferably 22 mm; each of the two hat side 46 has a height 56 15 mm to 35 mm, preferably 24.5 mm; and the a hat crown 47 of has width crown of the that-profile 57 of 15 mm to 25 mm, preferably 19 mm. The bracket 40 as further described herein may in some embodiments have a hat-shaped profile 40” shaped as a folded bracket metal sheet 40’ and formed into a distinctive hat structure 40” by folding.

[0122] The bracket 40 as further described herein may in some embodiments have a bracket 40 that is a hat-shaped profile 40” made from an extruded metal profile, made of iron-based metal, or preferably a lightweight metal, preferably an aluminum alloy.

[0123] Furthermore, the bracket 40 as described herein may in some embodiments have a total base width, equal to the width of two base members 58 plus the width of the crown 57, that results in a total width 45 of 45 mm to 80 mm, preferably 63 mm.

[0124] To provide a mean for fixating a wall mounted fan 30 onto the fan wall metal plate 22, the bracket 40 as described herein may in some embodiments be configured such that the bracket is configured with at least four holes for rivet nuts 52 preferably hexagonal-shaped to avoid free rotation of blind rivet nuts 42 and at least two blind rivet nuts 42 installed along the outstretched hat-shaped profile's 40” two base members 48. The bracket is provided with a hole pattern for rivet nuts 52 along each of the outstretched base members 48 as identical pairs of holes for blind rivet nuts 52.

[0125] The bracket 40, as further defined herein may in some embodiments preferably configured with at least six holes 51 for pop rivets 41 along the outstretched hat-shaped profile's 40” two base members 48. The pattern for holes for pop rivets 51 at each of the base members 48 are identical, in pair. Consecutive pop rivet will have a distance between two consecutive holes for pop rivets 51 along the outstretched bracket's 40 profile at a distance less than or equal to, or at least 150 mm.

[0126] To fixate the bracket 40 onto a stronger section of the fan wall metal plate, the bracket 40 as further specified herein may in some embodiments comprise self-threading sheet screws 29, to accommodate that the bracket 40 with a hole 54 for screw 29 for fixation in bracket 40, further designed to be screw fixated together with a top guide L-profile 28 and the top edge of a fan wall metal plate 22, preferably with a double folded top edge 27 for strength; and vibration reduction.

[0127] The brackets 40 as further described herein may in some embodiments be intended to be used in pairs of brackets 40. The pair of brackets 40 are collaborating in vibration management, and therefore also to prevent metal exhaustion at a fan wall system 20, with a fan wall metal plate 22 having a first planar surface 23 and a second planar surface 23.

[0128] For fixation, of the brackets 40, a set of pop rivets 41 for fixation of the bracket 40 onto the second planar surface 25 of the fan wall metal plate 22. A set of threaded bolts 44 are provided for detachable locking of an inlet nozzle plate 23 of a wall mounted fan 30 and with a fan wall metal plate 22 using screw fixation with the bracket 40 preferably using blind rivet nuts 42. The brackets 40 are configured to be vertically fixed at a fan wall 20 as a pair of brackets 40 surrounding, at typically a left- and right-hand side of an opening 24 on a second side 25 of a fan wall metal plate 22. Each bracket is designed to support fixation with pop rivets 41 onto the fan wall metal plate 22, to further reduce vibrations; with a fan wall system's 20 fan wall metal plate 22, using holes through the fan wall metal plate 26, and offering fixation of a wall mounted fan 30, to reduce risks for metal fatigue at a fan wall metal plate 22.

[0129] Improved fan wall system 20

[0130] In another embodiment, the invention is an improved fan wall system 20 enhanced using mentioned bracket 40. The fan wall system 20 is typically configured for installation and operation inside an air handling unit (AHU) 60.

[0131] The improved fan wall system 20 reduces vibration thus reducing the risk for metal exhaustion. Usually, the fan wall system 20 can be configured for operation inside an air handling unit 60, though other usage configurations exist for such a fan wall system 20. The fan wall system 20 is consists of but not limited to: a fan wall metal plate 22 with an opening 24 for a wall mounted fan 30 air inlet or air outlet 34, a wall mounted fan 30.

[0132] The wall mounted fan 30 further comprises an inlet nozzle plate 33 with an air inlet or air outlet 34, a motor 32 with an impeller 36 configured to propel an airflow thru the air inlet or air outlet 34 and an opening 24 at usually the center of the fan wall metal plate 22. The wall mounted fan 30 also often comprises a spider leg frame 31, or equivalent, that connects the motor 32 with the inlet nozzle plate 33. The nozzle plate 33 is provided with fixation holes for fixation of the wall mounted fan 30 with a first planar surface 23 of the fan wall metal plate 22. Further the fan wall system in some embodiments comprises at least a pair of brackets 40 as also described herein in some embodiments. Each bracket 40 is fixated vertically, preferably using pop rivets 41, onto the second planar surface 25 of the fan wall metal plate 22, and adjacent on opposite sides of the opening 24.

[0133] Each bracket 40 is also configured with at least two blind rivet nuts installed 42, to let the wall mounted fan 30 to be detachable fixated with at least four, preferably six, threaded bolts 44 which can be inserted through holes at the nozzle plate 33, holes 26 in the fan wall metal plate 22, and threaded with corresponding blind rivet nuts 42 installed in the bracket 40.

[0134] The improved fan wall system 20 as described herein may in some embodiments also further comprise but not limited to: a top guide L-profile 28 with screws 29 preferably self-threading screw 29, mounted from the first planar surface 23 through the double folded edge 27 and into each of bracket's 40 selfthreading hole 54, configured for the screw 29.

[0135] The fan wall metal plate 22 is further configured with a preferably double folded top edge 27 folded towards its first planar surface 23. This gives the top edge improved strength and an improved fixation point for the brackets 40.

[0136] In an embodiment the invention is a method for installation of the bracket 40 as a production or upgrading procedure for a fan wall system 20

[0137] The method is providing an improvement of a fan wall system's 20 lifespans including its motor 32 and fan wall system 20 material, by protecting against vibrations and metal exhaustion.

[0138] The method has at least four steps S200, S300, S400, and S500; as follows.

[0139] Normally, the first step (S200) is to install, unless already prepared, at least a pair of blind rivet nuts 42 through blind rivet holes 52, preferably hexagonal holes 52; by passing the blind rivet nut 42 from the base member 48 side. The base members 48 are forming a brim of the hat-profile towards the top crown 47, thus creating an installed blind rivet nut 42 for installation of a threaded bolt 44 through the wall mounted fan's 30 nozzle plate 33 and through the fan wall metal plate 22 with holes through the fan metal plate 26, for detachable locking with the blind rivet nut 42; The next step is: (S300) installing vertically at least a pair of brackets 40 as herein in some embodiments, with the brackets positioned with the two base members 48 forming a brim of the hat towards the fan wall metal plate's 22 second planar surface of the fan wall metal plate 25 adjacent to the opening 24, that is at a surface opposite to the first planar surface of the fan wall metal plate 23 where a wall mounted fan 30 is configured to be mounted at a second side opposite to the fan installation side.

[0140] Next step (S400) is installing pop rivets 41 thru the bracket's holes for pop rivets 51 and through the fan all metal plate 22 prepared with provided with corresponding holes 51. Alternatively, these can be provided with corresponding holes 51 after drilling in the fan wall metal plate 22.

[0141] The next step is (S500) installing threaded bolts 44 through the wall mounted fan's 30 nozzle plate 33 and through the fan wall metal plate 22 with holes through the fan metal plate 26 carrying the wall mounted fan 30, for detachable locking with the blind rivet nut 42, for vibration reduction and reduction in frequency dependent vibrations during fan wall system operation.

[0142] Finally the method may further include or comprise as step to further reinforce the connection with the brackets (40) following step (S600) by first installing the brackets 40 onto the top edge 27 of the fan wall metal plate 22, preferably using self-threading screws 29 by inserting the screws 29 from the first side of the fan wall metal plate 23 through a preferably double folded upper edge 27 that is preferably folded onto the first side of the fan wall metal plate 23, and then further through bracket's corresponding hole 54 for screw 29 for fixation of the bracket 40.

[0143] In method step (S600) the screw 29 may first pass through a hole in a top guide 28, if present, where the top guide 28 is preferably shaped as an L profile 28. Then a threaded screw 29 is inserted the fan wall metal plate 23 according to the previous step (S600), for improved strength and vibration reduction of the fan wall system 20 during operation of the wall mounted fan 30. In an embodiment the invention comprises a method for optimization and selection of the bracket proportions 40 and installation position in a fan wall system 20

[0144] The first step (SI 00) is about selecting the proper stiffness of the brackets 40 in relation to the wall fan metal sheet plate stiffness, and in relation to stiffness of spider legs. The method accordingly comprises the step (SI 00) precedes the earlier mentioned step (S200). Step (SI 00) involves selecting material stiffness of the brackets 40 in relation to the stiffness of the fan wall metal plate 22 such that either: a stiff fan wall metal plate 22 is matched with a soft bracket 40, or a soft fan wall metal plate 22 is matched with a stiff bracket 40; for vibration and noise reduction. Also, a stiff spider leg structure 31 is matched with a soft bracket 40, or a soft spider leg structure 31 is matched with a stiff bracket 40.

[0145] Furthermore the process of finding and selecting a configuration that is feasible or optimal for usage of the bracket may involve a method for determination of dimensioning of a wallfan system 20 for installation in an air handling unit 60 comprising the following steps:

[0146] Step (S700) is running a wall fan fixated to a sheet metal wall, without brackets 40 installed.

[0147] Step (S710) is identifying vibration patterns with a peak area around wall fan fixation points to a sheet metal wall using a Light Detection and Ranging (LIDAR) sensor, a high-speed camera, or an acoustic microphone array, also known as an acoustic camera.

[0148] Step (S720) is installing a first bracket 40 and a second bracket 40 at a position vertically and adjacent to the opening 24 at opposite sides of the opening 40, that is further explained herein in some embodiments.

[0149] Step (S730) is verifying vibration reduction effect by repeating step (S710) to (S720) until a sufficient vibration reduction is achieved and a best possible position, hole pattern and stiffness of the brackets 40 is identified; and finally:

[0150] Step (S740) is configuring production of brackets 40 and hole patterns for future optimized installation and operation as also described may in some embodiments. Reference Signs List

[0151] Description of reference numbers used in drawings are defined as follows. First a figure reference number is specified, and then a short name of the item, arrow, flow of information or method step is presented, and in some cases also briefly described. Method steps are denoted with a prefix “S” added to a number such as SI 00.

[0152] 20= Fan wall system.

[0153] 21= Fan wall system, as prior art without brackets.

[0154] 22= Fan wall metal plate, preferably 2 mm thick metal sheet material.

[0155] 22’= Fan wall metal plate, with vertical 90 degrees fold at vertical sides.

[0156] 23= First planar surface of the Fan wall metal plate 22.

[0157] 24= Opening, in Fan wall metal plate 22.

[0158] 25= Second planar surface of the Fan wall metal plate 22, that is the opposite side of the first 23.

[0159] 26= Hole, or holes through fan wall metal plate, for fixation of wall mounted fan 30 and brackets 40.

[0160] 27= Double folded top edge, of the fan wall metal plate 22.

[0161] 28= Top guide L-profile, configured to be screw mounted on top of the double folded top edge 27 of the fan wall metal plate 22.

[0162] 29= Screw, preferably a self-threading sheet screw for metal fixation, used for fixation of the L-profile 28.

[0163] 30= Wall mounted fan.

[0164] 31= Spider leg frame, connecting the motor with the intel nozzle plate.

[0165] 32= Motor.

[0166] 33= Ini et nozzl e pl ate .

[0167] 34= Air inlet or air outlet, at wall mounted fan 30.

[0168] 35= Fan wall fixation hole, at least six are used for fixation, but the wall mounted fan is usually provided with eight holes, at least one hole is positioned in each corner of the wall mounted fan’s 30 inlet nozzle plate 33.

[0169] 36= Impeller.

[0170] 40= Bracket, or brackets, for vibration cancellation and altering of vibration frequency and patterns. The brackets provide vibration reduction and a more even vibration spectrum. Some reinforcement to the structure is also provided. Selection of feasible brackets with existing fan wall metal plate 22, is made to avoid similar vibration resonance frequences and stiffness. Hence a soft bracket 40 can be matched with stiff fan wall metal plate 22, and vice versa.

[0171] 40’= Bracket 40 as metal sheet with fold marks before the hat-profile shape is formed. Forming the hat profile can be made using a dice, metal sheet folding machine, or using roll-forming; into a hat-profile.

[0172] 40’ ’= Bracekt 40 as a ready folded or formed hat-profile.

[0173] 41= Pop rivet.

[0174] 42= Blind rivet nut, installed, preferably but not limited to receive an M8 threaded bolt.

[0175] 44= Threaded bolt, preferably eight bolts are used. Four bolts are mounted through the brackets, hat-profiles, and four threaded bolts 44 are mounted through the fan wall metal plate 22.

[0176] 45= Base width of the hat-profile, preferably 63 mm.

[0177] 46= Side of hat-profile, with a height of the hat-profile 56, preferably 24.5 mm.

[0178] 47= Crown of hat profile.

[0179] 48= Base member of the hat-profile, preferably with a width of 22 mm. The two base members form a brim with a base width of the hat profile 45.

[0180] 49= Vertical cut-away intersection of the hat showing that the plane of the hole for pop rivet 51 and hole for blind rivet nut 52, are located at different distances length wise along the outstretched bracket 40.

[0181] 51= Hole for pop rivet 41, in bracket 40.

[0182] 52= Hole for blind rivet nut 42, in bracket 40. Preferably hexagonal holes 52 for hexagonal blind rivet nuts 42.

[0183] The blind rivet nut 52 serves as a nut for the threaded bolt 44 when attaching the inlet nozzle plate 33 with the fan wall plate 22, and bracket 40.

[0184] 53= Pop rivet distance 53, preferably of at least 150 mm between two pair of holes for pop rivet rivets 51.

[0185] 54= Hole for screw 29 for fixation in bracket 40. The preferably self-threading screw 29 connects the top guide L-profile 28 with the double folded top edge, of the fan wall metal plate 27, and bracket 40.

[0186] 56= Height of the hat-profile, preferably 24.5 mm.

[0187] 57= Width of the crown of the hat-profile, typically 19 mm.

[0188] 58= Width of each of the base members of the hat-profile, preferably 22 mm.

[0189] 59= Thickness of the hat-profile, 1 mm to 2.5 mm, preferably 2 mm. 60= Air handling unit, wherein the fan wall system 20 is configured to be detachable installed as a vertical wall, as seen in Fig. 2a and Fig. 2b.

[0190] 61= Installation and de-installation direction for fan wall system 20 at air handling unit (AHU) 60.

[0191] Method steps:

[0192] SI 00= Selecting the proper stiffness of the brackets 40 in relation to the wall fan sheet metal plate stiffness; and in relation to stiffness of spider legs.

[0193] S200= Normally the first step. Step S200 to install, onto bracket 40 unless already prepared, at least a pair of blind rivet nuts 42 through blind rivet holes 52, preferably hexagonal holes 52.

[0194] S300= Installing vertically at least a pair of brackets 40, that is the hat-profiles, positioned with the two base members 48 forming a brim of the hat towards the fan wall metal plate's 22 second planar surface of the fan wall metal plate 25 adjacent to the opening 24, that is at a surface opposite to the first planar surface of the fan wall metal plate 23 where a wall mounted fan 30 is configured to be mounted at a second side opposite to the fan installation side.

[0195] S400= Installing pop rivets 41 thru the bracket's holes for pop rivets 51 and through the fan all metal plate 22 prepared with provided with corresponding holes 51.

[0196] S500= Installing threaded bolts 44 through the wall mounted fan's 30 nozzle plate 33 and through the fan wall metal plate 22 with holes through the fan metal plate 26 carrying the wall mounted fan 30, for detachable locking with the blind rivet nut 42.

[0197] S600= Screwing screw 29 pass through a hole in a top guide 28, if present, where the top guide 28 is preferably shaped as an L profile 28.

[0198] S700= Running a wall fan fixated to a sheet metal wall, without brackets 40 installed.

[0199] S710= Identifying vibration patterns with a peak area around wall fan fixation points to a sheet metal wall.

[0200] S720= Installing a first bracket 40 and a second bracket 40 at a position vertically and adjacent to the opening 24 at opposite sides of the opening 40.

[0201] S730= Verifying vibration reduction effect by repeating step (S710) to (S720) until a sufficient vibration reduction is achieved and a best possible position, hole pattern and stiffness of the brackets 40 is identified.

[0202] S740= Configuring production of brackets 40 and hole patterns.

Claims

CLAIMS1. A vibration management bracket (40) configured to reduce the vibrations of a fan wall system (20) comprised in an air handling unit (60), the bracket (40) being made of sheet metal (40’) or extruded metal, with at least four holes configured to receive blind rivet nuts (52) and at least six holes configured to receive pop rivets (51), the bracket (40) CHARACTERIZED IN THAT the bracket (40 is of a hat-shaped profile and wherein the bracket (40) is configured to be fixed vertically onto the fan wall (20) for a vibration reduction effect, wherein the wall mounted fan 30 is detachable fixable to at least two blind rivet nuts (42) per bracket (40) .

2. The bracket (40) according to claim 1 wherein the hat-shaped profile (40”) comprises: a bracket metal sheet profile (40’) having two base members (48) forming a brim of the hat-profile, connected at 90-degree angle with each of the two hat sides (46) wherein each side (46) is connected at an opposite 90-degree angle with the crown (47),CHARACTERIZED IN THAT the thickness (59) of a bracket metal sheet profile (40’) is 1.5 mm to 3 mm, preferably 2 mm, each base member (48) has a width (58) of 15 mm to 25 mm, preferably 22 mm; each hat side (46) has a height (56) 15 mm to 35 mm, preferably 24.5 mm; and the a hat crown (47) of has width crown of the that-profile (57) of 15 mm to 25 mm, preferably 19 mm.

3. The bracket (40) according to claim 1 or claim 2 wherein the hat-shaped profile (40”) is a folded bracket metal sheet (40’) formed as a distinctive hat structure (40”) by folding.

4. The bracket (40) according to claim 1 or claim 2 where in the bracket (40) is a hatshaped profile (40”) extruded metal profile, made of iron-based metal, or a lightweight metal, preferably an aluminium alloy.

5. The bracket (40) according to any of claims 1 to 4, where in the total base width, equals the width of two base members (58) plus the width of the crown (57), wherein the total base width is 45 mm to 80 mm, preferably 63 mm.

6. The bracket (40) according to any of claims 1 to 5 wherein the bracket is configured with at least four holes for rivet nuts (52) preferably hexagonal-shaped with at least two blind rivet nuts (42) installed along the outstretched hat-shaped profile's (40”) two base members (48) CHARACTERIZED IN THAT the holes for rivet nuts (52) are provided as identical pairs along each of the outstretched base members 48.

7. The bracket (40) according to any of claims 1 to 6 wherein the bracket is configured with at least six holes (51) for pop rivets (41) along the outstretched hat-shaped profile's (40”) two base members (48), CHARACTERIZED IN THAT the pattern for holes for pop rivets (51) at each of the base members (48) are identical, and that the pop rivet distance (53) between two consecutive holes for pop rivets (51) along the outstretched bracket's (40) profile is less than or equal to at least 150 mm.

8. The bracket (40) according to any of claims 1 to 7 further CHARACTERIZED IN THAT the bracket (40) further comprises a self-threading sheet screw (29), and that the bracket (40) is configured with a hole (54) for screw (29) for fixation in bracket (40) configured to be screw fixated together with a top guide L-profile (28) and the top edge of a fan wall metal plate (22) preferably provided with a double folded top edge (27) for strength.

9. The bracket (40) according to any of claims 1 to 8 further for usage in pairs of brackets (40) for vibration management and metal exhaustion elimination at a fan wall system (20) having a fan wall metal plate (22) with a first planar surface (23) and a second planar surface (23), comprising:a set of pop rivets (41) for fixation of the bracket (40) onto the second planar surface (25) of fan wall the metal plate (22); and a set of threaded bolts (44) for detachable locking of an inlet nozzle plate (23) of a wall mounted fan (30) and with a fan wall metal plate (22) for screw fixation with the bracket (40) preferably using blind rivet nuts (42)WHERE IN the brackets (40) are configured to be vertically fixed at the fan wall (20) as a pair of brackets (40) surrounding an opening (24) on a second side (25) of a fan wall metal plate (22), for fixation with pop rivets (41); to reduce vibration at the fan wall's (20) fan wall metal plate (22) and holes through the fan wall metal plate (26) for fixation of a wall mounted fan (30), or to reduce risks for metal fatigue at a fan wall metal plate (22).

10. An fan wall system (20) for vibration reduction and metal exhaustion avoidance, configured for operation in an air handling unit (60), wherein the fan wall system (20) is comprising: a fan wall metal plate (22) with an opening (24) for a wall mounted fan (30) air inlet or air outlet (34), a wall mounted fan (30) further comprising: an inlet nozzle plate (33) with an air inlet or air outlet (34), a motor (32) with an impeller (36) configured to propel an airflow thru the air inlet or air outlet (34) and the opening (24) of the fan wall metal plate (22), a spider leg frame (31) that connects the motor (32) with the inlet nozzle plate (33), wherein the nozzle plate (33) is provided with fixation holes for fixation (35) of the wall mounted fan (30) with first planar surface (23) of the fan wall metal plate (22),CHARACTERIZED IN THAT the fan wall system further comprises at least a pair of brackets (40) according to any of claims 1 to 9, wherein the brackets (40) are of a hat profile and fixated vertically preferably using pop rivets (41) onto the second planar surface (25) of the fan wall metal plate (22)adjacent on opposite sides of the opening (24), and wherein each bracket (40) is configured with at least two blind rivet nuts installed (42), wherein the wall mounted fan (30) is configured to be detachable fixated with at least four, preferably six, threaded bolts (44) inserted through holes at the nozzle plate (33), holes (26) in the fan wall metal plate (22), and threaded with corresponding blind rivet nuts (42) installed in the bracket (40) and wherein the fan wall metal plate (22) has a different resonance frequency than the hatprofile.

11. The fan wall system (20), according to claim 10 further comprising: a top guide L-profile (28) with screws (29) preferably self-threading screw (29), mounted from the first planar surface (23) through the preferable double folded edge (27) and into each of bracket's (40) self-threading hole (54), configured for the screw (29),CHARACTERIZED IN THAT the fan wall metal plate (22) is configured with a preferably double folded top edge (27) folded towards its first planar surface (23).

12. A method for improvement of a fan wall system's (20) life-span of motor (32) and fan wall (20) material against vibrations and metal exhaustion, comprising the steps:(S200) installing unless already prepared, at least a pair of blind rivet nuts (42) preferably through blind rivet holes (52) preferably hexagonal holes (52), by passing the blind rivet nut (42) from the base member (48) side forming a brim of the hat profile towards the top crown (47), thus creating an installed blind rivet nut (42) for installation of a threaded bolt (44) through the wall mounted fan's (30) nozzle plate (33) and through the fan wall metal plate (22) with holes through the fan metal plate (26), for detachable locking with the blind rivet nut (42);(S300) installing vertically at least a pair of brackets (40) according to any of claims 1 to 9, with the brackets positioned with the two base members (48) forming a brim of the hat towards the fan wall metal plate's (22) second planar surface of the fan wall metal plate (25) adjacent to the opening (24),that is at a surface opposite to the first planar surface of the fan wall metal plate (23) where a wall mounted fan (30) is configured to be mounted, wherein the second side opposite to the fan installation side;(S400) installing pop rivets (41) thru the bracket's holes for pop rivets (51) and through the fan all metal plate (22) prepared with provided with corresponding holes (51), alternatively provided with corresponding holes (51) after drilling in the fan wall metal plate (22); and(S500) installing threaded bolts (44) through the wall mounted fan's (30) nozzle plate (33) and through the fan wall metal plate (22) with holes through the fan metal plate (26) carrying the wall mounted fan (30), for detachable locking with the blind rivet nut (42), for vibration reduction and reduction in frequency dependent vibrations during fan wall system operation, wherein the fan wall metal plate (22) has a different resonance frequency than the hat-profile.

13. The method according to claim 12 further comprising the step,(S600) installing the brackets (40) onto the top edge (27) of the fan wall metal plate (22), preferably using self-threading screws (29) by inserting the screws (29) from the first side of the fan wall metal plate (23) through a preferably double folded upper edge (27) that is preferably folded onto the first side of the fan wall metal plate (23), and then further through bracket's corresponding hole for screw (54) for fixation of the bracket (40).

14. The method according to claim 13 wherein the step (S600) where in the screw (29) first passes through a hole in the top guide (28) preferably shaped as an L profile (28), before the threaded screw (29) is inserted the fan wall metal plate (23) according to the method according to claim 12 or 13, for improved strength and vibration reduction of the fan wall system (20) during operation of the wall mounted fan (30).

15. The method according to any of claims 12 to 14 CHARACTERIZED IN THAT step (S100) precedes step (S200) wherein the step (S100) comprises:(SI 00) selecting material stiffness of the brackets (40) in relation to the stiffness of the fan wall metal plate (22) such that either: a stiff fan wall metal plate (22) is matched with a soft bracket (40); or a soft fan wall metal plate (22) is matched with a stiff bracket (40);for vibration and noise reduction.

16. The method according to any of claims 12 to 15 CHARACTERIZED IN THAT step(S100) precedes step (S200) wherein the step (S100) comprises:(SI 00) selecting material stiffness of the brackets (40) in relation to the stiffness of the spider legs (31) such that either: a stiff spider legs (31) is matched with a soft bracket (40); or a soft spider legs (31) is matched with a stiff bracket (40); for vibration and noise reduction.

17. A method for determination of dimensioning of a wall-fan system (20) for installation in an air handling unit (60) comprising the steps:(S700) running a wall fan fixated to a sheet metal wall, without brackets (40) installed;(S710) identifying vibration pattern with a peak area around wall fan fixation points to a sheet metal wall using a LIDAR, a high-speed camera, or an acoustic microphone array;(S720) installing a first bracket (40) and a second bracket (40) at a position vertically and adjacent to the opening (24) at opposite sides of the opening (40), according to any of claims 12 to 16;(S730) verifying vibration reduction effect by repeating step (S710) to (S720) until a sufficient vibration reduction is achieved and a best position, hole pattern and stiffness of the brackets (40) is identified;(S740) configuring production of brackets (40) and hole patterns for future optimized installation and operation according to any of claims 12 to 16.

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