Patent Application
20250003630
This invention generally relates to sound isolating ventilation panels, such as doors, and methods for manufacturing same.
In commercial and institutional buildings, it is standard for all interior spaces to have dedicated fresh air supplies and returns/exhausts. Sometimes this air is conditioned (heated/cooled, moisture controlled). Depending on the building, floorplan, mechanical system, outdoor air enters a building and moves through ventilation equipment and ducts as well as occupied spaces and interior ventilation openings before being exhausted outside. Most commercial buildings use mechanical fans to move air through a system and building, though some employ natural forces like thermal buoyancy and wind pressure. Common air transfer openings between rooms in buildings include door undercuts (the gap between the bottom of a door and the floor), grilles, and transfer ducts. The capacity for airflow depends on the cross-sectional area, flow path shape, and obstructions in the flow path. Through a given ventilation opening or duct, the differential air pressure and rate of airflow are directly related (airflow is proportional to the square root of the pressure difference). Ventilation system engineers design systems to provide air to each space given its floor area and occupancy, with minimum limits prescribed by standardization agencies.
For a panel (e.g. a door) of a given size that partitions spaces and provides means for air transfer, it is generally desirable to maximize the capacity for airflow so as to increase the panel's application to spaces that require higher airflow rates.
When sound is incident upon a panel, components of the energy are reflected, absorbed, and transmitted by the panel. Sound transmission is quantified by the Transmission Coefficient, tao, the proportion of energy transmitted relative to the total incident sound energy, as well as Transmission Loss, the decibel reduction in sound levels across the panel. For a given panel, both quantities vary across the frequency spectrum.
Given a sound source on one side of a single homogenous panel, sound transmission loss through the panel is primarily defined by the panel's mass per unit area, which increases with frequency at 6 db/octave. In
Additionally, panel stiffness influences transmission loss, and bending waves propagate in the plane of the panel with wavelengths dependent on the bulk modulus and density of the panel. For sound incident on the panel at angles other 90 degrees, when the incident angle and wavelength combine for a trace wavelength along the panel equal to the panel's bending wavelength a sort of resonance occurs, and this is known as ‘coincidence’. The coincidence effect allows more sound to transmit and spans bandwidths upwards from the ‘critical frequency’, fc, where grazing incidence wavelengths begin to influence bending waves in the panel, as illustrated in Region III.
The primary strategy to increase the sound transmission loss (increasing sound isolation) of a single homogenous panel is increasing its mass, which translates the transmission loss of the mass-controlled band upwards. Additionally, two more strategies can also increase transmission loss: decreasing stiffness—moves the critical frequency and coincidence effect dip upwards along the frequency axis; adding internal damping—reduces the magnitude of panel resonance and coincidence dips in the transmission loss.
Two panels separated by an airspace, present another option for increasing sound isolation. At the lower end of the frequency spectrum, the airspace acts as a spring and acoustically couples the panels to act as a single panel. For frequencies above which the separation distance is equal to a quarter wavelength, the airspace acts to decouple the two panels and transmission loss increases at 18 db/octave. Dips in sound transmission due to coincidence effects are also present here for each of the two panels. The transmission loss can be further increased by adding a sound-absorptive material between the two panels. This further decouples the two panels by attenuating waves traveling between the panels and reducing standing waves.
Airborne sound can be absorbed through dissipative or reactive means. Dissipative sound absorbers, such as open cell porous materials, resist the organized molecular motion of sound energy, converting it into heat. Reactive sound absorbers employ mechanical or acoustical resonance to elevate particle velocity across tuned frequency bands, this presents the opportunity for sound energy in these frequency bands to be absorbed (converted to heat) through the combined use of dissipative materials or inherently through air absorption. The term ‘baffle’ generally refers to constructions that absorb sound through dissipative or reactive means (example: interior ceiling tiles), and constructions that block sound (example: highway noise barriers).
The embodiments described in U.S. Pat. No. 10,612,239 entitled “PANEL AND PANEL STRUCTURE FOR VENTILATION AND BOTH REACTIVE AND DISSIPATIVE SOUND DAMPENING” allow for passive air transfer between rooms by way of a Z-shaped air channel through the grooves on the front/back faces and hollow centre. Sound transmission across the panel and through the air channel is dissipated through sound absorptive baffles in the hollow centre and resonators on the periphery of the grooves.
Previously disclosed embodiments in U.S. Pat. No. 10,612,239 present challenges associated with manufacturability (and therefore cost) as well as sound transmission performance. Challenges include:
Improved panels which address at least some of these challenges are desirable.
This invention has various aspects. These include, without limitation: sound isolating ventilation panel; methods for manufacturing sound isolating ventilation panels, and cartridges and core components useful in sound isolating ventilation panel.
In one aspect a sound isolating ventilation panel is provided. The panel includes: a core assembly comprising a plurality of horizontal channels; a pair of cartridges having hollow centers and flanking both sides of the core assembly; and a pair of hollow sides flanking the pair of cartridges. Each of the cartridges comprises a proximally facing side comprising a plurality of air channel side apertures and a distally facing side comprising a plurality of sound resonator side apertures. A vertically oriented ventilation groove is formed through a front face of a first one of the cartridges and a vertically oriented ventilation groove is formed through a back face of the second one of the cartridges. The ventilation grooves, the hollow centers, the air channel side apertures and the horizontal channels together partially define Z-shaped air channels. The sound resonator side apertures and the hollow sides partially define a plurality of resonators.
The frame may comprise a top rail, a bottom rail and two stiles, wherein the pair of cartridges may be disposed between the top rail and bottom rail, and wherein the top rail, the bottom rail, the two stiles and the distally facing sides may partially define the hollow sides.
The frame may comprise a front skin and a back skin, wherein the frame, core assembly and the pair of cartridges may be supportively disposed between the front skin and the back skin. The vertically oriented ventilation groove formed through the front face of the first one of the cartridges may also be formed through the front skin, and the vertically oriented ventilation groove formed through the back face of the second one of the cartridges may also be formed through the back skin.
Each of the cartridges may have a horizontal plane of symmetry and a vertical plane of symmetry.
Each of the plurality of air channel side apertures may align with a corresponding one of the plurality of horizontal channels.
The plurality of air channel side apertures may be identical and equidistantly spaced, and the plurality of sound resonator side apertures may be identical and equidistantly spaced.
The plurality of air channel side apertures may be larger than and fewer in number than the plurality of sound resonator side apertures.
The plurality of air channel side apertures may be arranged linearly in series, and wherein the plurality of sound resonator side apertures may be arranged linearly in series.
Each space between the air channel side apertures may be at least one inch.
Each of the cartridges may extend at least 80%, or at least 90% of a height of the panel.
The horizontal channels may be at least partially formed from folded corrugated fiberboard.
Interior surfaces of the horizontal channels may comprise sound absorbing linings of a porous, dissipative material such as open cell foam, mineral wool or fiberglass.
The core assembly may occupy substantially all of the space between the pair of cartridges.
The core assembly may comprise 6 to 24 adjacently arranged horizontal channels.
Walls between adjacent horizontal channels may comprise a plurality of apertures to increase exposed surface area of sound absorbing linings.
The hollow sides may comprise porous, dissipative sound absorbing material.
Another aspect provides a method of manufacturing a sound isolating ventilation panel comprising:
Step c. may further comprise inserting an insert into each of the cartridges, wherein the insert comprises blocking portions and receiving portions, the blocking portions for substantially blocking off the air channel side apertures and sound resonator side apertures from the receiving portions which are configured to receive dust and debris generated by step e. regardless of whether the vertically oriented ventilation grooves are formed in the front or back of the cartridge, and wherein after step e. the insert is removed from the cartridges through the vertically oriented ventilation grooves.
Prior to step c. the proximally facing side and the distally facing side may be manufactured by: (i) making cuts in a rectangular block having the length of the cartridges, (ii) stacking the cut blocks, and (iii) boring air channel side apertures or sound resonator side apertures through the stacked blocks.
Prior to step c. the proximally facing side and the distally facing side may be manufactured by: (i) boring slots sized to the air channel side apertures or the sound resonator side apertures through an elongated rectangular block having the length of the cartridges; (ii) making joinery profile cuts in the bored elongated rectangular block, (iii) ripping the profiled and bored elongated block into individual proximally facing sides or distally facing sides.
Prior to step c. the proximally facing side and the distally facing side may be manufactured by: (i) providing two sheets each having the length of the cartridges; sandwiching spaced apart ribs between the sheets, the spacing of the ribs matching the dimensions of the air channel side apertures or the sound resonator side apertures; and (ii) cutting the sheets into strips of the proximally facing sides or the distally facing sides.
Prior to step c. the cartridges may be manufactured by: (i) gluing the proximally facing side, the distally facing side, and two backers together to form a cartridge; (ii) stacking a plurality of cartridges from step (i); and (iii) pressing against the stack of cartridges in vertical and/or horizontal directions.
Another aspect provides a cartridge for a sound isolating ventilation panel, the cartridge comprising:
The cartridge may comprise a horizontal plane of symmetry and a vertical plane of symmetry.
The plurality of air channel side apertures may be identical and equidistantly spaced, and the plurality of sound resonator side apertures may be identical and equidistantly spaced.
The plurality of air channel side apertures may be larger than and fewer in number than the plurality of sound resonator side apertures.
The plurality of air channel side apertures may be arranged linearly in series, and wherein the plurality of sound resonator side apertures may be arranged linearly in series.
Each space between the air channel side apertures may be at least one inch.
Another aspect provides a core component for a sound isolating ventilation panel, the core component comprising a single corrugated fiberboard sheet folded to define two channels having rectangular cross sections.
The sheet may comprise a plurality of linearly arranged slots at a mid portion of the sheet and corresponding plurality of tabs at an end of the sheet for engaging the slots to facilitate forming at least one of the channels.
The two channels may be equally sized.
It is emphasized that the invention relates to all combinations of the above features, with one another and/or with other features that are described elsewhere herein and/or depicted in the drawings even if these are recited in different claims, different paragraphs and/or different sentences.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.
The accompanying drawings illustrate non-limiting example embodiments of the invention.
Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
As shown in
Methods of manufacturing a sound isolating ventilation panel such as panels 100, 200 are also provided. Steps include: (a) providing a frame comprising a top rail, a bottom rail and two stiles; (b) providing a core assembly comprising a plurality of horizontal channels; (c) providing a pair of cartridges comprising hollow centers, the cartridges positioned between the top rail and the bottom rail and flanking both sides of the core assembly, wherein each of the cartridges comprises a proximally facing side comprising a plurality of air channel side apertures aligned with the plurality of horizontal channels, and a distally facing side comprising a plurality of sound resonator side apertures; (d) providing a front skin and a back skin, whereby space between the stiles, the distally facing side and the front and back skins (the resonator cavities) as well as the sound resonator side apertures define resonators; (e) forming a vertically oriented ventilation groove through the front skin and a front face of a first one of the cartridges, and forming a vertically oriented ventilation groove through the back skin and a back face of the second one of the cartridges, whereby the ventilation grooves, the hollow centers, the air channel side apertures and the horizontal channels together define Z-shaped air channels.
As shown in
Compared for example to the embodiments described in U.S. Pat. No. 10,612,239, the present methods employ fewer total components, and fewer components at the layup stage, resulting in faster assembly for each door, and more doors in each stack, increasing manufacturing throughput. Furthermore, the components of the panels described herein are amenable to being sized for simple and accurate placement and alignment at assembly, since the combined surface area of the components occupy most of the panel's total surface area (e.g. see
Cartridges 140 are elongated, as shown in
Air channel side apertures 144 align with and connect to corresponding horizontal channels 122 to provide uninterrupted air flow therethrough. Air channel side apertures 144 are identical and equidistantly and linearly arranged in series. In some embodiments, space 156 between air channel side apertures 144 is at least one inch to provide sufficient structural support and stiffness to panel 100. In some embodiments air channel side apertures 144 are of different sizes and/or not spaced equidistantly.
Sound resonator side apertures 146, resonators 160, and skins 108, 110 define Hemholtz resonators of panel 100. Sound resonator side apertures 146 are identical and equidistantly and linearly arranged in series. Sound resonator side apertures 146 are smaller and more numerous than air channel side apertures 144. In some embodiments, the resonator can be tuned to absorb varying sound levels across varying frequency bands by varying the size, shape, and spacing of sound resonator side apertures 146, the thickness of the distally facing side 145 (i.e., the neck length of the resonator), the volume of resonator 160 between stile 106 and cartridge 140, as well as the addition of a quantity of and placement of sound absorptive material in resonator 160. In some embodiments sound resonator side apertures 146 are of different sizes and/or not spaced equidistantly.
A vertically oriented front ventilation groove 148 is formed through front skin 108, and front face 152 of a first one of cartridges 140, and a vertically oriented back ventilation groove 150 is formed through back skin 110, and a back face 154 of a second one of cartridges 140. Ventilation grooves 148, 150, hollow centers 142 and air channel side apertures 144 of cartridge 140, and horizontal channels 122 of core assembly 120, together define Z-shaped air channels through panel 100. Cartridge 140 provides structural support (tensile/compressive stiffness and strength) to skins 108, 110 around the perimeter of ventilation grooves 148, 150. The added thickness and stiffness provided by cartridge 140 when bonded to skins 108, 110 mitigates warping at the edges of ventilation grooves 148,150.
Since the interior of cartridges 140 form the visible interior surfaces of panel 100, in some embodiments cartridges 140 may be constructed of higher quality materials (e.g. plywood) with surfaces suitable for being pre-finished before cartridge 140 is assembled. Finishes can include primer, paint, clear coat, veneer and plastic laminate. These finishes can also be applied to the cut surfaces of cartridge 140 after ventilation grooves 148, 150 are formed.
As best shown in
In some embodiments, each of cartridges 140 extend at least 70%, at least 80%, or at least 90% of a height of panel 100.
Methods of manufacturing cartridges such as cartridge 140 are also provided. As shown in
As shown in
As shown in
As shown in
In yet other embodiments, the cartridges may be constructed of other materials and be printed, injection molded or extruded.
In panel 100, core assembly 120 is formed from six dual channel core elements 126. Core assembly 120 occupies all or substantially all of the space between the pair of cartridges 140 and rails 104.
Core assembly 120, and therefore in the case of panel 100, core elements 126, may be constructed from corrugated fiberboard. Corrugated fiberboard material is lightweight compared to other wood composite fibreboards, inherently sound absorptive, inexpensive, and can be produced cut to size with precision. Further, the relative elasticity of corrugated fiberboard limits mechanical connection between skins 108, 110, thereby isolating vibration and sound transmission. Constructing core assembly 120 from corrugated fiberboard therefore provides both structure (stiffness and compressive strength) and sound adsorption for panel 100.
In some embodiments core element 126 includes sound absorbing linings 124 as shown in
As shown in
In some embodiments, the core assembly may include 6 to 24 adjacently arranged horizontal channels. Instead of a dual channel core element, in some embodiments the core elements may be a single channel or a triple channel, for example.
Where a component (e.g. rail, stile, skin, channel, lining, aperture, groove, etc.) is referred to above, unless otherwise indicated, reference to that component should be interpreted as including as equivalents of that component any component which performs the function of the described component (i.e. that is functionally equivalent), including components which are not structurally equivalent to the disclosed structure which performs the function in the illustrated exemplary embodiments of the invention.
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof.
It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are consistent with the broadest interpretation of the specification as a whole.
This application claims priority to, and the benefit of, U.S. provisional patent application No. 63/220,827 filed 12 Jul. 2021 entitled SOUND ISOLATING VENTILATION PANELS AND METHODS FOR MANUFACTURING SAME, the entirety of which is incorporated by reference herein for all purposes. For purposes of the United States of America, this application claims the benefit under 35 U.S.C. § 119 of U.S. application Ser. No. 63/220,827 filed 12 Jul. 2021 and entitled SOUND ISOLATING VENTILATION PANELS AND METHODS FOR MANUFACTURING SAME.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CA2022/051067 | 7/7/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63220827 | Jul 2021 | US |
