Abstract:
A skylight having a shaped reflector placed inside of the skylight adjacent a lamp for providing uniform natural and artificial lighting. The shaped reflector is positioned a predetermined vertical distance and a predetermined horizontal distance within the housing of the skylight to provide uniform artificial illumination simulating natural daylight illumination. Thermal efficiencies are improved with placement of a thermal barrier between upper and lower housings and external positioning of electrical ballast. Installation efficiencies are improved with the formation of an integral curb between the upper and lower housings.

Description:
RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 61/279,029, filed Oct. 15, 2009. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates in general to improved skylights, and particularly to an energy efficient deep well skylight providing uniform day and night lighting that is thermally efficient and easy to install. 
     BACKGROUND OF THE INVENTION 
     Skylights or sky windows have often been used to illuminate the interior of buildings. Most skylights are passive devices that act as windows relying completely on natural daylight for illuminations. Some skylights have combined the benefits of natural lighting with artificial lighting. One such skylight is disclosed in U.S. Pat. No. 5,528,471 entitled “Skylight And Lamp Combination” issuing to Green on Jun. 18, 1996. Therein disclosed is a skylight and lamp combination for providing natural and artificial light to a room. A plurality of lamp fixtures is disposed within the housing of the skylight for emitting artificial light to the bottom end of the housing. The lamp fixtures are disclosed as being fluorescent light fixtures or incandescent light fixtures of conventional design. A retractable shade is also disclosed. For daytime darkening, the shade or blind is rolled over and the fluorescent lights are used alone or not depending on the shading needed during the day. Another skylight using artificial and natural lighting is disclosed in U.S. Pat. No. 7,057,821 entitled “Integrated Artificial and Natural Lighting System” issuing to Zincone on Jun. 6, 2006. Therein disclosed is a substantially self-contained and powered artificial and natural lighting system. Sensors detect illumination intensity to control the balance of natural and artificial light to maintain a predetermined illumination intensity. 
     While most skylights incorporating lamps or artificial lighting extend the practicality of skylights and their use for providing light when natural light is not available, they are often not as efficient as possible. Often the artificial light may be placed or positioned in a way that compromises the efficiency of the natural light or that provides artificial lighting that his harsh or substantially different than the natural lighting. 
     Additionally, skylights having deep wells are often thermally inefficient with substantial loss or gain of heat. Also, the installation of a skylight is often complicated and after installation is prone to leaking. Often special curbing or flashing is required to be manufactured on site adding to the time and cost of installation. 
     Therefore, there is a need for a more efficient skylight providing a natural and artificial lighting system that is easily installed, is energy efficient, and provides uniform lighting such that there is no perceived difference between the natural lighting and the artificial lighting. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an energy efficient deep well skylight that utilizes artificial lighting or fluorescent fixtures that maximizes fluorescent electric light performance while minimizing loss of daylight through the deep well skylight. The present invention results in a seamless light source making it difficult for the building occupants to distinguish between day lighting and artificial electric lighting. The placement and shape of a fluorescent or electrical fixture placed within the housing of the deep well skylight is optimized so as to provide uniform illumination, day or night. 
     A shaped reflector is used in combination with the artificial lighting or fluorescent lamps so as to provide uniform illumination. The shaped reflector has a curved horizontal artificial light reflector and an angled artificial light reflector placed a predetermined distance from the emerging light aperture and a predetermined distance laterally into the well of the skylight. A top natural light reflector is also used adjacent the shaped reflector. 
     An embodiment of the invention utilizes a thermal barrier so as to maximize the thermal insulation or “R” value of the deep well skylight. The thermal barrier, which may be a transparent sheet material, is placed in the plane of the thermal insulation of the roof. 
     In another embodiment of the invention, an integrated curb forms part of the deep well skylight housing or box, eliminating the need for separate curbs to be constructed or fabricated on site. 
     Accordingly, it is an object of the invention to provide an efficient skylight that provides a seamlessly transition from natural lighting to artificial lighting. 
     It is another object of the invention to maximize artificial light performance and minimize interference with natural lighting. 
     It is another object of the invention to improve the thermal efficiency of a skylight. 
     It is yet another object of the invention to make installation of a skylight easier and quicker. 
     It is an advantage of the present invention that uniform lighting is maintained with either natural or artificial lighting so that a user does not perceive a difference. 
     It is another advantage of the present invention that improved thermal insulation is obtained. 
     It is yet another advantage of the present invention that leaking after installation is substantially reduced or eliminated. 
     It is a feature of the invention that a shaped reflector is positioned a predetermined distance above an emerging aperture as a function of the size of the aperture. 
     It is a feature of the invention that a top natural light reflector is used minimizing the effect of the shaped reflector on natural lighting. 
     It is another feature of the invention that a thermal barrier is placed in the skylight in the plane of the thermal insulation in the ceiling. 
     It is yet another feature of the invention that an integral flange and curb is formed between an upper housing and a lower housing of the skylight. 
     These and other objects, advantages, and features will become readily apparent in view of the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically illustrates an embodiment of the invention. 
         FIG. 2  is an elevational view of an embodiment of the invention. 
         FIG. 3  is a bottom view of the embodiment of the invention illustrated in  FIG. 2 . 
         FIG. 4  is an enlarged view of circle  4  illustrated in  FIG. 2 . 
         FIG. 5  is a schematic of the shaped reflector. 
         FIG. 6  is a perspective view illustrating a deep well skylight housing or box with an integral curb. 
         FIG. 7  schematically illustrates means for attaching a deep well skylight window or dome to a deep well skylight housing or box. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  schematically illustrates a portion or section of the deep well skylight of the present invention. The deep well skylight assembly  10  comprises a window or dome  12  that is attached to an upper housing or curb  18 . The upper housing or curb  18  extends to lower housing  20 . An integral flange  32  separates the upper housing  18  from the lower housing  20 . The integral flange  32  rests on top of the roof or ceiling  22  and is covered by roof insulation  24 . Within the plane of the ceiling or roof  22 , or any insulation formed or attached to the roof or ceiling  22 , is placed a thermal barrier  14 . The thermal barrier  14  may be a transparent sheet of plastic material and separates the deep well skylight housing or box into an upper housing  18  and a lower housing  20 . The lower portion of the lower housing  20  is sealed with a lower lens  16  at the emerging aperture. The lower lens  16  is preferably a diffusion lens. Attached to the lower housing  20  is an artificial lighting or electric light fixture, and preferably a fluorescent light fixture. The fluorescent light fixture comprises a plurality of fluorescent lamps  28  that are powered by a ballast box  26  attached to the exterior surface of the lower housing  20 . The ballast box  26  powers the lamps  28 . 
     Adjacent to the fluorescent lamps  28  is a shaped reflector  30 . The shaped reflector  30  has a compound shape. The electric light fixture is placed a vertical distance B from the emerging aperture or bottom of the lower housing  20  and extends a horizontal distance A into the interior space formed by the lower housing  20 . 
     The overall design of the deep well skylight assembly  10  maximizes the artificial or electric light performance while minimizing the loss of daylight or natural lighting exiting the emerging aperture or lower lens  16 . The design facilitates a seamless transition from daylight during the day to electric or artificial lighting during the night or when daylight is inadequate or not available to satisfy predetermined lighting needs. The dimensions A and B are optimized to provide maximum performance. The shaped reflector  30  has a compound shape that has been optimized by ray tracing to result in maximum illumination to be directed to the lower lens  16  in a unifoini pattern. Dimension B is optimized to deliver the maximum amount of light or illumination onto the lower lens  16 . Dimension A, extending laterally or horizontally into the lower housing  20 , is preferably made as small a possible to reduce any attenuation of daylight or natural lighting entering the window or dome  12  during the day. However, dimension A must be sufficiently large so as to uniformly deliver artificial light so as to provide a seamless transition from daylight or natural illumination to artificial illumination. Accordingly, the combination of dimensions A and B deliver an almost or substantially uniform diffused light or illumination pattern on to the lower lens  16  that nearly matches the diffusion pattern of daylight or natural lighting. The dimensions A and B are optimized as a function of the aperture C of the deep well skylight assembly  10 . 
     As illustrated in  FIG. 1 , dimension A representing the distance the shaped reflector  30  extends laterally into the aperture C. Dimension A is approximately 11% of the aperture lateral dimension C. In a preferred embodiment, dimension A is approximately five inches and dimension C is approximately 45.88 inches. Therefore, the reflector extends laterally into the aperture approximately eleven percent of the aperture lateral dimension C. ( 5/45.88=0.11 or 11%) 
     The lamps  28  are placed approximately a vertical dimension B from the emerging aperture or lower lens  16 . Dimension B is preferably substantially 27% of dimension C or the aperture of the skylight. In a preferred embodiment, dimension B is approximately 12.25 inches and dimension C is approximately 45.88 inches. Therefore, the lamps  28  are placed vertically from the lower lens  16  in the lower housing  20  of the deep well skylight assembly  10  approximately 26.7% of the aperture dimension C. (12.25/45.88=0.267 or 26.7%) 
     The combination of providing a lighting fixture that extends laterally into the aperture dimension C of the lower housing  20  a predetermined distance and positioning the lamps  28  of the lighting fixture a predetermined distance vertically from the lower lens  16  makes possible a constant even illumination irrespective of the source of the illumination being either natural daylight or artificial light. Arrows  34  represent light rays from the lamps  28  and reflected from the shaped reflector  30 . As natural daylight is unavailable, the lamps  28  may be activated to supplement the natural daylight illumination or completely replace it with artificial light. Accordingly, the transition between natural daylight and artificial light is seamless, and the present invention provides substantially even uniform illumination. 
     The specific dimensions A and B, relative to or as a function of the dimension C have been found to permit the creation of artificial light that simulates natural daylight from the deep well skylight. Therefore the look, feel, and effect of the lighting are the same day or night or whether artificial or natural light is providing illumination. This makes the use of natural lighting much more practical and desirable, in that it assures that irrespective of the availability of natural lighting a consistent and uniform illumination is always obtained. 
     The present invention also provides an arraignment to improve the thermal characteristics of a deep well skylight. The ballast box  26  is located external to the lower housing  20  so that heat generated by the ballast box  26  is not generated within the interior of the deep well skylight assembly  10 . This also provides easy maintenance and access to the ballast box  26 . Additionally, the ballast box  26  will not interfere with light throughput within the interior of the deep well skylight assembly  10 . 
     Additionally, the position of the thermal barrier  14  being in the same plane as the thermal insulation of the roof or ceiling  22  maximizes the thermal insulation, or “R”, value. By placing the thermal barrier  14  in the same plane as the roof insulation or ceiling it forces any heat transfer into the upper air chamber within the upper housing  18 . If the thermal barrier  14  is placed above the roof insulation adjacent to ceiling  22 , there will be a thermal transfer into the lower chamber formed by the lower housing  20  and the thermal barrier  14  which would lower the insulating properties of the deep well skylight, or overall “R” value. 
       FIGS. 2-4  illustrate features of an embodiment of the invention in greater detail.  FIGS. 2-4  illustrate the shape and dimensions of a slightly modified shaped reflector  30 ′ incorporated into a deep well skylight assembly  10 . The reflector is preferably comprised of a radius section and two linear sections formed at a predetermined angle  36 , illustrated in  FIG. 4 . The predetermined angle  36  is preferably substantially one hundred and thirty five degrees. Attached to the lower housing  20  is a modified shaped reflector  30 ′. The modified shaped reflector  30 ′ has an angled artificial light reflector  30 ′ a  attached to a curved horizontal artificial light reflector  30 ′ b . The curved horizontal artificial light reflector  30 ′ b  has a linier horizontal portion and a curved portion adjacent lamp  28 . A top natural light reflector  30 ′ c  extends from the angled artificial light reflector  30 ′ a  from one end and attaches to the lower housing  20  at the other end. The top natural light reflector helps to direct natural light through the emerging aperture towards lower lens  16  and minimizes any interference or shadowing that could result from the modified shaped reflector  30 ′. 
       FIG. 5  schematically illustrates more clearly the arrangement of the modified shaped reflector  30 ′. The shaped reflector  30 ′ is attached to the lower housing  20  and extends into the skylight well. The shaped reflector  30 ′ includes a curved horizontal artificial light reflector  30 ′ b  having a curved portion adjacent the fluorescent lamps  28  and a linear horizontal portion attached to an angled artificial light reflector  30 ′ a . Angle  36  is preferably 135 degrees. A top natural light reflector  30 ′ c  extends from an end of the angled artificial light reflector  30 ′ a  to the lower housing  20 . The configuration of the shaped reflector  30 ′ makes possible efficient redirection of the illumination from the lamp  28  and minimizing the obstruction of the natural light entering the skylight and emerging at the lower lens  16 , illustrated in  FIGS. 1 and 2 . 
       FIG. 6  illustrates an embodiment of the present invention utilizing a deep well skylight housing or box  110  that has an integral curb  118 . An integral flange  132  separates the deep well skylight housing or box  110  into an upper housing or curb  118  and a lower housing  120 . The ballast in the ballast housing  126  powers the lamps  128 , which are placed in the interior of the deep well skylight box or housing  110 . The deep well skylight box or housing  110  is preferably made of galvanized steel or other suitable metal material that may come in four panel sections that are bolted together to form a box. The integral curb  118  is formed as part of the deep well skylight box or housing  110 . The integral curb  118  typically extends above a roof line. The integral curb  118  preferably has a thickness of approximately 1″ to 1.5″ so that a deep well skylight window or dome may be mounted thereon. Accordingly, the deep well skylight box or housing  110 , having the internal curb  118 , may be easily dropped into a cut out opening of a roof without the need for building up a separate wooden curb. This saves time in the installation and provides for an improved installation that may not readily leak. Additionally the curbing  118  may be insulated to improve thermal properties of the installed deep well skylight. 
       FIG. 7  illustrates a structure for installing a deep well skylight window or dome  212  onto an upper housing or curb  218  of a deep well skylight assembly. The lower housing  220  of a deep well skylight box or housing is attached or formed integrally with an upper housing or integral curb  218  that has an integral flange  232  adapted to rest on the surface of a roof or ceiling  222 . A flange  238  extends from the top surface of the upper housing or integral curb  218 . The flange  238  and the top surface of the upper housing or integral curb  218  form a flat surface for mounting the transparent window or dome  212  of the deep well skylight. A U-shaped seal  234  wraps around a flat portion of the window or dome  212  around the entire perimeter thereof. A pressure plate  236  is placed over the U-shaped seal  234  and forms a water tight seal between the pressure plate  236  and a top surface of the flange  238  and the upper housing or integral curb  218 . A bolt  240  extends through a portion of the pressure plate  236  and the flange  238  to securely hold the pressure plate  236  against the U-shaped seal  234  sealing the entire perimeter of the deep well skylight window or dome  212 . Accordingly, a very secure seal is established, preventing the possibility of any leakage. 
     This invention provides a shaped reflector that produces an artificial light distribution that is the same as the natural light distribution so that a user perceived no difference in artificial or natural light. This is highly desirable from a human factor working environment perspective. The horizontal and vertical positioning of the shaped reflector within the skylight is designed to maximize the lumen or illumination of the artificial light with minimal impact on the delivery of natural light. The shaped reflector provides illumination to the lower lens that substantially matches natural light delivered to the lower lens during daylight hours. The top natural light reflector is designed to minimize upward reflection or bounce from natural day lighting illumination. Therefore, the invention provides an efficient skylight providing uniform artificial and natural lighting that is easy to install and saves energy. 
     While various embodiments have been illustrated and described, it should be appreciated that various modifications may be made to the illustrated preferred embodiments without departing from the spirit and scope of this invention.