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Lumen Method
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 its simplest form, the lumen method is merely the total number of lumens available in a room divided by the area of the room. In order to perform this calculation, many factors, coefficients, lamp lumen data and other quantities must be gathered. Despite the scientific impression of the lumen method equations, there are inaccuracies and assumptions built into the method. Therefore, the lumen method should not typically be used as a standalone, final solution; it should be used as a tool in particularly uniform settings of lighting design if a simple, rough technique of illuminance quantification is desired.Steffy, LC, IES, FIALD, Gary 1963. ''Architectural Lighting Design, 2nd edition'' John Wiley & Sons, Inc., N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Architectural Lighting Design
Architectural lighting design is a field of work or study that is concerned with the design of lighting systems within the built environment, both interior and exterior. It can include manipulation and design of both daylight and electric light or both, to serve human needs. Lighting design is based in both science and the visual arts. The basic aim of lighting within the built environment is to enable occupants to see clearly and without discomfort. The objective of architectural lighting design is to balance the art and the science of lighting to create mood, visual interest and enhance the experience of a space or place whilst still meeting the technical and safety requirements. Overview The purpose of architectural lighting design is to balance the characteristics of light within a space to optimize the technical, the visual and, most recently, the non-visual components of ergonomics with respect to illumination of buildings or spaces. The technical requirements ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illuminance
In photometry (optics), photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness perception.International Electrotechnical Commission (IEC): ''International Electrotechnical Vocabulary.'ref. 845-21-060, illuminance/ref> Similarly, luminous emittance is the luminous flux per unit area emitted from a surface. Luminous emittance is also known as luminous exitance. In SI derived units, SI units illuminance is measured in lux (lx), or equivalently in lumen (unit), lumens per square metre (Lumen (unit), lm·meter, m−2). Luminous exitance is measured in lm·m−2 only, not lux. International Electrotechnical Commission (IEC): ''International Electrotechnical Vocabulary.'ref. 845-21-081, luminous exitance/ref> In the CGS system, the unit of illuminance is the phot, which is equal to . The foot-candle is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminaire
A light fixture (US English), light fitting (UK English), or luminaire is an electrical device containing an Lamp (electrical component), electric lamp that provides Lighting, illumination. All light fixtures have a fixture body and one or more lamps. The lamps may be in sockets for easy replacement—or, in the case of some LED fixtures, hard-wired in place. Fixtures may also have a switch to control the light, either attached to the lamp body or attached to the power cable. Permanent light fixtures, such as dining room chandeliers, may have no switch on the fixture itself, but rely on a wall switch. Fixtures require an electrical connection to a power source, typically AC mains power, but some run on battery power for camping or emergency lights. Permanent lighting fixtures are directly wired. Movable lamps have a electrical connectors, plug and cord that plugs into a wall socket. Light fixtures may also have other features, such as Mirror, reflectors for directing the light, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflectance
The reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the response of the electronic structure of the material to the electromagnetic field of light, and is in general a function of the frequency, or wavelength, of the light, its polarization, and the angle of incidence. The dependence of reflectance on the wavelength is called a ''reflectance spectrum'' or ''spectral reflectance curve''. Mathematical definitions Hemispherical reflectance The ''hemispherical reflectance'' of a surface, denoted , is defined as R = \frac, where is the radiant flux ''reflected'' by that surface and is the radiant flux ''received'' by that surface. Spectral hemispherical reflectance The ''spectral hemispherical reflectance in frequency'' and ''spectral hemispherical reflectance in wavelength'' of a surface, denoted and respectively, are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
