for various combinations of V and H. Angle B is the angle between the vertical plane of the row of luminaires and a REFERENCE tilted plane containing both the seeing task and the luminaire or row of luminaires. Figure 107.2 shows how angles a and B are defined. The direct illumination component for each luminaire or row of luminaires is determined by referring to the table of direct illumination components for the specific luminaire. The direct illumination components are based on the assumption that the luminaire is mounted 6 ft above the seeing task. If this mounting height is other than 6 ft, the v rect illumination component shown in Table 107.5 must be multiplied by 6/V where Vis the mounting height above the task. Thus the total direct illumination component would VERTICAL PLANE be the product of 6/V and the sum of the individual direct illumination components of each row. Reflected Illumination Components on the Horizontal FIGURE 107.2 Definition of angular coordinate sys- Surfaces. This is calculated in exactly the same manner as tems for direct illumination component. ne average illumination using the lumen method, except that the reflected radiation coefficient(rrc) is substituted for the coefficient of utilization. lamps/ uminaire x lumens/lp×RRC×LLF RH (1076) area/luminaire where RRC= LCw RPM(LCcc -LCw), LCw=wall luminance coefficient, LCac= ceiling cavity luminance coefficient, and RPM room position multiplier. The wall luminance coefficient and the ceiling cavity luminance coefficient are selected for the appropriate room cavity ratio and proper wall and ceiling cavity reflectances from the table of luminance coefficients in the same manner as the coefficient of utilization. The room position multiplier is a function of the room cavity ratio and of the location in the room of the point where the illumination is desired. Table 107. 6 lists the value of the RPM for each possible location of the part in the rooms of all room cavity ratios Figure 107.3 shows a grid diagram that illustrates the method of designating the location in the room by a Reflected Illumination Components on the Vertical Surfaces. To determine illumination reflected to vertical surfaces, the approximate average value is determined using the same general formula, but substituting WRRC all reflected radiation coefficient) for the coefficient of utilization lamps/ luminaire x lumens/lp×WRRC×LLF area/luminaire(on work plane) (107.7) WRRC E all luminance coefficient WDRC (1078) average wall reflectance where WDRC is the wall direct radiation coefficient, which is published for each room cavity ratio together with a table of wall luminance coefficients(see Table 107.5 for a specific type of luminance) e 2000 by CRC Press LLC© 2000 by CRC Press LLC for various combinations of V and H. Angle b is the angle between the vertical plane of the row of luminaires and a tilted plane containing both the seeing task and the luminaire or row of luminaires. Figure 107.2 shows how angles a and b are defined. The direct illumination component for each luminaire or row of luminaires is determined by referring to the table of direct illumination components for the specific luminaire. The direct illumination components are based on the assumption that the luminaire is mounted 6 ft above the seeing task. If this mounting height is other than 6 ft, the direct illumination component shown in Table 107.5 must be multiplied by 6/V, where V is the mounting height above the task. Thus the total direct illumination component would be the product of 6/V and the sum of the individual direct illumination components of each row. Reflected Illumination Components on the Horizontal Surfaces. This is calculated in exactly the same manner as the average illumination using the lumen method, except that the reflected radiation coefficient (RRC) is substituted for the coefficient of utilization. (107.6) where RRC = LCW + RPM (LCCC – LCW), LCW = wall luminance coefficient, LCCC = ceiling cavity luminance coefficient, and RPM = room position multiplier. The wall luminance coefficient and the ceiling cavity luminance coefficient are selected for the appropriate room cavity ratio and proper wall and ceiling cavity reflectances from the table of luminance coefficients in the same manner as the coefficient of utilization. The room position multiplier is a function of the room cavity ratio and of the location in the room of the point where the illumination is desired. Table 107.6 lists the value of the RPM for each possible location of the part in the rooms of all room cavity ratios. Figure 107.3 shows a grid diagram that illustrates the method of designating the location in the room by a letter and a number. Reflected Illumination Components on the Vertical Surfaces. To determine illumination reflected to vertical surfaces, the approximate average value is determined using the same general formula, but substituting WRRC (wall reflected radiation coefficient) for the coefficient of utilization: (107.7) where (107.8) where WDRC is the wall direct radiation coefficient, which is published for each room cavity ratio together with a table of wall luminance coefficients (see Table 107.5 for a specific type of luminance). FC lamps/luminaire lumens/lp RRC LLF area/luminaire RH = ¥ ¥ ¥ FC lamps/luminaire lumens/lp WRRC LLF area/luminaire (on work plane) RV = ¥ ¥ ¥ WRRC wall luminance coefficient average wall reflectance = – WDRC FIGURE 107.2 Definition of angular coordinate sys￾tems for direct illumination component