Patent Publication Number: US-2011063851-A1

Title: Efficient retrofit of light fixtures

Description:
RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/241,409, filed Sep. 11, 2009, the contents of which are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     Various embodiments relate generally to methods and associated apparatus for retrofitting light fixtures. 
     BACKGROUND 
     Lighting technology has advanced significantly in recent years. The incandescent, metal halide, and high-pressure sodium lamps (to name a few) that have been so common in the past are now being replaced with compact fluorescent, induction, LED, and other newer lamps. Such newer lamps provide several advantages, such as lower energy consumption, longer operational life, improved light output/distribution, energy rebates, tax refunds, and so on. 
     While the newer lamps are becoming more common in new construction, many existing buildings were constructed with the older kinds of light fixtures.  FIG. 1  shows an illustrative embodiment of such an older kind of light fixture  110 . The light fixture  110  includes a light fixture housing  112 , which is typically mounted to a ceiling, wall, or other fixed structure in a building. The light fixture  110  also includes a lamp holder  116 , which is coupled to the light fixture housing  112  via lamp-holder supports  118 . The light fixture  110  further includes a ballast  114  for regulating electric power to the lamp socket. The ballast  114  is coupled to the light fixture housing  112  via ballast supports  120 . A lamp cover  122  is also coupled to the light fixture housing  112  to conceal the interior components of the light fixture  110 . The lamp cover  122  and the visible aspects of the light fixture housing  112  provide the aesthetic appearance of the light fixture  110 . 
     There are several challenges associated with retrofitting existing buildings with newer kinds of light fixtures. Removing the entire existing light fixture  110  can be time consuming, and new light fixtures can be quite expensive. When this time and expense are multiplied over dozens of light fixtures in an existing building, many building owners simply decline to update their light fixtures. 
     Moreover, a building owner&#39;s decision whether to update his/her building&#39;s light fixtures can have significant environmental consequences. On one hand, leaving the existing light fixtures in place does not take advantage of the very significant energy savings offered by the newer kinds of light fixtures. On the other hand, removing dozens of light fixtures, like light fixture  110  of  FIG. 1 , and adding them to landfills can be quite wasteful. 
     SUMMARY 
     Embodiments of the present invention provide retrofit light fixture assemblies that can be added to existing light fixtures, thereby providing many of the advantages of the newer lighting technology without the time consumption or expense of completely swapping out existing light fixtures while also minimizing the amount of materials to be disposed of. 
     Preferred embodiments include a reflector that, when coupled with the newer kinds of lamps, can provide very significant reductions in energy consumption with similar (or even improved) light output/distribution as compared with the existing light fixture. In particularly preferred embodiments, the reflector is a mirrored reflector, which magnifies the light being produced by the newer kinds of lamps. In even more preferred embodiments, the mirrored reflector can be bent in such a way as to distribute the light in a manner that accords with the needs of the particular space being lit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings are illustrative of particular embodiments of the present invention and therefore do not limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in connection with the explanations in the following detailed description. Embodiments of the present invention will hereinafter be described in connection with the appended drawings, wherein like numerals denote like elements. 
         FIG. 1  is a perspective view of a conventional light fixture. 
         FIG. 2A  is a bottom view of a light fixture assembly according to embodiments of the present invention. 
         FIG. 2B  is a top view of the light fixture assembly of  FIG. 2A . 
         FIG. 2C  is an end view of the light fixture assembly of  FIG. 2A . 
         FIG. 3  is a bottom view of a light fixture assembly according to embodiments of the present invention. 
         FIG. 4  is a flow chart illustrating a method of designing and installing a retrofit light fixture assembly in accordance with embodiments of the present invention. 
         FIG. 5A  is a round downlight kit assembly in accordance with some embodiments of the present invention. 
         FIGS. 5B-5C  are round formed assemblies in accordance with some embodiments of the present invention. 
         FIG. 5D  is a rectangular kit assembly in accordance with some embodiments of the present invention. 
         FIGS. 5E-5F  are square (no notch) assemblies in accordance with some embodiments of the present invention. 
         FIG. 5G  is a round (with recessed lamp) assembly in accordance with some embodiments of the present invention. 
         FIG. 5H  is a round (with notches) assembly in accordance with some embodiments of the present invention. 
         FIGS. 5I-5J  are square retrofit (with notched sides) assemblies in accordance with some embodiments of the present invention. 
         FIG. 5K  is a wall sconce incandescent assembly in accordance with some embodiments of the present invention. 
         FIG. 5L  is a shoebox kit assembly in accordance with some embodiments of the present invention. 
         FIG. 5M  is a cylinder fixture kit assembly in accordance with some embodiments of the present invention. 
         FIG. 5N  is an induction shoebox kit assembly in accordance with some embodiments of the present invention. 
         FIG. 5O  is a glass wall sconce kit assembly in accordance with some embodiments of the present invention. 
         FIG. 5P  is a high bay conversion kit assembly in accordance with some embodiments of the present invention. 
         FIG. 5Q  is a Cooper HPTR2325 shoebox retrofit assembly in accordance with some embodiments of the present invention. 
         FIG. 5R  is a canopy kit (4 L) assembly in accordance with some embodiments of the present invention. 
         FIG. 5S  is a shoebox kit assembly in accordance with some embodiments of the present invention. 
         FIG. 5T  is a “Swan” fixture retrofit kit assembly in accordance with some embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides practical illustrations for implementing exemplary embodiments of the present invention. Examples of constructions, materials, dimensions, and manufacturing processes are provided for selected elements, and all other elements employ that which is known to those of skill in the field of the invention. Those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized. 
       FIGS. 2A-2C  show a light fixture assembly  10  according to some embodiments of the present invention. In many embodiments, the light fixture assembly  10  is a ready-to-install retrofit light fixture assembly. As discussed elsewhere herein, retrofit light fixture assemblies can be used to retrofit existing light fixtures with newer-technology lamps. However, it is to be understood that the concepts and features discussed herein in connection with retrofit light fixture assemblies can also be incorporated into new light fixtures to provide many of the same advantages. The light fixture assembly  10  of  FIGS. 2A-2C  lacks a housing (e.g.,  112  in  FIG. 1 ) and a lamp cover (e.g.,  122  in  FIG. 1 ) because the light fixture assembly  10  can be incorporated into an existing light fixture, making use of the existing housing and lamp cover. 
     The light fixture assembly  10  can include a reflector  12  for magnifying the light produced by the lamp and distributing it according to the needs of the space. The reflector  12  can serve as the primary support structure of the light fixture assembly  10  and can be adapted to couple to a light fixture housing (e.g.,  112  in  FIG. 1 ) to create a retrofit light fixture. In many embodiments, ridge sections  34  (discussed in greater detail below) and/or other structural features of the reflector  12  can be adapted to aid in coupling the reflector  12  to the light fixture housing. Other fasteners and/or hardware can be incorporated into the reflector  12  and/or the light fixture housing to couple the reflector  12  to the housing. The reflector  12  can include a lamp-socket aperture  22  in the downward-reflecting section  18 . The function of the lamp-socket aperture  22  is discussed in greater detail below. 
     As shown, the reflector  12  has an exposed side  14 , and a non-exposed side  16 . The exposed side  14  is generally illuminated when a lamp is installed and activated. The non-exposed side  16  is generally where other components of the light fixture assembly  10  are positioned, thereby preventing those components from creating shadows. 
     The shape of the reflector  12  can be adjusted to control the distribution of light. As shown, the reflector  12  has multiple sections, including a downward-reflecting section  18 , two downward-and-outward-reflecting sections  20 , and two ridge sections  34 . The downward-reflecting section  18  generally functions to reflect light in a downward vertical direction when the light fixture is oriented horizontally. The downward-and-outward-reflecting sections  20  can be positioned proximate to opposing edges of the downward-reflecting section  18 . The downward-and-outward-reflecting sections  20  add a horizontal component to the direction in which they reflect light when the light fixture is oriented horizontally. (Of course, if the light fixture is oriented other than horizontally (e.g., vertically on a wall rather than horizontally on a ceiling), the direction in which the downward-reflecting section  18  and the downward-and-outward-reflecting sections  20  reflect light is changed accordingly.) In many embodiments, the downward-and-outward-reflecting sections  20  can form obtuse angles with the downward-reflecting section  18 , with angle θ being between 90° and 180°. In some configurations, the downward-and-outward-reflecting sections  20  can be arranged symmetrically about the lamp-socket aperture  22 . Similarly, in embodiments with multiple lamp-socket apertures (e.g.,  FIG. 3 ), the downward-and-outward-reflecting sections  20  can be arranged symmetrically about the lamp-socket apertures. As shown, the ridge sections  34  are positioned proximate to the downward-and-outward-reflecting sections  20 , thereby enabling the ridge sections  34  to contribute in coupling the light fixture assembly  10  to the light fixture housing. 
     Though the reflector  12  of  FIGS. 2A-2C  include one downward-reflecting section  18 , two downward-and-outward-reflecting sections  20 , and two ridge sections  34 , many alternative configurations are possible, depending on the type of light fixture, the desired light output/distribution, and a variety of other factors. Various reflector configurations are shown in  FIGS. 5A-5T . 
     In particularly preferred embodiments, the reflector  12  can be a mirrored reflector. The mirrored finish on the exposed side  14  of the reflector  12  can greatly enhance the reflecting capabilities of the reflector  12 . The mirrored finish can be highly reflective and/or polished. In some embodiments, the thickness of the reflector  12  can be approximately 0.032 inches. Reflector materials can be chosen based on their ability to withstand (e.g., not peel or flake) exposure to varied temperatures. In some embodiments, the mirrored reflector can provide approximately 95% reflection. In some embodiments a white reflector can be used. In some such embodiments, the white reflector can provide approximately 92% reflection. 
     The light fixture assembly  10  can include a lamp holder  24  that is physically attached to the non-exposed side  16  of the reflector. Physical attachment of the lamp holder  24  to the reflector  12  can be an important aspect of making the light fixture assembly  10  a ready-to-install light fixture assembly. As shown in  FIG. 1 , the lamp holder  116  of a light fixture  110  is typically attached directly to the housing  112 . This is true even for light fixtures that have some form of reflector. Referring to  FIG. 1  and  FIGS. 2A-2C , if the retrofit lamp holder  24  is not physically attached to the reflector  12 , the operator charged with retrofitting the target light fixture  110  must first go up and remove the existing lamp holder  116  and corresponding supports  118  and then install the retrofit lamp holder  24  and reflector  12  in two separate steps. The extra step can take a considerable amount of time, and when that time is multiplied over dozens of light fixtures, the difference can be quite significant. In contrast, if the lamp holder  24  is already physically attached to the reflector  12 , and all the operator needs to do after removing the existing lamp holder  116  and corresponding supports  118  is couple the reflector  12  to the housing  112 , considerable time savings can be realized. 
     The lamp holder  24  can include a lamp socket  26  that is configured to receive a lamp. Examples of lamps that can be used in connection with embodiments of the present invention include CFL, induction, LED, HID, and so on. The lamp socket  26  can be configured to receive the lamp through the lamp-socket aperture  22  of the reflector  12 . In some embodiments, the entrance of the lamp socket  26  extends past the lamp-socket aperture  22 ; in some embodiments, the entrance of the lamp socket  26  is flush with the reflector; and in some embodiments, the lamp socket  26  is on the non-exposed side  16  of the reflector  12 . 
       FIG. 3  shows a light fixture assembly  10  configured to accommodate two lamps. The reflector  12  includes a lamp-socket aperture  22 ′ in the downward-reflecting section  18 . The lamp holder  24  includes a lamp socket  26 ′ configured to receive a second lamp through lamp-socket aperture  22 ′ of the reflector  12 . The quantity and arrangement of lamp sockets and lamp-socket apertures can vary depending on the type of light fixture, the desired light output/distribution, and a variety of other factors. Various configurations are shown in  FIGS. 5A-5T . 
     Referring again to  FIGS. 2A-2C , the light fixture assembly  10  can include a ballast for regulating electrical power to the lamp socket  26 . In some embodiments, the ballast  30  can be a retrofit ballast. The ballast  30  can include a ballast-power electrical connector  32  that is adapted to connect to a power source within the light fixture housing (e.g.,  112  in  FIG. 1 ). In preferred embodiments, the ballast  30  can be programmable (e.g., for parking garages or outdoor lighting). In particularly preferred embodiments, the ballast  30  can be configured to accommodate motion-sensor lamps. 
     In various embodiments of the present invention, the ballast  30  can be positioned in a few different ways relative to the reflector  12 . In some embodiments, the ballast can be physically attached to the non-exposed side  16  of the reflector  12 . In some such embodiments, the ballast  30  can be arranged on the non-exposed side  16  of the reflector  12  so as not to interfere with an existing ballast (e.g.,  114  in  FIG. 1 ) within the light fixture housing (e.g.,  112  in  FIG. 1 ) when installed. In embodiments in which space within the existing housing is more limited, the ballast  30  can be connected via electrical connectors to the lamp holder  24  of the light fixture assembly  10  (discussed in greater detail below) but not physically attached to the reflector  12 . In such embodiments, the ballast  30  can be positioned within the existing housing (or elsewhere—e.g., within a lamp pole) wherever space permits. 
     As alluded to above, the light fixture assembly  10  can include lamp-socket-ballast electrical connectors  28  that electrically connect the lamp socket  26  and the ballast  30 . Like the physical attachment of the lamp holder  24  to the reflector  12  discussed above, the lamp-socket-ballast electrical connectors  28  can play an important role in making the light fixture assembly  10  a ready-to-install retrofit light fixture assembly. The physical attachment between the reflector  12  and the lamp holder  24  and between the lamp holder  24  and the ballast  30  (and often between the ballast  30  and the reflector  12 ), an operator can easily carry the whole light fixture assembly  10  to the target light fixture in one trip to perform the retrofit. 
     The light fixture assembly  10  can be used in methods of quickly and efficiently retrofitting a target light fixture (e.g.,  110  in  FIG. 1 ) while minimizing materials to be disposed of. A ready-to-install retrofit light fixture assembly  10  can be provided. The ballast-power electrical connector  32  can be connected to a power source within an existing light fixture housing (e.g.,  112  in  FIG. 1 ) of the target light fixture. The reflector  12  can be coupled to the existing light fixture housing, thereby eliminating any need to remove and dispose of the existing light fixture housing. In some preferred embodiments, the reflector  12  can be positioned such that the retrofit ballast  30  does not interfere with an existing ballast (e.g.,  114  in  FIG. 1 ) within the existing light fixture housing before coupling the reflector  12  to the existing light fixture housing, thereby eliminating any need to dispose of the existing ballast. In many embodiments, coupling the reflector  12  to the existing light fixture housing includes mating the ridge sections  34  with corresponding features of the existing light fixture housing. 
     Retrofit methods discussed herein can target several different kinds of existing light fixtures. Examples of target light fixture assemblies include low bay fixtures, high bay fixtures, shoebox fixtures, wall pack fixtures, street light fixtures, wall sconce fixtures, canopy fixtures, recessed fixtures, recessed ceiling fixtures, exterior bollard fixtures, exterior swan/gooseneck fixtures, and so on. 
     Retrofit methods discussed herein can provide various advantages. For example, many retrofit light fixtures produced via retrofit light fixture assemblies discussed herein can require less than 50% of the wattage of the corresponding target light fixtures. Some preferred retrofit light fixtures produced via retrofit light fixture assemblies discussed herein can require less than 35% of the wattage of the corresponding target light fixtures. Some particularly preferred retrofit light fixtures produced via retrofit light fixture assemblies discussed herein can require less than 25% of the wattage of the corresponding target light fixtures. The following table illustrates conversions that have been achieved by embodiments of the present invention: 
                                             Target Light Fixture   Retrofit Light Fixture                          400-Watt Metal Halide or   165-Watt CFL           High-Pressure Sodium               250-Watt Metal Halide or    84-Watt CFL           High-Pressure Sodium               175-Watt Metal Halide or    57-Watt CFL           High-Pressure Sodium               150-Watt Metal Halide or    57-Watt CFL           High-Pressure Sodium               100-Watt Metal Halide or    42-Watt CFL           High-Pressure Sodium                70-Watt Metal Halide or    26-Watt CFL           High-Pressure Sodium                        
A ratio of light output to electrical power consumption can be likewise improved. Embodiments of the present invention can also significantly reduce a building&#39;s carbon footprint. Additionally, given the reduction in energy input achieved by many embodiments of the present invention, the resulting retrofit light fixture can also operate at a substantially reduced temperature, thereby improving the longevity of the retrofit light fixture. Many embodiments of the present invention work well in outdoor environments, even in cold weather climates.
 
       FIG. 4  illustrates a method of designing and installing a retrofit light fixture assembly in accordance with embodiments of the present invention. The method typically commences with a retrofitter (e.g., an electrician) receiving a request to retrofit a target light fixture ( 410 ). The request can come from any building owner who wants to retrofit one or more light fixtures in his/her building. 
     Having received the request to retrofit a target light fixture, the retrofitter can determine design parameters for the retrofit light fixture assembly ( 412 ). Examples of design parameters can include a desired light output level, a light distribution pattern, and a configuration of an existing light fixture housing of the target light fixture. In particularly preferred embodiments, design parameters can further include the cost of installing/maintaining the newer lamps, the ease of maintenance of the eventual retrofit light fixture, and other similar factors. Applicable building codes also often factor into the design of the retrofit light fixture assembly. 
     With the design parameters in hand, the retrofitter can select a reflector, a retrofit ballast, and a lamp holder based on those design parameters ( 414 ). The reflector, retrofit ballast, and lamp holder can have attributes such as those discussed elsewhere herein. 
     The retrofitter can then construct the retrofit light fixture assembly ( 416 ). The lamp holder can be physically attached to the non-exposed side of the reflector. One or more lamp sockets of the lamp holder can each be configured to receive a lamp through a lamp-socket aperture of the reflector. The lamp socket(s) can be electrically connected to the retrofit ballast via lamp-socket-ballast electrical connectors. 
     In constructing the retrofit light fixture assembly, the arrangement of the retrofit ballast can depend on a variety of factors, such as the type of target light fixture. In some embodiments (e.g., garage fixtures, low bay fixtures, wall sconces, swan fixtures, bollard fixtures, street fixtures, shoebox fixtures, wall pack fixtures, canopy fixtures, etc.), constructing the retrofit light fixture assembly can include physically attaching the retrofit ballast to the non-exposed side of the reflector. In some embodiments (e.g., high bay fixtures, canopy fixtures, shoebox fixtures, bollard fixtures, street fixtures, wall pack fixtures, etc.), the retrofit ballast can be electrically connected to the lamp socket(s) but not physically attached to the reflector. Such considerations are also discussed elsewhere herein. 
     With the retrofit light fixture fully constructed, the retrofitter can install the retrofit light fixture assembly ( 418 ). In preferred embodiments, this can be done by disconnecting but not removing an existing ballast of the target light fixture. Installation can include electrically connecting the retrofit ballast to a power source within the existing light fixture housing via a ballast-power electrical connector. Installation can further include coupling the reflector to the existing light fixture housing, thereby eliminating any need to remove and dispose of the existing light fixture housing. In embodiments in which the retrofit ballast is electrically connected to the lamp socket(s) but not physically attached to the reflector, installation can involve coupling the retrofit ballast to the existing light fixture housing. In preferred embodiments, only the existing lamp holder (e.g.,  116  in  FIG. 1 ) and the corresponding supports (e.g.,  118  in  FIG. 1 ) need to be removed and disposed of. All of the other components can either be reused or remain within the existing housing in an inoperable state. 
     The retrofitter can then determine how the retrofit light fixture assembly performs in comparison to the design parameters ( 420 ). The retrofitter can use standard measurement techniques. If the retrofit light fixture assembly does not conform to the design parameters, the retrofitter can make changes to the retrofit light fixture assembly in order to bring performance of the retrofit light fixture assembly into conformance with the design parameters ( 422 ). Such changes can include changing the bend configuration of the reflector, adding or subtracting lamp sockets, changing the configuration of the lamp socket(s), and so on. Retrofit light fixture assemblies that conform to the design parameters can provide several advantages, such as those discussed elsewhere herein. 
     When the retrofit light fixture assembly conforms to the design parameters, the retrofitter can construct a plurality of duplicate retrofit light fixture assemblies ( 424 ). The retrofitter can then retrofit a plurality of duplicate target light fixture assemblies with the duplicate retrofit light fixture assemblies. In some embodiments, retrofitting the duplicate target light fixture assemblies with the duplicate retrofit light fixture assemblies can be done at a rate of one retrofit per 20 minutes. In preferred embodiments, retrofitting the duplicate target light fixture assemblies with the duplicate retrofit light fixture assemblies can be done at a rate of one retrofit per 15 minutes. In particularly preferred embodiments, retrofitting the duplicate target light fixture assemblies with the duplicate retrofit light fixture assemblies can be done at a rate of one retrofit per 10 minutes. Such time measurements are taken from when the retrofitter removes the lamp cover to when he/she restores the lamp cover. 
     In the foregoing detailed description, the invention has been described with reference to specific embodiments. However, it may be appreciated that various modifications and changes can be made without departing from the scope of the invention as set forth in the appended claims. Thus, some of the features of preferred embodiments described herein are not necessarily included in preferred embodiments of the invention which are intended for alternative uses.