How do luminaire manufacturers prevent glare?
The smaller bulb diameters and higher light outputs of T5 lamps increase the light emitted per unit area or the luminance of the lamp bulb walls. A T5 or T5 high output (T5 HO) lamp has 60% of the surface area of a T8 lamp. Because, however, a standard T5 lamp has nearly identical light output to a T8 lamp (2,900 lumens versus 2,950 lumens), the surface luminance of a standard T5 lamp is 1.64 times as much as a T8 lamp. Further, the light output of a T5 HO lamp is 5,000 lumens, so the surface luminance is 2.83 times as high as a T8 lamp (see the CASE STUDY ). The higher surface luminance, without any shields or diffusers, results in more glare and discomfort for room occupants. Unless the lamps are properly shielded, these high-luminance light sources may also annoy workers by reflecting off of computer screens or other visual display units. To avoid glare from the high-luminance bulb walls of T5 lamps, luminaire manufacturers design indirect and direct/indirect luminaires that keep th
