Patent Publication Number: US-9888633-B1

Title: Air cooled horticulture lighting fixture

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/665,381 filed on Mar. 23, 2015, which is a continuation-in-part of U.S. patent application Ser. No. 13/945,794 filed on Jul. 18, 2013, now U.S. Pat. No. 9,016,907 issued on Apr. 28, 2015, and is a continuation-in-part of U.S. Design patent application Ser. No. 29/493,634 filed on Jun. 11, 2014, now U.S. Design Pat. D748,849 issued on Feb. 2, 2016. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     This invention relates generally to horticulture light fixtures for growing plants indoors, and particularly to an air cooled fixture used in confined indoor growing spaces that burns a high intensity horticulture lamp. 
     DESCRIPTION OF RELATED AND PRIOR ART 
     Horticulture light fixtures used for growing plants in confined indoor spaces must provide adequate light to grow plants, while not excessively raising the temperature of the growing environment. Removal of the heat generated by the fixture is commonly achieved by forcing cooling air around the lamp and through the fixture, exhausting the same out of the growing environment. The air used for cooling the fixture is not mixed with the growing atmosphere, as the growing atmosphere is specially controlled and often enhanced with Carbon Dioxide to aid in plant development and health. 
     Innovations in electronic ballast technology made feasible for use in the indoor garden industry an improved high pressure sodium TIPS&#39; grow lamp that is connected to power at each end of the lamp, thus the term “Double Ended”. The double ended lamp as powered from each end is also supported by sockets at each end, thereby eliminating the need for a frame support wire inside the lamp as required in standard single ended HPS lamps. The absence of frame wire eliminates shadows that commonly plague single ended HPS lamps. The double ended lamp further benefits from a smaller arc tube that is gas filled rather than vacuum encapsulated. The smaller arc tube equates to a smaller point source of light, thereby improving light projection control and photometric performance. The double ended HPS lamp proves to be more efficient than its single ended HPS lamp equivalent, last longer than like wattage HPS lamps, and produces more light in beneficial wavelength for growing plants than any single ended HPS lamps of the same light output rating. 
     The double ended HPS lamp, with all of its light output performance advantages, has a significant particularity in operation, specifically when cooling the lamp. Operating temperatures at the lamp envelope surface must be maintained within a narrow operating range else the double ended HPS lamp&#39;s efficiencies in electrical power conversion into light energy are significantly reduced. When impacted by moving air, the double ended HPS lamp draws excessive electrical current which may cause failure or shutdown of the ballast powering the lamp. When bounded by stagnant air held at constant operating temperature the double ended HPS lamp proves more efficient in converting electricity to light energy and produces more light in the plant usable spectrum. This particularity in the double ended HPS lamp makes it an excellent grow lamp, but also thwarted earlier attempts to enclose, seal, and air cool the double ended HPS lamp to be used in confined indoor growing application due to the lamp&#39;s substantial sensitivity to moving cooling air. 
     Another challenges not resolved by the prior art involves sealing the glass sheet to the bottom of the fixture. The reflector interior temperatures when burning a double ended HPS lamp cause failures of gasket materials. Further, the ultraviolet and infrared light energies produced by the double ended HPS lamp degrade and make brittle rubber, neoprene, and most other gasket materials suitable for sealing the glass sheet. 
     Gavita, a lighting company from Holland produces various fixtures utilizing the double ended HPS lamp. The usual configuration includes a reflector with a spine, the spine having a socket on each opposing end such that the double ended lamp is suspended under a reflector over the plants. The reflector is not sealed from the growing environment, nor is there a housing enclosure or ducts to facilitate forced air cooling. The Gavita fixtures provide the benefit of the high performing double ended HPS lamp, but lacks air cooling capability which is necessary in many indoor growing applications as discussed above. 
     What is needed, are horticulture lighting fixtures and methods for using such fixtures that address particular aspects of the high intensity horticulture lamps use in such fixtures. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, one object of the present invention is to provide an air cooled double ended HPS lamp fixture for growing plants in confined indoor environments. 
     A further object of this invention is to provide a fixture construct wherein the excessive heat generated by the lamp is removed using a stream of forced air. 
     It is another object of the present invention to provide a stagnant air space around the lamp that is maintained at constant temperatures within the reflector during operation to prevent the lamp from drawing excessive current when subjected to temperatures differentials, or direct moving cooling air. 
     Another object of the present invention is to provide a positive air tight seal between the fixture and the growing environment using a gasket that is protected from the lamp&#39;s damaging light. 
     This invention further features turbulence enhancement of the cooling air stream by a diverter that disrupts the air stream creating eddies over the top of the reflector. 
     An object of the present invention is to provide a horticulture lighting fixture that allows for improved operation of single ended high pressure sodium horticulture lamps. 
     An object of the present invention is to provide a horticulture lighting fixture that allows for improved operation of a high intensity horticulture lamp tube oriented horizontally and substantially parallel to the fixture opening. 
     An object of the present invention is to provide alternative structures for an air cooled horticulture lighting fixture that utilizes a cooling chamber to remove heat conducted through reflective material isolating the lamp from the cooling chamber. 
     Other objects, advantages, and features of this invention will become apparent from the following detailed description of the invention when contemplated with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Elements in the figures have not necessarily been drawn to scale in order to enhance their clarity and improve understanding of these various elements and embodiments of the invention. Furthermore, elements that are known to be common and well understood to those in the industry such as electrical power connection are not necessarily depicted in order to provide a clear view of the various embodiments of the invention, thus the drawings are generalized in form in the interest of clarity and conciseness. 
         FIG. 1  shows an isometric exploded view of a preferred embodiment of the inventive fixture. 
         FIG. 2  is a cutaway exploded side view of the fixture in  FIG. 1 . 
         FIG. 3  is a diagrammatically section end view of the fixture in  FIG. 1 . 
         FIG. 3A  is a perspective exploded view of the flow disruptor in  FIG. 1 . 
         FIG. 3B  is a perspective exploded view of the flow disruptor in  FIG. 3A  further including turbulators. 
         FIG. 4  is a cutaway corner of the fixture in  FIG. 1  showing the compressively deformed shadowed gasket. 
         FIG. 5  is a front end view of a fixture having a different flow disruptor structure than shown in  FIG. 3 , according to preferred embodiments. 
         FIG. 6  is a rear end view of the fixture depicted in  FIG. 5 , according to preferred embodiments. 
         FIG. 7  is a top view of the fixture depicted in  FIGS. 5 and 6 , according to preferred embodiments. 
         FIG. 8  is a bottom view of the fixture depicted in  FIGS. 5-7 , showing incorporation of a single ended lamp socket protruding from an aperture in the reflector interior surface, according to preferred embodiments. 
         FIG. 9  is a perspective view of the fixture shown in  FIGS. 5-8 , as viewed from below, according to preferred embodiments. 
         FIG. 10  is a perspective view of an air flow diverter or disruptor structure, according to various preferred embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     As depicted and shown in the FIGS., a “heat sink” is a component used for absorbing, transferring, or dissipating heat from a system. Here, the reflector  100  acts as the “heat sink” for the lamp  2  which is isolated from the cooling air stream  310  within the reflector interior side  101 . The reflector  100  convectively transfers heat generated by the lamp  2  into the cooling air stream  310 . “Convectively transfers” refers to the transport of heat by a moving fluid which is in contact with a heated component. Here, the fluid is air, specifically the cooling air stream  310  and the heated component is the reflector  100 . Due to the special prerequisite criteria that the double ended high pressure sodium (HPS) lamp  2  be isolated from moving air, and specifically the cooling air stream  310 , the heat transfer is performed convectively from the reflector exterior side  102  to the cooling air stream  310 . The rate at which the heat transfer can convectively occur depends on the capacity of the replenishable fluid (i.e. cooling air stream  310 ) to absorb the heat energy via intimate contact with the relatively high temperature at the reflector exterior surface  102 . This relationship is expressed by the equation q=hAΔT, wherein, “h” is the fluid convection coefficient that is derived from the fluid&#39;s variables including composition, temperature, velocity and turbulence. “Turbulence” referring to a chaotic flow regime wherein the fluid/air undergoes irregular changes in magnitude and direction, swirling and flowing in eddies. “Laminar” flow referring to a smooth streamlined flow or regular parallel patterns, generally having a boundary layer of air against the surface over which the laminar flow moves. When cooling with a heat sink device within a cooling medium such as air, turbulent flow proves more effective in transferring heat energy from the heat sink into the flowing air. Turbulent flow acts to scrub away the boundary layer or push away the stagnant layer of air that is closest to the heat sink, thereby enhancing the fluid convection coefficient increasing heat transfer. Turbulent flow also increases velocities and pressures on the surface to be cooled, increasing thermal transfer. The term “Turbulator” as referenced herein is a device that enhances disruption of a laminar flow into a more turbulent flow. 
     Although repeated reference may be made to a preferred embodiment, and although preferred embodiments may be described in the context of a horticulture lighting fixture configured to use a double ended high pressure sodium lamp, various embodiments are described that the inventor discovered apply to other types of lamps and especially high intensity lamps used for horticulture applications and those lamps that benefit from various aspects of the various embodiments. The various inventive aspects are separable and may apply to lighting fixtures generally, to lighting fixtures requiring cooling, to lighting fixtures with air cooling features and using lamps that have improved performance when the lamp is isolated from moving air used to cool the fixture, to lighting fixtures that use a single ended type high intensity horticulture lamp, or to other applications. 
     Referring now to  FIG. 1-2 , a preferred embodiment of the fixture comprises a reflector  100  captured within a housing  200  defining a cooling chamber  300  within the air space located between the reflector exterior side  102  and housing interior  220 , the cooling chamber  300  being in air communication with a first duct and second duct. A cooling air stream  310  is disposed through the cooling chamber  300  between the first duct  235  and the second duct  245 . Two lamp sockets  230 A-B located partially through two opposing reflector apertures  105 A-B provide the install location for the double ended HPS lamp within the reflector interior side  101 . A flow disruptor  160  fixates over each socket  230 A-B and aperture  105 A-B diverting moving air from entering the reflector interior side  101  while further creating air eddies and local air turbulence within the cooling chamber  300  between the sockets over the reflector top  104  at the reflector&#39;s  100  hottest spot, substantially above the lamp  2 . The flow disruptor  160  interference with the cooling air stream  310  creates air eddies, increases local vortex velocities within the cooling chamber  300 , scrubs away boundary layers of air proximal to the reflector exterior side  102  that reduce heat transfer, thereby enhancing convective heat transfer from the reflector  100  into the cooling air stream  310 . 
     With reference to  FIG. 1  and  FIG. 2 , the fixture  1  includes a housing  200 , a reflector  100  captured within the housing  200 , a cooling chamber  300  defined by the air space between the housing  200  interior and the reflector exterior side  102 . The cooling chamber  300  being in air communication with a first duct  235  and second duct  245 , located substantially on opposite sides of the housing  200 . Between the first duct  235  and the second duct  245  flows the cooling air stream  310  through the cooling chamber  300 , the cooling air stream  310  which is pushed or pulled by remote fan not shown but commonly used in the prior art, connected by hose or ducting to the first duct  235 . 
     Before flowing over the reflector top  104 , the cooling air stream  310  is split or deflected by the flow disruptor  160  enhancing turbulent flow thereby increasing thermal transfer from the reflector interior side  101 , through the reflector  100 , convectively transferring from the reflector exterior side  102  into the cooling air stream  310 . The hottest area of the reflector  100  is the reflector top  104  directly above the lamp  2 , which is the closest structure to the light source. As captured within the housing  200 , the reflector  100  has a reflector top air gap  104 A defined between the reflector top  104  and the housing interior  220 . The reflector top  104  air gap  104 A for the preferred embodiment using a 1000 watt double ended HPS lamp is ⅜ of an inch, which provides ample cooling chamber  300  space for turbulent air movement as between the reflector top  104  and the housing interior  220  facilitating adequate cooling while maintaining an acceptably air insulated housing  200  exterior temperature. 
     By cutaway illustration with dashed lines in  FIG. 2 , the lamp  2  is shown installed by its ends into the sockets  230 A-B within the reflector interior side  101  near the reflector top  104 . The lamp  2  is shown oriented parallel to the cooling air stream  310 , however, the robust design allows for the lamp  2  to be oriented within the reflector  100  at any diverging angle relative to the cooling air stream  310 . 
     As shown diagrammatically by sectioned view in  FIG. 3 , cooling air directions being depicted by arrows illustrates the cooling air stream  310  as impacted by the flow disruptor  160 . In operation, the cooling air stream  310  is being forced to move with a fan (not shown) either by fan push or fan pull through the first duct  235 , then into and through the cooling chamber  300  to be exhausted out the second duct  245 . The cooling air stream  310  is diverted and split by a flow disruptor  160  directing part of the air over one side of the reflector exterior  102 , the other part over the other side of the reflector exterior  102 . The diverted cooling air stream  310  is redirected within the fixture  1  such that moving air is discouraged from pressuring any apertures, gaps, or through holes in the reflector  100 . 
     As depicted in  FIG. 3  and shown in  FIG. 3A , the flow disruptor  160  constructed to be deflecting and disrupting to moving air and arranged to attach over at least one socket  230  and enclose at least one aperture  105  such that cooling air moving through the cooling chamber  300  is diverted and disrupted into a more turbulent flow than a laminar flow regime. A preferred embodiment locates the flow disruptor  160  to encourage deflection of moving air away from the sockets  230  and aperture  105  as discussed above, essentially fulfilling two functions, creating turbulence within the cooling chamber  300  while also redirecting moving air away from reflector areas  100  that may be subject to leaks. The flow disruptor  160  location is not limited to enclosing the sockets  230  or apertures  105 , as a flow disruptor  160  located within the first duct  235  or second annular duct  245 , depending on which receives the incoming cooling air stream  310 , is effective at introducing turbulence into the cooling air stream  310 , and depending on which configuration may be preferred. Additional flow disruptors  160  working independently or in cooperation may be included within the cooling chamber  300  mounted to the reflector  100  or the housing  200 . 
     The preferred embodiment design of the flow disruptor  160  shown in  FIG. 3A  is simply constructed from a first sheet metal portion  160 A and a second sheet metal portion  160 B, the preferred metal being steel over aluminum, as the thermal conductivity of the flow disruptor  160  is not as important as the costs associated with manufacture, but in practice both metals are suitable. As shown in  FIG. 3A , the flow disruptor  160  is impervious to moving air to facilitate the dual function of deflecting moving air away from the reflector apertures  105  while also creating turbulence within the cooling chamber  300 . 
     As shown in  FIG. 3B , an enhanced flow disruptor  160  having turbulators  161  illustratively depicted as rows of through holes. The turbulators  161  could also be fins, blades, vents, or grating, most any disrupting structure, redirecting channel, or obstacle for the cooling air stream  310  will cause turbulence and thereby increase thermal conductivity from the reflector  100  into the cooling air stream  310 . 
     As discussed above, the reflector  100  is a thermally conductive component of the fixture acting as a heat sink for the lamp  2 . The reflector  100  preferably is constructed from aluminum, which is the favored material because of its relatively high thermal conductivity, easily shaped and formed, and highly reflective when polished. The high thermal conductivity of aluminum provides beneficial heat transfer between the reflector interior side  101  to the reflector exterior side  102  thermally transferring or heat sinking through the reflector  100 . Steel is also a suitable material, however the lower thermal conductivity makes aluminum the preferred reflector  100  material. 
     As shown in the FIGS., openings, gaps, or spaces through the reflector  100  are preferably filled, blocked, or covered such that the reflector interior side  101  is substantially sealed from moving air. As assembled and captured within the housing  200 , a first socket  230 A is disposed to fill a reflector  100  first aperture  105 A sealing the first aperture  105 A from moving air. A second socket  230 B is disposed to fill the second aperture  105 B sealing the second aperture  105 B against moving air. The first socket  230 A and second socket  230 B constructed and arranged to cooperatively receive the ends of the double ended HPS lamp  2  as located within the reflector interior side  101  between the two sockets  230 A-B. As shown from the side in  FIG. 2  and by depiction in  FIG. 3 , flow disruptors  160  attach over the sockets  230 A-B and over both apertures  105 A-B within the path of the cooling air stream  310 . In this way, the flow disruptors  160  enclose any opening or space between either socket  230 A-B and aperture  105 A-B respectively, thereby diverting air moving through the cooling chamber  300  away from any potential opening into the reflector interior side  101 . Filling of each aperture  105 A-B by partial insert of each socket  230 A-B requires precise manufacturing tolerances or specially formed sockets  230  in order to prevent or substantially stop moving air from traveling around the socket  230  into the reflector interior side  101 . Heat resistant sealing mediums like metal tape or high temp calk are available to positively seal the aperture  105  to the socket  230  thereby diverting the cooling air path  310  from entering the reflector interior side  101 . However, high temperature sealing mediums tend to be expensive, and application of the sealing medium as performed manually is often messy, slow, and leaves one more step in the manufacturing process subject to human error. As discussed herein, a preferred embodiment utilizes flow disruptors  160  constructed from sheet metal that are impervious to air rather than sealing mediums. However sealing mediums if properly applied will work in the place of a flow disruptor  160  for the limited purpose of sealing the reflector interior  101 , but lack the aerodynamic structure necessary to disturb the cooling air stream  310  creating turbulence between the first socket  230 A and second socket  230 B for enhanced convective transfer of heat from the reflector  100  into the cooling air stream  310 . 
     In  FIG. 4  a sectional view with a close up of the bottom corner of the fixture  1  showing by illustration the cooling chamber  300  as defined between the reflector  100  and the housing  200 . The cooling chamber  300  is shown in cross section demonstrating from top to bottom the relative size of air space between the reflector  100  and the housing  200  for the preferred embodiment. As shown, there is only one continuous cooling chamber  300 , however several smaller cooling chambers  300  split by disruptors  160  or mounting fins between the housing interior  220  and the reflector  100  provide greater control of the movement of the cooling air stream  310  through the fixture  1 . 
     The lower left close up view shown in  FIG. 4  of the bottom corner of the fixture  1  demonstrates the lower lip  103  of the reflector  100  location as captured within the housing  200 , wherein the lower lip  103  is adjacent to and slightly extending below the housing lower edge  210 . As captured, the reflector&#39;s  100  lower lip  103  and housing lower edge  210  thermally transfer heat energy. This heat sinking occurring between the reflector&#39;s  100  hotter lower lip  103  and the housing  200  cooler lower edge  210  makes the lower lip  103  the coolest part of the reflector  100 , making for the most suitable place to seal the reflector  100  using a gasket  31 . A specially formed reflector lip  103  protectively shadows the gasket  31  from damaging light energy produced by the double ended HPS lamp  2  thereby preventing premature failure of the gasket  31  during operation. As compressed, the gasket seals against the housing edge surface slightly deforming  31 A to further seal against the reflector lip  103 . In this way, a double redundant seal is provided between the fixture interior and the growing environment, while also providing a positive air tight seal between the cooling chamber  300  and the reflector interior side  101  that is not as susceptible to premature seal failure. 
     As shown in  FIG. 4 , a compressive sealing between a glass sheet  30  and the housing edge  210  with a gasket  31  sandwiched in between thereby seals the growing environment from the fixture interior, in preferred embodiments. The gasket  31  being located relative to the reflector  100  such that the reflector lower lip  103  shadows or blocks direct light  2 A produced by the lamp from impacting the gasket  31 . As shown, the glass sheet  30  is preferably held in place compressively by at least one latch  32  with enough compressive force to deform the gasket  31 . The deformed gasket  31 A sealingly contacts the lower lip  103  making a second redundant seal against the coolest part of the reflector  100  at the lower lip  103  which is shadowed and protected from the direct light energy produced by the lamp  2 . For a preferred embodiment the gasket  31  is constructed of a porous neoprene material, however many suitable heat resistant gasket materials may be used to construct the gasket  31 . 
     In less preferred embodiments, the gasket  31  may be, as shown in  FIG. 4 , compressed between the lower lip  103  and the perimeter material shown retaining the glass  30  and fastenable to latch  32 , but without the glass sheet  30  itself. That is, in less preferred embodiments the glass sheet  30  may be omitted with the structure shown in  FIG. 4  still providing isolation between the reflector interior  101  and the cooling chamber  300 . As shown, the housing  200  cooler lower edge  210  may be formed so as to maintain a substantially sealed lower edge  210  portion of the cooling chamber  300 . The inventor discovered horticulture applications not requiring the thermal protective aspects (i.e. to protect plants growing under the fixture from burning) benefit from increase light projected from the lamp and reflector interior  101  when a glass sheet  30  is not used with the fixture. Without the glass sheet  30 , the inventor discovered, an open (i.e. no glass) air cooled horticulture lighting fixture is provided that beneficially isolates cooling air flow from the lamp, which the inventor discovered in turn improves light performance from the fixture. 
     In some embodiments, the fixture  1  may comprise an air cooled horticulture lighting fixture having the cooling chamber  300  and other features previously described, except configured with a different flow disruptor  560  as shown in  FIG. 5  which is a front end view of a fixture  1  having a different flow disruptor  560  structure than shown in  FIG. 3 . The cooling air stream  310 , as shown, flows in through a first duct  235  and is diverted by a disruptor  560 , with part of the moving air diverted to one side of the reflector exterior  102  by a first angled surface  502  and part of the moving air diverted to the other side of the reflector exterior  102  by a second angled surface  504 . The diverted cooling air stream  310  is redirected within the fixture  1  such that moving air is discouraged from pressuring any apertures, gaps, or through holes in the reflector  100 . 
     In some embodiments a disruptor such as the disruptor  560  is oriented in one or the other of the first duct  235  or the second duct  245 , or both the first duct  235  and the second duct  245 , as illustrated in  FIG. 2 . In one embodiment, as shown in  FIGS. 5 and 6 , a disrupter  560  is oriented in the first duct  235  but not the second duct  245 .  FIG. 6  is a rear end view of the fixture depicted in  FIG. 5 , according to preferred embodiments, with the cooling air stream  310  flowing over and around the reflector exterior  102  and out of the second duct  245 . 
       FIG. 7  is a top view of the fixture depicted in  FIGS. 5 and 6 , according to preferred embodiments, and  FIG. 8  is a bottom view of the fixture depicted in  FIGS. 5-7 , showing incorporation of a single ended lamp socket  830  protruding from an aperture  805  in the reflector interior surface  101 , according to preferred embodiments.  FIG. 9  is a perspective view of the fixture shown in  FIGS. 5-8 , as viewed from below, according to preferred embodiments. 
     The socket  830  preferably receives a single ended high pressure sodium horticulture lamp, orienting the (tube shaped) lamp (not shown) to extend from the socket  830  nearest the first duct  235  longitudinally in a direction toward the second duct  245 . The lamp when fit into the socket  830  is preferably oriented substantially parallel to a longitudinal axis extending between the first duct  235  and the second duct  245 . In preferred embodiments, the lamp when fit into the socket  830  is oriented substantially parallel to a plane formed by the lower edges  210  of the housing  200 , or parallel to a plane formed by the lower lip  103  of the reflector  100 , and on the reflector interior  101  side of the reflector  100 , isolated from the cooling chamber  300 . 
     In preferred embodiments, the portion of the socket  830  extending through the aperture  805  in the reflector  100  comprises structure that discourages air flow from pressuring the aperture  805 , and preferably comprises structure in common with the disruptor  560 .  FIG. 10  is a perspective view of an air flow diverter or disruptor  560  structure, according to various preferred embodiments. Preferably the flow disruptor  560  shown in  FIG. 10  is simply constructed from a first sheet metal portion  560 A and a second sheet metal portion  560 B. Also preferably, the disruptor  560  comprises diverter surfaces  502  and  504  on one end, with similarly angled diverter surfaces on the other end, so that air moving longitudinally in either direction to or from the first duct  235  or the second duct  245  is diverted around the aperture  805  in the reflector  100  and portions of the socket  830  extending into the reflector exterior side  102 . 
     The various embodiments described herein may have cooling air pushed or pulled through the cooling chamber  300  by fan or other forced air apparatus, and in either direction. The robust fixture  1  cools effectively with either a negative pressure or positive pressure within the housing  200  due to the isolated reflector  100  interior side  101 . Two fans used in cooperation may be implemented without diverging from the disclosed embodiment, and linking fixtures together along one cooling system is also feasible, similar to current ‘daisy chaining’ configurations. 
     Also illustrated in  FIGS. 8 and 9  are surface regions of reflector interior  101 , shown numbered consecutively from  852  to  869 . Each surface region is preferably (as shown) a flat interior surface of the reflector interior  101 . The inventor discovered that using different surface finishes for different regions affect the light intensity directed to particular target areas. Depending upon the particular type of lamp bulb used, choosing a mirror reflective finish, in one embodiment, for regions in the corners—shown numbered consecutively from  852  to  859 —and a hammertone reflective surface finish in the side and end regions—shown numbered consecutively from  860  to  869 —may soften hot spots in the light projected from the fixture  1  that would otherwise exist if a mirror reflective finish were used. In another embodiment, choosing the reverse—mirror finish in the side and end regions and hammertone finish in the corners—may achieve the softening of hot spots, depending upon the particular type of lamp bulb used, for example whether a double ended HPS bulb or a single ended HPS bulb is used in the horticulture lighting fixture  1  as shown and described in the FIGS. In similar fashion, the inventor discovered that any particular region—any one or more of the regions consecutively numbered from  852  to  869 —may comprise a hammertone finish with the rest of the regions being a mirror reflective finish, to maximize the amount of light directed to the plant growing target and selectively soften hot spots that may be characteristic for particular types or manufacture of horticulture high intensity lamp bulbs. 
     The foregoing detailed description has been presented for purposes of illustration. To improve understanding while increasing clarity in disclosure, not all of the electrical power connection or mechanical components of the air cooled horticulture light fixture were included, and the invention is presented with components and elements most necessary to the understanding of the inventive apparatus. The intentionally omitted components or elements may assume any number of known forms from which one of normal skill in the art having knowledge of the information disclosed herein will readily realize. It is understood that certain forms of the invention have been illustrated and described, but the invention is not limited thereto excepting the limitations included in the following claims and allowable functional equivalents thereof.