Optical: systems and elements – Building interior illumination with reflected – refracted or... – Slats or strips
Reexamination Certificate
1999-02-12
2001-05-29
Mahoney, Christopher E. (Department: 2851)
Optical: systems and elements
Building interior illumination with reflected, refracted or...
Slats or strips
C359S597000, C160S104000
Reexamination Certificate
active
06239910
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to interior space illumination systems and, in particular, to a mini-optical light shelf daylighting system that implements an efficient daylighting system in the paradigm of a window treatment to redirect incident sunlight into an interior space and on to the ceiling plane to illuminate the interior space.
PROBLEM
It is a problem in the field of interior space illumination to provide a cost effective mode of illumination that makes use of the incident sunlight without the need for complex systems or significant occupant intervention. Existing daylighting systems are either of limited effectiveness, limited applicability due to their architectural limitations, or require complex and expensive mechanical and electronic control mechanisms.
Each year in the United States, over $350 billion is spent on energy for residential, commercial, and industrial buildings. Of this amount, more than $212 billion was spent during 1996 to purchase electricity, with 32% of that amount being used to operate commercial buildings: office, retail, institutional, but not industrial. Of this use, approximately 35% of the electricity consumption was related to lighting and another 6% was attributable to the air conditioning energy required to remove the excess heat generated by electric lighting. Thus, lighting is typically the largest end-use for electricity, annually consuming approximately 310 billion kWh.
There is a need for systems that provide improved energy efficiency and environmental quality. One such example is the need to reduce the consumption of electricity for lighting. One option for reducing electricity consumption for lighting is to use daylight to illuminate occupied building spaces. These systems are termed “daylighting systems.” The key to the widespread use of daylighting systems is the provision of such a system that is both inexpensive and easily applied to both new and existing buildings. In addition to the savings attributed to reduced electricity consumption, daylighting systems typically also result in increased productivity by the occupants of the illuminated space, reduced health problems evidenced by the occupants of the illuminated space and pollution reduction. This is because there appears to be a strong correlation between the quality of the luminous environment and the overall health and productivity of the occupants. These ancillary benefits can produce savings that dwarf the savings attributable to electricity consumption reduction, since studies indicate that, over the life of the building, approximately 97% of the operating cost of commercial space is the salaries of the occupants and any improvement in the performance of the occupants of the building space results in a significant economic benefit.
One such existing daylighting system is the traditional light shelf, which comprises an optical device which receives daylight that is transmitted through a window and redirects it onto the interior ceiling plane, thereby creating a useful source of interior illumination. The basic light shelf concept typically comprises a wide flat elongated interior light shelf located adjacent to a window and protruding into a room from the exterior wall of a building, and/or an exterior light shelf of similar construction projecting from the exterior wall of the building, coplanar with the interior light shelf to receive incident sunlight. The incident sunlight is reflected by the interior and/or exterior light shelves onto the ceiling of the occupied space by a diffuse or specular horizontal or slightly sloped surface of the light shelf, which light reflecting surface is located above a view glazing. However, the interior light shelf typically protrudes a significant distance into the occupied space and is problematic from architectural, mechanical and aesthetic standpoints in many room applications.
U.S. Pat. No. 5,285,315 discloses a system that uses light reflective elements that are sandwiched between two panes of glass to redirect sunlight into the interior space of a building. The reflective elements comprise both stationary and movable elements that function to redirect the incident sunlight to the back walls of the room, above eye level without striking the ceiling. The problem with this light reflecting system is that it is expensive to implement and produces illumination of variable quality. The existing glazing must also be replaced to implement this system, thereby rendering this system expensive and impractical to implement in existing buildings.
U.S. Pat. No. 4,557,565 discloses a system of refractive structures that are used to collect and redirect light into a building. The refractive structures comprise a planar solid transparent light deflecting panel or plate that is formed of a plurality of parallel identically spaced apart triangular ribs located on one face. With the panel in its vertical orientation and placed over a window opening, the panel substantially reflects external incident direct sunlight into the building interior. The panels are designed to require seasonal adjustments to compensate for the seasonal variations in the angle and nature of the incident sunlight. The refractive panels are expensive to implement and require periodic adjustment by the occupant to compensate for changes in the incident sunlight.
U.S. Pat. No. 5,293,305 discloses a light guidance system that illuminates the interior of a building by using a light deflection device equipped with a light source. The light guidance system is mounted in a window and both reflects sunlight coming from outside of the building as well as electric light coming from the light source. The light guidance system comprises several light reflective elements that are disposed parallel to one another and spaced apart from one another such that light from outside the building is reflected by the top surface of the light reflective elements and light from an internal light source is reflected by the bottom surface of the light reflective elements into the room. The light reflective elements function both to shade the interior from direct sunlight while also redirecting both the incident sunlight and the light from the light source into the room to provide indirect lighting. A problem with this light guidance system is that it relies on the close spatial-optical relationship between the electric lighting located at the window and the incident sunlight through the window. Another problem with this light guidance system is that it blocks the view through the window and relies on the placement of a source of electric light at the window. Thus, it is expensive to implement and requires expensive adaptation of existing installations to accommodate the light source.
U.S. Pat. No. 4,883,340 discloses a solar lighting apparatus that is mounted on the roof of a building to provide illumination of the interior of the building. The solar lighting apparatus comprises a reflector assembly that is rotatable about a vertical axis for tracking the daily movements of the sun. The reflector panel comprises multiple panels that are mounted on a frame over a skylight opening and the frame is rotated by the operation of solar tracking electronics. A problem with the solar lighting apparatus is that it is effective only for the room area located on the top floor of a multiple story building. In addition, it relies on electronics and mechanical tracking apparatus to collect and redirect the incident sunlight.
Thus, the field of interior space illumination systems is devoid of an inexpensive, practical, effective and simple to use daylighting system that can be easily implemented in both existing building applications as well as in new building construction.
SOLUTION
The above-described problems are solved and a technical advance achieved in the field by the present mini-optical light shelf daylighting system. The mini-optical light shelf is a daylighting system implemented in the paradigm of a window treatment that is applicable to both new installations as well as existing window
Architectural Energy Corporation
Dutz, Graziano & Forest, P.C.
Mahoney Christopher E.
LandOfFree
Mini-optical light shelf daylighting system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mini-optical light shelf daylighting system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mini-optical light shelf daylighting system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2494466