What luminaires are available for T5 lamps? - cont'd
The small diameter of T5 and T5 high output (T5 HO) lamps makes them
nearly line sources with high optical controllability. Their
quasi-line-source quality allows for a compact optical system that can
accurately deliver the light emitted from the light source to where it is
needed and therefore achieves a highly efficient optical design.
The higher output of T5 HO lamps may also help increase optical efficiency.
Because a T5 HO lamp (5,000 lumens) has nearly 70% more lumen output
than a T8 lamp (2,950 lumens), a one-lamp luminaire using T5 HO lamps
may replace a two-lamp luminaire using T8 lamps (5,000 lumens) (see Do T5 luminaires perform better than T8 luminaires?). As the number of lamps in a luminaire decreases, the light control
generally becomes more efficient and flexible. For instance, a one-lamp
luminaire can be built with higher optical flexibility than a two-lamp
luminaire. This optical advantage of one-lamp luminaires results in
a wider batwing-shaped upward light distribution that can increase illuminance
uniformity on the ceiling and floor. It also permits a higher mounting
height (shorter distance from the ceiling). The ability to achieve high
uniformity may let workplane illuminance easily reach IESNA standards.
If the optical system is well designed, the light output from
a one-lamp luminaire using a T5 HO lamp can exceed that from a two-lamp
luminaire using T8 lamps. As discussed in Do T5 luminaires perform better than T8 luminaires?, a two-lamp luminaire using T5 HO lamps often has more light output than a three-lamp luminaire
using T8 lamps. When lighting designers specify these T5 HO luminaires
instead of T8 luminaires, they can often use fewer luminaires per project,
especially for large commercial projects.