Abstract:
A luminaire housing with a lamp compartment and ballast compartment that are isolated from each other is provided. The housing includes a lamp compartment, a ballast compartment, and an air gap chamber separating the two compartments from each other. The air gap chamber provides a degree of thermal isolation that reduces the amount of heat generated by the lamps that is transferred from the lamp compartment to the ballast compartment. The luminaire can also include a ventilated top cover and a bottom door configured to attach to the lamp compartment while leaving an air gap therebetween. These and other optional features improve the air circulation within the lamp compartment and allow heat generated by the lamps to exit the luminaire housing, further reducing the heat transferred to the ballast compartment, thereby improving the lifespan and performance of the ballasts.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates generally to light fixtures, and more specifically to a housing for a luminaire that includes a lamp compartment and a ballast compartment that are thermally isolated from each other. 
       BACKGROUND 
       [0002]    Luminaires can include one or more lamps connected to one or more ballasts that control the current flowing through the lamps. By controlling the current flowing through the lamps, the ballasts can be used to control the brightness of the lamps in the luminaires. The lamps used in luminaires, like other sources of light, often generate a significant amount of heat. The heat generated by lamps generally increases as the brightness of the lamps increases. Moreover, the heat generated by the lamps can cause damage to the ballasts. This damage can lead to a decrease in the lifespan of the ballasts, and therefore, the functionality of the luminaire. 
         [0003]    Manufacturers of conventional luminaires have developed a few solutions to increase the lifespan of ballasts in luminaire housings, but each of these solutions has associated disadvantages and limitations. For example, luminaires can be configured to have the lamps disposed within the luminaire housing and the ballasts placed outside of—and separated from—the housing. In such cases, the ballasts may be placed at a different location from the luminaire housing altogether. Such a configuration can lead to increased costs, due in part to several feet of extra wiring. Maintenance of the luminaire also can become more difficult if the luminaire components are not kept together in a single housing. Further, the external wiring and connections may lead to a decreased aesthetic appearance. 
         [0004]    Another conventional method of increasing the lifespan of ballasts in luminaire housings is to decrease the power levels of the lamps, which in turn can decrease their brightness or light output. Decreasing the power level and brightness of the lamps will generally decrease the heat generated by the lamps. This reduced heat may reduce the damage to the ballasts, thereby increasing the ballast lifespan. However, lamps with decreased brightness may be less useful in circumstances where bright lighting is desirable or necessary. Further, operating the lamps at a reduced brightness may be inefficient and cause premature failure of the lamps. 
         [0005]    Decreasing the power level and brightness of lamps to achieve a greater ballast lifespan may be particularly problematic with luminaires utilizing compact fluorescent lamps (CFLs). Luminaires using CFLs may not emit as much light output when compared to high intensity discharge (HID) lamp luminaires. Thus, decreasing the brightness of CFLs may make CFL luminaires impractical or insufficient for providing necessary lighting in certain applications, such as industrial, commercial, retail, and sports lighting applications where HID lamps may currently be more commonly used. Moreover, decreasing the power level supplied to CFLs may strain the lamp, thereby decreasing the lifespan of the lamp as well. 
         [0006]    Therefore, a need in the art exists for providing a luminaire that lacks the limitations described previously. Specifically, a need in the art exists for a luminaire housing that can hold ballasts and lamps disposed therein while reducing the damage to the ballasts caused by heat generated by the lamps. A need in the art also exists for a luminaire that can increase the lifespan of ballasts without reducing the brightness of CFLs or other lamps disposed therein. 
       SUMMARY 
       [0007]    The present invention provides a luminaire with a single housing for the ballasts and lamps that can reduce the damage to ballasts caused by heat generated by the lamps. Specifically, the invention can provide a luminaire with a single housing having a ballast compartment and a lamp compartment that are at least partially thermally isolated from each other. By thermally isolating the ballasts from at least a portion of the heat generated by the lamps, the luminaire can improve light output when compared to conventional luminaires, while increasing the lifespan of the ballasts. This increased light output can increase the utility of CFLs or other types of lamps used in the luminaires. 
         [0008]    For one aspect of the present invention, the luminaire can include housing having a lamp compartment, a ballast compartment, and an air gap chamber disposed therebetween. The air gap chamber can thermally isolate the lamp compartment from the ballast compartment, thereby reducing the heat generated by the lamps that is transferred to the ballasts. 
         [0009]    In another aspect of the present invention, the luminaire housing can include a lamp compartment and a ballast compartment. The lamp compartment can have a first wall positioned along the outer perimeter of the lamp compartment. The ballast compartment can include an inner perimeter and an outer perimeter. A second wall can be positioned along the inner perimeter of the ballast compartment. The first wall and the second wall can make up a double wall separating the lamp compartment from the ballast compartment. In such an arrangement, the first wall and the second wall can be separated by the air gap chamber. 
         [0010]    The luminaire housing also can include additional features that provide ventilation to reduce the heat transferred from the lamp compartment to the ballast compartment. For example, the luminaire housing can include a perforated top positioned above the lamp compartment, through which heat generated by the lamps may exit the luminaire. Additionally, the luminaire housing can include a door assembly configured to attach to the lamp compartment, while leaving a gap therebetween. This gap can allow ambient air from outside the luminaire to enter the lamp compartment between the door and the lamp compartment and provide improved air circulation in the lamp compartment. The improved air circulation can cause more heat to exit the lamp compartment and the luminaire housing altogether, which in turn reduces the heat transferred to the ballasts in the ballast compartment. 
         [0011]    These and other aspects, features, and embodiments of the invention will become apparent to a person of ordinary skill in the art upon consideration of the following detailed description of illustrated embodiments exemplifying the best mode for carrying out the invention as presently perceived. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    For a more complete understanding of exemplary embodiments of the present invention and the advantages thereof, reference is now made to the following description in conjunction with the accompanying figures described as follows. 
           [0013]      FIG. 1  is a top perspective view of a luminaire housing, according to an exemplary embodiment. 
           [0014]      FIG. 2  is a cross-sectional view of a portion of the luminaire housing of  FIG. 1 , according to an exemplary embodiment. 
           [0015]      FIG. 3A  is a top perspective view of a door assembly for the luminaire housing of  FIG. 1 , according to an exemplary embodiment. 
           [0016]      FIG. 3B  is a bottom perspective view of the luminaire housing of  FIG. 1  with the door assembly of  FIG. 3A  attached thereto, according to an exemplary embodiment. 
           [0017]      FIG. 3C  is a bottom perspective view of the luminaire housing of  FIG. 1  depicting the door assembly of  FIG. 3A  being attached thereto, according to an exemplary embodiment. 
           [0018]      FIG. 4A  is a top perspective view of the luminaire housing of  FIG. 1  with a top assembly attached thereto, according to an exemplary embodiment. 
           [0019]      FIG. 4B  is an exploded view of the luminaire housing and top assembly of  FIG. 4A , according to an exemplary embodiment. 
           [0020]      FIG. 5  is a side perspective view of the luminaire housing of  FIG. 1  disposed in a pendant mount, according to an exemplary embodiment. 
           [0021]      FIG. 6  is a side perspective view of the luminaire housing of  FIG. 1  with a suspension cable mount, according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0022]    The following description of exemplary embodiments refers to the attached drawings, in which like numerals indicate like elements throughout the several figures. 
         [0023]      FIG. 1  is a top perspective view of a luminaire housing  100 , according to an exemplary embodiment.  FIG. 2  is a cross-sectional view of a portion of the luminaire housing  100  of  FIG. 1 , according to an exemplary embodiment. Exemplary components of the luminaire housing  100  will be described with reference to  FIGS. 1 and 2 . The luminaire housing  100  includes a ballast compartment  104  and a lamp compartment  102 , separated by an air gap chamber  106 . The exemplary lamp compartment  102  is arranged in a wheel-and-spoke arrangement, having a center hub portion  107  and six spokes  108 . In an alternative exemplary embodiment, lamp holders (not shown) can be mounted to the lamp compartment  102  to provide support to the lamps  120  disposed therein. Lamp holders can either be mounted to a wall of the lamp compartment  102 , the bottom of the lamp compartment  102 , or the bottom of the spoke  108 . 
         [0024]    The size of the lamp compartment  102  can vary based on the size and/or number of the lamps  120  that will be housed in the luminaire, as well as the particular application for the luminaire. In certain exemplary embodiments, the lamp compartment  102  is approximately circular in shape and has a diameter between one and three feet, and thus a radius between six and eighteen inches. The radius can be measured from the center of the lamp compartment  102  to an outer wall  110  of the lamp compartment  102 . Additionally, though the embodiment illustrated in  FIG. 1  includes six spokes  108 , in various alternative embodiments, the lamp compartment  102  includes any number of spokes  108 , including as few as one spoke  108 . 
         [0025]    Each exemplary spoke  108  of the lamp compartment  102  serves as a reflector. In one exemplary embodiment, the spokes  108  are painted white, which can diffuse light generated by the corresponding lamps  120 . Additionally, each spoke  108  is positioned relative to the lamp  120  such that it directs light emitted by the lamp  120  toward a desired direction. For example, when the luminaire is suspended or attached to a ceiling, the spokes  108  direct light from the lamps  120  downward to provide enhanced illumination to the area beneath the luminaire. Such an exemplary spoke  108  is approximately V-shaped to direct light accordingly. Other shapes can be used, as will be recognized by one of ordinary skill in the art, depending on the location desired to be illuminated by the luminaire. In an alternative embodiment, the lamp compartment  102  can include an additional reflector (not shown) located between each of the spokes  108 . Such a reflector can be made of a reflective, metallic material, such as aluminum. 
         [0026]    In certain exemplary embodiments, each spoke  108  also includes an opening  112 . The opening  112  is positioned directly above the base of the lamp  120 . The opening  112  provides ventilation for the lamp  108 . In another exemplary embodiment, the lamp compartment  102  and/or each spoke  108  includes an insulating material (not shown) for reducing the amount of heat generated by the lamp  120  that may reach the ballast compartment  104 . The insulating material can, for example, include an insulating plastic material. Such insulating material is positioned on the wall  110  of the lamp compartment  102 . In certain exemplary embodiments, the insulating material is used in addition to, or instead of, metallic and other non-insulating materials used to form the components of the lamp compartment  102 . 
         [0027]    In another exemplary embodiment, each spoke  108  also includes a socket bracket  116 . The socket bracket  116  is mounted to the lamp compartment  102 , and can be attached thereto by a fastener, such as a screw (not shown). In various alternative embodiments, the socket brackets  116  can be mounted to the bottom of the lamp compartment  102  or the bottom of the spoke  108 . As will be recognized by one of ordinary skill in the art having the benefit of the present disclosure, the location and/or mounting method of the socket brackets  116  can be varied. 
         [0028]    The socket bracket  116  holds a lamp socket  114  within the lamp compartment  102 . The socket  114  is configured to accept the insertion of a CFL or other lamp  120  therein, and to allow the removal of the lamp  120  therefrom. The socket  114  is also in electrical communication with a ballast  122  that is used to control the lamp  120 . 
         [0029]    In certain exemplary embodiments, the lamps  120  housed within the lamp compartment  102  are compact fluorescent lamps (CFLs). The CFLs used include an amalgam in the base of the lamp  120 . In a particular embodiment, the amalgam in the base of the lamp  120  includes mercury and other components. The amalgam helps ignite the CFL and helps the CFL provide more consistent light output. In various alternative embodiments, suitable lamps  120  other than CFLs also can be used, as will be recognized by one of ordinary skill in the art having the benefit of the present disclosure. Moreover, regardless of the type of lamps  120  disposed in the lamp compartment  102 , lamps  120  with various sizes and/or wattages can be used. In certain exemplary embodiments, the lamps  120  used are CFLs with a wattage between 30 and 120 watts. 
         [0030]    Each spoke  108  of the lamp compartment  102  also includes a wire way  128  for power leads (not shown) to go from the ballasts  122  to the center hub  107  for wiring to the incoming line leads (not shown). Power from the ballasts  122  to the lamps  120  is supplied by wires going through the wire ways  128  and the opening  112  above the socket  114  and into the ballast compartment  104 . The exemplary lamp compartment  102  further includes a connection  126  for the junction box, which can be a cord with a strain relief or a threaded pipe pendant leading from the junction box to an external junction box (not shown) supplied by the installer. The external junction box connects the internal junction box to multiple power supply circuits. 
         [0031]    In certain exemplary embodiments, the ballast compartment  104  houses one or more ballasts  122  connected to one or more of the lamps  120  in the lamp compartment  102 . In another exemplary embodiment, the ballast compartment  104  is attached to or integral with the lamp compartment  102 . The ballast compartment  104 , like the lamp compartment  102 , is approximately circular in one exemplary embodiment. The ballast compartment  104  has an inner wall  130  and an outer wall  132 , and a corresponding inner diameter and outer diameter. In one exemplary embodiment, the ballast compartment  104  and lamp compartment  102  are substantially concentric, with the inner diameter of the ballast compartment  104  being greater than the diameter of the lamp compartment  102 , and the outer diameter of the ballast compartment  104  being greater than the inner diameter. In a particular exemplary embodiment, the width of the ballast compartment  104  (i.e., the distance between the inner  130  and outer walls  132  of the ballast compartment  104 ) is between two and two-and-a-half inches. 
         [0032]    As shown in  FIG. 1 , in certain exemplary embodiments, three ballasts  122  are used to control the power supplied to the six lamps  120 . In various alternative embodiments, any suitable number of ballasts  122  are used to control the lamps  120  in the lamp compartment  102 . In one exemplary embodiment, the ballasts  122  vary the power supplied from the junction box to the lamps  120 . This can be accomplished in a variety of ways. In one exemplary embodiment, dimming ballasts  122  are used. In such an embodiment, a secondary device, such as a photo-control or motion detector, will control the amount of current to the ballast  122 , which in turn will control the current from the ballast  122  to the lamp  120 . In another exemplary embodiment, the ballasts  122  are wired from the internal junction box in such a manner as to control the current supplied to each ballast  122  individually, thereby allowing each pair of lamps  120  connected to each ballast  122  to be turned on or off independently. In yet another exemplary embodiment, the central power is wired to an emergency battery pack which will power one ballast  122 . The ballast  122  then can power one or two lamps  120  in the event of a power outage. 
         [0033]    In certain exemplary embodiments, each ballast  122  is secured within the ballast compartment  104  by a ballast bracket  124 . In various exemplary embodiments, the ballast bracket  124  is made of any suitable metallic material, as will be recognized by one of ordinary skill in the art having the benefit of the present disclosure. In a particular exemplary embodiment, the ballast bracket  124  is made from a material such as aluminum that absorbs and/or dissipates heat from the ballasts  122 , thereby functioning as a heat sink for the ballast  122 . 
         [0034]    In another exemplary embodiment, as shown in  FIG. 2 , the ballast compartment  104  includes a separate heat sink  136 . The heat sink  136  is made of any suitable metallic material, such as aluminum. In one exemplary embodiment, the heat sink  136  is integral with the ballast compartment  104 . 
         [0035]    As will be recognized by one of ordinary skill in the art having the benefit of the present disclosure, the method of securing ballasts  122  in the ballast compartment  104  can be varied in accordance with the invention. In one exemplary embodiment, the ballasts  122  can be secured to the ballast compartment  104  by a fastener such as a screw  118 . In such an embodiment, the ballast compartment  104  and the ballast bracket  124  each include a hole through which a screw  118  is inserted to secure the ballast bracket  124  in place. In one particular exemplary embodiment, securing the ballast  122  within the ballast compartment  104  includes placing the ballast  122  within the ballast compartment  104 , sliding or placing the ballast bracket  124  over the ballast  122 , and fastening the screw  118  to secure the ballast  122  and ballast bracket  124  to the ballast compartment  104 . 
         [0036]    The luminaire housing  100  also includes an air gap chamber  106  separating the lamp compartment  102  from the ballast compartment  104 . In one exemplary embodiment, the air gap chamber  106  also is substantially circular, and is approximately concentric with the lamp compartment  102  and the ballast compartment  104 . In other embodiments, the air gap chamber  106 , lamp compartment  102 , and/or ballast compartment  104  can be of any other shape, such as rectangular or polygonal. In a particular exemplary embodiment, the air gap chamber  106  has a width of approximately one-half inch. 
         [0037]    In certain exemplary embodiments, the ballast compartment  104  and lamp compartment  102  are mechanically integrated. For example, although the air gap chamber  106  separates the lamp compartment  102  from the ballast compartment  104 , a bridge member  134  connects the ballast compartment  104  and the lamp compartment  102  at one or more locations. In a particular exemplary embodiment, as shown in  FIG. 1 , a bridge member  134  made of the same material used to make the ballast compartment  104  and/or lamp compartment  102  extends over the air gap chamber  106  and connects the ballast compartment  104  to the lamp compartment  102  at various locations. Specifically, the bridge member  134  extends from each spoke  108  of the lamp compartment  102  to the inner wall  130  of the ballast compartment  104 . This mechanical integration of the ballast compartment  104  and lamp compartment  102  facilitates the use of a single luminaire housing  100  to house the ballast compartment  104  and lamp compartment  102 . The use of a single luminaire housing  100  provides increased convenience in installing and/or operating the luminaire. 
         [0038]    In certain exemplary embodiments, the air gap chamber  106  is defined by a double wall. The double wall is typically made of two separate walls. In one embodiment, the two walls of the double wall are the outer wall  110  of the lamp compartment  102  and the inner wall  130  of the ballast compartment  104 . The exemplary double walls are made from aluminum or another suitable metallic, composite, or high temperature thermally insulating thermoplastic material. 
         [0039]    Even if the lamp compartment  102  and ballast compartment  104  are mechanically integrated, the air gap chamber  106  can thermally isolate—at least partially—the ballast compartment  104  and the lamp compartment  102 . In one exemplary embodiment, air flows into the air gap chamber  106 . This air flow provides ventilation for the luminaire, and absorbs some of the heat generated by the lamp  120 . The air flow through the air gap chamber  106  thus reduces the amount of heat that is transferred from the lamp compartment  102  to the ballast  122  in the ballast compartment  104 . By reducing the amount of heat transferred to the ballast compartment  104 , the heat-related damage to the ballast  122  is reduced, and thus, the ballast  122  life span is increased. 
         [0040]    In addition, reducing the amount of heat transferred to the ballast compartment  104  also allows the lamps  120  in the lamp compartments  102  to operate at a higher temperature than in conventional luminaires without damaging to the ballasts  122 . In certain exemplary embodiments, the luminaire utilizes CFLs, and the CFLs operate at a higher temperature, such as a temperature at or near the optimal operating temperature of the CFLs. If the CFLs operate at or near their optimal temperature, they operate more efficiently and provide increase light output as compared to CFLs that operate at lower temperatures. Thus, the air gap chamber  106 , by thermally isolating the lamp compartment  102  from the ballast compartment  104  and dissipating heat generated from the lamps  120 , enables luminaires to use CFLs with light output. Such luminaires can be used in applications where bright lighting is desired, such as industrial, commercial, retail, and sports lighting applications where HID lamps  120  may currently be used. 
         [0041]      FIG. 3A  is a top perspective view of a door assembly  300  for the luminaire housing  100  of  FIG. 1 , according to an exemplary embodiment.  FIG. 3B  is a bottom perspective view of the luminaire housing  100  of  FIG. 1  with the door assembly  300  of  FIG. 3A  attached thereto, according to an exemplary embodiment.  FIG. 3C  is a bottom perspective view of the luminaire housing  100  of  FIG. 1  depicting the door assembly  300  of  FIG. 3A  being attached thereto, according to an exemplary embodiment. Referring now to  FIGS. 3A-3C , the exemplary door assembly  300  provides a bottom cover to the luminaire housing  100 , enclosing the lamp compartment  102 . In certain exemplary embodiments, the door assembly  300  includes a transparent or translucent lens  302 , through which at least a portion of the light generated by the luminaire&#39;s lamps  120  can pass. The lens  302  is attached to the door assembly  300  via one or more lens retaining brackets  304 . 
         [0042]    In certain exemplary embodiments, lens retaining brackets  304  are located on the door assembly  300 . In one exemplary embodiment, the door assembly  300  includes a lip  305  on which the lens retaining brackets  304  are located. The lip  305  has approximately the same diameter and/or circumferential dimensions as the lamp compartment  102 . The door assembly  300  also includes torsion springs  306  for hinging the door assembly  300  to the lamp compartment  102  of the luminaire housing  100  and removing the door assembly  300  therefrom. 
         [0043]    In another exemplary embodiment, the door assembly  300  is attached to the lamp compartment  102  and configured to allow for air to flow into the lamp compartment  102 . For example, as shown in  FIG. 2 , an opening  308  or air gap is provided between the outside wall  110  of the lamp compartment  102  and the door assembly  300 . In such an embodiment, air flows from outside the luminaire (e.g., from below the luminaire), through the opening  308  between the door assembly  300  and the lamp compartment  102 , and into the lamp compartment  102 . The air flow improves the ventilation in the lamp compartment  102 , by enabling air from outside of the lamp compartment  102  to enter the lamp compartment  102 . Taking into account principles of convection, the flow of relatively cool air into the lamp compartment  102  causes the heat generated by the lamps  120  to dissipate, such as through the opening  112  in the spoke  108  described previously. 
         [0044]      FIG. 4A  is a top perspective view of the luminaire housing  100  of  FIG. 1  with a top assembly  400  attached thereto, according to an exemplary embodiment.  FIG. 4B  is an exploded view of the luminaire housing  100  and top assembly  400  of  FIG. 4A , according to an exemplary embodiment. Now referring to  FIGS. 4A and 4B , the top assembly  400  includes a ballast compartment cover  404 , a lamp compartment cover  402 , and/or a perforated top  406 . In one exemplary embodiment, the lamp compartment cover  402  and perforated top  406  can be made from one piece. 
         [0045]    In certain exemplary embodiments, the ballast compartment cover  404  is shaped to fit on top of the ballast compartment  104 . For example, the ballast compartment cover  404  is approximately circular, and has an inner diameter and an outer diameter. The inner diameter and outer diameter of the ballast compartment cover  404  is approximately equal to the inner diameter and outer diameter of the ballast compartment  104 . In one exemplary embodiment, the ballast compartment cover  404  is made from the same material as the ballast compartment  104 . Alternatively, the ballast compartment  104  can be made from a variety of other suitable materials, such as aluminum. As will be recognized by one of ordinary skill in the art having the benefit of the present disclosure, any material—metallic or thermo-plastic—can be used to form the ballast compartment  104 , as long as the thermal requirements are met. 
         [0046]    In another exemplary embodiment, the ballast compartment cover  404  is placed over the ballast compartment  104  so as to cover the ballasts  122  and ballast brackets  124  therein. This exemplary ballast compartment cover  404  includes tabs  408  along the inner diameter of the ballast compartment cover  404 . Screws  118  or other fasteners are inserted into the tabs  408  (and then into corresponding holes in the ballast compartment  104 ) to secure the ballast compartment cover  404  to the ballast compartment  104 . As described previously with reference to securing ballasts  122  to the ballast compartment  104 , the method and configuration of securing the ballast compartment cover  404  to the ballast compartment  104  can be varied. 
         [0047]    In certain exemplary embodiments, the perforated top  406  is configured to fit over the lamp compartment  102 . For example, the perforated top  406  is approximately circular in shape, having approximately the same diameter as the lamp compartment  102 . Additionally, the perforated top  406  includes an opening  414  that provides access to the junction box connection  126  in the lamp compartment  102 . The opening  414  is typically located approximately in the center of the perforated top  406 , such that when the perforated top  406  is placed over the lamp compartment  102 , the opening  414  is located above the junction box connection  126 . 
         [0048]    In another exemplary embodiment, the perforated top  406  is made from a metallic material, such as aluminum. The perforations  416  in the perforated top  406  provide additional ventilation for the lamp compartment  102 . Heat generated by the lamps  120  rises and escapes through the perforations  416  in the perforated top  406 . The perforations  416  thus help reduce the amount of heat generated by the lamps  120  that is transferred to the ballast compartment  104 . 
         [0049]    In various exemplary embodiments, the size, number, and/or position of the perforations  416  on the perforated top  406  can vary, as may be recognized by one of ordinary skill in the art having the benefit of the present disclosure. In an alternative embodiment, the top assembly  400  includes a top  406  without perforations  416 . 
         [0050]    In certain exemplary embodiments, the lamp compartment cover  402  is configured to fit above the perforated top  406 . The exemplary lamp compartment cover  402  is shaped similarly to the lamp compartment  102 . In one exemplary embodiment, the lamp compartment cover  402  is substantially circular, with a diameter approximately equal to the diameter of the perforated top  406  and/or the lamp compartment  102 . In a particular exemplary embodiment, the lamp compartment cover  402  is shaped in a wheel-and-spoke configuration, and has spokes  412  the same as or substantially similar to those described previously with reference to the lamp compartment  102 . The lamp compartment cover  402  is designed such that, upon attaching the top assembly  400  to the luminaire housing  100 , the spokes  412  of the lamp compartment cover  402  generally align with the spokes  108  of the lamp compartment  102 . 
         [0051]    In certain exemplary embodiments, the lamp compartment cover  402  is made from the same material as the lamp compartment  102 . Alternatively, the lamp compartment cover  402  can be made from a variety of other suitable materials, such as aluminum or a high temperature thermally insulating thermo-plastic material. 
         [0052]    In another exemplary embodiment, the lamp compartment cover  402  is placed over the lamp compartment  102  so as to cover the lamps  120  and spokes  108  therein. The exemplary lamp compartment cover  402  includes tabs  410  along its circumference. Screws  118  or other fasteners are inserted into the holes in tabs  410  (and then into corresponding holes in the ballast compartment  104 ) to secure the lamp compartment cover  402  to the lamp compartment  102 . 
         [0053]    The top assembly  400  can be attached to the luminaire housing  100 . In one exemplary embodiment, the ballast compartment cover  404  is placed on top of the ballast compartment  104  such that the tabs  408  disposed along an inner diameter of the ballast compartment cover  404  are aligned with corresponding holes or openings in the luminaire housing  100 . The perforated top  406  is then placed above the lamp compartment  102 , and the lamp compartment cover  402  is placed over the perforated top  406 . In yet another exemplary embodiment, the lamp compartment cover  402  is placed such that the tabs  410  disposed along the perimeter of the lamp compartment cover  402  are aligned with corresponding holes or openings in the luminaire housing  100 . In a particular exemplary embodiment, the holes or openings in the luminaire housing  100 , with which the tabs  408 ,  410  of the ballast compartment cover  404  and lamp compartment cover  402  are aligned, are located on the bridge member  134  of the luminaire housing  100 . Fasteners, such as screws  118 , are used to attach the lamp compartment cover  402  and ballast compartment cover  404  to the luminaire housing  100 . In another exemplary embodiment, the perforated top  406  is secured within the top assembly  400  by being secured between the lamp compartment cover  402  and the ballast compartment cover  404 , once the top assembly  400  has been attached to the luminaire housing  100 . 
         [0054]    An exemplary luminaire housing  100  utilizes one or more of the air gap chambers  106 , openings  112  in the spokes  108  of the lamp compartment  102 , openings  308  between the door assembly  300  and the lamp compartment  102 , and perforations in the top  406  to reduce the heat transferred from the lamps  120  to the ballast compartment  104 . 
         [0055]      FIG. 5  is a side perspective view of the luminaire housing  100  of  FIG. 1  disposed in a pendant mount  500 , according to an exemplary embodiment. Referring now to  FIG. 5 , the exemplary pendant mount  500  includes a pendant  502  or attachment member that provides support to the luminaire housing  100 . The pendant  502  can be attached to a ceiling or other surface of the room or area in which the luminaire will be mounted. In another exemplary embodiment, the pendant  502  also houses power cables and other electrical components for use with the luminaire. For example, a portion of wires connecting an external power supply to the junction box can be disposed within the pendant  502 . 
         [0056]      FIG. 6  is a side perspective view of the luminaire housing  100  of  FIG. 1  with a suspension cable mount  600 , according to an exemplary embodiment. Now referring to  FIG. 6 , the exemplary suspension cable mount  600  includes an attachment member  602  that, like the pendant  502  of the pendant mount  500  of  FIG. 5 , provides support to the luminaire housing  100  and houses power cables and other electrical components for use with the luminaire. 
         [0057]    In certain exemplary embodiments, the attachment member  602  includes pendant  604 , middle junction box  606 , and power cord  608  sections. In another exemplary embodiment, the pendant section  604  of the attachment member  602  is attached to a ceiling or other surface of the room or area in which the luminaire will be mounted, and the power cord section  608  is connected to the luminaire housing  100 . In a particular exemplary embodiment, the power cord section  608  connects to the top assembly  400  of the luminaire housing  100 . In this embodiment, the middle junction box section  606  is attached to or integral with the pendant section  604  and the power cord section  608 . In another exemplary embodiment, the middle junction box section  606  receives power from an external junction box (not shown) and provides power to the internal junction box connection  126  in the housing  100 . 
         [0058]    In another exemplary embodiment, the suspension cable mount  600  further includes suspension cables  610  to support the luminaire housing  100 . The suspension cables  610  extend from the middle junction box section  606  to the luminaire housing  100  or top assembly  400  thereof. In a particular exemplary embodiment, the suspension cable mount  600  includes three suspension cables  610  that extend from the middle junction box section  606  to the top assembly  400  of the luminaire housing  100 . 
         [0059]    In other embodiments, the luminaire housing  100  is attached to a variety of other mounts. For example, the luminaire housing  100  can be attached to a surface mount, for mounting to a surface such as a wall, instead of hanging from a ceiling, as with the pendant mounts  500  and suspension cable mounts  600 . Other mounting assemblies also can be used, as may be recognized by one of ordinary skill in the art having the benefit of the present disclosure. 
         [0060]    In conclusion, the foregoing exemplary embodiments enable a luminaire with a single housing  100  having a ballast compartment  104  and a lamp compartment  102  that are separated by an air gap chamber  106 . Many other modifications, features, and embodiments will become evident to a person of ordinary skill in the art having the benefit of the present disclosure. It should be appreciated, therefore, that many aspects of the invention were described above by way of example only and are not intended as required or essential elements of the invention unless explicitly stated otherwise. It should also be understood that the invention is not restricted to the illustrated embodiments and that various modifications can be made within the spirit and scope of the following claims.