The invention relates to acoustic hoods and light fixtures for use with a suspended ceiling. More particularly, the invention relates to an acoustic hood for use with or integrally formed with a light fixture for a suspended ceiling system. The invention further relates to a method of decreasing sound transfer from a light fixture in a suspended ceiling.
Many types of buildings, such as commercial and government office buildings, utilize suspended ceilings. Suspended ceilings typically include a suspension grid system and acoustical panels. The grid system for example may be used to suspend the panels, otherwise known as tiles, from the overhead building structure generally in a single plane. The suspended ceiling is formed by coupling the grid to hangar wires attached to the building structure, and thus the load of the grid system with its associated lighting components, air distribution components, and acoustical panels is transferred to the building structure by the hanger wires. A variety of types of lay-in ceiling panels are available for use with exposed grids including cast, water-felted, fiber glass, gypsum, and metal.
Grid systems may be formed using main beams or “tees,” cross tees, and hangers. The main beams are metal framing members that are hung from the hangers. The cross tees typically are metal framing members snap-fitted to the main beams, perpendicular thereto.
One popular variant of the suspended ceiling is a suspended ceiling system that utilizes a grid framework formed of inverted T-shaped frame members for the main tees and cross tees. The frame members are configured to form a suspended grid including multiple grid elements, which are known as modules. These modules may be provided in any practicable size, with 24-inch squares being a common module size. The suspended ceiling is formed by installing ceiling tiles in a number of modules such that each edge portion of the bottom surface of each tile is supported by an inverted T cross bar—a main or cross tee. The suspended ceiling system is completed by including required utilities in the system such as fire sprinklers, heating, ventilating and air conditioning (HVAC) elements, and lighting fixtures. Suspended ceiling systems for example may provide decoration, light reflection, and/or masking of utility infrastructure.
In many applications, it is desirable that a suspended ceiling system provide a significant degree of acoustic insulation or damping. In particular, in an office environment where speech privacy is important, it is desirable to limit the amount of sound that can otherwise travel through the ceiling in one office, conference room, or space and be readily received in another office, conference room, or space.
Utilizing ceiling tiles made from sound absorbing material can provide a measure of acoustic insulation in a suspended ceiling system. For example, U.S. Pat. No. 5,832,685 to Hermanson is directed to a self-supporting, sound absorbing interior surface panel as well as a suspended ceiling module comprising a support structure, such as a tee bar grid, and a panel which could be supported within the module in either tegular or coffered orientation.
Using sound absorbing ceiling tiles alone, however, does not provide acoustic insulation at modules of a suspended ceiling system where lighting fixtures are installed. To this end, various devices are known for providing acoustic insulation with respect to lighting fixtures.
For example, U.S. Pat. No. 4,094,379 to Steinberger is directed to a sound-absorption panel. The panel is suspended in horizontal position toward a light and need only be translucent to permit light to pass downwardly and so as hide objects above the ceiling.
U.S. Pat. No. 6,450,289 B 1 to Field et al. is directed to a noise attenuation device. A noise attenuator is disclosed for use adjacent to a light fitting for attenuating noise from air conditioning or an air supply to offices. The attenuator can be connected to the duct system above a standard vent slot adjacent a light fitting and connected to an office air conditioning system.
U.S. Pat. No. 6,481,173 B 1 to Roy et al. is directed to a flat panel sound radiator with special edge details. A flat panel radiator is mounted inside a tegular frame with the lower edge of the tegular frame below the flanges of the main beams. The radiator panel can be fabricated from a honeycomb core. A combination of containment elements and isolation elements are used to isolate the radiator panel from the tegular frame both mechanically and acoustically. An acoustic scrim is attached to the bottom of the tegular frame.
Despite these developments, there remains a need for an improved acoustic housing that can be positioned above a lighting fixture installed in a suspended ceiling system. There further remains a need for an acoustic housing such as an acoustic hood that is not supported by ceiling tiles, thereby allowing ceiling tiles to be removed or replaced without being disturbed. Additionally, there remains a need to an acoustic housing that is formed in multiple parts for ease of installation in the constricted confines presented by known suspended ceiling systems. There also remains a need for a recessed light fixture that includes an acoustic component such as at least one soundproofing layer, thereby providing sound absorption where the light fixture is installed as a component of a suspended ceiling system.
The invention relates to an acoustic hood for a light fixture in a suspended ceiling, the acoustic hood including a partially enclosed space formed between a plurality of wall portions. The wall portions may be a plurality of sides that together define the partially enclosed space. At least one of the sides may have at least one utility slot, at least one positioning slot, and/or at least one ventilation opening.
The acoustic hood may be formed of fiberglass which in some embodiments may have a thickness between about 0.5 inch and about 1.5 inches. In some embodiments, the acoustic hood may be formed of unitary construction, while in other embodiments the acoustic hood may be formed of several portions such as two separate and substantially symmetrical portions.
The acoustic hood may be configured and dimensioned to have a noise reduction coefficient of at least about 0.70, at least about 0.80, or at least about 0.90.
In one exemplary embodiment, the acoustic hood may have a first layer formed of fiberglass and a second layer, wherein the acoustic hood is configured and dimensioned to have a noise reduction coefficient of at least about 0.7 and a sound transmission class of at least about 20.
In another exemplary embodiment, the acoustic hood may have a first layer formed of fiberglass and a second layer, wherein the acoustic hood is configured and dimensioned to have a noise reduction coefficient of at least about 0.8 and a sound transmission class of at least about 30.
The invention also relates to a light fixture including a first layer formed of a first material selected from the group consisting of fiberglass and polyester, a second layer formed of metal, and at least one socket configured to connect to a light source. The first and second layers may be coupled to one another and form a partially enclosed space. In addition, the first and second layers may mate together and may be nested. In some embodiments, the first layer may be nested within the second layer, while in other embodiments the second layer may be nested within the first layer.
The light fixture may further include a third layer formed of a mesh, wherein the third layer mates with and is coupled to at least one of the first and second layers. The light fixture also may include a ballast, a starter switch, and/or a diffuser.
The first material may be fiberglass with a thickness between about 0.5 inch and about 1.5 inches. Moreover, the partially enclosed space may be configured and dimensioned to have a noise reduction coefficient of at least about 0.7, at least about 0.8, or at least about 0.9.
The invention also relates to a light fixture including a first layer formed of a first material selected from the group consisting of fiberglass and polyester, a second layer formed of a second material, and at least one socket configured to connect to a light source. The first and second layers may be coupled to one another and form a partially enclosed space, and the light fixture may be configured and dimensioned to have a noise reduction coefficient of at least about 0.7 and a sound transmission class of at least about 20. In some embodiments, the light fixture may be configured and dimensioned to have a noise reduction coefficient of at least about 0.8 and a sound transmission class of at least about 20.
The invention further relates to a suspended ceiling system including a grid formed by a plurality of frame members, at least one acoustic panel supported by the grid, a light fixture supported by the grid, and an acoustic hood for the light fixture, the acoustic hood including a partially enclosed space formed between a plurality of wall portions. The suspended ceiling system may further include at least one light source disposed in the light fixture.
In addition, the invention relates to a suspended ceiling system including a grid formed by a plurality of frame members, at least one acoustic panel supported by the grid, and a light fixture supported by the grid. The light fixture may have a first layer formed of a first material selected from the group consisting of fiberglass and polyester, a second layer formed of metal, and at least one socket configured to connect to a light source, with the first and second layers being coupled to one another and forming a partially enclosed space. At least one light source may be disposed in the light fixture.
Furthermore, the invention relates to a method of decreasing sound transfer from a light fixture in a suspended ceiling, the method comprising: disposing an acoustic housing spaced from the light fixture. The method may further comprise: supporting the acoustic housing on at least one frame member of the suspended ceiling so that the acoustic housing and light fixture do not contact one another.
In some embodiments, the acoustic housing may include at least one positioning slot and the at least one frame member may include a protruding portion, the method further including: registering the at least one positioning slot with the protruding portion so that the acoustic housing is supported on the at least one frame member.
The method may further include: at least partially surrounding the light fixture with the acoustic housing.
Also, the method may further include: supporting at least one edge of the acoustic housing on at least one frame member of the suspended ceiling so that the acoustic housing and light fixture do not contact one another.
In some embodiments, the method includes: coupling at least one spacer to the acoustic housing; and coupling the at least one spacer to at least one frame member of the suspended ceiling. The spacer may have a slot and the at least one frame member may have an inverted T-shape with a stem portion, the method further including disposing the stem portion in the slot.
In some embodiments, the acoustic housing may have substantially symmetrical halves, and the method may further include: supporting a first of the halves; and supporting a second of the halves.
In other embodiments, the method may include: coupling at least one spacer to the light fixture; and coupling the acoustic housing to the spacer so that the acoustic housing is supported by the light fixture in spaced relation thereto. The spacer may be a post.
In yet other embodiments, the method may include: supporting the acoustic housing from an overlying surface which may be selected from the group consisting of concrete structure, an I-beam, and a ribbed steel pan.
In yet further embodiments, the method may include: coupling the acoustic housing to a hanger; coupling the hanger to the overlying surface; wherein the acoustic housing is supported by the overlying surface in spaced relation thereto. The hanger may be a metal cable.
In some embodiments of the method, the acoustic housing may provide a noise reduction coefficient of at least 0.7, at least 0.8, or at least 0.9. Also, in some embodiments of the method, the acoustic housing provides a sound transmission class of at least about 15, at least about 20, at least about 25, or at least about 30.
The invention additionally relates to an acoustic housing provided for use with lighting fixtures installed as part of a suspended ceiling system. The acoustic housing may be formed from a sound absorbing material and may include a top surface and sides that define an open space, and may be positioned above an installed light fixture. The acoustic housing may be supported on inverted T-shaped frame members of suspended ceiling systems or may be otherwise supported over an underlying lighting fixture.
Preferred features of the present invention are disclosed in the accompanying drawings, wherein:
Referring initially to
Turning to
In a preferred exemplary embodiment of acoustic housing 100, the perimeter formed by lower edges 116 is generally square and each lower edge 116 has a length L1 or L2 of about 31 inches. Also, upper edge regions 116a each may have a length L3 of about 24 inches. In an alternate embodiment, the perimeter formed by lower edges 116 for example may be rectangular such that L1 and L2 are different from one another.
As shown in
In addition, utility slots 120 provide a passage for utilities in and out of the space between the underlying light fixture 16, top surface 114 and sides 112, such as an electric conduit to the underlying light fixture 16. As shown in
Positioning slots 122 also are provided to allow acoustic housing 100 to be positioned in relation to an underlying grid formed from inverted T-shaped frame members, as will be discussed below. As shown in
A variety of slots or openings may be provided instead of, or in addition to those described above, such as circular holes or a field of spaced perforations throughout the housing.
In a preferred exemplary embodiment, acoustic housing 100 may be formed from layered and molded pliant fiberglass with a thickness between about 0.5 inch and about 1.5 inches, preferably between about 0.8 inch and about 1.3 inches, and more preferably about 1 inch. Acoustic housing 100 can be formed by positioning a plurality of layers of “light density” fiberglass in a mold formed to the desired shape. The fiberglass layers then may be successively compressed in the mold at a temperature, for example, of about 400° F., to form acoustic housing 100. After molding, acoustic housing 100 is formed from molded pliant fiberglass having a density of between about 4 lbs. per cubic foot and about 10 lbs. per cubic foot. In some embodiments, acoustic housing 100 preferably has a minimum density of about 6 lbs. per cubic foot. Additional components such as a binder may be included with the fiberglass during the molding process as necessary to form acoustic housing 100 having desired rigid characteristics of portions 135a, 135b. Acoustic housing 100 alternatively may be formed from other sound absorbing materials such as polyester or another polymer. Alternatively, or in addition, acoustic housing 100 may be formed from a sound reflecting material such as molded polyvinyl chloride (PVC). An acoustic housing 100 formed from a sound reflecting material such as PVC may be more rigid and/or of narrower cross-section than molded pliant fiberglass. Acoustic housing 100 may be formed from any suitable sound reflecting material, such as any suitable plastic or other polymeric material. Acoustic housing 100 formed from a sound reflecting material having a narrow cross section may include openings such as vent slots 118, utility slots 120, and positioning slots 122, as shown in
In some embodiments, acoustic housing 100 may include layers of both sound absorbing material and sound reflecting material. For example, acoustic housing 100 may include an a first layer of sound absorbing molded pliant fiberglass as well as a second layer of sound reflecting PVC. Preferably, the first layer has a cross-sectional thickness greater than the second layer. The sound reflecting PVC, for example, may have a cross-sectional thickness between about one-quarter inch and about three-eighth inch.
In some embodiments, acoustic housing 100 may include a first layer effective in absorbing sounds such as the human speech frequency range above 125 Hz, and a second layer effective in reflecting sounds such as lower frequency airborne noise originating, for example, from HVAC or other mechanical components located above a suspended ceiling system.
Also in a preferred exemplary embodiment, acoustic housing 100 may be formed from multiple portions. For example, as shown in
Referring now to
Alternatively, as shown in
Referring now to
During installation, a head of bolt 204 (not shown) is disposed on the inside surface of light fixture 16 while magnet 208 is disposed on the outside surface 16b as shown in
In another securing system, shown in
Referring now to
Thus, advantageously, although ceiling tiles often must be removed or displaced from their location in the ceiling grid to permit maintenance of pipes, electrical equipment, air handling equipment, or other matters to be performed above the suspended ceiling, an acoustic housing 100 supported by the frame members 12 need not be moved. Because of the size and weight of acoustic housing 100, it is preferable that housing 100 be left in place once installed. In addition, advantageously the alignment of acoustic housing 100 supported by the frame members 12 may be maintained during such maintenance operations, so that it is unnecessary to adjust and realign housing 100 to provide the desired acoustic shielding each time maintenance may be performed.
Referring next to
As shown in
Although the aforementioned embodiments of the present invention involve acoustic housings that may be at least partially spaced from separate fixtures 16, other exemplary embodiments of the present invention involve an acoustic housing that is configured and dimensioned to form part of a fixture 16. In particular, referring now to
As shown, middle acoustic housing 604 may be positioned within outer housing 606 which both also may include a plurality of holes 604a, 606a, respectively, to provide ventilation for acoustic recessed light fixture 600 as well as a passageway for physical connections such as electrical connections to lighting elements 17. Outer housing 606 also includes sides 606b, an upper surface 606c and an opening 606d defined by sides 606b and upper surface 606c. Outer housing 606 may be formed from metal such as steel and may be constructed, for example, by stamping a rolled steel sheet into a predetermined shape having desired dimensions, or alternatively housing 606 may be formed of any other suitable material such as polymeric material.
Similar to outer housing 606, middle acoustic housing 604 may include a plurality of sides 604b, an upper surface 604c, and an opening 604d defined by sides 604b and upper surface 604c. The shape and dimensions of housings 604, 606 preferably are selected to permit middle acoustic housing 604 and outer housing 606 to closely mate when housing 604 is positioned in opening 606d to form a nested configuration. Preferably, stepped regions or flanges 604e, 606e mate. In some embodiments, middle acoustic housing 604 may be formed from layered and molded pliant fiberglass with a thickness of approximately 1 inch. Middle housing 604 for example may have a thickness between about 0.3 inch and 1.5 inch, between about 0.5 inch and 1.3 inches, or between 0.8 inch and 1.3 inches. Acoustic housing 604 alternatively may be formed from other sound absorbing materials such as polyester.
An inner layer 602 optionally may be included and may be formed from any suitable acoustically transparent material such as steel wire mesh or alternatively another material such as a polymeric material. Inner layer 602 may have a plurality of sides 602b, an upper surface 602c, and an opening 602d defined by sides 602b and upper surface 602c. Inner layer 602 may be configured and dimensioned in a manner that facilitates nesting of inner layer 602 within opening 604d of acoustic housing 604, similar to the nesting previously described for components 604, 606. Inner layer 602 may additionally include a flange 602e that can be secured to flange 604e during nesting.
In some exemplary embodiments, an acoustic housing 604 is custom molded and secured to outer layer 606; in other exemplary embodiments, a suitably configured and dimensioned layer 606 instead may be nested within an acoustic housing 604 so that housing 604 instead surrounds a preferably metal layer 606.
In some embodiments, as described above with reference to acoustic housing 100, acoustical light fixture 600 may include a layer 602, 604, 606 formed of a sound absorbing material such as fiberglass, and another layer 602, 604, 606 formed of a sound reflecting material such as PVC. As shown in
In some embodiments, light fixture 600 may include a first layer effective in absorbing sounds such as the human speech frequency range above 125 Hz, and a second layer effective in reflecting sounds such as lower frequency airborne noise originating, for example, from HVAC or other mechanical components located above a suspended ceiling system.
Acoustic recessed light fixture 600 additionally includes lighting elements 17 as shown schematically in
As with previously described acoustic housing 100, the light fixture 600 also may include features such as utility slots, positioning slots, and ventilation openings. In addition, layers 602, 604, 606 optionally may be supplied in a prefabricated, assembled condition in which the layers are already coupled together, or alternatively layers 602, 604, 606 optionally may be supplied separately for possible assembly “on-site.” Also, in order to provide a variety of options for materials, fixture weight, noise reduction coefficient (as will be described shortly), and other properties in order to meet a desired end use, the materials and dimensions of layers 602, 604, 606 may be selectable from a set of standardized or custom options. Thus, the components may be individually available for custom fabrication for a buyer, or otherwise individually available for on-site assembly. Moreover, although in one embodiment of fixture 600, two or more of layers 602, 604, 606 are coupled together to form an integral unit, in another embodiment of fixture 600 multiple layers may form a fixture 600 which has several sections that fit together to form the light fixture housing. For example, the light fixture housing formed by layers 602, 604, 606 may be supplied in multipiece construction such as two substantially symmetrical portions that together form the housing as previously described with respect to acoustic housing 100 with interface 135. Each of the optional methods previously described for acoustic housing 100 for coupling the pieces together in such a multipiece construction apply equally to a multipiece housing formed of layers 602, 604, 606.
Although described and shown with reference to a substantially rectangular recessed light fixture, it should be noted that the present invention is applicable to other forms of recessed lights, including without limitation cylindrical can light installations and fluorescent troffer light systems.
In one preferred exemplary embodiment of the present invention, the suspended ceiling and components meet ASTM Standard C635-04 entitled “Standard Specification for the Manufacture, Performance, and Testing of Metal Suspension Systems for Acoustical Tile and Lay-in Panel Ceilings” and ASTM Standard C636-04 entitled “Standard Practice for Installation of Metal Ceiling Suspension Systems for Acoustical Tile and Lay-In Panels,” and these standards are incorporated herein by reference thereto. In addition, acoustic housings and light fixtures 100, 600, respectively, preferably have a Class A fire rating. Also, acoustic housings and light fixtures 100, 600, respectively, preferably may have a noise reduction coefficient (NRC) of between about 0.05 and about 1.0, and more preferably have an NRC of at least 0.7, at least 0.8, or at least 0.9. In one exemplary preferred embodiment, acoustic housings and light fixtures 100, 600, respectively, have an NRC of between about 0.8 and about 0.9.
For the purposes of the present invention, the NRC is calculated according to ASTM Standard C423-02a entitled “Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method,” which is incorporated herein by reference thereto.
While the NRC generally is a measure of the effectiveness of absorbing sound waves, the sound transmission class (STC) generally is a measure of the effectiveness of blocking sound waves.
For acoustic housings and light fixtures 100, 600 that are formed from a sound reflecting material, such as PVC, in accordance with the present invention, in some embodiments they have an STC of at least about 15, at least about 20, at least about 25, or at least about 30. As the STC increases, sources of speech-related noise are blocked to a greater degree. Thus, in order to block undesired speech transmission, for example, in one exemplary embodiment an STC of at least about 20 is desirable.
The STC is determined, particularly for air-borne sound at speech frequencies, according to ASTM Standard E90-04 entitled “Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements” and ASTM Standard E413-04 entitled “Classification for Rating Sound Insulation,” which are incorporated herein by reference thereto. It is known that the STC's of laboratory samples of acoustic housings or light fixtures 100, 600 may not be the same as STC's measured in field tests in installations in actual building settings, and thus a different ASTM standard covers a method for measurement of airborne sound insulation in buildings. For the purposes of the present invention, STC's described herein are to be determined according to the aforementioned ASTM Standards E90-04 and E413-04.
While various descriptions of the present invention are described above, it should be understood that the various features can be used singly or in any combination thereof. Therefore, this invention is not to be limited to only the specifically preferred embodiments depicted herein.
Further, it should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains. For example, hanger assemblies 300, 301 can employ any suitable means for attaching an end of hanger wire 304 to an overlying surface. Additionally, any known method may be used to secure acoustic housing 100 to a hanger wire. Regarding spacer 200, any suitable hardware or combination of hardware may be used to provide the desired spacing. Other types of recessed light fixtures for suspended ceilings, such as recessed can lights, also may be acoustically shielded in accordance with the principles of the present invention. In addition, other components of suspended ceilings may be acoustically shielded using housings as disclosed herein, such as HVAC elements. Furthermore, although acoustic housing 100 has been described in an exemplary two-part embodiment with symmetrical halves, other constructions for facilitating installation such as collapsible one-piece embodiments are envisioned to permit positioning through ceiling grids. Moreover, if an air plenum is formed between ceiling tiles 14 and structure of the building, it may be desirable to form housing 100 to be aerodynamic to facilitate air movement. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is accordingly defined as set forth in the appended claims.
This application is a continuation of U.S. patent application Ser. No. 15/688,539 filed Aug. 28, 2017 and entitled “Acoustic Systems for Lighting in Suspended Ceilings,” which is a continuation of U.S. patent application Ser. No. 13/175,935 filed Jul. 4, 2011, issued as U.S. Pat. No. 9,745,744, and entitled “Acoustic Systems for Lighting in Suspended Ceilings,” which is a continuation of U.S. patent application Ser. No. 12/013,294 filed Jan. 11, 2008, issued as U.S. Pat. No. 7,971,680, and entitled “Acoustic Systems for Lighting in Suspended Ceilings,” and further is a continuation of the U.S. National Stage designation of co-pending International Patent Application PCT/US2006/026735 filed Jul. 11, 2006, which claims the benefits of U.S. Provisional Application No. 60/698,017 filed Jul. 12, 2005 and entitled “Acoustic Systems for Lighting in Suspended Ceilings” under 35 U.S.C. § 119(e), and the entire contents of all of these applications are expressly incorporated herein by reference thereto.
Number | Date | Country | |
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60698017 | Jul 2005 | US |
Number | Date | Country | |
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Parent | 15688539 | Aug 2017 | US |
Child | 16253215 | US | |
Parent | 13175935 | Jul 2011 | US |
Child | 15688539 | US | |
Parent | 12013294 | Jan 2008 | US |
Child | 13175935 | US | |
Parent | PCT/US2006/026735 | Jul 2006 | US |
Child | 12013294 | US |