C4-11:12 Flashcards
Proper design of a lighting installation requires use of two calculating procedures:
- Computing illuminance from a point source
- Computing average illuminance levels
In lighting design, E is used as a symbol for __________. And I is the symbol for ___________.
Illuminance and luminous intensity
States that the illuminance at a point on a plane perpendicular to the line joining the point and a source is inversely proportional to the square between the source and the plane.
Inverse square law
States that illuminance (E) at a point on a plane is proportional to the cosine of the angle of light incidence, where the angle of light incidence is measured between the direction of the incident light and the normal to the plane of the surface.
Cosine law of incidence
Average illuminance at a reference work plane.
Target illumination
Usually horizontally positioned, at which work is performed and on which the illuminance is specified and measured.
Work plane
The currently accepted method for calculating average illuminance levels for indoor areas unless the light distribution is extremely asymmetric.
Zonal cavity method
A room is made up of three spaces called ________.
cavities
The space between the luminaires and the work plane is referred to as the ________.
room cavity
The space between the work plane and the floor is called the ___________.
Floor cavity
The space between the ceiling and the luminaires is defined as the _________.
ceiling cavity
Is an approximate maximum spacing-to-mounting height ratio required to ensure uniform illumination on the work plane.
Spacing Criterion
It is the center-to-center luminaire spacing.
Spacing
The distance between the plane of the luminaires and reference work plane.
Mounting height
The power consumed for illumination divided by the area served by the lighting installation. It is frequently used as a measure of installed building lighting efficiency.
Unit power density
Both a science and an art, and there is no single correct lighting solution for all situations.
Architectural Lighting Design
A non uniform, balanced use of all types of architectural lighting. Tends to create a composition quality that best suits good atmosphere within most spaces by blending color rendering and other properties of the different light sources.
Layered Light
The most essential form of lighting because it is the basic background of light for almost every room.
Ambient Lighting
Illuminates a specific visual function and can influence the effectiveness of the individual performing task.
Task/Local Lighting
Used to add drama and emphasize a particular object or area.
Accent Lighting
Aesthetically adds interest to the space by blending with other types of lighting to give an overall “feel” to a space.
Decorative Lighting
The transitional space from public to private and exterior to interior. If offers the first impression of a home or building.
Entrances
This space can take advantage of a beautiful vista out the window and good natural ambient light daylight. At night, an ambient light source should be provided to compensate for daylight.
Offices/Studies
In this space, the best light washes the face from all directions, softening shadows. There should be sufficient light to see detail for grooming but not so much to cause glare and discomfort.
Restrooms/Bathrooms
