Some Unique Terms in Lighting 1. LUMEN : The lumen is the time rate flow of light 10 lumens 350 lumens 750 lumens
2. LUMINOUS INTENSITY (candlepower ): Light emitted in a particular direction.
3. ILLUMINANCE (level of illumination ): Calculated as the number of lumens (lm) per unit area. The units : A. footcandles (fc) = lm/ft2 B. lux (lx) = lm/m2
LIGHTING DESIGN PROCEDURE A.Analyzing The Space B.Source Selection C.lumanaire selection D.lighting calculation method
A.Analyzing The Space Is the area to be used for more than one purpose?
B.Source Selection High intensity discharge (HID) lamps[ industrial lighting]. Fluorescent lamps are used for [offices\Houses\shops … ]. Incandescent lamps [bedrooms\toilets ].
C.Lumanaire Selection. ENVIRONMENTS: - Hazardous Locations. - High or Low Temperatures HEIGHT Some luminaries are designed for use heights that is below 7.6 meters.
D. Lighting Calculation Method E = (N * LL * CU * LLF)/(area) Where E = maintained level of illumination N = number of luminaire Area = area of the space to be lighted LL = initial rated lamp lumens CU = coefficient of utilization LLF = light loss factor
Coefficient of Utilization (CU) 1. Room Cavity Ratio (RCR) 2. Reflectances
References Frier, John P. and Mary E. Gazley Frier. Industrial Lighting Systems. 1980. McGraw-Hill, Inc. Kaufman. John E. and Jack F. Christensen. IES Lighting Handbook.1972. Waverly Press, Inc: USA. Nuckolls, James L. Interior Lighting for Environmental Designers.1976. John Wiley and Sons, Inc: USA.