Page 81 - GRIHA Manual Volume II - Introduction to National Rating System
P. 81
Sustainable site planning 73
Table 2 Comparison of different types of light sources
Light source Lumen output Luminous Average life (Hr at CRI
50% failure rate)
eficacy (lm/W)
Fluorescent 1200–3250 80–95 10 000 80–89
lamps (T8 and T5)
(14–36W)
Compact 240–2400 40–70 10 000 80–89
luorescent lamps
(CFLs) (5–32 W)
High-pressure 3500– 58–110 20 000 20–89
sodium vapour 120 000
(HPSV) (50–1000
W)
High-pressure 1800– 30–50 12 000 40–59
mercury vapour 57 000
(HPMV) (50–1000
W)
Metal halides 3500– 70–110 15 000 60–90
(35–2000 W) 24 0000
Light emitting diode 4–100 40–65 50 000 80
(LED) (single LED
0.1–0.3–3 W)
Notes
1. Please refer manufacturer’s catalogue for speciic data.
2. Luminous eficacy varies with the wattage of the lamps.
3. Luminous eficacy values have been speciied considering ballast losses.
Ballasts
Ballasts are current limiting devices in an electrical circuit. In case of discharge lamps, ballasts counter
the negative resistance of the lamp and aid in voltage build-up required for starting fluorescent
lamps. Ballast losses account for almost 15% of lamp wattage. New high frequency electronic
ballasts help in saving 20%–30% of energy as compared to traditional magnetic ballasts.
Lighting controls
Outdoor lighting is required during evening and night time. However, it is not necessary to operate
all outdoor lights from dusk to dawn. Depending on specific requirements, different outdoor lights
Table 2 Comparison of different types of light sources
Light source Lumen output Luminous Average life (Hr at CRI
50% failure rate)
eficacy (lm/W)
Fluorescent 1200–3250 80–95 10 000 80–89
lamps (T8 and T5)
(14–36W)
Compact 240–2400 40–70 10 000 80–89
luorescent lamps
(CFLs) (5–32 W)
High-pressure 3500– 58–110 20 000 20–89
sodium vapour 120 000
(HPSV) (50–1000
W)
High-pressure 1800– 30–50 12 000 40–59
mercury vapour 57 000
(HPMV) (50–1000
W)
Metal halides 3500– 70–110 15 000 60–90
(35–2000 W) 24 0000
Light emitting diode 4–100 40–65 50 000 80
(LED) (single LED
0.1–0.3–3 W)
Notes
1. Please refer manufacturer’s catalogue for speciic data.
2. Luminous eficacy varies with the wattage of the lamps.
3. Luminous eficacy values have been speciied considering ballast losses.
Ballasts
Ballasts are current limiting devices in an electrical circuit. In case of discharge lamps, ballasts counter
the negative resistance of the lamp and aid in voltage build-up required for starting fluorescent
lamps. Ballast losses account for almost 15% of lamp wattage. New high frequency electronic
ballasts help in saving 20%–30% of energy as compared to traditional magnetic ballasts.
Lighting controls
Outdoor lighting is required during evening and night time. However, it is not necessary to operate
all outdoor lights from dusk to dawn. Depending on specific requirements, different outdoor lights
