Ad
related to: calculate light fixtures needed for room ideas pdf file meaning in marathi
Search results
Results From The WOW.Com Content Network
A foot-candle (sometimes foot candle; abbreviated fc, lm/ft 2, or sometimes ft-c) is a non-SI unit of illuminance or light intensity. The foot-candle is defined as one lumen per square foot. This unit is commonly used in lighting layouts in parts of the world where United States customary units are used, mainly the United States. [1]
In lighting design, the lumen method, (also called zonal cavity method), is a simplified method to calculate the light level in a room.The method is a series of calculations that uses horizontal illuminance criteria to establish a uniform luminaire layout in a space.
In architecture, light reflectance value (LRV), is a measure of visible and usable light that is reflected from a surface when illuminated by a light source. [1] The measurement is most commonly used by design professionals, such as architectural color consultants , architects , environmental graphic designers and interior designers .
The former sense is sometimes called luminous efficacy of radiation, [4] and the latter luminous efficacy of a light source [5] or overall luminous efficacy. [ 6 ] [ 7 ] Not all wavelengths of light are equally visible, or equally effective at stimulating human vision, due to the spectral sensitivity of the human eye ; radiation in the infrared ...
The history of electric light is well documented, [11] and with the developments in lighting technology the profession of lighting developed alongside it. The development of high-efficiency, low-cost fluorescent lamps led to a reliance on electric light and a uniform blanket approach to lighting, but the energy crisis of the 1970s required more design consideration and reinvigorated the use of ...
In photometry, luminous flux or luminous power [citation needed] is the measure of the perceived power of light. It differs from radiant flux , the measure of the total power of electromagnetic radiation (including infrared , ultraviolet , and visible light), in that luminous flux is adjusted to reflect the varying sensitivity of the human eye ...
For example, some of the light emitted by a luminaire may exit away from the desired plane and is therefore wasted. A CU measures the light actually reaching the desired plane as a percentage of the total light produced by the fixture. The value for direct lighting varies from 0.2 to 0.5 while that of indirect lighting varies from 0.1 to 0.3
An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in lumen per watt. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb" to the ...